Cluster: improve anti-affinity algo in redis-trib.rb.

See #3462 and related PRs. We use a simple algorithm to calculate the level of affinity violation, and then an optimizer that performs random swaps until things improve.
Merge pull request #4540 from hqin6/unstable
2017-12-18 15:49:45 +01:00 · 2017-12-15 12:41:02 +01:00 · 2017-12-15 11:06:58 +08:00 · 2017-12-14 22:14:45 +01:00 · 2017-12-14 12:21:32 +01:00 · 2017-12-14 12:19:36 +01:00
150 changed files with 13738 additions and 4837 deletions
@@ -1,4 +1,4 @@
-This README is just a fast *quick start* document. You can find more detailed documentation at http://redis.io.
+This README is just a fast *quick start* document. You can find more detailed documentation at [redis.io](https://redis.io).

 What is Redis?
 --------------
@@ -4,3 +4,4 @@
 /*.so
 /*.dylib
 /*.a
+/*.pc
@@ -1,6 +1,39 @@
 language: c
+sudo: false
 compiler:
  - gcc
  - clang

-script: make && make check
+os:
+  - linux
+  - osx
+
+before_script:
+    - if [ "$TRAVIS_OS_NAME" == "osx" ] ; then brew update; brew install redis; fi
+
+addons:
+  apt:
+    packages:
+    - libc6-dbg
+    - libc6-dev
+    - libc6:i386
+    - libc6-dev-i386
+    - libc6-dbg:i386
+    - gcc-multilib
+    - valgrind
+
+env:
+    - CFLAGS="-Werror"
+    - PRE="valgrind --track-origins=yes --leak-check=full"
+    - TARGET="32bit" TARGET_VARS="32bit-vars" CFLAGS="-Werror"
+    - TARGET="32bit" TARGET_VARS="32bit-vars" PRE="valgrind --track-origins=yes --leak-check=full"
+
+matrix:
+  exclude:
+    - os: osx
+      env: PRE="valgrind --track-origins=yes --leak-check=full"
+
+    - os: osx
+      env: TARGET="32bit" TARGET_VARS="32bit-vars" PRE="valgrind --track-origins=yes --leak-check=full"
+
+script: make $TARGET CFLAGS="$CFLAGS" && make check PRE="$PRE" && make $TARGET_VARS hiredis-example
@@ -1,3 +1,128 @@
+### 1.0.0 (unreleased)
+
+**Fixes**:
+
+* Catch a buffer overflow when formatting the error message
+* Import latest upstream sds. This breaks applications that are linked against the old hiredis v0.13
+* Fix warnings, when compiled with -Wshadow
+* Make hiredis compile in Cygwin on Windows, now CI-tested
+
+**BREAKING CHANGES**:
+
+* Change `redisReply.len` to `size_t`, as it denotes the the size of a string
+
+User code should compare this to `size_t` values as well.
+If it was used to compare to other values, casting might be necessary or can be removed, if casting was applied before.
+
+* Remove backwards compatibility macro's
+
+This removes the following old function aliases, use the new name now:
+
+| Old                         | New                    |
+| --------------------------- | ---------------------- |
+| redisReplyReaderCreate      | redisReaderCreate      |
+| redisReplyReaderCreate      | redisReaderCreate      |
+| redisReplyReaderFree        | redisReaderFree        |
+| redisReplyReaderFeed        | redisReaderFeed        |
+| redisReplyReaderGetReply    | redisReaderGetReply    |
+| redisReplyReaderSetPrivdata | redisReaderSetPrivdata |
+| redisReplyReaderGetObject   | redisReaderGetObject   |
+| redisReplyReaderGetError    | redisReaderGetError    |
+
+* The `DEBUG` variable in the Makefile was renamed to `DEBUG_FLAGS`
+
+Previously it broke some builds for people that had `DEBUG` set to some arbitrary value,
+due to debugging other software.
+By renaming we avoid unintentional name clashes.
+
+Simply rename `DEBUG` to `DEBUG_FLAGS` in your environment to make it working again.
+
+### 0.13.3 (2015-09-16)
+
+* Revert "Clear `REDIS_CONNECTED` flag when connection is closed".
+* Make tests pass on FreeBSD (Thanks, Giacomo Olgeni)
+
+
+If the `REDIS_CONNECTED` flag is cleared,
+the async onDisconnect callback function will never be called.
+This causes problems as the disconnect is never reported back to the user.
+
+### 0.13.2 (2015-08-25)
+
+* Prevent crash on pending replies in async code (Thanks, @switch-st)
+* Clear `REDIS_CONNECTED` flag when connection is closed (Thanks, Jerry Jacobs)
+* Add MacOS X addapter (Thanks, @dizzus)
+* Add Qt adapter (Thanks, Pietro Cerutti)
+* Add Ivykis adapter (Thanks, Gergely Nagy)
+
+All adapters are provided as is and are only tested where possible.
+
+### 0.13.1 (2015-05-03)
+
+This is a bug fix release.
+The new `reconnect` method introduced new struct members, which clashed with pre-defined names in pre-C99 code.
+Another commit forced C99 compilation just to make it work, but of course this is not desirable for outside projects.
+Other non-C99 code can now use hiredis as usual again.
+Sorry for the inconvenience.
+
+* Fix memory leak in async reply handling (Salvatore Sanfilippo)
+* Rename struct member to avoid name clash with pre-c99 code (Alex Balashov, ncopa)
+
+### 0.13.0 (2015-04-16)
+
+This release adds a minimal Windows compatibility layer.
+The parser, standalone since v0.12.0, can now be compiled on Windows
+(and thus used in other client libraries as well)
+
+* Windows compatibility layer for parser code (tzickel)
+* Properly escape data printed to PKGCONF file (Dan Skorupski)
+* Fix tests when assert() undefined (Keith Bennett, Matt Stancliff)
+* Implement a reconnect method for the client context, this changes the structure of `redisContext` (Aaron Bedra)
+
+### 0.12.1 (2015-01-26)
+
+* Fix `make install`: DESTDIR support, install all required files, install PKGCONF in proper location
+* Fix `make test` as 32 bit build on 64 bit platform
+
+### 0.12.0 (2015-01-22)
+
+* Add optional KeepAlive support
+
+* Try again on EINTR errors
+
+* Add libuv adapter
+
+* Add IPv6 support
+
+* Remove possiblity of multiple close on same fd
+
+* Add ability to bind source address on connect
+
+* Add redisConnectFd() and redisFreeKeepFd()
+
+* Fix getaddrinfo() memory leak
+
+* Free string if it is unused (fixes memory leak)
+
+* Improve redisAppendCommandArgv performance 2.5x
+
+* Add support for SO_REUSEADDR
+
+* Fix redisvFormatCommand format parsing
+
+* Add GLib 2.0 adapter
+
+* Refactor reading code into read.c
+
+* Fix errno error buffers to not clobber errors
+
+* Generate pkgconf during build
+
+* Silence _BSD_SOURCE warnings
+
+* Improve digit counting for multibulk creation
+
+
 ### 0.11.0

 * Increase the maximum multi-bulk reply depth to 7.
@@ -3,13 +3,25 @@
 # Copyright (C) 2010-2011 Pieter Noordhuis <pcnoordhuis at gmail dot com>
 # This file is released under the BSD license, see the COPYING file

-OBJ=net.o hiredis.o sds.o async.o
-EXAMPLES=hiredis-example hiredis-example-libevent hiredis-example-libev
+OBJ=net.o hiredis.o sds.o async.o read.o
+EXAMPLES=hiredis-example hiredis-example-libevent hiredis-example-libev hiredis-example-glib
 TESTS=hiredis-test
 LIBNAME=libhiredis
+PKGCONFNAME=hiredis.pc

-HIREDIS_MAJOR=0
-HIREDIS_MINOR=11
+HIREDIS_MAJOR=$(shell grep HIREDIS_MAJOR hiredis.h | awk '{print $$3}')
+HIREDIS_MINOR=$(shell grep HIREDIS_MINOR hiredis.h | awk '{print $$3}')
+HIREDIS_PATCH=$(shell grep HIREDIS_PATCH hiredis.h | awk '{print $$3}')
+HIREDIS_SONAME=$(shell grep HIREDIS_SONAME hiredis.h | awk '{print $$3}')
+
+# Installation related variables and target
+PREFIX?=/usr/local
+INCLUDE_PATH?=include/hiredis
+LIBRARY_PATH?=lib
+PKGCONF_PATH?=pkgconfig
+INSTALL_INCLUDE_PATH= $(DESTDIR)$(PREFIX)/$(INCLUDE_PATH)
+INSTALL_LIBRARY_PATH= $(DESTDIR)$(PREFIX)/$(LIBRARY_PATH)
+INSTALL_PKGCONF_PATH= $(INSTALL_LIBRARY_PATH)/$(PKGCONF_PATH)

 # redis-server configuration used for testing
 REDIS_PORT=56379
@@ -25,15 +37,16 @@ export REDIS_TEST_CONFIG

 # Fallback to gcc when $CC is not in $PATH.
 CC:=$(shell sh -c 'type $(CC) >/dev/null 2>/dev/null && echo $(CC) || echo gcc')
+CXX:=$(shell sh -c 'type $(CXX) >/dev/null 2>/dev/null && echo $(CXX) || echo g++')
 OPTIMIZATION?=-O3
 WARNINGS=-Wall -W -Wstrict-prototypes -Wwrite-strings
-DEBUG?= -g -ggdb
-REAL_CFLAGS=$(OPTIMIZATION) -fPIC $(CFLAGS) $(WARNINGS) $(DEBUG) $(ARCH)
+DEBUG_FLAGS?= -g -ggdb
+REAL_CFLAGS=$(OPTIMIZATION) -fPIC $(CFLAGS) $(WARNINGS) $(DEBUG_FLAGS) $(ARCH)
 REAL_LDFLAGS=$(LDFLAGS) $(ARCH)

 DYLIBSUFFIX=so
 STLIBSUFFIX=a
-DYLIB_MINOR_NAME=$(LIBNAME).$(DYLIBSUFFIX).$(HIREDIS_MAJOR).$(HIREDIS_MINOR)
+DYLIB_MINOR_NAME=$(LIBNAME).$(DYLIBSUFFIX).$(HIREDIS_SONAME)
 DYLIB_MAJOR_NAME=$(LIBNAME).$(DYLIBSUFFIX).$(HIREDIS_MAJOR)
 DYLIBNAME=$(LIBNAME).$(DYLIBSUFFIX)
 DYLIB_MAKE_CMD=$(CC) -shared -Wl,-soname,$(DYLIB_MINOR_NAME) -o $(DYLIBNAME) $(LDFLAGS)
@@ -49,19 +62,20 @@ ifeq ($(uname_S),SunOS)
 endif
 ifeq ($(uname_S),Darwin)
  DYLIBSUFFIX=dylib
-  DYLIB_MINOR_NAME=$(LIBNAME).$(HIREDIS_MAJOR).$(HIREDIS_MINOR).$(DYLIBSUFFIX)
-  DYLIB_MAJOR_NAME=$(LIBNAME).$(HIREDIS_MAJOR).$(DYLIBSUFFIX)
+  DYLIB_MINOR_NAME=$(LIBNAME).$(HIREDIS_SONAME).$(DYLIBSUFFIX)
  DYLIB_MAKE_CMD=$(CC) -shared -Wl,-install_name,$(DYLIB_MINOR_NAME) -o $(DYLIBNAME) $(LDFLAGS)
 endif

-all: $(DYLIBNAME)
+all: $(DYLIBNAME) $(STLIBNAME) hiredis-test $(PKGCONFNAME)

 # Deps (use make dep to generate this)
-net.o: net.c fmacros.h net.h hiredis.h
-async.o: async.c async.h hiredis.h sds.h dict.c dict.h
-hiredis.o: hiredis.c fmacros.h hiredis.h net.h sds.h
+async.o: async.c fmacros.h async.h hiredis.h read.h sds.h net.h dict.c dict.h
+dict.o: dict.c fmacros.h dict.h
+hiredis.o: hiredis.c fmacros.h hiredis.h read.h sds.h net.h
+net.o: net.c fmacros.h net.h hiredis.h read.h sds.h
+read.o: read.c fmacros.h read.h sds.h
 sds.o: sds.c sds.h
-test.o: test.c hiredis.h
+test.o: test.c fmacros.h hiredis.h read.h sds.h

 $(DYLIBNAME): $(OBJ)
 	$(DYLIB_MAKE_CMD) $(OBJ)
@@ -79,6 +93,15 @@ hiredis-example-libevent: examples/example-libevent.c adapters/libevent.h $(STLI
 hiredis-example-libev: examples/example-libev.c adapters/libev.h $(STLIBNAME)
 	$(CC) -o examples/$@ $(REAL_CFLAGS) $(REAL_LDFLAGS) -I. $< -lev $(STLIBNAME)

+hiredis-example-glib: examples/example-glib.c adapters/glib.h $(STLIBNAME)
+	$(CC) -o examples/$@ $(REAL_CFLAGS) $(REAL_LDFLAGS) $(shell pkg-config --cflags --libs glib-2.0) -I. $< $(STLIBNAME)
+
+hiredis-example-ivykis: examples/example-ivykis.c adapters/ivykis.h $(STLIBNAME)
+	$(CC) -o examples/$@ $(REAL_CFLAGS) $(REAL_LDFLAGS) -I. $< -livykis $(STLIBNAME)
+
+hiredis-example-macosx: examples/example-macosx.c adapters/macosx.h $(STLIBNAME)
+	$(CC) -o examples/$@ $(REAL_CFLAGS) $(REAL_LDFLAGS) -I. $< -framework CoreFoundation $(STLIBNAME)
+
 ifndef AE_DIR
 hiredis-example-ae:
 	@echo "Please specify AE_DIR (e.g. <redis repository>/src)"
@@ -94,7 +117,20 @@ hiredis-example-libuv:
 	@false
 else
 hiredis-example-libuv: examples/example-libuv.c adapters/libuv.h $(STLIBNAME)
-	$(CC) -o examples/$@ $(REAL_CFLAGS) $(REAL_LDFLAGS) -I. -I$(LIBUV_DIR)/include $< $(LIBUV_DIR)/.libs/libuv.a -lpthread $(STLIBNAME)
+	$(CC) -o examples/$@ $(REAL_CFLAGS) $(REAL_LDFLAGS) -I. -I$(LIBUV_DIR)/include $< $(LIBUV_DIR)/.libs/libuv.a -lpthread -lrt $(STLIBNAME)
+endif
+
+ifeq ($(and $(QT_MOC),$(QT_INCLUDE_DIR),$(QT_LIBRARY_DIR)),)
+hiredis-example-qt:
+	@echo "Please specify QT_MOC, QT_INCLUDE_DIR AND QT_LIBRARY_DIR"
+	@false
+else
+hiredis-example-qt: examples/example-qt.cpp adapters/qt.h $(STLIBNAME)
+	$(QT_MOC) adapters/qt.h -I. -I$(QT_INCLUDE_DIR) -I$(QT_INCLUDE_DIR)/QtCore | \
+	    $(CXX) -x c++ -o qt-adapter-moc.o -c - $(REAL_CFLAGS) -I. -I$(QT_INCLUDE_DIR) -I$(QT_INCLUDE_DIR)/QtCore
+	$(QT_MOC) examples/example-qt.h -I. -I$(QT_INCLUDE_DIR) -I$(QT_INCLUDE_DIR)/QtCore | \
+	    $(CXX) -x c++ -o qt-example-moc.o -c - $(REAL_CFLAGS) -I. -I$(QT_INCLUDE_DIR) -I$(QT_INCLUDE_DIR)/QtCore
+	$(CXX) -o examples/$@ $(REAL_CFLAGS) $(REAL_LDFLAGS) -I. -I$(QT_INCLUDE_DIR) -I$(QT_INCLUDE_DIR)/QtCore -L$(QT_LIBRARY_DIR) qt-adapter-moc.o qt-example-moc.o $< -pthread $(STLIBNAME) -lQtCore
 endif

 hiredis-example: examples/example.c $(STLIBNAME)
@@ -103,14 +139,16 @@ hiredis-example: examples/example.c $(STLIBNAME)
 examples: $(EXAMPLES)

 hiredis-test: test.o $(STLIBNAME)
-	$(CC) -o $@ $(REAL_LDFLAGS) $< $(STLIBNAME)
+
+hiredis-%: %.o $(STLIBNAME)
+	$(CC) $(REAL_CFLAGS) -o $@ $(REAL_LDFLAGS) $< $(STLIBNAME)

 test: hiredis-test
 	./hiredis-test

 check: hiredis-test
 	@echo "$$REDIS_TEST_CONFIG" | $(REDIS_SERVER) -
-	./hiredis-test -h 127.0.0.1 -p $(REDIS_PORT) -s /tmp/hiredis-test-redis.sock || \
+	$(PRE) ./hiredis-test -h 127.0.0.1 -p $(REDIS_PORT) -s /tmp/hiredis-test-redis.sock || \
 			( kill `cat /tmp/hiredis-test-redis.pid` && false )
 	kill `cat /tmp/hiredis-test-redis.pid`

@@ -118,29 +156,38 @@ check: hiredis-test
 	$(CC) -std=c99 -pedantic -c $(REAL_CFLAGS) $<

 clean:
-	rm -rf $(DYLIBNAME) $(STLIBNAME) $(TESTS) examples/hiredis-example* *.o *.gcda *.gcno *.gcov
+	rm -rf $(DYLIBNAME) $(STLIBNAME) $(TESTS) $(PKGCONFNAME) examples/hiredis-example* *.o *.gcda *.gcno *.gcov

 dep:
 	$(CC) -MM *.c

-# Installation related variables and target
-PREFIX?=/usr/local
-INSTALL_INCLUDE_PATH= $(PREFIX)/include/hiredis
-INSTALL_LIBRARY_PATH= $(PREFIX)/lib
-
 ifeq ($(uname_S),SunOS)
  INSTALL?= cp -r
 endif

 INSTALL?= cp -a

-install: $(DYLIBNAME) $(STLIBNAME)
+$(PKGCONFNAME): hiredis.h
+	@echo "Generating $@ for pkgconfig..."
+	@echo prefix=$(PREFIX) > $@
+	@echo exec_prefix=\$${prefix} >> $@
+	@echo libdir=$(PREFIX)/$(LIBRARY_PATH) >> $@
+	@echo includedir=$(PREFIX)/$(INCLUDE_PATH) >> $@
+	@echo >> $@
+	@echo Name: hiredis >> $@
+	@echo Description: Minimalistic C client library for Redis. >> $@
+	@echo Version: $(HIREDIS_MAJOR).$(HIREDIS_MINOR).$(HIREDIS_PATCH) >> $@
+	@echo Libs: -L\$${libdir} -lhiredis >> $@
+	@echo Cflags: -I\$${includedir} -D_FILE_OFFSET_BITS=64 >> $@
+
+install: $(DYLIBNAME) $(STLIBNAME) $(PKGCONFNAME)
 	mkdir -p $(INSTALL_INCLUDE_PATH) $(INSTALL_LIBRARY_PATH)
-	$(INSTALL) hiredis.h async.h adapters $(INSTALL_INCLUDE_PATH)
+	$(INSTALL) hiredis.h async.h read.h sds.h adapters $(INSTALL_INCLUDE_PATH)
 	$(INSTALL) $(DYLIBNAME) $(INSTALL_LIBRARY_PATH)/$(DYLIB_MINOR_NAME)
-	cd $(INSTALL_LIBRARY_PATH) && ln -sf $(DYLIB_MINOR_NAME) $(DYLIB_MAJOR_NAME)
-	cd $(INSTALL_LIBRARY_PATH) && ln -sf $(DYLIB_MAJOR_NAME) $(DYLIBNAME)
+	cd $(INSTALL_LIBRARY_PATH) && ln -sf $(DYLIB_MINOR_NAME) $(DYLIBNAME)
 	$(INSTALL) $(STLIBNAME) $(INSTALL_LIBRARY_PATH)
+	mkdir -p $(INSTALL_PKGCONF_PATH)
+	$(INSTALL) $(PKGCONFNAME) $(INSTALL_PKGCONF_PATH)

 32bit:
 	@echo ""
@@ -148,6 +195,10 @@ install: $(DYLIBNAME) $(STLIBNAME)
 	@echo ""
 	$(MAKE) CFLAGS="-m32" LDFLAGS="-m32"

+32bit-vars:
+	$(eval CFLAGS=-m32)
+	$(eval LDFLAGS=-m32)
+
 gprof:
 	$(MAKE) CFLAGS="-pg" LDFLAGS="-pg"

@@ -163,4 +214,4 @@ coverage: gcov
 noopt:
 	$(MAKE) OPTIMIZATION=""

-.PHONY: all test check clean dep install 32bit gprof gcov noopt
+.PHONY: all test check clean dep install 32bit 32bit-vars gprof gcov noopt
@@ -1,11 +1,13 @@
 [![Build Status](https://travis-ci.org/redis/hiredis.png)](https://travis-ci.org/redis/hiredis)

+**This Readme reflects the latest changed in the master branch. See [v0.13.3](https://github.com/redis/hiredis/tree/v0.13.3) for the Readme and documentation for the latest release.**
+
 # HIREDIS

 Hiredis is a minimalistic C client library for the [Redis](http://redis.io/) database.

 It is minimalistic because it just adds minimal support for the protocol, but
-at the same time it uses an high level printf-alike API in order to make it
+at the same time it uses a high level printf-alike API in order to make it
 much higher level than otherwise suggested by its minimal code base and the
 lack of explicit bindings for every Redis command.

@@ -20,7 +22,15 @@ Redis version >= 1.2.0.
 The library comes with multiple APIs. There is the
 *synchronous API*, the *asynchronous API* and the *reply parsing API*.

-## UPGRADING
+## Upgrading to `1.0.0`
+
+Version 1.0.0 marks a stable release of hiredis.
+It includes some minor breaking changes, mostly to make the exposed API more uniform and self-explanatory.
+It also bundles the updated `sds` library, to sync up with upstream and Redis.
+For most applications a recompile against the new hiredis should be enough.
+For code changes see the [Changelog](CHANGELOG.md).
+
+## Upgrading from `<0.9.0`

 Version 0.9.0 is a major overhaul of hiredis in every aspect. However, upgrading existing
 code using hiredis should not be a big pain. The key thing to keep in mind when
@@ -31,51 +41,62 @@ the stateless 0.0.1 that only has a file descriptor to work with.

 To consume the synchronous API, there are only a few function calls that need to be introduced:

-    redisContext *redisConnect(const char *ip, int port);
-    void *redisCommand(redisContext *c, const char *format, ...);
-    void freeReplyObject(void *reply);
+```c
+redisContext *redisConnect(const char *ip, int port);
+void *redisCommand(redisContext *c, const char *format, ...);
+void freeReplyObject(void *reply);
+```

 ### Connecting

 The function `redisConnect` is used to create a so-called `redisContext`. The
 context is where Hiredis holds state for a connection. The `redisContext`
-struct has an integer `err` field that is non-zero when an the connection is in
+struct has an integer `err` field that is non-zero when the connection is in
 an error state. The field `errstr` will contain a string with a description of
 the error. More information on errors can be found in the **Errors** section.
 After trying to connect to Redis using `redisConnect` you should
 check the `err` field to see if establishing the connection was successful:
-
-    redisContext *c = redisConnect("127.0.0.1", 6379);
-    if (c != NULL && c->err) {
+```c
+redisContext *c = redisConnect("127.0.0.1", 6379);
+if (c == NULL || c->err) {
+    if (c) {
        printf("Error: %s\n", c->errstr);
        // handle error
+    } else {
+        printf("Can't allocate redis context\n");
    }
+}
+```
+
+*Note: A `redisContext` is not thread-safe.*

 ### Sending commands

 There are several ways to issue commands to Redis. The first that will be introduced is
 `redisCommand`. This function takes a format similar to printf. In the simplest form,
 it is used like this:
-
-    reply = redisCommand(context, "SET foo bar");
+```c
+reply = redisCommand(context, "SET foo bar");
+```

 The specifier `%s` interpolates a string in the command, and uses `strlen` to
 determine the length of the string:
-
-    reply = redisCommand(context, "SET foo %s", value);
-
+```c
+reply = redisCommand(context, "SET foo %s", value);
+```
 When you need to pass binary safe strings in a command, the `%b` specifier can be
 used. Together with a pointer to the string, it requires a `size_t` length argument
 of the string:
-
-    reply = redisCommand(context, "SET foo %b", value, (size_t) valuelen);
-
+```c
+reply = redisCommand(context, "SET foo %b", value, (size_t) valuelen);
+```
 Internally, Hiredis splits the command in different arguments and will
 convert it to the protocol used to communicate with Redis.
 One or more spaces separates arguments, so you can use the specifiers
 anywhere in an argument:
-
-    reply = redisCommand(context, "SET key:%s %s", myid, value);
+```c
+reply = redisCommand(context, "SET key:%s %s", myid, value);
+```

 ### Using replies

@@ -114,11 +135,11 @@ was received:
      Redis may reply with nested arrays but this is fully supported.

 Replies should be freed using the `freeReplyObject()` function.
-Note that this function will take care of freeing sub-replies objects
+Note that this function will take care of freeing sub-reply objects
 contained in arrays and nested arrays, so there is no need for the user to
 free the sub replies (it is actually harmful and will corrupt the memory).

-**Important:** the current version of hiredis (0.10.0) free's replies when the
+**Important:** the current version of hiredis (0.10.0) frees replies when the
 asynchronous API is used. This means you should not call `freeReplyObject` when
 you use this API. The reply is cleaned up by hiredis _after_ the callback
 returns. This behavior will probably change in future releases, so make sure to
@@ -127,19 +148,19 @@ keep an eye on the changelog when upgrading (see issue #39).
 ### Cleaning up

 To disconnect and free the context the following function can be used:
-
-    void redisFree(redisContext *c);
-
-This function immediately closes the socket and then free's the allocations done in
+```c
+void redisFree(redisContext *c);
+```
+This function immediately closes the socket and then frees the allocations done in
 creating the context.

 ### Sending commands (cont'd)

 Together with `redisCommand`, the function `redisCommandArgv` can be used to issue commands.
 It has the following prototype:
-
-    void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
-
+```c
+void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
+```
 It takes the number of arguments `argc`, an array of strings `argv` and the lengths of the
 arguments `argvlen`. For convenience, `argvlen` may be set to `NULL` and the function will
 use `strlen(3)` on every argument to determine its length. Obviously, when any of the arguments
@@ -169,10 +190,10 @@ The function `redisGetReply` is exported as part of the Hiredis API and can be u
 is expected on the socket. To pipeline commands, the only things that needs to be done is
 filling up the output buffer. For this cause, two commands can be used that are identical
 to the `redisCommand` family, apart from not returning a reply:
-
-    void redisAppendCommand(redisContext *c, const char *format, ...);
-    void redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
-
+```c
+void redisAppendCommand(redisContext *c, const char *format, ...);
+void redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
+```
 After calling either function one or more times, `redisGetReply` can be used to receive the
 subsequent replies. The return value for this function is either `REDIS_OK` or `REDIS_ERR`, where
 the latter means an error occurred while reading a reply. Just as with the other commands,
@@ -180,24 +201,24 @@ the `err` field in the context can be used to find out what the cause of this er

 The following examples shows a simple pipeline (resulting in only a single call to `write(2)` and
 a single call to `read(2)`):
-
-    redisReply *reply;
-    redisAppendCommand(context,"SET foo bar");
-    redisAppendCommand(context,"GET foo");
-    redisGetReply(context,&reply); // reply for SET
-    freeReplyObject(reply);
-    redisGetReply(context,&reply); // reply for GET
-    freeReplyObject(reply);
-
+```c
+redisReply *reply;
+redisAppendCommand(context,"SET foo bar");
+redisAppendCommand(context,"GET foo");
+redisGetReply(context,&reply); // reply for SET
+freeReplyObject(reply);
+redisGetReply(context,&reply); // reply for GET
+freeReplyObject(reply);
+```
 This API can also be used to implement a blocking subscriber:
-
-    reply = redisCommand(context,"SUBSCRIBE foo");
+```c
+reply = redisCommand(context,"SUBSCRIBE foo");
+freeReplyObject(reply);
+while(redisGetReply(context,&reply) == REDIS_OK) {
+    // consume message
    freeReplyObject(reply);
-    while(redisGetReply(context,&reply) == REDIS_OK) {
-        // consume message
-        freeReplyObject(reply);
-    }
-
+}
+```
 ### Errors

 When a function call is not successful, depending on the function either `NULL` or `REDIS_ERR` is
@@ -237,58 +258,62 @@ should be checked after creation to see if there were errors creating the connec
 Because the connection that will be created is non-blocking, the kernel is not able to
 instantly return if the specified host and port is able to accept a connection.

-    redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);
-    if (c->err) {
-        printf("Error: %s\n", c->errstr);
-        // handle error
-    }
+*Note: A `redisAsyncContext` is not thread-safe.*
+
+```c
+redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);
+if (c->err) {
+    printf("Error: %s\n", c->errstr);
+    // handle error
+}
+```

 The asynchronous context can hold a disconnect callback function that is called when the
 connection is disconnected (either because of an error or per user request). This function should
 have the following prototype:
-
-    void(const redisAsyncContext *c, int status);
-
+```c
+void(const redisAsyncContext *c, int status);
+```
 On a disconnect, the `status` argument is set to `REDIS_OK` when disconnection was initiated by the
 user, or `REDIS_ERR` when the disconnection was caused by an error. When it is `REDIS_ERR`, the `err`
 field in the context can be accessed to find out the cause of the error.

-The context object is always free'd after the disconnect callback fired. When a reconnect is needed,
+The context object is always freed after the disconnect callback fired. When a reconnect is needed,
 the disconnect callback is a good point to do so.

 Setting the disconnect callback can only be done once per context. For subsequent calls it will
 return `REDIS_ERR`. The function to set the disconnect callback has the following prototype:
-
-    int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn);
-
+```c
+int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn);
+```
 ### Sending commands and their callbacks

 In an asynchronous context, commands are automatically pipelined due to the nature of an event loop.
 Therefore, unlike the synchronous API, there is only a single way to send commands.
 Because commands are sent to Redis asynchronously, issuing a command requires a callback function
 that is called when the reply is received. Reply callbacks should have the following prototype:
-
-    void(redisAsyncContext *c, void *reply, void *privdata);
-
+```c
+void(redisAsyncContext *c, void *reply, void *privdata);
+```
 The `privdata` argument can be used to curry arbitrary data to the callback from the point where
 the command is initially queued for execution.

 The functions that can be used to issue commands in an asynchronous context are:
-
-    int redisAsyncCommand(
-      redisAsyncContext *ac, redisCallbackFn *fn, void *privdata,
-      const char *format, ...);
-    int redisAsyncCommandArgv(
-      redisAsyncContext *ac, redisCallbackFn *fn, void *privdata,
-      int argc, const char **argv, const size_t *argvlen);
-
+```c
+int redisAsyncCommand(
+  redisAsyncContext *ac, redisCallbackFn *fn, void *privdata,
+  const char *format, ...);
+int redisAsyncCommandArgv(
+  redisAsyncContext *ac, redisCallbackFn *fn, void *privdata,
+  int argc, const char **argv, const size_t *argvlen);
+```
 Both functions work like their blocking counterparts. The return value is `REDIS_OK` when the command
 was successfully added to the output buffer and `REDIS_ERR` otherwise. Example: when the connection
 is being disconnected per user-request, no new commands may be added to the output buffer and `REDIS_ERR` is
 returned on calls to the `redisAsyncCommand` family.

-If the reply for a command with a `NULL` callback is read, it is immediately free'd. When the callback
-for a command is non-`NULL`, the memory is free'd immediately following the callback: the reply is only
+If the reply for a command with a `NULL` callback is read, it is immediately freed. When the callback
+for a command is non-`NULL`, the memory is freed immediately following the callback: the reply is only
 valid for the duration of the callback.

 All pending callbacks are called with a `NULL` reply when the context encountered an error.
@@ -296,14 +321,14 @@ All pending callbacks are called with a `NULL` reply when the context encountere
 ### Disconnecting

 An asynchronous connection can be terminated using:
-
-    void redisAsyncDisconnect(redisAsyncContext *ac);
-
+```c
+void redisAsyncDisconnect(redisAsyncContext *ac);
+```
 When this function is called, the connection is **not** immediately terminated. Instead, new
 commands are no longer accepted and the connection is only terminated when all pending commands
 have been written to the socket, their respective replies have been read and their respective
 callbacks have been executed. After this, the disconnection callback is executed with the
-`REDIS_OK` status and the context object is free'd.
+`REDIS_OK` status and the context object is freed.

 ### Hooking it up to event library *X*

@@ -316,12 +341,12 @@ Hiredis comes with a reply parsing API that makes it easy for writing higher
 level language bindings.

 The reply parsing API consists of the following functions:
-
-    redisReader *redisReaderCreate(void);
-    void redisReaderFree(redisReader *reader);
-    int redisReaderFeed(redisReader *reader, const char *buf, size_t len);
-    int redisReaderGetReply(redisReader *reader, void **reply);
-
+```c
+redisReader *redisReaderCreate(void);
+void redisReaderFree(redisReader *reader);
+int redisReaderFeed(redisReader *reader, const char *buf, size_t len);
+int redisReaderGetReply(redisReader *reader, void **reply);
+```
 The same set of functions are used internally by hiredis when creating a
 normal Redis context, the above API just exposes it to the user for a direct
 usage.
@@ -361,7 +386,7 @@ Both when using the Reader API directly or when using it indirectly via a
 normal Redis context, the redisReader structure uses a buffer in order to
 accumulate data from the server.
 Usually this buffer is destroyed when it is empty and is larger than 16
-kb in order to avoid wasting memory in unused buffers
+KiB in order to avoid wasting memory in unused buffers

 However when working with very big payloads destroying the buffer may slow
 down performances considerably, so it is possible to modify the max size of
@@ -371,9 +396,9 @@ value for an idle buffer, so the buffer will never get freed.

 For instance if you have a normal Redis context you can set the maximum idle
 buffer to zero (unlimited) just with:
-
-    context->reader->maxbuf = 0;
-
+```c
+context->reader->maxbuf = 0;
+```
 This should be done only in order to maximize performances when working with
 large payloads. The context should be set back to `REDIS_READER_MAX_BUF` again
 as soon as possible in order to prevent allocation of useless memory.
@@ -381,4 +406,6 @@ as soon as possible in order to prevent allocation of useless memory.
 ## AUTHORS

 Hiredis was written by Salvatore Sanfilippo (antirez at gmail) and
-Pieter Noordhuis (pcnoordhuis at gmail) and is released under the BSD license.
+Pieter Noordhuis (pcnoordhuis at gmail) and is released under the BSD license.  
+Hiredis is currently maintained by Matt Stancliff (matt at genges dot com) and
+Jan-Erik Rediger (janerik at fnordig dot com)
@@ -0,0 +1,153 @@
+#ifndef __HIREDIS_GLIB_H__
+#define __HIREDIS_GLIB_H__
+
+#include <glib.h>
+
+#include "../hiredis.h"
+#include "../async.h"
+
+typedef struct
+{
+    GSource source;
+    redisAsyncContext *ac;
+    GPollFD poll_fd;
+} RedisSource;
+
+static void
+redis_source_add_read (gpointer data)
+{
+    RedisSource *source = (RedisSource *)data;
+    g_return_if_fail(source);
+    source->poll_fd.events |= G_IO_IN;
+    g_main_context_wakeup(g_source_get_context((GSource *)data));
+}
+
+static void
+redis_source_del_read (gpointer data)
+{
+    RedisSource *source = (RedisSource *)data;
+    g_return_if_fail(source);
+    source->poll_fd.events &= ~G_IO_IN;
+    g_main_context_wakeup(g_source_get_context((GSource *)data));
+}
+
+static void
+redis_source_add_write (gpointer data)
+{
+    RedisSource *source = (RedisSource *)data;
+    g_return_if_fail(source);
+    source->poll_fd.events |= G_IO_OUT;
+    g_main_context_wakeup(g_source_get_context((GSource *)data));
+}
+
+static void
+redis_source_del_write (gpointer data)
+{
+    RedisSource *source = (RedisSource *)data;
+    g_return_if_fail(source);
+    source->poll_fd.events &= ~G_IO_OUT;
+    g_main_context_wakeup(g_source_get_context((GSource *)data));
+}
+
+static void
+redis_source_cleanup (gpointer data)
+{
+    RedisSource *source = (RedisSource *)data;
+
+    g_return_if_fail(source);
+
+    redis_source_del_read(source);
+    redis_source_del_write(source);
+    /*
+     * It is not our responsibility to remove ourself from the
+     * current main loop. However, we will remove the GPollFD.
+     */
+    if (source->poll_fd.fd >= 0) {
+        g_source_remove_poll((GSource *)data, &source->poll_fd);
+        source->poll_fd.fd = -1;
+    }
+}
+
+static gboolean
+redis_source_prepare (GSource *source,
+                      gint    *timeout_)
+{
+    RedisSource *redis = (RedisSource *)source;
+    *timeout_ = -1;
+    return !!(redis->poll_fd.events & redis->poll_fd.revents);
+}
+
+static gboolean
+redis_source_check (GSource *source)
+{
+    RedisSource *redis = (RedisSource *)source;
+    return !!(redis->poll_fd.events & redis->poll_fd.revents);
+}
+
+static gboolean
+redis_source_dispatch (GSource      *source,
+                       GSourceFunc   callback,
+                       gpointer      user_data)
+{
+    RedisSource *redis = (RedisSource *)source;
+
+    if ((redis->poll_fd.revents & G_IO_OUT)) {
+        redisAsyncHandleWrite(redis->ac);
+        redis->poll_fd.revents &= ~G_IO_OUT;
+    }
+
+    if ((redis->poll_fd.revents & G_IO_IN)) {
+        redisAsyncHandleRead(redis->ac);
+        redis->poll_fd.revents &= ~G_IO_IN;
+    }
+
+    if (callback) {
+        return callback(user_data);
+    }
+
+    return TRUE;
+}
+
+static void
+redis_source_finalize (GSource *source)
+{
+    RedisSource *redis = (RedisSource *)source;
+
+    if (redis->poll_fd.fd >= 0) {
+        g_source_remove_poll(source, &redis->poll_fd);
+        redis->poll_fd.fd = -1;
+    }
+}
+
+static GSource *
+redis_source_new (redisAsyncContext *ac)
+{
+    static GSourceFuncs source_funcs = {
+        .prepare  = redis_source_prepare,
+        .check     = redis_source_check,
+        .dispatch = redis_source_dispatch,
+        .finalize = redis_source_finalize,
+    };
+    redisContext *c = &ac->c;
+    RedisSource *source;
+
+    g_return_val_if_fail(ac != NULL, NULL);
+
+    source = (RedisSource *)g_source_new(&source_funcs, sizeof *source);
+    source->ac = ac;
+    source->poll_fd.fd = c->fd;
+    source->poll_fd.events = 0;
+    source->poll_fd.revents = 0;
+    g_source_add_poll((GSource *)source, &source->poll_fd);
+
+    ac->ev.addRead = redis_source_add_read;
+    ac->ev.delRead = redis_source_del_read;
+    ac->ev.addWrite = redis_source_add_write;
+    ac->ev.delWrite = redis_source_del_write;
+    ac->ev.cleanup = redis_source_cleanup;
+    ac->ev.data = source;
+
+    return (GSource *)source;
+}
+
+#endif /* __HIREDIS_GLIB_H__ */
@@ -0,0 +1,81 @@
+#ifndef __HIREDIS_IVYKIS_H__
+#define __HIREDIS_IVYKIS_H__
+#include <iv.h>
+#include "../hiredis.h"
+#include "../async.h"
+
+typedef struct redisIvykisEvents {
+    redisAsyncContext *context;
+    struct iv_fd fd;
+} redisIvykisEvents;
+
+static void redisIvykisReadEvent(void *arg) {
+    redisAsyncContext *context = (redisAsyncContext *)arg;
+    redisAsyncHandleRead(context);
+}
+
+static void redisIvykisWriteEvent(void *arg) {
+    redisAsyncContext *context = (redisAsyncContext *)arg;
+    redisAsyncHandleWrite(context);
+}
+
+static void redisIvykisAddRead(void *privdata) {
+    redisIvykisEvents *e = (redisIvykisEvents*)privdata;
+    iv_fd_set_handler_in(&e->fd, redisIvykisReadEvent);
+}
+
+static void redisIvykisDelRead(void *privdata) {
+    redisIvykisEvents *e = (redisIvykisEvents*)privdata;
+    iv_fd_set_handler_in(&e->fd, NULL);
+}
+
+static void redisIvykisAddWrite(void *privdata) {
+    redisIvykisEvents *e = (redisIvykisEvents*)privdata;
+    iv_fd_set_handler_out(&e->fd, redisIvykisWriteEvent);
+}
+
+static void redisIvykisDelWrite(void *privdata) {
+    redisIvykisEvents *e = (redisIvykisEvents*)privdata;
+    iv_fd_set_handler_out(&e->fd, NULL);
+}
+
+static void redisIvykisCleanup(void *privdata) {
+    redisIvykisEvents *e = (redisIvykisEvents*)privdata;
+
+    iv_fd_unregister(&e->fd);
+    free(e);
+}
+
+static int redisIvykisAttach(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+    redisIvykisEvents *e;
+
+    /* Nothing should be attached when something is already attached */
+    if (ac->ev.data != NULL)
+        return REDIS_ERR;
+
+    /* Create container for context and r/w events */
+    e = (redisIvykisEvents*)malloc(sizeof(*e));
+    e->context = ac;
+
+    /* Register functions to start/stop listening for events */
+    ac->ev.addRead = redisIvykisAddRead;
+    ac->ev.delRead = redisIvykisDelRead;
+    ac->ev.addWrite = redisIvykisAddWrite;
+    ac->ev.delWrite = redisIvykisDelWrite;
+    ac->ev.cleanup = redisIvykisCleanup;
+    ac->ev.data = e;
+
+    /* Initialize and install read/write events */
+    IV_FD_INIT(&e->fd);
+    e->fd.fd = c->fd;
+    e->fd.handler_in = redisIvykisReadEvent;
+    e->fd.handler_out = redisIvykisWriteEvent;
+    e->fd.handler_err = NULL;
+    e->fd.cookie = e->context;
+
+    iv_fd_register(&e->fd);
+
+    return REDIS_OK;
+}
+#endif
@@ -30,13 +30,13 @@

 #ifndef __HIREDIS_LIBEVENT_H__
 #define __HIREDIS_LIBEVENT_H__
-#include <event.h>
+#include <event2/event.h>
 #include "../hiredis.h"
 #include "../async.h"

 typedef struct redisLibeventEvents {
    redisAsyncContext *context;
-    struct event rev, wev;
+    struct event *rev, *wev;
 } redisLibeventEvents;

 static void redisLibeventReadEvent(int fd, short event, void *arg) {
@@ -53,28 +53,28 @@ static void redisLibeventWriteEvent(int fd, short event, void *arg) {

 static void redisLibeventAddRead(void *privdata) {
    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
-    event_add(&e->rev,NULL);
+    event_add(e->rev,NULL);
 }

 static void redisLibeventDelRead(void *privdata) {
    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
-    event_del(&e->rev);
+    event_del(e->rev);
 }

 static void redisLibeventAddWrite(void *privdata) {
    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
-    event_add(&e->wev,NULL);
+    event_add(e->wev,NULL);
 }

 static void redisLibeventDelWrite(void *privdata) {
    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
-    event_del(&e->wev);
+    event_del(e->wev);
 }

 static void redisLibeventCleanup(void *privdata) {
    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
-    event_del(&e->rev);
-    event_del(&e->wev);
+    event_del(e->rev);
+    event_del(e->wev);
    free(e);
 }

@@ -99,10 +99,10 @@ static int redisLibeventAttach(redisAsyncContext *ac, struct event_base *base) {
    ac->ev.data = e;

    /* Initialize and install read/write events */
-    event_set(&e->rev,c->fd,EV_READ,redisLibeventReadEvent,e);
-    event_set(&e->wev,c->fd,EV_WRITE,redisLibeventWriteEvent,e);
-    event_base_set(base,&e->rev);
-    event_base_set(base,&e->wev);
+    e->rev = event_new(base, c->fd, EV_READ, redisLibeventReadEvent, e);
+    e->wev = event_new(base, c->fd, EV_WRITE, redisLibeventWriteEvent, e);
+    event_add(e->rev, NULL);
+    event_add(e->wev, NULL);
    return REDIS_OK;
 }
 #endif
@@ -1,5 +1,6 @@
 #ifndef __HIREDIS_LIBUV_H__
 #define __HIREDIS_LIBUV_H__
+#include <stdlib.h>
 #include <uv.h>
 #include "../hiredis.h"
 #include "../async.h"
@@ -11,7 +12,6 @@ typedef struct redisLibuvEvents {
  int                events;
 } redisLibuvEvents;

-int redisLibuvAttach(redisAsyncContext*, uv_loop_t*);

 static void redisLibuvPoll(uv_poll_t* handle, int status, int events) {
  redisLibuvEvents* p = (redisLibuvEvents*)handle->data;
@@ -20,10 +20,10 @@ static void redisLibuvPoll(uv_poll_t* handle, int status, int events) {
    return;
  }

-  if (events & UV_READABLE) {
+  if (p->context != NULL && (events & UV_READABLE)) {
    redisAsyncHandleRead(p->context);
  }
-  if (events & UV_WRITABLE) {
+  if (p->context != NULL && (events & UV_WRITABLE)) {
    redisAsyncHandleWrite(p->context);
  }
 }
@@ -83,6 +83,7 @@ static void on_close(uv_handle_t* handle) {
 static void redisLibuvCleanup(void *privdata) {
  redisLibuvEvents* p = (redisLibuvEvents*)privdata;

+  p->context = NULL; // indicate that context might no longer exist
  uv_close((uv_handle_t*)&p->handle, on_close);
 }

@@ -0,0 +1,114 @@
+//
+//  Created by Дмитрий Бахвалов on 13.07.15.
+//  Copyright (c) 2015 Dmitry Bakhvalov. All rights reserved.
+//
+
+#ifndef __HIREDIS_MACOSX_H__
+#define __HIREDIS_MACOSX_H__
+
+#include <CoreFoundation/CoreFoundation.h>
+
+#include "../hiredis.h"
+#include "../async.h"
+
+typedef struct {
+    redisAsyncContext *context;
+    CFSocketRef socketRef;
+    CFRunLoopSourceRef sourceRef;
+} RedisRunLoop;
+
+static int freeRedisRunLoop(RedisRunLoop* redisRunLoop) {
+    if( redisRunLoop != NULL ) {
+        if( redisRunLoop->sourceRef != NULL ) {
+            CFRunLoopSourceInvalidate(redisRunLoop->sourceRef);
+            CFRelease(redisRunLoop->sourceRef);
+        }
+        if( redisRunLoop->socketRef != NULL ) {
+            CFSocketInvalidate(redisRunLoop->socketRef);
+            CFRelease(redisRunLoop->socketRef);
+        }
+        free(redisRunLoop);
+    }
+    return REDIS_ERR;
+}
+
+static void redisMacOSAddRead(void *privdata) {
+    RedisRunLoop *redisRunLoop = (RedisRunLoop*)privdata;
+    CFSocketEnableCallBacks(redisRunLoop->socketRef, kCFSocketReadCallBack);
+}
+
+static void redisMacOSDelRead(void *privdata) {
+    RedisRunLoop *redisRunLoop = (RedisRunLoop*)privdata;
+    CFSocketDisableCallBacks(redisRunLoop->socketRef, kCFSocketReadCallBack);
+}
+
+static void redisMacOSAddWrite(void *privdata) {
+    RedisRunLoop *redisRunLoop = (RedisRunLoop*)privdata;
+    CFSocketEnableCallBacks(redisRunLoop->socketRef, kCFSocketWriteCallBack);
+}
+
+static void redisMacOSDelWrite(void *privdata) {
+    RedisRunLoop *redisRunLoop = (RedisRunLoop*)privdata;
+    CFSocketDisableCallBacks(redisRunLoop->socketRef, kCFSocketWriteCallBack);
+}
+
+static void redisMacOSCleanup(void *privdata) {
+    RedisRunLoop *redisRunLoop = (RedisRunLoop*)privdata;
+    freeRedisRunLoop(redisRunLoop);
+}
+
+static void redisMacOSAsyncCallback(CFSocketRef __unused s, CFSocketCallBackType callbackType, CFDataRef __unused address, const void __unused *data, void *info) {
+    redisAsyncContext* context = (redisAsyncContext*) info;
+
+    switch (callbackType) {
+        case kCFSocketReadCallBack:
+            redisAsyncHandleRead(context);
+            break;
+
+        case kCFSocketWriteCallBack:
+            redisAsyncHandleWrite(context);
+            break;
+
+        default:
+            break;
+    }
+}
+
+static int redisMacOSAttach(redisAsyncContext *redisAsyncCtx, CFRunLoopRef runLoop) {
+    redisContext *redisCtx = &(redisAsyncCtx->c);
+
+    /* Nothing should be attached when something is already attached */
+    if( redisAsyncCtx->ev.data != NULL ) return REDIS_ERR;
+
+    RedisRunLoop* redisRunLoop = (RedisRunLoop*) calloc(1, sizeof(RedisRunLoop));
+    if( !redisRunLoop ) return REDIS_ERR;
+
+    /* Setup redis stuff */
+    redisRunLoop->context = redisAsyncCtx;
+
+    redisAsyncCtx->ev.addRead  = redisMacOSAddRead;
+    redisAsyncCtx->ev.delRead  = redisMacOSDelRead;
+    redisAsyncCtx->ev.addWrite = redisMacOSAddWrite;
+    redisAsyncCtx->ev.delWrite = redisMacOSDelWrite;
+    redisAsyncCtx->ev.cleanup  = redisMacOSCleanup;
+    redisAsyncCtx->ev.data     = redisRunLoop;
+
+    /* Initialize and install read/write events */
+    CFSocketContext socketCtx = { 0, redisAsyncCtx, NULL, NULL, NULL };
+
+    redisRunLoop->socketRef = CFSocketCreateWithNative(NULL, redisCtx->fd,
+                                                       kCFSocketReadCallBack | kCFSocketWriteCallBack,
+                                                       redisMacOSAsyncCallback,
+                                                       &socketCtx);
+    if( !redisRunLoop->socketRef ) return freeRedisRunLoop(redisRunLoop);
+
+    redisRunLoop->sourceRef = CFSocketCreateRunLoopSource(NULL, redisRunLoop->socketRef, 0);
+    if( !redisRunLoop->sourceRef ) return freeRedisRunLoop(redisRunLoop);
+
+    CFRunLoopAddSource(runLoop, redisRunLoop->sourceRef, kCFRunLoopDefaultMode);
+
+    return REDIS_OK;
+}
+
+#endif
+
@@ -0,0 +1,135 @@
+/*-
+ * Copyright (C) 2014 Pietro Cerutti <gahr@gahr.ch>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __HIREDIS_QT_H__
+#define __HIREDIS_QT_H__
+#include <QSocketNotifier>
+#include "../async.h"
+
+static void RedisQtAddRead(void *);
+static void RedisQtDelRead(void *);
+static void RedisQtAddWrite(void *);
+static void RedisQtDelWrite(void *);
+static void RedisQtCleanup(void *);
+
+class RedisQtAdapter : public QObject {
+
+    Q_OBJECT
+
+    friend
+    void RedisQtAddRead(void * adapter) {
+        RedisQtAdapter * a = static_cast<RedisQtAdapter *>(adapter);
+        a->addRead();
+    }
+
+    friend
+    void RedisQtDelRead(void * adapter) {
+        RedisQtAdapter * a = static_cast<RedisQtAdapter *>(adapter);
+        a->delRead();
+    }
+
+    friend
+    void RedisQtAddWrite(void * adapter) {
+        RedisQtAdapter * a = static_cast<RedisQtAdapter *>(adapter);
+        a->addWrite();
+    }
+
+    friend
+    void RedisQtDelWrite(void * adapter) {
+        RedisQtAdapter * a = static_cast<RedisQtAdapter *>(adapter);
+        a->delWrite();
+    }
+
+    friend
+    void RedisQtCleanup(void * adapter) {
+        RedisQtAdapter * a = static_cast<RedisQtAdapter *>(adapter);
+        a->cleanup();
+    }
+
+    public:
+        RedisQtAdapter(QObject * parent = 0)
+            : QObject(parent), m_ctx(0), m_read(0), m_write(0) { }
+
+        ~RedisQtAdapter() {
+            if (m_ctx != 0) {
+                m_ctx->ev.data = NULL;
+            }
+        }
+
+        int setContext(redisAsyncContext * ac) {
+            if (ac->ev.data != NULL) {
+                return REDIS_ERR;
+            }
+            m_ctx = ac;
+            m_ctx->ev.data = this;
+            m_ctx->ev.addRead = RedisQtAddRead;
+            m_ctx->ev.delRead = RedisQtDelRead;
+            m_ctx->ev.addWrite = RedisQtAddWrite;
+            m_ctx->ev.delWrite = RedisQtDelWrite;
+            m_ctx->ev.cleanup = RedisQtCleanup;
+            return REDIS_OK;
+        }
+
+    private:
+        void addRead() {
+            if (m_read) return;
+            m_read = new QSocketNotifier(m_ctx->c.fd, QSocketNotifier::Read, 0);
+            connect(m_read, SIGNAL(activated(int)), this, SLOT(read()));
+        }
+
+        void delRead() {
+            if (!m_read) return;
+            delete m_read;
+            m_read = 0;
+        }
+
+        void addWrite() {
+            if (m_write) return;
+            m_write = new QSocketNotifier(m_ctx->c.fd, QSocketNotifier::Write, 0);
+            connect(m_write, SIGNAL(activated(int)), this, SLOT(write()));
+        }
+
+        void delWrite() {
+            if (!m_write) return;
+            delete m_write;
+            m_write = 0;
+        }
+
+        void cleanup() {
+            delRead();
+            delWrite();
+        }
+
+    private slots:
+        void read() { redisAsyncHandleRead(m_ctx); }
+        void write() { redisAsyncHandleWrite(m_ctx); }
+
+    private:
+        redisAsyncContext * m_ctx;
+        QSocketNotifier * m_read;
+        QSocketNotifier * m_write;
+};
+
+#endif /* !__HIREDIS_QT_H__ */
@@ -0,0 +1,36 @@
+# Appveyor configuration file for CI build of hiredis on Windows (under Cygwin)
+environment:
+    matrix:
+        - CYG_ROOT: C:\cygwin64
+          CYG_SETUP: setup-x86_64.exe
+          CYG_MIRROR: http://cygwin.mirror.constant.com
+          CYG_CACHE: C:\cygwin64\var\cache\setup
+          CYG_BASH: C:\cygwin64\bin\bash
+          CC: gcc
+        - CYG_ROOT: C:\cygwin
+          CYG_SETUP: setup-x86.exe
+          CYG_MIRROR: http://cygwin.mirror.constant.com
+          CYG_CACHE: C:\cygwin\var\cache\setup
+          CYG_BASH: C:\cygwin\bin\bash
+          CC: gcc
+          TARGET: 32bit
+          TARGET_VARS: 32bit-vars
+
+# Cache Cygwin files to speed up build
+cache:
+    - '%CYG_CACHE%'
+clone_depth: 1
+
+# Attempt to ensure we don't try to convert line endings to Win32 CRLF as this will cause build to fail
+init:
+    - git config --global core.autocrlf input
+
+# Install needed build dependencies
+install:
+    - ps: 'Start-FileDownload "http://cygwin.com/$env:CYG_SETUP" -FileName "$env:CYG_SETUP"'
+    - '%CYG_SETUP% --quiet-mode --no-shortcuts --only-site --root "%CYG_ROOT%" --site "%CYG_MIRROR%" --local-package-dir "%CYG_CACHE%" --packages automake,bison,gcc-core,libtool,make,gettext-devel,gettext,intltool,pkg-config,clang,llvm > NUL 2>&1'
+    - '%CYG_BASH% -lc "cygcheck -dc cygwin"'
+
+build_script:
+    - 'echo building...'
+    - '%CYG_BASH% -lc "cd $APPVEYOR_BUILD_FOLDER; exec 0</dev/null; make LDFLAGS=$LDFLAGS CC=$CC $TARGET CFLAGS=$CFLAGS && make LDFLAGS=$LDFLAGS CC=$CC $TARGET_VARS hiredis-example"'
@@ -58,7 +58,7 @@
    } while(0);

 /* Forward declaration of function in hiredis.c */
-void __redisAppendCommand(redisContext *c, char *cmd, size_t len);
+int __redisAppendCommand(redisContext *c, const char *cmd, size_t len);

 /* Functions managing dictionary of callbacks for pub/sub. */
 static unsigned int callbackHash(const void *key) {
@@ -142,6 +142,9 @@ static redisAsyncContext *redisAsyncInitialize(redisContext *c) {
 /* We want the error field to be accessible directly instead of requiring
 * an indirection to the redisContext struct. */
 static void __redisAsyncCopyError(redisAsyncContext *ac) {
+    if (!ac)
+        return;
+
    redisContext *c = &(ac->c);
    ac->err = c->err;
    ac->errstr = c->errstr;
@@ -173,6 +176,14 @@ redisAsyncContext *redisAsyncConnectBind(const char *ip, int port,
    return ac;
 }

+redisAsyncContext *redisAsyncConnectBindWithReuse(const char *ip, int port,
+                                                  const char *source_addr) {
+    redisContext *c = redisConnectBindNonBlockWithReuse(ip,port,source_addr);
+    redisAsyncContext *ac = redisAsyncInitialize(c);
+    __redisAsyncCopyError(ac);
+    return ac;
+}
+
 redisAsyncContext *redisAsyncConnectUnix(const char *path) {
    redisContext *c;
    redisAsyncContext *ac;
@@ -407,7 +418,8 @@ void redisProcessCallbacks(redisAsyncContext *ac) {
        if (reply == NULL) {
            /* When the connection is being disconnected and there are
             * no more replies, this is the cue to really disconnect. */
-            if (c->flags & REDIS_DISCONNECTING && sdslen(c->obuf) == 0) {
+            if (c->flags & REDIS_DISCONNECTING && sdslen(c->obuf) == 0
+                && ac->replies.head == NULL) {
                __redisAsyncDisconnect(ac);
                return;
            }
@@ -477,7 +489,7 @@ void redisProcessCallbacks(redisAsyncContext *ac) {
 }

 /* Internal helper function to detect socket status the first time a read or
- * write event fires. When connecting was not succesful, the connect callback
+ * write event fires. When connecting was not successful, the connect callback
 * is called with a REDIS_ERR status and the context is free'd. */
 static int __redisAsyncHandleConnect(redisAsyncContext *ac) {
    redisContext *c = &(ac->c);
@@ -551,8 +563,8 @@ void redisAsyncHandleWrite(redisAsyncContext *ac) {

 /* Sets a pointer to the first argument and its length starting at p. Returns
 * the number of bytes to skip to get to the following argument. */
-static char *nextArgument(char *start, char **str, size_t *len) {
-    char *p = start;
+static const char *nextArgument(const char *start, const char **str, size_t *len) {
+    const char *p = start;
    if (p[0] != '$') {
        p = strchr(p,'$');
        if (p == NULL) return NULL;
@@ -568,14 +580,15 @@ static char *nextArgument(char *start, char **str, size_t *len) {
 /* Helper function for the redisAsyncCommand* family of functions. Writes a
 * formatted command to the output buffer and registers the provided callback
 * function with the context. */
-static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, char *cmd, size_t len) {
+static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *cmd, size_t len) {
    redisContext *c = &(ac->c);
    redisCallback cb;
    int pvariant, hasnext;
-    char *cstr, *astr;
+    const char *cstr, *astr;
    size_t clen, alen;
-    char *p;
+    const char *p;
    sds sname;
+    int ret;

    /* Don't accept new commands when the connection is about to be closed. */
    if (c->flags & (REDIS_DISCONNECTING | REDIS_FREEING)) return REDIS_ERR;
@@ -599,9 +612,11 @@ static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void
        while ((p = nextArgument(p,&astr,&alen)) != NULL) {
            sname = sdsnewlen(astr,alen);
            if (pvariant)
-                dictReplace(ac->sub.patterns,sname,&cb);
+                ret = dictReplace(ac->sub.patterns,sname,&cb);
            else
-                dictReplace(ac->sub.channels,sname,&cb);
+                ret = dictReplace(ac->sub.channels,sname,&cb);
+
+            if (ret == 0) sdsfree(sname);
        }
    } else if (strncasecmp(cstr,"unsubscribe\r\n",13) == 0) {
        /* It is only useful to call (P)UNSUBSCRIBE when the context is
@@ -637,6 +652,11 @@ int redisvAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdat
    int len;
    int status;
    len = redisvFormatCommand(&cmd,format,ap);
+
+    /* We don't want to pass -1 or -2 to future functions as a length. */
+    if (len < 0)
+        return REDIS_ERR;
+
    status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
    free(cmd);
    return status;
@@ -652,11 +672,16 @@ int redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata
 }

 int redisAsyncCommandArgv(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, int argc, const char **argv, const size_t *argvlen) {
-    char *cmd;
+    sds cmd;
    int len;
    int status;
-    len = redisFormatCommandArgv(&cmd,argc,argv,argvlen);
+    len = redisFormatSdsCommandArgv(&cmd,argc,argv,argvlen);
    status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
-    free(cmd);
+    sdsfree(cmd);
+    return status;
+}
+
+int redisAsyncFormattedCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *cmd, size_t len) {
+    int status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
    return status;
 }
@@ -103,6 +103,8 @@ typedef struct redisAsyncContext {
 /* Functions that proxy to hiredis */
 redisAsyncContext *redisAsyncConnect(const char *ip, int port);
 redisAsyncContext *redisAsyncConnectBind(const char *ip, int port, const char *source_addr);
+redisAsyncContext *redisAsyncConnectBindWithReuse(const char *ip, int port,
+                                                  const char *source_addr);
 redisAsyncContext *redisAsyncConnectUnix(const char *path);
 int redisAsyncSetConnectCallback(redisAsyncContext *ac, redisConnectCallback *fn);
 int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn);
@@ -118,6 +120,7 @@ void redisAsyncHandleWrite(redisAsyncContext *ac);
 int redisvAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, va_list ap);
 int redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, ...);
 int redisAsyncCommandArgv(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, int argc, const char **argv, const size_t *argvlen);
+int redisAsyncFormattedCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *cmd, size_t len);

 #ifdef __cplusplus
 }
@@ -161,7 +161,7 @@ static int dictReplace(dict *ht, void *key, void *val) {
    dictEntry *entry, auxentry;

    /* Try to add the element. If the key
-     * does not exists dictAdd will suceed. */
+     * does not exists dictAdd will succeed. */
    if (dictAdd(ht, key, val) == DICT_OK)
        return 1;
    /* It already exists, get the entry */
@@ -293,7 +293,7 @@ static void dictReleaseIterator(dictIterator *iter) {

 /* Expand the hash table if needed */
 static int _dictExpandIfNeeded(dict *ht) {
-    /* If the hash table is empty expand it to the intial size,
+    /* If the hash table is empty expand it to the initial size,
     * if the table is "full" dobule its size. */
    if (ht->size == 0)
        return dictExpand(ht, DICT_HT_INITIAL_SIZE);
@@ -0,0 +1,73 @@
+#include <stdlib.h>
+
+#include <hiredis.h>
+#include <async.h>
+#include <adapters/glib.h>
+
+static GMainLoop *mainloop;
+
+static void
+connect_cb (const redisAsyncContext *ac G_GNUC_UNUSED,
+            int status)
+{
+    if (status != REDIS_OK) {
+        g_printerr("Failed to connect: %s\n", ac->errstr);
+        g_main_loop_quit(mainloop);
+    } else {
+        g_printerr("Connected...\n");
+    }
+}
+
+static void
+disconnect_cb (const redisAsyncContext *ac G_GNUC_UNUSED,
+               int status)
+{
+    if (status != REDIS_OK) {
+        g_error("Failed to disconnect: %s", ac->errstr);
+    } else {
+        g_printerr("Disconnected...\n");
+        g_main_loop_quit(mainloop);
+    }
+}
+
+static void
+command_cb(redisAsyncContext *ac,
+           gpointer r,
+           gpointer user_data G_GNUC_UNUSED)
+{
+    redisReply *reply = r;
+
+    if (reply) {
+        g_print("REPLY: %s\n", reply->str);
+    }
+
+    redisAsyncDisconnect(ac);
+}
+
+gint
+main (gint argc     G_GNUC_UNUSED,
+      gchar *argv[] G_GNUC_UNUSED)
+{
+    redisAsyncContext *ac;
+    GMainContext *context = NULL;
+    GSource *source;
+
+    ac = redisAsyncConnect("127.0.0.1", 6379);
+    if (ac->err) {
+        g_printerr("%s\n", ac->errstr);
+        exit(EXIT_FAILURE);
+    }
+
+    source = redis_source_new(ac);
+    mainloop = g_main_loop_new(context, FALSE);
+    g_source_attach(source, context);
+
+    redisAsyncSetConnectCallback(ac, connect_cb);
+    redisAsyncSetDisconnectCallback(ac, disconnect_cb);
+    redisAsyncCommand(ac, command_cb, NULL, "SET key 1234");
+    redisAsyncCommand(ac, command_cb, NULL, "GET key");
+
+    g_main_loop_run(mainloop);
+
+    return EXIT_SUCCESS;
+}
@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+
+#include <hiredis.h>
+#include <async.h>
+#include <adapters/ivykis.h>
+
+void getCallback(redisAsyncContext *c, void *r, void *privdata) {
+    redisReply *reply = r;
+    if (reply == NULL) return;
+    printf("argv[%s]: %s\n", (char*)privdata, reply->str);
+
+    /* Disconnect after receiving the reply to GET */
+    redisAsyncDisconnect(c);
+}
+
+void connectCallback(const redisAsyncContext *c, int status) {
+    if (status != REDIS_OK) {
+        printf("Error: %s\n", c->errstr);
+        return;
+    }
+    printf("Connected...\n");
+}
+
+void disconnectCallback(const redisAsyncContext *c, int status) {
+    if (status != REDIS_OK) {
+        printf("Error: %s\n", c->errstr);
+        return;
+    }
+    printf("Disconnected...\n");
+}
+
+int main (int argc, char **argv) {
+    signal(SIGPIPE, SIG_IGN);
+
+    iv_init();
+
+    redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);
+    if (c->err) {
+        /* Let *c leak for now... */
+        printf("Error: %s\n", c->errstr);
+        return 1;
+    }
+
+    redisIvykisAttach(c);
+    redisAsyncSetConnectCallback(c,connectCallback);
+    redisAsyncSetDisconnectCallback(c,disconnectCallback);
+    redisAsyncCommand(c, NULL, NULL, "SET key %b", argv[argc-1], strlen(argv[argc-1]));
+    redisAsyncCommand(c, getCallback, (char*)"end-1", "GET key");
+
+    iv_main();
+
+    iv_deinit();
+
+    return 0;
+}
@@ -0,0 +1,66 @@
+//
+//  Created by Дмитрий Бахвалов on 13.07.15.
+//  Copyright (c) 2015 Dmitry Bakhvalov. All rights reserved.
+//
+
+#include <stdio.h>
+
+#include <hiredis.h>
+#include <async.h>
+#include <adapters/macosx.h>
+
+void getCallback(redisAsyncContext *c, void *r, void *privdata) {
+    redisReply *reply = r;
+    if (reply == NULL) return;
+    printf("argv[%s]: %s\n", (char*)privdata, reply->str);
+
+    /* Disconnect after receiving the reply to GET */
+    redisAsyncDisconnect(c);
+}
+
+void connectCallback(const redisAsyncContext *c, int status) {
+    if (status != REDIS_OK) {
+        printf("Error: %s\n", c->errstr);
+        return;
+    }
+    printf("Connected...\n");
+}
+
+void disconnectCallback(const redisAsyncContext *c, int status) {
+    if (status != REDIS_OK) {
+        printf("Error: %s\n", c->errstr);
+        return;
+    }
+    CFRunLoopStop(CFRunLoopGetCurrent());
+    printf("Disconnected...\n");
+}
+
+int main (int argc, char **argv) {
+    signal(SIGPIPE, SIG_IGN);
+
+    CFRunLoopRef loop = CFRunLoopGetCurrent();
+    if( !loop ) {
+        printf("Error: Cannot get current run loop\n");
+        return 1;
+    }
+
+    redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);
+    if (c->err) {
+        /* Let *c leak for now... */
+        printf("Error: %s\n", c->errstr);
+        return 1;
+    }
+
+    redisMacOSAttach(c, loop);
+
+    redisAsyncSetConnectCallback(c,connectCallback);
+    redisAsyncSetDisconnectCallback(c,disconnectCallback);
+
+    redisAsyncCommand(c, NULL, NULL, "SET key %b", argv[argc-1], strlen(argv[argc-1]));
+    redisAsyncCommand(c, getCallback, (char*)"end-1", "GET key");
+
+    CFRunLoopRun();
+
+    return 0;
+}
+
@@ -0,0 +1,46 @@
+#include <iostream>
+using namespace std;
+
+#include <QCoreApplication>
+#include <QTimer>
+
+#include "example-qt.h"
+
+void getCallback(redisAsyncContext *, void * r, void * privdata) {
+
+    redisReply * reply = static_cast<redisReply *>(r);
+    ExampleQt * ex = static_cast<ExampleQt *>(privdata);
+    if (reply == nullptr || ex == nullptr) return;
+
+    cout << "key: " << reply->str << endl;
+
+    ex->finish();
+}
+
+void ExampleQt::run() {
+
+    m_ctx = redisAsyncConnect("localhost", 6379);
+
+    if (m_ctx->err) {
+        cerr << "Error: " << m_ctx->errstr << endl;
+        redisAsyncFree(m_ctx);
+        emit finished();
+    }
+
+    m_adapter.setContext(m_ctx);
+
+    redisAsyncCommand(m_ctx, NULL, NULL, "SET key %s", m_value);
+    redisAsyncCommand(m_ctx, getCallback, this, "GET key");
+}
+
+int main (int argc, char **argv) {
+
+    QCoreApplication app(argc, argv);
+
+    ExampleQt example(argv[argc-1]);
+
+    QObject::connect(&example, SIGNAL(finished()), &app, SLOT(quit()));
+    QTimer::singleShot(0, &example, SLOT(run()));
+
+    return app.exec();
+}
@@ -0,0 +1,32 @@
+#ifndef __HIREDIS_EXAMPLE_QT_H
+#define __HIREDIS_EXAMPLE_QT_H
+
+#include <adapters/qt.h>
+
+class ExampleQt : public QObject {
+
+    Q_OBJECT
+
+    public:
+        ExampleQt(const char * value, QObject * parent = 0)
+            : QObject(parent), m_value(value) {}
+
+    signals:
+        void finished();
+
+    public slots:
+        void run();
+
+    private:
+        void finish() { emit finished(); }
+
+    private:
+        const char * m_value;
+        redisAsyncContext * m_ctx;
+        RedisQtAdapter m_adapter;
+
+    friend
+    void getCallback(redisAsyncContext *, void *, void *);
+};
+
+#endif /* !__HIREDIS_EXAMPLE_QT_H */
@@ -57,7 +57,7 @@ int main(int argc, char **argv) {
    for (j = 0; j < 10; j++) {
        char buf[64];

-        snprintf(buf,64,"%d",j);
+        snprintf(buf,64,"%u",j);
        reply = redisCommand(c,"LPUSH mylist element-%s", buf);
        freeReplyObject(reply);
    }
@@ -1,23 +1,24 @@
 #ifndef __HIREDIS_FMACRO_H
 #define __HIREDIS_FMACRO_H

-#if !defined(_BSD_SOURCE)
+#if defined(__linux__)
 #define _BSD_SOURCE
+#define _DEFAULT_SOURCE
 #endif

-#if defined(_AIX)
-#define _ALL_SOURCE
+#if defined(__CYGWIN__)
+#include <sys/cdefs.h>
 #endif

 #if defined(__sun__)
 #define _POSIX_C_SOURCE 200112L
-#elif defined(__linux__) || defined(__OpenBSD__) || defined(__NetBSD__)
-#define _XOPEN_SOURCE 600
 #else
-#define _XOPEN_SOURCE
+#if !(defined(__APPLE__) && defined(__MACH__))
+#define _XOPEN_SOURCE 600
+#endif
 #endif

-#if __APPLE__ && __MACH__
+#if defined(__APPLE__) && defined(__MACH__)
 #define _OSX
 #endif

@@ -1,6 +1,8 @@
 /*
 * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
- * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
 *
 * All rights reserved.
 *
@@ -73,6 +75,9 @@ void freeReplyObject(void *reply) {
    redisReply *r = reply;
    size_t j;

+    if (r == NULL)
+        return;
+
    switch(r->type) {
    case REDIS_REPLY_INTEGER:
        break; /* Nothing to free */
@@ -183,504 +188,23 @@ static void *createNilObject(const redisReadTask *task) {
    return r;
 }

-static void __redisReaderSetError(redisReader *r, int type, const char *str) {
-    size_t len;
-
-    if (r->reply != NULL && r->fn && r->fn->freeObject) {
-        r->fn->freeObject(r->reply);
-        r->reply = NULL;
-    }
-
-    /* Clear input buffer on errors. */
-    if (r->buf != NULL) {
-        sdsfree(r->buf);
-        r->buf = NULL;
-        r->pos = r->len = 0;
-    }
-
-    /* Reset task stack. */
-    r->ridx = -1;
-
-    /* Set error. */
-    r->err = type;
-    len = strlen(str);
-    len = len < (sizeof(r->errstr)-1) ? len : (sizeof(r->errstr)-1);
-    memcpy(r->errstr,str,len);
-    r->errstr[len] = '\0';
-}
-
-static size_t chrtos(char *buf, size_t size, char byte) {
-    size_t len = 0;
-
-    switch(byte) {
-    case '\\':
-    case '"':
-        len = snprintf(buf,size,"\"\\%c\"",byte);
-        break;
-    case '\n': len = snprintf(buf,size,"\"\\n\""); break;
-    case '\r': len = snprintf(buf,size,"\"\\r\""); break;
-    case '\t': len = snprintf(buf,size,"\"\\t\""); break;
-    case '\a': len = snprintf(buf,size,"\"\\a\""); break;
-    case '\b': len = snprintf(buf,size,"\"\\b\""); break;
-    default:
-        if (isprint(byte))
-            len = snprintf(buf,size,"\"%c\"",byte);
-        else
-            len = snprintf(buf,size,"\"\\x%02x\"",(unsigned char)byte);
-        break;
-    }
-
-    return len;
-}
-
-static void __redisReaderSetErrorProtocolByte(redisReader *r, char byte) {
-    char cbuf[8], sbuf[128];
-
-    chrtos(cbuf,sizeof(cbuf),byte);
-    snprintf(sbuf,sizeof(sbuf),
-        "Protocol error, got %s as reply type byte", cbuf);
-    __redisReaderSetError(r,REDIS_ERR_PROTOCOL,sbuf);
-}
-
-static void __redisReaderSetErrorOOM(redisReader *r) {
-    __redisReaderSetError(r,REDIS_ERR_OOM,"Out of memory");
-}
-
-static char *readBytes(redisReader *r, unsigned int bytes) {
-    char *p;
-    if (r->len-r->pos >= bytes) {
-        p = r->buf+r->pos;
-        r->pos += bytes;
-        return p;
-    }
-    return NULL;
-}
-
-/* Find pointer to \r\n. */
-static char *seekNewline(char *s, size_t len) {
-    int pos = 0;
-    int _len = len-1;
-
-    /* Position should be < len-1 because the character at "pos" should be
-     * followed by a \n. Note that strchr cannot be used because it doesn't
-     * allow to search a limited length and the buffer that is being searched
-     * might not have a trailing NULL character. */
-    while (pos < _len) {
-        while(pos < _len && s[pos] != '\r') pos++;
-        if (s[pos] != '\r') {
-            /* Not found. */
-            return NULL;
-        } else {
-            if (s[pos+1] == '\n') {
-                /* Found. */
-                return s+pos;
-            } else {
-                /* Continue searching. */
-                pos++;
-            }
-        }
-    }
-    return NULL;
-}
-
-/* Read a long long value starting at *s, under the assumption that it will be
- * terminated by \r\n. Ambiguously returns -1 for unexpected input. */
-static long long readLongLong(char *s) {
-    long long v = 0;
-    int dec, mult = 1;
-    char c;
-
-    if (*s == '-') {
-        mult = -1;
-        s++;
-    } else if (*s == '+') {
-        mult = 1;
-        s++;
-    }
-
-    while ((c = *(s++)) != '\r') {
-        dec = c - '0';
-        if (dec >= 0 && dec < 10) {
-            v *= 10;
-            v += dec;
-        } else {
-            /* Should not happen... */
-            return -1;
-        }
-    }
-
-    return mult*v;
-}
-
-static char *readLine(redisReader *r, int *_len) {
-    char *p, *s;
-    int len;
-
-    p = r->buf+r->pos;
-    s = seekNewline(p,(r->len-r->pos));
-    if (s != NULL) {
-        len = s-(r->buf+r->pos);
-        r->pos += len+2; /* skip \r\n */
-        if (_len) *_len = len;
-        return p;
-    }
-    return NULL;
-}
-
-static void moveToNextTask(redisReader *r) {
-    redisReadTask *cur, *prv;
-    while (r->ridx >= 0) {
-        /* Return a.s.a.p. when the stack is now empty. */
-        if (r->ridx == 0) {
-            r->ridx--;
-            return;
-        }
-
-        cur = &(r->rstack[r->ridx]);
-        prv = &(r->rstack[r->ridx-1]);
-        assert(prv->type == REDIS_REPLY_ARRAY);
-        if (cur->idx == prv->elements-1) {
-            r->ridx--;
-        } else {
-            /* Reset the type because the next item can be anything */
-            assert(cur->idx < prv->elements);
-            cur->type = -1;
-            cur->elements = -1;
-            cur->idx++;
-            return;
-        }
-    }
-}
-
-static int processLineItem(redisReader *r) {
-    redisReadTask *cur = &(r->rstack[r->ridx]);
-    void *obj;
-    char *p;
-    int len;
-
-    if ((p = readLine(r,&len)) != NULL) {
-        if (cur->type == REDIS_REPLY_INTEGER) {
-            if (r->fn && r->fn->createInteger)
-                obj = r->fn->createInteger(cur,readLongLong(p));
-            else
-                obj = (void*)REDIS_REPLY_INTEGER;
-        } else {
-            /* Type will be error or status. */
-            if (r->fn && r->fn->createString)
-                obj = r->fn->createString(cur,p,len);
-            else
-                obj = (void*)(size_t)(cur->type);
-        }
-
-        if (obj == NULL) {
-            __redisReaderSetErrorOOM(r);
-            return REDIS_ERR;
-        }
-
-        /* Set reply if this is the root object. */
-        if (r->ridx == 0) r->reply = obj;
-        moveToNextTask(r);
-        return REDIS_OK;
-    }
-
-    return REDIS_ERR;
-}
-
-static int processBulkItem(redisReader *r) {
-    redisReadTask *cur = &(r->rstack[r->ridx]);
-    void *obj = NULL;
-    char *p, *s;
-    long len;
-    unsigned long bytelen;
-    int success = 0;
-
-    p = r->buf+r->pos;
-    s = seekNewline(p,r->len-r->pos);
-    if (s != NULL) {
-        p = r->buf+r->pos;
-        bytelen = s-(r->buf+r->pos)+2; /* include \r\n */
-        len = readLongLong(p);
-
-        if (len < 0) {
-            /* The nil object can always be created. */
-            if (r->fn && r->fn->createNil)
-                obj = r->fn->createNil(cur);
-            else
-                obj = (void*)REDIS_REPLY_NIL;
-            success = 1;
-        } else {
-            /* Only continue when the buffer contains the entire bulk item. */
-            bytelen += len+2; /* include \r\n */
-            if (r->pos+bytelen <= r->len) {
-                if (r->fn && r->fn->createString)
-                    obj = r->fn->createString(cur,s+2,len);
-                else
-                    obj = (void*)REDIS_REPLY_STRING;
-                success = 1;
-            }
-        }
-
-        /* Proceed when obj was created. */
-        if (success) {
-            if (obj == NULL) {
-                __redisReaderSetErrorOOM(r);
-                return REDIS_ERR;
-            }
-
-            r->pos += bytelen;
-
-            /* Set reply if this is the root object. */
-            if (r->ridx == 0) r->reply = obj;
-            moveToNextTask(r);
-            return REDIS_OK;
-        }
-    }
-
-    return REDIS_ERR;
-}
-
-static int processMultiBulkItem(redisReader *r) {
-    redisReadTask *cur = &(r->rstack[r->ridx]);
-    void *obj;
-    char *p;
-    long elements;
-    int root = 0;
-
-    /* Set error for nested multi bulks with depth > 7 */
-    if (r->ridx == 8) {
-        __redisReaderSetError(r,REDIS_ERR_PROTOCOL,
-            "No support for nested multi bulk replies with depth > 7");
-        return REDIS_ERR;
-    }
-
-    if ((p = readLine(r,NULL)) != NULL) {
-        elements = readLongLong(p);
-        root = (r->ridx == 0);
-
-        if (elements == -1) {
-            if (r->fn && r->fn->createNil)
-                obj = r->fn->createNil(cur);
-            else
-                obj = (void*)REDIS_REPLY_NIL;
-
-            if (obj == NULL) {
-                __redisReaderSetErrorOOM(r);
-                return REDIS_ERR;
-            }
-
-            moveToNextTask(r);
-        } else {
-            if (r->fn && r->fn->createArray)
-                obj = r->fn->createArray(cur,elements);
-            else
-                obj = (void*)REDIS_REPLY_ARRAY;
-
-            if (obj == NULL) {
-                __redisReaderSetErrorOOM(r);
-                return REDIS_ERR;
-            }
-
-            /* Modify task stack when there are more than 0 elements. */
-            if (elements > 0) {
-                cur->elements = elements;
-                cur->obj = obj;
-                r->ridx++;
-                r->rstack[r->ridx].type = -1;
-                r->rstack[r->ridx].elements = -1;
-                r->rstack[r->ridx].idx = 0;
-                r->rstack[r->ridx].obj = NULL;
-                r->rstack[r->ridx].parent = cur;
-                r->rstack[r->ridx].privdata = r->privdata;
-            } else {
-                moveToNextTask(r);
-            }
-        }
-
-        /* Set reply if this is the root object. */
-        if (root) r->reply = obj;
-        return REDIS_OK;
-    }
-
-    return REDIS_ERR;
-}
-
-static int processItem(redisReader *r) {
-    redisReadTask *cur = &(r->rstack[r->ridx]);
-    char *p;
-
-    /* check if we need to read type */
-    if (cur->type < 0) {
-        if ((p = readBytes(r,1)) != NULL) {
-            switch (p[0]) {
-            case '-':
-                cur->type = REDIS_REPLY_ERROR;
-                break;
-            case '+':
-                cur->type = REDIS_REPLY_STATUS;
-                break;
-            case ':':
-                cur->type = REDIS_REPLY_INTEGER;
-                break;
-            case '$':
-                cur->type = REDIS_REPLY_STRING;
-                break;
-            case '*':
-                cur->type = REDIS_REPLY_ARRAY;
-                break;
-            default:
-                __redisReaderSetErrorProtocolByte(r,*p);
-                return REDIS_ERR;
-            }
-        } else {
-            /* could not consume 1 byte */
-            return REDIS_ERR;
-        }
-    }
-
-    /* process typed item */
-    switch(cur->type) {
-    case REDIS_REPLY_ERROR:
-    case REDIS_REPLY_STATUS:
-    case REDIS_REPLY_INTEGER:
-        return processLineItem(r);
-    case REDIS_REPLY_STRING:
-        return processBulkItem(r);
-    case REDIS_REPLY_ARRAY:
-        return processMultiBulkItem(r);
-    default:
-        assert(NULL);
-        return REDIS_ERR; /* Avoid warning. */
-    }
-}
-
-redisReader *redisReaderCreate(void) {
-    redisReader *r;
-
-    r = calloc(sizeof(redisReader),1);
-    if (r == NULL)
-        return NULL;
-
-    r->err = 0;
-    r->errstr[0] = '\0';
-    r->fn = &defaultFunctions;
-    r->buf = sdsempty();
-    r->maxbuf = REDIS_READER_MAX_BUF;
-    if (r->buf == NULL) {
-        free(r);
-        return NULL;
-    }
-
-    r->ridx = -1;
-    return r;
-}
-
-void redisReaderFree(redisReader *r) {
-    if (r->reply != NULL && r->fn && r->fn->freeObject)
-        r->fn->freeObject(r->reply);
-    if (r->buf != NULL)
-        sdsfree(r->buf);
-    free(r);
-}
-
-int redisReaderFeed(redisReader *r, const char *buf, size_t len) {
-    sds newbuf;
-
-    /* Return early when this reader is in an erroneous state. */
-    if (r->err)
-        return REDIS_ERR;
-
-    /* Copy the provided buffer. */
-    if (buf != NULL && len >= 1) {
-        /* Destroy internal buffer when it is empty and is quite large. */
-        if (r->len == 0 && r->maxbuf != 0 && sdsavail(r->buf) > r->maxbuf) {
-            sdsfree(r->buf);
-            r->buf = sdsempty();
-            r->pos = 0;
-
-            /* r->buf should not be NULL since we just free'd a larger one. */
-            assert(r->buf != NULL);
-        }
-
-        newbuf = sdscatlen(r->buf,buf,len);
-        if (newbuf == NULL) {
-            __redisReaderSetErrorOOM(r);
-            return REDIS_ERR;
-        }
-
-        r->buf = newbuf;
-        r->len = sdslen(r->buf);
-    }
-
-    return REDIS_OK;
-}
-
-int redisReaderGetReply(redisReader *r, void **reply) {
-    /* Default target pointer to NULL. */
-    if (reply != NULL)
-        *reply = NULL;
-
-    /* Return early when this reader is in an erroneous state. */
-    if (r->err)
-        return REDIS_ERR;
-
-    /* When the buffer is empty, there will never be a reply. */
-    if (r->len == 0)
-        return REDIS_OK;
-
-    /* Set first item to process when the stack is empty. */
-    if (r->ridx == -1) {
-        r->rstack[0].type = -1;
-        r->rstack[0].elements = -1;
-        r->rstack[0].idx = -1;
-        r->rstack[0].obj = NULL;
-        r->rstack[0].parent = NULL;
-        r->rstack[0].privdata = r->privdata;
-        r->ridx = 0;
-    }
-
-    /* Process items in reply. */
-    while (r->ridx >= 0)
-        if (processItem(r) != REDIS_OK)
-            break;
-
-    /* Return ASAP when an error occurred. */
-    if (r->err)
-        return REDIS_ERR;
-
-    /* Discard part of the buffer when we've consumed at least 1k, to avoid
-     * doing unnecessary calls to memmove() in sds.c. */
-    if (r->pos >= 1024) {
-        sdsrange(r->buf,r->pos,-1);
-        r->pos = 0;
-        r->len = sdslen(r->buf);
-    }
-
-    /* Emit a reply when there is one. */
-    if (r->ridx == -1) {
-        if (reply != NULL)
-            *reply = r->reply;
-        r->reply = NULL;
-    }
-    return REDIS_OK;
-}
-
-/* Calculate the number of bytes needed to represent an integer as string. */
-static int intlen(int i) {
-    int len = 0;
-    if (i < 0) {
-        len++;
-        i = -i;
-    }
-    do {
-        len++;
-        i /= 10;
-    } while(i);
-    return len;
+/* Return the number of digits of 'v' when converted to string in radix 10.
+ * Implementation borrowed from link in redis/src/util.c:string2ll(). */
+static uint32_t countDigits(uint64_t v) {
+  uint32_t result = 1;
+  for (;;) {
+    if (v < 10) return result;
+    if (v < 100) return result + 1;
+    if (v < 1000) return result + 2;
+    if (v < 10000) return result + 3;
+    v /= 10000U;
+    result += 4;
+  }
 }

 /* Helper that calculates the bulk length given a certain string length. */
 static size_t bulklen(size_t len) {
-    return 1+intlen(len)+2+len+2;
+    return 1+countDigits(len)+2+len+2;
 }

 int redisvFormatCommand(char **target, const char *format, va_list ap) {
@@ -692,6 +216,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
    char **curargv = NULL, **newargv = NULL;
    int argc = 0;
    int totlen = 0;
+    int error_type = 0; /* 0 = no error; -1 = memory error; -2 = format error */
    int j;

    /* Abort if there is not target to set */
@@ -708,19 +233,19 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
            if (*c == ' ') {
                if (touched) {
                    newargv = realloc(curargv,sizeof(char*)*(argc+1));
-                    if (newargv == NULL) goto err;
+                    if (newargv == NULL) goto memory_err;
                    curargv = newargv;
                    curargv[argc++] = curarg;
                    totlen += bulklen(sdslen(curarg));

                    /* curarg is put in argv so it can be overwritten. */
                    curarg = sdsempty();
-                    if (curarg == NULL) goto err;
+                    if (curarg == NULL) goto memory_err;
                    touched = 0;
                }
            } else {
                newarg = sdscatlen(curarg,c,1);
-                if (newarg == NULL) goto err;
+                if (newarg == NULL) goto memory_err;
                curarg = newarg;
                touched = 1;
            }
@@ -751,17 +276,14 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
                /* Try to detect printf format */
                {
                    static const char intfmts[] = "diouxX";
+                    static const char flags[] = "#0-+ ";
                    char _format[16];
                    const char *_p = c+1;
                    size_t _l = 0;
                    va_list _cpy;

                    /* Flags */
-                    if (*_p != '\0' && *_p == '#') _p++;
-                    if (*_p != '\0' && *_p == '0') _p++;
-                    if (*_p != '\0' && *_p == '-') _p++;
-                    if (*_p != '\0' && *_p == ' ') _p++;
-                    if (*_p != '\0' && *_p == '+') _p++;
+                    while (*_p != '\0' && strchr(flags,*_p) != NULL) _p++;

                    /* Field width */
                    while (*_p != '\0' && isdigit(*_p)) _p++;
@@ -829,7 +351,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {

                fmt_invalid:
                    va_end(_cpy);
-                    goto err;
+                    goto format_err;

                fmt_valid:
                    _l = (_p+1)-c;
@@ -848,7 +370,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
                }
            }

-            if (newarg == NULL) goto err;
+            if (newarg == NULL) goto memory_err;
            curarg = newarg;

            touched = 1;
@@ -860,7 +382,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
    /* Add the last argument if needed */
    if (touched) {
        newargv = realloc(curargv,sizeof(char*)*(argc+1));
-        if (newargv == NULL) goto err;
+        if (newargv == NULL) goto memory_err;
        curargv = newargv;
        curargv[argc++] = curarg;
        totlen += bulklen(sdslen(curarg));
@@ -872,11 +394,11 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
    curarg = NULL;

    /* Add bytes needed to hold multi bulk count */
-    totlen += 1+intlen(argc)+2;
+    totlen += 1+countDigits(argc)+2;

    /* Build the command at protocol level */
    cmd = malloc(totlen+1);
-    if (cmd == NULL) goto err;
+    if (cmd == NULL) goto memory_err;

    pos = sprintf(cmd,"*%d\r\n",argc);
    for (j = 0; j < argc; j++) {
@@ -894,20 +416,29 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
    *target = cmd;
    return totlen;

-err:
-    while(argc--)
-        sdsfree(curargv[argc]);
-    free(curargv);
+format_err:
+    error_type = -2;
+    goto cleanup;

-    if (curarg != NULL)
-        sdsfree(curarg);
+memory_err:
+    error_type = -1;
+    goto cleanup;
+
+cleanup:
+    if (curargv) {
+        while(argc--)
+            sdsfree(curargv[argc]);
+        free(curargv);
+    }
+
+    sdsfree(curarg);

    /* No need to check cmd since it is the last statement that can fail,
     * but do it anyway to be as defensive as possible. */
    if (cmd != NULL)
        free(cmd);

-    return -1;
+    return error_type;
 }

 /* Format a command according to the Redis protocol. This function
@@ -928,9 +459,69 @@ int redisFormatCommand(char **target, const char *format, ...) {
    va_start(ap,format);
    len = redisvFormatCommand(target,format,ap);
    va_end(ap);
+
+    /* The API says "-1" means bad result, but we now also return "-2" in some
+     * cases.  Force the return value to always be -1. */
+    if (len < 0)
+        len = -1;
+
    return len;
 }

+/* Format a command according to the Redis protocol using an sds string and
+ * sdscatfmt for the processing of arguments. This function takes the
+ * number of arguments, an array with arguments and an array with their
+ * lengths. If the latter is set to NULL, strlen will be used to compute the
+ * argument lengths.
+ */
+int redisFormatSdsCommandArgv(sds *target, int argc, const char **argv,
+                              const size_t *argvlen)
+{
+    sds cmd;
+    unsigned long long totlen;
+    int j;
+    size_t len;
+
+    /* Abort on a NULL target */
+    if (target == NULL)
+        return -1;
+
+    /* Calculate our total size */
+    totlen = 1+countDigits(argc)+2;
+    for (j = 0; j < argc; j++) {
+        len = argvlen ? argvlen[j] : strlen(argv[j]);
+        totlen += bulklen(len);
+    }
+
+    /* Use an SDS string for command construction */
+    cmd = sdsempty();
+    if (cmd == NULL)
+        return -1;
+
+    /* We already know how much storage we need */
+    cmd = sdsMakeRoomFor(cmd, totlen);
+    if (cmd == NULL)
+        return -1;
+
+    /* Construct command */
+    cmd = sdscatfmt(cmd, "*%i\r\n", argc);
+    for (j=0; j < argc; j++) {
+        len = argvlen ? argvlen[j] : strlen(argv[j]);
+        cmd = sdscatfmt(cmd, "$%u\r\n", len);
+        cmd = sdscatlen(cmd, argv[j], len);
+        cmd = sdscatlen(cmd, "\r\n", sizeof("\r\n")-1);
+    }
+
+    assert(sdslen(cmd)==totlen);
+
+    *target = cmd;
+    return totlen;
+}
+
+void redisFreeSdsCommand(sds cmd) {
+    sdsfree(cmd);
+}
+
 /* Format a command according to the Redis protocol. This function takes the
 * number of arguments, an array with arguments and an array with their
 * lengths. If the latter is set to NULL, strlen will be used to compute the
@@ -942,8 +533,12 @@ int redisFormatCommandArgv(char **target, int argc, const char **argv, const siz
    size_t len;
    int totlen, j;

+    /* Abort on a NULL target */
+    if (target == NULL)
+        return -1;
+
    /* Calculate number of bytes needed for the command */
-    totlen = 1+intlen(argc)+2;
+    totlen = 1+countDigits(argc)+2;
    for (j = 0; j < argc; j++) {
        len = argvlen ? argvlen[j] : strlen(argv[j]);
        totlen += bulklen(len);
@@ -970,6 +565,10 @@ int redisFormatCommandArgv(char **target, int argc, const char **argv, const siz
    return totlen;
 }

+void redisFreeCommand(char *cmd) {
+    free(cmd);
+}
+
 void __redisSetError(redisContext *c, int type, const char *str) {
    size_t len;

@@ -982,10 +581,14 @@ void __redisSetError(redisContext *c, int type, const char *str) {
    } else {
        /* Only REDIS_ERR_IO may lack a description! */
        assert(type == REDIS_ERR_IO);
-        strerror_r(errno,c->errstr,sizeof(c->errstr));
+        __redis_strerror_r(errno, c->errstr, sizeof(c->errstr));
    }
 }

+redisReader *redisReaderCreate(void) {
+    return redisReaderCreateWithFunctions(&defaultFunctions);
+}
+
 static redisContext *redisContextInit(void) {
    redisContext *c;

@@ -997,24 +600,72 @@ static redisContext *redisContextInit(void) {
    c->errstr[0] = '\0';
    c->obuf = sdsempty();
    c->reader = redisReaderCreate();
+    c->tcp.host = NULL;
+    c->tcp.source_addr = NULL;
+    c->unix_sock.path = NULL;
+    c->timeout = NULL;
+
+    if (c->obuf == NULL || c->reader == NULL) {
+        redisFree(c);
+        return NULL;
+    }
+
    return c;
 }

 void redisFree(redisContext *c) {
+    if (c == NULL)
+        return;
    if (c->fd > 0)
        close(c->fd);
    if (c->obuf != NULL)
        sdsfree(c->obuf);
    if (c->reader != NULL)
        redisReaderFree(c->reader);
+    if (c->tcp.host)
+        free(c->tcp.host);
+    if (c->tcp.source_addr)
+        free(c->tcp.source_addr);
+    if (c->unix_sock.path)
+        free(c->unix_sock.path);
+    if (c->timeout)
+        free(c->timeout);
    free(c);
 }

 int redisFreeKeepFd(redisContext *c) {
-	int fd = c->fd;
-	c->fd = -1;
-	redisFree(c);
-	return fd;
+    int fd = c->fd;
+    c->fd = -1;
+    redisFree(c);
+    return fd;
+}
+
+int redisReconnect(redisContext *c) {
+    c->err = 0;
+    memset(c->errstr, '\0', strlen(c->errstr));
+
+    if (c->fd > 0) {
+        close(c->fd);
+    }
+
+    sdsfree(c->obuf);
+    redisReaderFree(c->reader);
+
+    c->obuf = sdsempty();
+    c->reader = redisReaderCreate();
+
+    if (c->connection_type == REDIS_CONN_TCP) {
+        return redisContextConnectBindTcp(c, c->tcp.host, c->tcp.port,
+                c->timeout, c->tcp.source_addr);
+    } else if (c->connection_type == REDIS_CONN_UNIX) {
+        return redisContextConnectUnix(c, c->unix_sock.path, c->timeout);
+    } else {
+        /* Something bad happened here and shouldn't have. There isn't
+           enough information in the context to reconnect. */
+        __redisSetError(c,REDIS_ERR_OTHER,"Not enough information to reconnect");
+    }
+
+    return REDIS_ERR;
 }

 /* Connect to a Redis instance. On error the field error in the returned
@@ -1064,6 +715,15 @@ redisContext *redisConnectBindNonBlock(const char *ip, int port,
    return c;
 }

+redisContext *redisConnectBindNonBlockWithReuse(const char *ip, int port,
+                                                const char *source_addr) {
+    redisContext *c = redisContextInit();
+    c->flags &= ~REDIS_BLOCK;
+    c->flags |= REDIS_REUSEADDR;
+    redisContextConnectBindTcp(c,ip,port,NULL,source_addr);
+    return c;
+}
+
 redisContext *redisConnectUnix(const char *path) {
    redisContext *c;

@@ -1162,10 +822,10 @@ int redisBufferRead(redisContext *c) {
 /* Write the output buffer to the socket.
 *
 * Returns REDIS_OK when the buffer is empty, or (a part of) the buffer was
- * succesfully written to the socket. When the buffer is empty after the
+ * successfully written to the socket. When the buffer is empty after the
 * write operation, "done" is set to 1 (if given).
 *
- * Returns REDIS_ERR if an error occured trying to write and sets
+ * Returns REDIS_ERR if an error occurred trying to write and sets
 * c->errstr to hold the appropriate error string.
 */
 int redisBufferWrite(redisContext *c, int *done) {
@@ -1274,6 +934,9 @@ int redisvAppendCommand(redisContext *c, const char *format, va_list ap) {
    if (len == -1) {
        __redisSetError(c,REDIS_ERR_OOM,"Out of memory");
        return REDIS_ERR;
+    } else if (len == -2) {
+        __redisSetError(c,REDIS_ERR_OTHER,"Invalid format string");
+        return REDIS_ERR;
    }

    if (__redisAppendCommand(c,cmd,len) != REDIS_OK) {
@@ -1296,21 +959,21 @@ int redisAppendCommand(redisContext *c, const char *format, ...) {
 }

 int redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen) {
-    char *cmd;
+    sds cmd;
    int len;

-    len = redisFormatCommandArgv(&cmd,argc,argv,argvlen);
+    len = redisFormatSdsCommandArgv(&cmd,argc,argv,argvlen);
    if (len == -1) {
        __redisSetError(c,REDIS_ERR_OOM,"Out of memory");
        return REDIS_ERR;
    }

    if (__redisAppendCommand(c,cmd,len) != REDIS_OK) {
-        free(cmd);
+        sdsfree(cmd);
        return REDIS_ERR;
    }

-    free(cmd);
+    sdsfree(cmd);
    return REDIS_OK;
 }

@@ -1321,7 +984,7 @@ int redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const s
 * context is non-blocking, the "reply" pointer will not be used and the
 * command is simply appended to the write buffer.
 *
- * Returns the reply when a reply was succesfully retrieved. Returns NULL
+ * Returns the reply when a reply was successfully retrieved. Returns NULL
 * otherwise. When NULL is returned in a blocking context, the error field
 * in the context will be set.
 */
@@ -1,6 +1,8 @@
 /*
 * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
- * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
 *
 * All rights reserved.
 *
@@ -31,26 +33,16 @@

 #ifndef __HIREDIS_H
 #define __HIREDIS_H
-#include <stdio.h> /* for size_t */
+#include "read.h"
 #include <stdarg.h> /* for va_list */
 #include <sys/time.h> /* for struct timeval */
+#include <stdint.h> /* uintXX_t, etc */
+#include "sds.h" /* for sds */

 #define HIREDIS_MAJOR 0
-#define HIREDIS_MINOR 11
-#define HIREDIS_PATCH 0
-
-#define REDIS_ERR -1
-#define REDIS_OK 0
-
-/* When an error occurs, the err flag in a context is set to hold the type of
- * error that occured. REDIS_ERR_IO means there was an I/O error and you
- * should use the "errno" variable to find out what is wrong.
- * For other values, the "errstr" field will hold a description. */
-#define REDIS_ERR_IO 1 /* Error in read or write */
-#define REDIS_ERR_EOF 3 /* End of file */
-#define REDIS_ERR_PROTOCOL 4 /* Protocol error */
-#define REDIS_ERR_OOM 5 /* Out of memory */
-#define REDIS_ERR_OTHER 2 /* Everything else... */
+#define HIREDIS_MINOR 13
+#define HIREDIS_PATCH 3
+#define HIREDIS_SONAME 0.13

 /* Connection type can be blocking or non-blocking and is set in the
 * least significant bit of the flags field in redisContext. */
@@ -79,17 +71,39 @@
 /* Flag that is set when monitor mode is active */
 #define REDIS_MONITORING 0x40

-#define REDIS_REPLY_STRING 1
-#define REDIS_REPLY_ARRAY 2
-#define REDIS_REPLY_INTEGER 3
-#define REDIS_REPLY_NIL 4
-#define REDIS_REPLY_STATUS 5
-#define REDIS_REPLY_ERROR 6
-
-#define REDIS_READER_MAX_BUF (1024*16)  /* Default max unused reader buffer. */
+/* Flag that is set when we should set SO_REUSEADDR before calling bind() */
+#define REDIS_REUSEADDR 0x80

 #define REDIS_KEEPALIVE_INTERVAL 15 /* seconds */

+/* number of times we retry to connect in the case of EADDRNOTAVAIL and
+ * SO_REUSEADDR is being used. */
+#define REDIS_CONNECT_RETRIES  10
+
+/* strerror_r has two completely different prototypes and behaviors
+ * depending on system issues, so we need to operate on the error buffer
+ * differently depending on which strerror_r we're using. */
+#ifndef _GNU_SOURCE
+/* "regular" POSIX strerror_r that does the right thing. */
+#define __redis_strerror_r(errno, buf, len)                                    \
+    do {                                                                       \
+        strerror_r((errno), (buf), (len));                                     \
+    } while (0)
+#else
+/* "bad" GNU strerror_r we need to clean up after. */
+#define __redis_strerror_r(errno, buf, len)                                    \
+    do {                                                                       \
+        char *err_str = strerror_r((errno), (buf), (len));                     \
+        /* If return value _isn't_ the start of the buffer we passed in,       \
+         * then GNU strerror_r returned an internal static buffer and we       \
+         * need to copy the result into our private buffer. */                 \
+        if (err_str != (buf)) {                                                \
+            strncpy((buf), err_str, ((len) - 1));                              \
+            buf[(len)-1] = '\0';                                               \
+        }                                                                      \
+    } while (0)
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -98,61 +112,13 @@ extern "C" {
 typedef struct redisReply {
    int type; /* REDIS_REPLY_* */
    long long integer; /* The integer when type is REDIS_REPLY_INTEGER */
-    int len; /* Length of string */
+    size_t len; /* Length of string */
    char *str; /* Used for both REDIS_REPLY_ERROR and REDIS_REPLY_STRING */
    size_t elements; /* number of elements, for REDIS_REPLY_ARRAY */
    struct redisReply **element; /* elements vector for REDIS_REPLY_ARRAY */
 } redisReply;

-typedef struct redisReadTask {
-    int type;
-    int elements; /* number of elements in multibulk container */
-    int idx; /* index in parent (array) object */
-    void *obj; /* holds user-generated value for a read task */
-    struct redisReadTask *parent; /* parent task */
-    void *privdata; /* user-settable arbitrary field */
-} redisReadTask;
-
-typedef struct redisReplyObjectFunctions {
-    void *(*createString)(const redisReadTask*, char*, size_t);
-    void *(*createArray)(const redisReadTask*, int);
-    void *(*createInteger)(const redisReadTask*, long long);
-    void *(*createNil)(const redisReadTask*);
-    void (*freeObject)(void*);
-} redisReplyObjectFunctions;
-
-/* State for the protocol parser */
-typedef struct redisReader {
-    int err; /* Error flags, 0 when there is no error */
-    char errstr[128]; /* String representation of error when applicable */
-
-    char *buf; /* Read buffer */
-    size_t pos; /* Buffer cursor */
-    size_t len; /* Buffer length */
-    size_t maxbuf; /* Max length of unused buffer */
-
-    redisReadTask rstack[9];
-    int ridx; /* Index of current read task */
-    void *reply; /* Temporary reply pointer */
-
-    redisReplyObjectFunctions *fn;
-    void *privdata;
-} redisReader;
-
-/* Public API for the protocol parser. */
 redisReader *redisReaderCreate(void);
-void redisReaderFree(redisReader *r);
-int redisReaderFeed(redisReader *r, const char *buf, size_t len);
-int redisReaderGetReply(redisReader *r, void **reply);
-
-/* Backwards compatibility, can be removed on big version bump. */
-#define redisReplyReaderCreate redisReaderCreate
-#define redisReplyReaderFree redisReaderFree
-#define redisReplyReaderFeed redisReaderFeed
-#define redisReplyReaderGetReply redisReaderGetReply
-#define redisReplyReaderSetPrivdata(_r, _p) (int)(((redisReader*)(_r))->privdata = (_p))
-#define redisReplyReaderGetObject(_r) (((redisReader*)(_r))->reply)
-#define redisReplyReaderGetError(_r) (((redisReader*)(_r))->errstr)

 /* Function to free the reply objects hiredis returns by default. */
 void freeReplyObject(void *reply);
@@ -161,6 +127,14 @@ void freeReplyObject(void *reply);
 int redisvFormatCommand(char **target, const char *format, va_list ap);
 int redisFormatCommand(char **target, const char *format, ...);
 int redisFormatCommandArgv(char **target, int argc, const char **argv, const size_t *argvlen);
+int redisFormatSdsCommandArgv(sds *target, int argc, const char ** argv, const size_t *argvlen);
+void redisFreeCommand(char *cmd);
+void redisFreeSdsCommand(sds cmd);
+
+enum redisConnectionType {
+    REDIS_CONN_TCP,
+    REDIS_CONN_UNIX
+};

 /* Context for a connection to Redis */
 typedef struct redisContext {
@@ -170,16 +144,45 @@ typedef struct redisContext {
    int flags;
    char *obuf; /* Write buffer */
    redisReader *reader; /* Protocol reader */
+
+    enum redisConnectionType connection_type;
+    struct timeval *timeout;
+
+    struct {
+        char *host;
+        char *source_addr;
+        int port;
+    } tcp;
+
+    struct {
+        char *path;
+    } unix_sock;
+
 } redisContext;

 redisContext *redisConnect(const char *ip, int port);
 redisContext *redisConnectWithTimeout(const char *ip, int port, const struct timeval tv);
 redisContext *redisConnectNonBlock(const char *ip, int port);
-redisContext *redisConnectBindNonBlock(const char *ip, int port, const char *source_addr);
+redisContext *redisConnectBindNonBlock(const char *ip, int port,
+                                       const char *source_addr);
+redisContext *redisConnectBindNonBlockWithReuse(const char *ip, int port,
+                                                const char *source_addr);
 redisContext *redisConnectUnix(const char *path);
 redisContext *redisConnectUnixWithTimeout(const char *path, const struct timeval tv);
 redisContext *redisConnectUnixNonBlock(const char *path);
 redisContext *redisConnectFd(int fd);
+
+/**
+ * Reconnect the given context using the saved information.
+ *
+ * This re-uses the exact same connect options as in the initial connection.
+ * host, ip (or path), timeout and bind address are reused,
+ * flags are used unmodified from the existing context.
+ *
+ * Returns REDIS_OK on successful connect or REDIS_ERR otherwise.
+ */
+int redisReconnect(redisContext *c);
+
 int redisSetTimeout(redisContext *c, const struct timeval tv);
 int redisEnableKeepAlive(redisContext *c);
 void redisFree(redisContext *c);
@@ -1,7 +1,9 @@
 /* Extracted from anet.c to work properly with Hiredis error reporting.
 *
- * Copyright (c) 2006-2011, Salvatore Sanfilippo <antirez at gmail dot com>
- * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
 *
 * All rights reserved.
 *
@@ -47,6 +49,7 @@
 #include <stdio.h>
 #include <poll.h>
 #include <limits.h>
+#include <stdlib.h>

 #include "net.h"
 #include "sds.h"
@@ -67,7 +70,7 @@ static void __redisSetErrorFromErrno(redisContext *c, int type, const char *pref

    if (prefix != NULL)
        len = snprintf(buf,sizeof(buf),"%s: ",prefix);
-    strerror_r(errno,buf+len,sizeof(buf)-len);
+    __redis_strerror_r(errno, (char *)(buf + len), sizeof(buf) - len);
    __redisSetError(c,type,buf);
 }

@@ -138,7 +141,7 @@ int redisKeepAlive(redisContext *c, int interval) {
        return REDIS_ERR;
    }
 #else
-#ifndef __sun
+#if defined(__GLIBC__) && !defined(__FreeBSD_kernel__)
    val = interval;
    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &val, sizeof(val)) < 0) {
        __redisSetError(c,REDIS_ERR_OTHER,strerror(errno));
@@ -175,19 +178,15 @@ static int redisSetTcpNoDelay(redisContext *c) {

 #define __MAX_MSEC (((LONG_MAX) - 999) / 1000)

-static int redisContextWaitReady(redisContext *c, const struct timeval *timeout) {
-    struct pollfd   wfd[1];
-    long msec;
-
-    msec          = -1;
-    wfd[0].fd     = c->fd;
-    wfd[0].events = POLLOUT;
+static int redisContextTimeoutMsec(redisContext *c, long *result)
+{
+    const struct timeval *timeout = c->timeout;
+    long msec = -1;

    /* Only use timeout when not NULL. */
    if (timeout != NULL) {
        if (timeout->tv_usec > 1000000 || timeout->tv_sec > __MAX_MSEC) {
-            __redisSetErrorFromErrno(c, REDIS_ERR_IO, NULL);
-            redisContextCloseFd(c);
+            *result = msec;
            return REDIS_ERR;
        }

@@ -198,6 +197,16 @@ static int redisContextWaitReady(redisContext *c, const struct timeval *timeout)
        }
    }

+    *result = msec;
+    return REDIS_OK;
+}
+
+static int redisContextWaitReady(redisContext *c, long msec) {
+    struct pollfd   wfd[1];
+
+    wfd[0].fd     = c->fd;
+    wfd[0].events = POLLOUT;
+
    if (errno == EINPROGRESS) {
        int res;

@@ -256,10 +265,57 @@ int redisContextSetTimeout(redisContext *c, const struct timeval tv) {
 static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
                                   const struct timeval *timeout,
                                   const char *source_addr) {
-    int s, rv;
+    int s, rv, n;
    char _port[6];  /* strlen("65535"); */
    struct addrinfo hints, *servinfo, *bservinfo, *p, *b;
    int blocking = (c->flags & REDIS_BLOCK);
+    int reuseaddr = (c->flags & REDIS_REUSEADDR);
+    int reuses = 0;
+    long timeout_msec = -1;
+
+    servinfo = NULL;
+    c->connection_type = REDIS_CONN_TCP;
+    c->tcp.port = port;
+
+    /* We need to take possession of the passed parameters
+     * to make them reusable for a reconnect.
+     * We also carefully check we don't free data we already own,
+     * as in the case of the reconnect method.
+     *
+     * This is a bit ugly, but atleast it works and doesn't leak memory.
+     **/
+    if (c->tcp.host != addr) {
+        if (c->tcp.host)
+            free(c->tcp.host);
+
+        c->tcp.host = strdup(addr);
+    }
+
+    if (timeout) {
+        if (c->timeout != timeout) {
+            if (c->timeout == NULL)
+                c->timeout = malloc(sizeof(struct timeval));
+
+            memcpy(c->timeout, timeout, sizeof(struct timeval));
+        }
+    } else {
+        if (c->timeout)
+            free(c->timeout);
+        c->timeout = NULL;
+    }
+
+    if (redisContextTimeoutMsec(c, &timeout_msec) != REDIS_OK) {
+        __redisSetError(c, REDIS_ERR_IO, "Invalid timeout specified");
+        goto error;
+    }
+
+    if (source_addr == NULL) {
+        free(c->tcp.source_addr);
+        c->tcp.source_addr = NULL;
+    } else if (c->tcp.source_addr != source_addr) {
+        free(c->tcp.source_addr);
+        c->tcp.source_addr = strdup(source_addr);
+    }

    snprintf(_port, 6, "%d", port);
    memset(&hints,0,sizeof(hints));
@@ -271,7 +327,7 @@ static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
     * as this would add latency to every connect. Otherwise a more sensible
     * route could be: Use IPv6 if both addresses are available and there is IPv6
     * connectivity. */
-    if ((rv = getaddrinfo(addr,_port,&hints,&servinfo)) != 0) {
+    if ((rv = getaddrinfo(c->tcp.host,_port,&hints,&servinfo)) != 0) {
         hints.ai_family = AF_INET6;
         if ((rv = getaddrinfo(addr,_port,&hints,&servinfo)) != 0) {
            __redisSetError(c,REDIS_ERR_OTHER,gai_strerror(rv));
@@ -279,21 +335,31 @@ static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
        }
    }
    for (p = servinfo; p != NULL; p = p->ai_next) {
+addrretry:
        if ((s = socket(p->ai_family,p->ai_socktype,p->ai_protocol)) == -1)
            continue;

        c->fd = s;
        if (redisSetBlocking(c,0) != REDIS_OK)
            goto error;
-        if (source_addr) {
+        if (c->tcp.source_addr) {
            int bound = 0;
            /* Using getaddrinfo saves us from self-determining IPv4 vs IPv6 */
-            if ((rv = getaddrinfo(source_addr, NULL, &hints, &bservinfo)) != 0) {
+            if ((rv = getaddrinfo(c->tcp.source_addr, NULL, &hints, &bservinfo)) != 0) {
                char buf[128];
                snprintf(buf,sizeof(buf),"Can't get addr: %s",gai_strerror(rv));
                __redisSetError(c,REDIS_ERR_OTHER,buf);
                goto error;
            }
+
+            if (reuseaddr) {
+                n = 1;
+                if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char*) &n,
+                               sizeof(n)) < 0) {
+                    goto error;
+                }
+            }
+
            for (b = bservinfo; b != NULL; b = b->ai_next) {
                if (bind(s,b->ai_addr,b->ai_addrlen) != -1) {
                    bound = 1;
@@ -314,8 +380,15 @@ static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
                continue;
            } else if (errno == EINPROGRESS && !blocking) {
                /* This is ok. */
+            } else if (errno == EADDRNOTAVAIL && reuseaddr) {
+                if (++reuses >= REDIS_CONNECT_RETRIES) {
+                    goto error;
+                } else {
+                    redisContextCloseFd(c);
+                    goto addrretry;
+                }
            } else {
-                if (redisContextWaitReady(c,timeout) != REDIS_OK)
+                if (redisContextWaitReady(c,timeout_msec) != REDIS_OK)
                    goto error;
            }
        }
@@ -356,19 +429,40 @@ int redisContextConnectBindTcp(redisContext *c, const char *addr, int port,
 int redisContextConnectUnix(redisContext *c, const char *path, const struct timeval *timeout) {
    int blocking = (c->flags & REDIS_BLOCK);
    struct sockaddr_un sa;
+    long timeout_msec = -1;

    if (redisCreateSocket(c,AF_LOCAL) < 0)
        return REDIS_ERR;
    if (redisSetBlocking(c,0) != REDIS_OK)
        return REDIS_ERR;

+    c->connection_type = REDIS_CONN_UNIX;
+    if (c->unix_sock.path != path)
+        c->unix_sock.path = strdup(path);
+
+    if (timeout) {
+        if (c->timeout != timeout) {
+            if (c->timeout == NULL)
+                c->timeout = malloc(sizeof(struct timeval));
+
+            memcpy(c->timeout, timeout, sizeof(struct timeval));
+        }
+    } else {
+        if (c->timeout)
+            free(c->timeout);
+        c->timeout = NULL;
+    }
+
+    if (redisContextTimeoutMsec(c,&timeout_msec) != REDIS_OK)
+        return REDIS_ERR;
+
    sa.sun_family = AF_LOCAL;
    strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);
    if (connect(c->fd, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
        if (errno == EINPROGRESS && !blocking) {
            /* This is ok. */
        } else {
-            if (redisContextWaitReady(c,timeout) != REDIS_OK)
+            if (redisContextWaitReady(c,timeout_msec) != REDIS_OK)
                return REDIS_ERR;
        }
    }
@@ -1,7 +1,9 @@
 /* Extracted from anet.c to work properly with Hiredis error reporting.
 *
- * Copyright (c) 2006-2011, Salvatore Sanfilippo <antirez at gmail dot com>
- * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
 *
 * All rights reserved.
 *
@@ -35,7 +37,7 @@

 #include "hiredis.h"

-#if defined(__sun) || defined(_AIX)
+#if defined(__sun)
 #define AF_LOCAL AF_UNIX
 #endif

@@ -0,0 +1,525 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include "fmacros.h"
+#include <string.h>
+#include <stdlib.h>
+#ifndef _MSC_VER
+#include <unistd.h>
+#endif
+#include <assert.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include "read.h"
+#include "sds.h"
+
+static void __redisReaderSetError(redisReader *r, int type, const char *str) {
+    size_t len;
+
+    if (r->reply != NULL && r->fn && r->fn->freeObject) {
+        r->fn->freeObject(r->reply);
+        r->reply = NULL;
+    }
+
+    /* Clear input buffer on errors. */
+    if (r->buf != NULL) {
+        sdsfree(r->buf);
+        r->buf = NULL;
+        r->pos = r->len = 0;
+    }
+
+    /* Reset task stack. */
+    r->ridx = -1;
+
+    /* Set error. */
+    r->err = type;
+    len = strlen(str);
+    len = len < (sizeof(r->errstr)-1) ? len : (sizeof(r->errstr)-1);
+    memcpy(r->errstr,str,len);
+    r->errstr[len] = '\0';
+}
+
+static size_t chrtos(char *buf, size_t size, char byte) {
+    size_t len = 0;
+
+    switch(byte) {
+    case '\\':
+    case '"':
+        len = snprintf(buf,size,"\"\\%c\"",byte);
+        break;
+    case '\n': len = snprintf(buf,size,"\"\\n\""); break;
+    case '\r': len = snprintf(buf,size,"\"\\r\""); break;
+    case '\t': len = snprintf(buf,size,"\"\\t\""); break;
+    case '\a': len = snprintf(buf,size,"\"\\a\""); break;
+    case '\b': len = snprintf(buf,size,"\"\\b\""); break;
+    default:
+        if (isprint(byte))
+            len = snprintf(buf,size,"\"%c\"",byte);
+        else
+            len = snprintf(buf,size,"\"\\x%02x\"",(unsigned char)byte);
+        break;
+    }
+
+    return len;
+}
+
+static void __redisReaderSetErrorProtocolByte(redisReader *r, char byte) {
+    char cbuf[8], sbuf[128];
+
+    chrtos(cbuf,sizeof(cbuf),byte);
+    snprintf(sbuf,sizeof(sbuf),
+        "Protocol error, got %s as reply type byte", cbuf);
+    __redisReaderSetError(r,REDIS_ERR_PROTOCOL,sbuf);
+}
+
+static void __redisReaderSetErrorOOM(redisReader *r) {
+    __redisReaderSetError(r,REDIS_ERR_OOM,"Out of memory");
+}
+
+static char *readBytes(redisReader *r, unsigned int bytes) {
+    char *p;
+    if (r->len-r->pos >= bytes) {
+        p = r->buf+r->pos;
+        r->pos += bytes;
+        return p;
+    }
+    return NULL;
+}
+
+/* Find pointer to \r\n. */
+static char *seekNewline(char *s, size_t len) {
+    int pos = 0;
+    int _len = len-1;
+
+    /* Position should be < len-1 because the character at "pos" should be
+     * followed by a \n. Note that strchr cannot be used because it doesn't
+     * allow to search a limited length and the buffer that is being searched
+     * might not have a trailing NULL character. */
+    while (pos < _len) {
+        while(pos < _len && s[pos] != '\r') pos++;
+        if (pos==_len) {
+            /* Not found. */
+            return NULL;
+        } else {
+            if (s[pos+1] == '\n') {
+                /* Found. */
+                return s+pos;
+            } else {
+                /* Continue searching. */
+                pos++;
+            }
+        }
+    }
+    return NULL;
+}
+
+/* Read a long long value starting at *s, under the assumption that it will be
+ * terminated by \r\n. Ambiguously returns -1 for unexpected input. */
+static long long readLongLong(char *s) {
+    long long v = 0;
+    int dec, mult = 1;
+    char c;
+
+    if (*s == '-') {
+        mult = -1;
+        s++;
+    } else if (*s == '+') {
+        mult = 1;
+        s++;
+    }
+
+    while ((c = *(s++)) != '\r') {
+        dec = c - '0';
+        if (dec >= 0 && dec < 10) {
+            v *= 10;
+            v += dec;
+        } else {
+            /* Should not happen... */
+            return -1;
+        }
+    }
+
+    return mult*v;
+}
+
+static char *readLine(redisReader *r, int *_len) {
+    char *p, *s;
+    int len;
+
+    p = r->buf+r->pos;
+    s = seekNewline(p,(r->len-r->pos));
+    if (s != NULL) {
+        len = s-(r->buf+r->pos);
+        r->pos += len+2; /* skip \r\n */
+        if (_len) *_len = len;
+        return p;
+    }
+    return NULL;
+}
+
+static void moveToNextTask(redisReader *r) {
+    redisReadTask *cur, *prv;
+    while (r->ridx >= 0) {
+        /* Return a.s.a.p. when the stack is now empty. */
+        if (r->ridx == 0) {
+            r->ridx--;
+            return;
+        }
+
+        cur = &(r->rstack[r->ridx]);
+        prv = &(r->rstack[r->ridx-1]);
+        assert(prv->type == REDIS_REPLY_ARRAY);
+        if (cur->idx == prv->elements-1) {
+            r->ridx--;
+        } else {
+            /* Reset the type because the next item can be anything */
+            assert(cur->idx < prv->elements);
+            cur->type = -1;
+            cur->elements = -1;
+            cur->idx++;
+            return;
+        }
+    }
+}
+
+static int processLineItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    void *obj;
+    char *p;
+    int len;
+
+    if ((p = readLine(r,&len)) != NULL) {
+        if (cur->type == REDIS_REPLY_INTEGER) {
+            if (r->fn && r->fn->createInteger)
+                obj = r->fn->createInteger(cur,readLongLong(p));
+            else
+                obj = (void*)REDIS_REPLY_INTEGER;
+        } else {
+            /* Type will be error or status. */
+            if (r->fn && r->fn->createString)
+                obj = r->fn->createString(cur,p,len);
+            else
+                obj = (void*)(size_t)(cur->type);
+        }
+
+        if (obj == NULL) {
+            __redisReaderSetErrorOOM(r);
+            return REDIS_ERR;
+        }
+
+        /* Set reply if this is the root object. */
+        if (r->ridx == 0) r->reply = obj;
+        moveToNextTask(r);
+        return REDIS_OK;
+    }
+
+    return REDIS_ERR;
+}
+
+static int processBulkItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    void *obj = NULL;
+    char *p, *s;
+    long len;
+    unsigned long bytelen;
+    int success = 0;
+
+    p = r->buf+r->pos;
+    s = seekNewline(p,r->len-r->pos);
+    if (s != NULL) {
+        p = r->buf+r->pos;
+        bytelen = s-(r->buf+r->pos)+2; /* include \r\n */
+        len = readLongLong(p);
+
+        if (len < 0) {
+            /* The nil object can always be created. */
+            if (r->fn && r->fn->createNil)
+                obj = r->fn->createNil(cur);
+            else
+                obj = (void*)REDIS_REPLY_NIL;
+            success = 1;
+        } else {
+            /* Only continue when the buffer contains the entire bulk item. */
+            bytelen += len+2; /* include \r\n */
+            if (r->pos+bytelen <= r->len) {
+                if (r->fn && r->fn->createString)
+                    obj = r->fn->createString(cur,s+2,len);
+                else
+                    obj = (void*)REDIS_REPLY_STRING;
+                success = 1;
+            }
+        }
+
+        /* Proceed when obj was created. */
+        if (success) {
+            if (obj == NULL) {
+                __redisReaderSetErrorOOM(r);
+                return REDIS_ERR;
+            }
+
+            r->pos += bytelen;
+
+            /* Set reply if this is the root object. */
+            if (r->ridx == 0) r->reply = obj;
+            moveToNextTask(r);
+            return REDIS_OK;
+        }
+    }
+
+    return REDIS_ERR;
+}
+
+static int processMultiBulkItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    void *obj;
+    char *p;
+    long elements;
+    int root = 0;
+
+    /* Set error for nested multi bulks with depth > 7 */
+    if (r->ridx == 8) {
+        __redisReaderSetError(r,REDIS_ERR_PROTOCOL,
+            "No support for nested multi bulk replies with depth > 7");
+        return REDIS_ERR;
+    }
+
+    if ((p = readLine(r,NULL)) != NULL) {
+        elements = readLongLong(p);
+        root = (r->ridx == 0);
+
+        if (elements == -1) {
+            if (r->fn && r->fn->createNil)
+                obj = r->fn->createNil(cur);
+            else
+                obj = (void*)REDIS_REPLY_NIL;
+
+            if (obj == NULL) {
+                __redisReaderSetErrorOOM(r);
+                return REDIS_ERR;
+            }
+
+            moveToNextTask(r);
+        } else {
+            if (r->fn && r->fn->createArray)
+                obj = r->fn->createArray(cur,elements);
+            else
+                obj = (void*)REDIS_REPLY_ARRAY;
+
+            if (obj == NULL) {
+                __redisReaderSetErrorOOM(r);
+                return REDIS_ERR;
+            }
+
+            /* Modify task stack when there are more than 0 elements. */
+            if (elements > 0) {
+                cur->elements = elements;
+                cur->obj = obj;
+                r->ridx++;
+                r->rstack[r->ridx].type = -1;
+                r->rstack[r->ridx].elements = -1;
+                r->rstack[r->ridx].idx = 0;
+                r->rstack[r->ridx].obj = NULL;
+                r->rstack[r->ridx].parent = cur;
+                r->rstack[r->ridx].privdata = r->privdata;
+            } else {
+                moveToNextTask(r);
+            }
+        }
+
+        /* Set reply if this is the root object. */
+        if (root) r->reply = obj;
+        return REDIS_OK;
+    }
+
+    return REDIS_ERR;
+}
+
+static int processItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    char *p;
+
+    /* check if we need to read type */
+    if (cur->type < 0) {
+        if ((p = readBytes(r,1)) != NULL) {
+            switch (p[0]) {
+            case '-':
+                cur->type = REDIS_REPLY_ERROR;
+                break;
+            case '+':
+                cur->type = REDIS_REPLY_STATUS;
+                break;
+            case ':':
+                cur->type = REDIS_REPLY_INTEGER;
+                break;
+            case '$':
+                cur->type = REDIS_REPLY_STRING;
+                break;
+            case '*':
+                cur->type = REDIS_REPLY_ARRAY;
+                break;
+            default:
+                __redisReaderSetErrorProtocolByte(r,*p);
+                return REDIS_ERR;
+            }
+        } else {
+            /* could not consume 1 byte */
+            return REDIS_ERR;
+        }
+    }
+
+    /* process typed item */
+    switch(cur->type) {
+    case REDIS_REPLY_ERROR:
+    case REDIS_REPLY_STATUS:
+    case REDIS_REPLY_INTEGER:
+        return processLineItem(r);
+    case REDIS_REPLY_STRING:
+        return processBulkItem(r);
+    case REDIS_REPLY_ARRAY:
+        return processMultiBulkItem(r);
+    default:
+        assert(NULL);
+        return REDIS_ERR; /* Avoid warning. */
+    }
+}
+
+redisReader *redisReaderCreateWithFunctions(redisReplyObjectFunctions *fn) {
+    redisReader *r;
+
+    r = calloc(sizeof(redisReader),1);
+    if (r == NULL)
+        return NULL;
+
+    r->err = 0;
+    r->errstr[0] = '\0';
+    r->fn = fn;
+    r->buf = sdsempty();
+    r->maxbuf = REDIS_READER_MAX_BUF;
+    if (r->buf == NULL) {
+        free(r);
+        return NULL;
+    }
+
+    r->ridx = -1;
+    return r;
+}
+
+void redisReaderFree(redisReader *r) {
+    if (r->reply != NULL && r->fn && r->fn->freeObject)
+        r->fn->freeObject(r->reply);
+    if (r->buf != NULL)
+        sdsfree(r->buf);
+    free(r);
+}
+
+int redisReaderFeed(redisReader *r, const char *buf, size_t len) {
+    sds newbuf;
+
+    /* Return early when this reader is in an erroneous state. */
+    if (r->err)
+        return REDIS_ERR;
+
+    /* Copy the provided buffer. */
+    if (buf != NULL && len >= 1) {
+        /* Destroy internal buffer when it is empty and is quite large. */
+        if (r->len == 0 && r->maxbuf != 0 && sdsavail(r->buf) > r->maxbuf) {
+            sdsfree(r->buf);
+            r->buf = sdsempty();
+            r->pos = 0;
+
+            /* r->buf should not be NULL since we just free'd a larger one. */
+            assert(r->buf != NULL);
+        }
+
+        newbuf = sdscatlen(r->buf,buf,len);
+        if (newbuf == NULL) {
+            __redisReaderSetErrorOOM(r);
+            return REDIS_ERR;
+        }
+
+        r->buf = newbuf;
+        r->len = sdslen(r->buf);
+    }
+
+    return REDIS_OK;
+}
+
+int redisReaderGetReply(redisReader *r, void **reply) {
+    /* Default target pointer to NULL. */
+    if (reply != NULL)
+        *reply = NULL;
+
+    /* Return early when this reader is in an erroneous state. */
+    if (r->err)
+        return REDIS_ERR;
+
+    /* When the buffer is empty, there will never be a reply. */
+    if (r->len == 0)
+        return REDIS_OK;
+
+    /* Set first item to process when the stack is empty. */
+    if (r->ridx == -1) {
+        r->rstack[0].type = -1;
+        r->rstack[0].elements = -1;
+        r->rstack[0].idx = -1;
+        r->rstack[0].obj = NULL;
+        r->rstack[0].parent = NULL;
+        r->rstack[0].privdata = r->privdata;
+        r->ridx = 0;
+    }
+
+    /* Process items in reply. */
+    while (r->ridx >= 0)
+        if (processItem(r) != REDIS_OK)
+            break;
+
+    /* Return ASAP when an error occurred. */
+    if (r->err)
+        return REDIS_ERR;
+
+    /* Discard part of the buffer when we've consumed at least 1k, to avoid
+     * doing unnecessary calls to memmove() in sds.c. */
+    if (r->pos >= 1024) {
+        sdsrange(r->buf,r->pos,-1);
+        r->pos = 0;
+        r->len = sdslen(r->buf);
+    }
+
+    /* Emit a reply when there is one. */
+    if (r->ridx == -1) {
+        if (reply != NULL)
+            *reply = r->reply;
+        r->reply = NULL;
+    }
+    return REDIS_OK;
+}
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#ifndef __HIREDIS_READ_H
+#define __HIREDIS_READ_H
+#include <stdio.h> /* for size_t */
+
+#define REDIS_ERR -1
+#define REDIS_OK 0
+
+/* When an error occurs, the err flag in a context is set to hold the type of
+ * error that occurred. REDIS_ERR_IO means there was an I/O error and you
+ * should use the "errno" variable to find out what is wrong.
+ * For other values, the "errstr" field will hold a description. */
+#define REDIS_ERR_IO 1 /* Error in read or write */
+#define REDIS_ERR_EOF 3 /* End of file */
+#define REDIS_ERR_PROTOCOL 4 /* Protocol error */
+#define REDIS_ERR_OOM 5 /* Out of memory */
+#define REDIS_ERR_OTHER 2 /* Everything else... */
+
+#define REDIS_REPLY_STRING 1
+#define REDIS_REPLY_ARRAY 2
+#define REDIS_REPLY_INTEGER 3
+#define REDIS_REPLY_NIL 4
+#define REDIS_REPLY_STATUS 5
+#define REDIS_REPLY_ERROR 6
+
+#define REDIS_READER_MAX_BUF (1024*16)  /* Default max unused reader buffer. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct redisReadTask {
+    int type;
+    int elements; /* number of elements in multibulk container */
+    int idx; /* index in parent (array) object */
+    void *obj; /* holds user-generated value for a read task */
+    struct redisReadTask *parent; /* parent task */
+    void *privdata; /* user-settable arbitrary field */
+} redisReadTask;
+
+typedef struct redisReplyObjectFunctions {
+    void *(*createString)(const redisReadTask*, char*, size_t);
+    void *(*createArray)(const redisReadTask*, int);
+    void *(*createInteger)(const redisReadTask*, long long);
+    void *(*createNil)(const redisReadTask*);
+    void (*freeObject)(void*);
+} redisReplyObjectFunctions;
+
+typedef struct redisReader {
+    int err; /* Error flags, 0 when there is no error */
+    char errstr[128]; /* String representation of error when applicable */
+
+    char *buf; /* Read buffer */
+    size_t pos; /* Buffer cursor */
+    size_t len; /* Buffer length */
+    size_t maxbuf; /* Max length of unused buffer */
+
+    redisReadTask rstack[9];
+    int ridx; /* Index of current read task */
+    void *reply; /* Temporary reply pointer */
+
+    redisReplyObjectFunctions *fn;
+    void *privdata;
+} redisReader;
+
+/* Public API for the protocol parser. */
+redisReader *redisReaderCreateWithFunctions(redisReplyObjectFunctions *fn);
+void redisReaderFree(redisReader *r);
+int redisReaderFeed(redisReader *r, const char *buf, size_t len);
+int redisReaderGetReply(redisReader *r, void **reply);
+
+#define redisReaderSetPrivdata(_r, _p) (int)(((redisReader*)(_r))->privdata = (_p))
+#define redisReaderGetObject(_r) (((redisReader*)(_r))->reply)
+#define redisReaderGetError(_r) (((redisReader*)(_r))->errstr)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
@@ -89,9 +89,9 @@ sds sdsnewlen(const void *init, size_t initlen) {
    unsigned char *fp; /* flags pointer. */

    sh = s_malloc(hdrlen+initlen+1);
+    if (sh == NULL) return NULL;
    if (!init)
        memset(sh, 0, hdrlen+initlen+1);
-    if (sh == NULL) return NULL;
    s = (char*)sh+hdrlen;
    fp = ((unsigned char*)s)-1;
    switch(type) {
@@ -577,14 +577,12 @@ sds sdscatprintf(sds s, const char *fmt, ...) {
 * %% - Verbatim "%" character.
 */
 sds sdscatfmt(sds s, char const *fmt, ...) {
-    size_t initlen = sdslen(s);
    const char *f = fmt;
    int i;
    va_list ap;

    va_start(ap,fmt);
-    f = fmt;    /* Next format specifier byte to process. */
-    i = initlen; /* Position of the next byte to write to dest str. */
+    i = sdslen(s); /* Position of the next byte to write to dest str. */
    while(*f) {
        char next, *str;
        size_t l;
@@ -79,7 +79,7 @@ struct __attribute__ ((__packed__)) sdshdr64 {
 #define SDS_TYPE_64 4
 #define SDS_TYPE_MASK 7
 #define SDS_TYPE_BITS 3
-#define SDS_HDR_VAR(T,s) struct sdshdr##T *sh = (void*)((s)-(sizeof(struct sdshdr##T)));
+#define SDS_HDR_VAR(T,s) struct sdshdr##T *sh = (struct sdshdr##T *)((s)-(sizeof(struct sdshdr##T)));
 #define SDS_HDR(T,s) ((struct sdshdr##T *)((s)-(sizeof(struct sdshdr##T))))
 #define SDS_TYPE_5_LEN(f) ((f)>>SDS_TYPE_BITS)

@@ -1,6 +1,7 @@
 /* SDSLib 2.0 -- A C dynamic strings library
 *
 * Copyright (c) 2006-2015, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2015, Oran Agra
 * Copyright (c) 2015, Redis Labs, Inc
 * All rights reserved.
 *
@@ -36,7 +37,6 @@
 * the include of your alternate allocator if needed (not needed in order
 * to use the default libc allocator). */

-#include "zmalloc.h"
-#define s_malloc zmalloc
-#define s_realloc zrealloc
-#define s_free zfree
+#define s_malloc malloc
+#define s_realloc realloc
+#define s_free free
@@ -11,6 +11,7 @@
 #include <limits.h>

 #include "hiredis.h"
+#include "net.h"

 enum connection_type {
    CONN_TCP,
@@ -29,7 +30,7 @@ struct config {

    struct {
        const char *path;
-    } unix;
+    } unix_sock;
 };

 /* The following lines make up our testing "framework" :) */
@@ -43,6 +44,13 @@ static long long usec(void) {
    return (((long long)tv.tv_sec)*1000000)+tv.tv_usec;
 }

+/* The assert() calls below have side effects, so we need assert()
+ * even if we are compiling without asserts (-DNDEBUG). */
+#ifdef NDEBUG
+#undef assert
+#define assert(e) (void)(e)
+#endif
+
 static redisContext *select_database(redisContext *c) {
    redisReply *reply;

@@ -51,7 +59,7 @@ static redisContext *select_database(redisContext *c) {
    assert(reply != NULL);
    freeReplyObject(reply);

-    /* Make sure the DB is empty */
+    /* Make sure the DB is emtpy */
    reply = redisCommand(c,"DBSIZE");
    assert(reply != NULL);
    if (reply->type == REDIS_REPLY_INTEGER && reply->integer == 0) {
@@ -89,10 +97,10 @@ static redisContext *connect(struct config config) {
    if (config.type == CONN_TCP) {
        c = redisConnect(config.tcp.host, config.tcp.port);
    } else if (config.type == CONN_UNIX) {
-        c = redisConnectUnix(config.unix.path);
+        c = redisConnectUnix(config.unix_sock.path);
    } else if (config.type == CONN_FD) {
        /* Create a dummy connection just to get an fd to inherit */
-        redisContext *dummy_ctx = redisConnectUnix(config.unix.path);
+        redisContext *dummy_ctx = redisConnectUnix(config.unix_sock.path);
        if (dummy_ctx) {
            int fd = disconnect(dummy_ctx, 1);
            printf("Connecting to inherited fd %d\n", fd);
@@ -107,6 +115,7 @@ static redisContext *connect(struct config config) {
        exit(1);
    } else if (c->err) {
        printf("Connection error: %s\n", c->errstr);
+        redisFree(c);
        exit(1);
    }

@@ -215,6 +224,22 @@ static void test_format_commands(void) {
    test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$7\r\nfoo\0xxx\r\n$3\r\nbar\r\n",len) == 0 &&
        len == 4+4+(3+2)+4+(7+2)+4+(3+2));
    free(cmd);
+
+    sds sds_cmd;
+
+    sds_cmd = sdsempty();
+    test("Format command into sds by passing argc/argv without lengths: ");
+    len = redisFormatSdsCommandArgv(&sds_cmd,argc,argv,NULL);
+    test_cond(strncmp(sds_cmd,"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\nbar\r\n",len) == 0 &&
+        len == 4+4+(3+2)+4+(3+2)+4+(3+2));
+    sdsfree(sds_cmd);
+
+    sds_cmd = sdsempty();
+    test("Format command into sds by passing argc/argv with lengths: ");
+    len = redisFormatSdsCommandArgv(&sds_cmd,argc,argv,lens);
+    test_cond(strncmp(sds_cmd,"*3\r\n$3\r\nSET\r\n$7\r\nfoo\0xxx\r\n$3\r\nbar\r\n",len) == 0 &&
+        len == 4+4+(3+2)+4+(7+2)+4+(3+2));
+    sdsfree(sds_cmd);
 }

 static void test_append_formatted_commands(struct config config) {
@@ -318,16 +343,31 @@ static void test_reply_reader(void) {
    redisReaderFree(reader);
 }

+static void test_free_null(void) {
+    void *redisCtx = NULL;
+    void *reply = NULL;
+
+    test("Don't fail when redisFree is passed a NULL value: ");
+    redisFree(redisCtx);
+    test_cond(redisCtx == NULL);
+
+    test("Don't fail when freeReplyObject is passed a NULL value: ");
+    freeReplyObject(reply);
+    test_cond(reply == NULL);
+}
+
 static void test_blocking_connection_errors(void) {
    redisContext *c;

    test("Returns error when host cannot be resolved: ");
-    c = redisConnect((char*)"idontexist.local", 6379);
+    c = redisConnect((char*)"idontexist.test", 6379);
    test_cond(c->err == REDIS_ERR_OTHER &&
        (strcmp(c->errstr,"Name or service not known") == 0 ||
-         strcmp(c->errstr,"Can't resolve: idontexist.local") == 0 ||
+         strcmp(c->errstr,"Can't resolve: idontexist.test") == 0 ||
         strcmp(c->errstr,"nodename nor servname provided, or not known") == 0 ||
         strcmp(c->errstr,"No address associated with hostname") == 0 ||
+         strcmp(c->errstr,"Temporary failure in name resolution") == 0 ||
+         strcmp(c->errstr,"hostname nor servname provided, or not known") == 0 ||
         strcmp(c->errstr,"no address associated with name") == 0));
    redisFree(c);

@@ -337,7 +377,7 @@ static void test_blocking_connection_errors(void) {
        strcmp(c->errstr,"Connection refused") == 0);
    redisFree(c);

-    test("Returns error when the unix socket path doesn't accept connections: ");
+    test("Returns error when the unix_sock socket path doesn't accept connections: ");
    c = redisConnectUnix((char*)"/tmp/idontexist.sock");
    test_cond(c->err == REDIS_ERR_IO); /* Don't care about the message... */
    redisFree(c);
@@ -421,6 +461,52 @@ static void test_blocking_connection(struct config config) {
    disconnect(c, 0);
 }

+static void test_blocking_connection_timeouts(struct config config) {
+    redisContext *c;
+    redisReply *reply;
+    ssize_t s;
+    const char *cmd = "DEBUG SLEEP 3\r\n";
+    struct timeval tv;
+
+    c = connect(config);
+    test("Successfully completes a command when the timeout is not exceeded: ");
+    reply = redisCommand(c,"SET foo fast");
+    freeReplyObject(reply);
+    tv.tv_sec = 0;
+    tv.tv_usec = 10000;
+    redisSetTimeout(c, tv);
+    reply = redisCommand(c, "GET foo");
+    test_cond(reply != NULL && reply->type == REDIS_REPLY_STRING && memcmp(reply->str, "fast", 4) == 0);
+    freeReplyObject(reply);
+    disconnect(c, 0);
+
+    c = connect(config);
+    test("Does not return a reply when the command times out: ");
+    s = write(c->fd, cmd, strlen(cmd));
+    tv.tv_sec = 0;
+    tv.tv_usec = 10000;
+    redisSetTimeout(c, tv);
+    reply = redisCommand(c, "GET foo");
+    test_cond(s > 0 && reply == NULL && c->err == REDIS_ERR_IO && strcmp(c->errstr, "Resource temporarily unavailable") == 0);
+    freeReplyObject(reply);
+
+    test("Reconnect properly reconnects after a timeout: ");
+    redisReconnect(c);
+    reply = redisCommand(c, "PING");
+    test_cond(reply != NULL && reply->type == REDIS_REPLY_STATUS && strcmp(reply->str, "PONG") == 0);
+    freeReplyObject(reply);
+
+    test("Reconnect properly uses owned parameters: ");
+    config.tcp.host = "foo";
+    config.unix_sock.path = "foo";
+    redisReconnect(c);
+    reply = redisCommand(c, "PING");
+    test_cond(reply != NULL && reply->type == REDIS_REPLY_STATUS && strcmp(reply->str, "PONG") == 0);
+    freeReplyObject(reply);
+
+    disconnect(c, 0);
+}
+
 static void test_blocking_io_errors(struct config config) {
    redisContext *c;
    redisReply *reply;
@@ -444,7 +530,7 @@ static void test_blocking_io_errors(struct config config) {

    test("Returns I/O error when the connection is lost: ");
    reply = redisCommand(c,"QUIT");
-    if (major >= 2 && minor > 0) {
+    if (major > 2 || (major == 2 && minor > 0)) {
        /* > 2.0 returns OK on QUIT and read() should be issued once more
         * to know the descriptor is at EOF. */
        test_cond(strcasecmp(reply->str,"OK") == 0 &&
@@ -482,7 +568,8 @@ static void test_invalid_timeout_errors(struct config config) {

    c = redisConnectWithTimeout(config.tcp.host, config.tcp.port, config.tcp.timeout);

-    test_cond(c->err == REDIS_ERR_IO);
+    test_cond(c->err == REDIS_ERR_IO && strcmp(c->errstr, "Invalid timeout specified") == 0);
+    redisFree(c);

    test("Set error when an invalid timeout sec value is given to redisConnectWithTimeout: ");

@@ -491,8 +578,7 @@ static void test_invalid_timeout_errors(struct config config) {

    c = redisConnectWithTimeout(config.tcp.host, config.tcp.port, config.tcp.timeout);

-    test_cond(c->err == REDIS_ERR_IO);
-
+    test_cond(c->err == REDIS_ERR_IO && strcmp(c->errstr, "Invalid timeout specified") == 0);
    redisFree(c);
 }

@@ -666,7 +752,7 @@ int main(int argc, char **argv) {
            .host = "127.0.0.1",
            .port = 6379
        },
-        .unix = {
+        .unix_sock = {
            .path = "/tmp/redis.sock"
        }
    };
@@ -687,7 +773,7 @@ int main(int argc, char **argv) {
            cfg.tcp.port = atoi(argv[0]);
        } else if (argc >= 2 && !strcmp(argv[0],"-s")) {
            argv++; argc--;
-            cfg.unix.path = argv[0];
+            cfg.unix_sock.path = argv[0];
        } else if (argc >= 1 && !strcmp(argv[0],"--skip-throughput")) {
            throughput = 0;
        } else if (argc >= 1 && !strcmp(argv[0],"--skip-inherit-fd")) {
@@ -702,27 +788,31 @@ int main(int argc, char **argv) {
    test_format_commands();
    test_reply_reader();
    test_blocking_connection_errors();
+    test_free_null();

    printf("\nTesting against TCP connection (%s:%d):\n", cfg.tcp.host, cfg.tcp.port);
    cfg.type = CONN_TCP;
    test_blocking_connection(cfg);
+    test_blocking_connection_timeouts(cfg);
    test_blocking_io_errors(cfg);
    test_invalid_timeout_errors(cfg);
    test_append_formatted_commands(cfg);
    if (throughput) test_throughput(cfg);

-    printf("\nTesting against Unix socket connection (%s):\n", cfg.unix.path);
+    printf("\nTesting against Unix socket connection (%s):\n", cfg.unix_sock.path);
    cfg.type = CONN_UNIX;
    test_blocking_connection(cfg);
+    test_blocking_connection_timeouts(cfg);
    test_blocking_io_errors(cfg);
    if (throughput) test_throughput(cfg);

    if (test_inherit_fd) {
-        printf("\nTesting against inherited fd (%s):\n", cfg.unix.path);
+        printf("\nTesting against inherited fd (%s):\n", cfg.unix_sock.path);
        cfg.type = CONN_FD;
        test_blocking_connection(cfg);
    }

+
    if (fails) {
        printf("*** %d TESTS FAILED ***\n", fails);
        return 1;
@@ -0,0 +1,42 @@
+#ifndef _WIN32_HELPER_INCLUDE
+#define _WIN32_HELPER_INCLUDE
+#ifdef _MSC_VER
+
+#ifndef inline
+#define inline __inline
+#endif
+
+#ifndef va_copy
+#define va_copy(d,s) ((d) = (s))
+#endif
+
+#ifndef snprintf
+#define snprintf c99_snprintf
+
+__inline int c99_vsnprintf(char* str, size_t size, const char* format, va_list ap)
+{
+    int count = -1;
+
+    if (size != 0)
+        count = _vsnprintf_s(str, size, _TRUNCATE, format, ap);
+    if (count == -1)
+        count = _vscprintf(format, ap);
+
+    return count;
+}
+
+__inline int c99_snprintf(char* str, size_t size, const char* format, ...)
+{
+    int count;
+    va_list ap;
+
+    va_start(ap, format);
+    count = c99_vsnprintf(str, size, format, ap);
+    va_end(ap);
+
+    return count;
+}
+#endif
+
+#endif
+#endif
@@ -1,13 +0,0 @@
-/* Drop in replacement for zmalloc.h in order to just use libc malloc without
- * any wrappering. */
-
-#ifndef ZMALLOC_H
-#define ZMALLOC_H
-
-#define zmalloc malloc
-#define zrealloc realloc
-#define zcalloc(x) calloc(x,1)
-#define zfree free
-#define zstrdup strdup
-
-#endif
@@ -100,3 +100,7 @@
 #  define JEMALLOC_RESTRICT_RETURN
 #  define JEMALLOC_ALLOCATOR
 #endif
+
+/* This version of Jemalloc, modified for Redis, has the je_get_defrag_hint()
+ * function. */
+#define JEMALLOC_FRAG_HINT
@@ -2591,3 +2591,35 @@ jemalloc_postfork_child(void)
 }

 /******************************************************************************/
+
+/* Helps the application decide if a pointer is worth re-allocating in order to reduce fragmentation.
+ * returns 0 if the allocation is in the currently active run,
+ * or when it is not causing any frag issue (large or huge bin)
+ * returns the bin utilization and run utilization both in fixed point 16:16.
+ * If the application decides to re-allocate it should use MALLOCX_TCACHE_NONE when doing so. */
+JEMALLOC_EXPORT int JEMALLOC_NOTHROW
+je_get_defrag_hint(void* ptr, int *bin_util, int *run_util) {
+    int defrag = 0;
+    arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
+    if (likely(chunk != ptr)) { /* indication that this is not a HUGE alloc */
+        size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
+        size_t mapbits = arena_mapbits_get(chunk, pageind);
+        if (likely((mapbits & CHUNK_MAP_LARGE) == 0)) { /* indication that this is not a LARGE alloc */
+            arena_t *arena = extent_node_arena_get(&chunk->node);
+            size_t rpages_ind = pageind - arena_mapbits_small_runind_get(chunk, pageind);
+            arena_run_t *run = &arena_miscelm_get(chunk, rpages_ind)->run;
+            arena_bin_t *bin = &arena->bins[run->binind];
+            malloc_mutex_lock(&bin->lock);
+            /* runs that are in the same chunk in as the current chunk, are likely to be the next currun */
+            if (chunk != (arena_chunk_t *)CHUNK_ADDR2BASE(bin->runcur)) {
+                arena_bin_info_t *bin_info = &arena_bin_info[run->binind];
+                size_t availregs = bin_info->nregs * bin->stats.curruns;
+                *bin_util = (bin->stats.curregs<<16) / availregs;
+                *run_util = ((bin_info->nregs - run->nfree)<<16) / bin_info->nregs;
+                defrag = 1;
+            }
+            malloc_mutex_unlock(&bin->lock);
+        }
+    }
+    return defrag;
+}
@@ -59,7 +59,7 @@
 # internet, binding to all the interfaces is dangerous and will expose the
 # instance to everybody on the internet. So by default we uncomment the
 # following bind directive, that will force Redis to listen only into
-# the IPv4 lookback interface address (this means Redis will be able to
+# the IPv4 loopback interface address (this means Redis will be able to
 # accept connections only from clients running into the same computer it
 # is running).
 #
@@ -185,6 +185,14 @@ logfile ""
 # dbid is a number between 0 and 'databases'-1
 databases 16

+# By default Redis shows an ASCII art logo only when started to log to the
+# standard output and if the standard output is a TTY. Basically this means
+# that normally a logo is displayed only in interactive sessions.
+#
+# However it is possible to force the pre-4.0 behavior and always show a
+# ASCII art logo in startup logs by setting the following option to yes.
+always-show-logo yes
+
 ################################ SNAPSHOTTING  ################################
 #
 # Save the DB on disk:
@@ -288,7 +296,9 @@ dir ./
 #
 # 2) if slave-serve-stale-data is set to 'no' the slave will reply with
 #    an error "SYNC with master in progress" to all the kind of commands
-#    but to INFO and SLAVEOF.
+#    but to INFO, SLAVEOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,
+#    SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB,
+#    COMMAND, POST, HOST: and LATENCY.
 #
 slave-serve-stale-data yes

@@ -402,6 +412,10 @@ repl-disable-tcp-nodelay no
 # need to elapse, starting from the time the last slave disconnected, for
 # the backlog buffer to be freed.
 #
+# Note that slaves never free the backlog for timeout, since they may be
+# promoted to masters later, and should be able to correctly "partially
+# resynchronize" with the slaves: hence they should always accumulate backlog.
+#
 # A value of 0 means to never release the backlog.
 #
 # repl-backlog-ttl 3600
@@ -448,7 +462,7 @@ slave-priority 100
 # offers this information, which is used, among other tools, by
 # Redis Sentinel in order to discover slave instances.
 # Another place where this info is available is in the output of the
-# "ROLE" command of a masteer.
+# "ROLE" command of a master.
 #
 # The listed IP and address normally reported by a slave is obtained
 # in the following way:
@@ -594,7 +608,7 @@ slave-priority 100
 # deletion of the object. It means that the server stops processing new commands
 # in order to reclaim all the memory associated with an object in a synchronous
 # way. If the key deleted is associated with a small object, the time needed
-# in order to execute th DEL command is very small and comparable to most other
+# in order to execute the DEL command is very small and comparable to most other
 # O(1) or O(log_N) commands in Redis. However if the key is associated with an
 # aggregated value containing millions of elements, the server can block for
 # a long time (even seconds) in order to complete the operation.
@@ -609,7 +623,7 @@ slave-priority 100
 # It's up to the design of the application to understand when it is a good
 # idea to use one or the other. However the Redis server sometimes has to
 # delete keys or flush the whole database as a side effect of other operations.
-# Specifically Redis deletes objects independently of an user call in the
+# Specifically Redis deletes objects independently of a user call in the
 # following scenarios:
 #
 # 1) On eviction, because of the maxmemory and maxmemory policy configurations,
@@ -818,7 +832,7 @@ lua-time-limit 5000
 # A slave of a failing master will avoid to start a failover if its data
 # looks too old.
 #
-# There is no simple way for a slave to actually have a exact measure of
+# There is no simple way for a slave to actually have an exact measure of
 # its "data age", so the following two checks are performed:
 #
 # 1) If there are multiple slaves able to failover, they exchange messages
@@ -902,7 +916,7 @@ lua-time-limit 5000
 # Docker and other containers).
 #
 # In order to make Redis Cluster working in such environments, a static
-# configuration where each node known its public address is needed. The
+# configuration where each node knows its public address is needed. The
 # following two options are used for this scope, and are:
 #
 # * cluster-announce-ip
@@ -1216,3 +1230,66 @@ aof-rewrite-incremental-fsync yes
 #
 # lfu-log-factor 10
 # lfu-decay-time 1
+
+########################### ACTIVE DEFRAGMENTATION #######################
+#
+# WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested
+# even in production and manually tested by multiple engineers for some
+# time.
+#
+# What is active defragmentation?
+# -------------------------------
+#
+# Active (online) defragmentation allows a Redis server to compact the
+# spaces left between small allocations and deallocations of data in memory,
+# thus allowing to reclaim back memory.
+#
+# Fragmentation is a natural process that happens with every allocator (but
+# less so with Jemalloc, fortunately) and certain workloads. Normally a server
+# restart is needed in order to lower the fragmentation, or at least to flush
+# away all the data and create it again. However thanks to this feature
+# implemented by Oran Agra for Redis 4.0 this process can happen at runtime
+# in an "hot" way, while the server is running.
+#
+# Basically when the fragmentation is over a certain level (see the
+# configuration options below) Redis will start to create new copies of the
+# values in contiguous memory regions by exploiting certain specific Jemalloc
+# features (in order to understand if an allocation is causing fragmentation
+# and to allocate it in a better place), and at the same time, will release the
+# old copies of the data. This process, repeated incrementally for all the keys
+# will cause the fragmentation to drop back to normal values.
+#
+# Important things to understand:
+#
+# 1. This feature is disabled by default, and only works if you compiled Redis
+#    to use the copy of Jemalloc we ship with the source code of Redis.
+#    This is the default with Linux builds.
+#
+# 2. You never need to enable this feature if you don't have fragmentation
+#    issues.
+#
+# 3. Once you experience fragmentation, you can enable this feature when
+#    needed with the command "CONFIG SET activedefrag yes".
+#
+# The configuration parameters are able to fine tune the behavior of the
+# defragmentation process. If you are not sure about what they mean it is
+# a good idea to leave the defaults untouched.
+
+# Enabled active defragmentation
+# activedefrag yes
+
+# Minimum amount of fragmentation waste to start active defrag
+# active-defrag-ignore-bytes 100mb
+
+# Minimum percentage of fragmentation to start active defrag
+# active-defrag-threshold-lower 10
+
+# Maximum percentage of fragmentation at which we use maximum effort
+# active-defrag-threshold-upper 100
+
+# Minimal effort for defrag in CPU percentage
+# active-defrag-cycle-min 25
+
+# Maximal effort for defrag in CPU percentage
+# active-defrag-cycle-max 75
+
@@ -14,6 +14,7 @@

 release_hdr := $(shell sh -c './mkreleasehdr.sh')
 uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')
+uname_M := $(shell sh -c 'uname -m 2>/dev/null || echo not')
 OPTIMIZATION?=-O2
 DEPENDENCY_TARGETS=hiredis linenoise lua
 NODEPS:=clean distclean
@@ -27,11 +28,19 @@ PREFIX?=/usr/local
 INSTALL_BIN=$(PREFIX)/bin
 INSTALL=install

-# Default allocator
+# Default allocator defaults to Jemalloc if it's not an ARM
+MALLOC=libc
+ifneq ($(uname_M),armv6l)
+ifneq ($(uname_M),armv7l)
 ifeq ($(uname_S),Linux)
 	MALLOC=jemalloc
-else
-	MALLOC=libc
+endif
+endif
+endif
+
+# To get ARM stack traces if Redis crashes we need a special C flag.
+ifneq (,$(findstring armv,$(uname_M)))
+        CFLAGS+=-funwind-tables
 endif

 # Backwards compatibility for selecting an allocator
@@ -61,6 +70,13 @@ DEBUG=-g -ggdb

 ifeq ($(uname_S),SunOS)
 	# SunOS
+        ifneq ($(@@),32bit)
+		CFLAGS+= -m64
+		LDFLAGS+= -m64
+	endif
+	DEBUG=-g
+	DEBUG_FLAGS=-g
+	export CFLAGS LDFLAGS DEBUG DEBUG_FLAGS
 	INSTALL=cp -pf
 	FINAL_CFLAGS+= -D__EXTENSIONS__ -D_XPG6
 	FINAL_LIBS+= -ldl -lnsl -lsocket -lresolv -lpthread -lrt
@@ -128,14 +144,13 @@ endif

 REDIS_SERVER_NAME=redis-server
 REDIS_SENTINEL_NAME=redis-sentinel
-REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o
+REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o redis-check-aof.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o defrag.o siphash.o rax.o t_stream.o listpack.c
 REDIS_CLI_NAME=redis-cli
 REDIS_CLI_OBJ=anet.o adlist.o redis-cli.o zmalloc.o release.o anet.o ae.o crc64.o
 REDIS_BENCHMARK_NAME=redis-benchmark
 REDIS_BENCHMARK_OBJ=ae.o anet.o redis-benchmark.o adlist.o zmalloc.o redis-benchmark.o
 REDIS_CHECK_RDB_NAME=redis-check-rdb
 REDIS_CHECK_AOF_NAME=redis-check-aof
-REDIS_CHECK_AOF_OBJ=redis-check-aof.o

 all: $(REDIS_SERVER_NAME) $(REDIS_SENTINEL_NAME) $(REDIS_CLI_NAME) $(REDIS_BENCHMARK_NAME) $(REDIS_CHECK_RDB_NAME) $(REDIS_CHECK_AOF_NAME)
 	@echo ""
@@ -191,6 +206,10 @@ $(REDIS_SENTINEL_NAME): $(REDIS_SERVER_NAME)
 $(REDIS_CHECK_RDB_NAME): $(REDIS_SERVER_NAME)
 	$(REDIS_INSTALL) $(REDIS_SERVER_NAME) $(REDIS_CHECK_RDB_NAME)

+# redis-check-aof
+$(REDIS_CHECK_AOF_NAME): $(REDIS_SERVER_NAME)
+	$(REDIS_INSTALL) $(REDIS_SERVER_NAME) $(REDIS_CHECK_AOF_NAME)
+
 # redis-cli
 $(REDIS_CLI_NAME): $(REDIS_CLI_OBJ)
 	$(REDIS_LD) -o $@ $^ ../deps/hiredis/libhiredis.a ../deps/linenoise/linenoise.o $(FINAL_LIBS)
@@ -199,12 +218,8 @@ $(REDIS_CLI_NAME): $(REDIS_CLI_OBJ)
 $(REDIS_BENCHMARK_NAME): $(REDIS_BENCHMARK_OBJ)
 	$(REDIS_LD) -o $@ $^ ../deps/hiredis/libhiredis.a $(FINAL_LIBS)

-# redis-check-aof
-$(REDIS_CHECK_AOF_NAME): $(REDIS_CHECK_AOF_OBJ)
-	$(REDIS_LD) -o $@ $^ $(FINAL_LIBS)
-
-dict-benchmark: dict.c zmalloc.c sds.c
-	$(REDIS_CC) $(FINAL_CFLAGS) dict.c zmalloc.c sds.c -D DICT_BENCHMARK_MAIN -o dict-benchmark
+dict-benchmark: dict.c zmalloc.c sds.c siphash.c
+	$(REDIS_CC) $(FINAL_CFLAGS) $^ -D DICT_BENCHMARK_MAIN -o $@ $(FINAL_LIBS)

 # Because the jemalloc.h header is generated as a part of the jemalloc build,
 # building it should complete before building any other object. Instead of
@@ -238,7 +253,7 @@ lcov:
 	@genhtml --legend -o lcov-html redis.info

 test-sds: sds.c sds.h
-	$(REDIS_CC) sds.c zmalloc.c -DSDS_TEST_MAIN -o /tmp/sds_test
+	$(REDIS_CC) sds.c zmalloc.c -DSDS_TEST_MAIN $(FINAL_LIBS) -o /tmp/sds_test
 	/tmp/sds_test

 .PHONY: lcov
@@ -261,6 +276,9 @@ noopt:
 valgrind:
 	$(MAKE) OPTIMIZATION="-O0" MALLOC="libc"

+helgrind:
+	$(MAKE) OPTIMIZATION="-O0" MALLOC="libc" CFLAGS="-D__ATOMIC_VAR_FORCE_SYNC_MACROS"
+
 src/help.h:
 	@../utils/generate-command-help.rb > help.h

@@ -52,10 +52,8 @@ list *listCreate(void)
    return list;
 }

-/* Free the whole list.
- *
- * This function can't fail. */
-void listRelease(list *list)
+/* Remove all the elements from the list without destroying the list itself. */
+void listEmpty(list *list)
 {
    unsigned long len;
    listNode *current, *next;
@@ -68,6 +66,16 @@ void listRelease(list *list)
        zfree(current);
        current = next;
    }
+    list->head = list->tail = NULL;
+    list->len = 0;
+}
+
+/* Free the whole list.
+ *
+ * This function can't fail. */
+void listRelease(list *list)
+{
+    listEmpty(list);
    zfree(list);
 }

@@ -333,3 +341,22 @@ void listRotate(list *list) {
    tail->next = list->head;
    list->head = tail;
 }
+
+/* Add all the elements of the list 'o' at the end of the
+ * list 'l'. The list 'other' remains empty but otherwise valid. */
+void listJoin(list *l, list *o) {
+    if (o->head)
+        o->head->prev = l->tail;
+
+    if (l->tail)
+        l->tail->next = o->head;
+    else
+        l->head = o->head;
+
+    if (o->tail) l->tail = o->tail;
+    l->len += o->len;
+
+    /* Setup other as an empty list. */
+    o->head = o->tail = NULL;
+    o->len = 0;
+}
@@ -72,6 +72,7 @@ typedef struct list {
 /* Prototypes */
 list *listCreate(void);
 void listRelease(list *list);
+void listEmpty(list *list);
 list *listAddNodeHead(list *list, void *value);
 list *listAddNodeTail(list *list, void *value);
 list *listInsertNode(list *list, listNode *old_node, void *value, int after);
@@ -85,6 +86,7 @@ listNode *listIndex(list *list, long index);
 void listRewind(list *list, listIter *li);
 void listRewindTail(list *list, listIter *li);
 void listRotate(list *list);
+void listJoin(list *l, list *o);

 /* Directions for iterators */
 #define AL_START_HEAD 0
@@ -75,6 +75,7 @@ aeEventLoop *aeCreateEventLoop(int setsize) {
    eventLoop->stop = 0;
    eventLoop->maxfd = -1;
    eventLoop->beforesleep = NULL;
+    eventLoop->aftersleep = NULL;
    if (aeApiCreate(eventLoop) == -1) goto err;
    /* Events with mask == AE_NONE are not set. So let's initialize the
     * vector with it. */
@@ -343,6 +344,7 @@ static int processTimeEvents(aeEventLoop *eventLoop) {
 * if flags has AE_FILE_EVENTS set, file events are processed.
 * if flags has AE_TIME_EVENTS set, time events are processed.
 * if flags has AE_DONT_WAIT set the function returns ASAP until all
+ * if flags has AE_CALL_AFTER_SLEEP set, the aftersleep callback is called.
 * the events that's possible to process without to wait are processed.
 *
 * The function returns the number of events processed. */
@@ -397,7 +399,14 @@ int aeProcessEvents(aeEventLoop *eventLoop, int flags)
            }
        }

+        /* Call the multiplexing API, will return only on timeout or when
+         * some event fires. */
        numevents = aeApiPoll(eventLoop, tvp);
+
+        /* After sleep callback. */
+        if (eventLoop->aftersleep != NULL && flags & AE_CALL_AFTER_SLEEP)
+            eventLoop->aftersleep(eventLoop);
+
        for (j = 0; j < numevents; j++) {
            aeFileEvent *fe = &eventLoop->events[eventLoop->fired[j].fd];
            int mask = eventLoop->fired[j].mask;
@@ -452,7 +461,7 @@ void aeMain(aeEventLoop *eventLoop) {
    while (!eventLoop->stop) {
        if (eventLoop->beforesleep != NULL)
            eventLoop->beforesleep(eventLoop);
-        aeProcessEvents(eventLoop, AE_ALL_EVENTS);
+        aeProcessEvents(eventLoop, AE_ALL_EVENTS|AE_CALL_AFTER_SLEEP);
    }
 }

@@ -463,3 +472,7 @@ char *aeGetApiName(void) {
 void aeSetBeforeSleepProc(aeEventLoop *eventLoop, aeBeforeSleepProc *beforesleep) {
    eventLoop->beforesleep = beforesleep;
 }
+
+void aeSetAfterSleepProc(aeEventLoop *eventLoop, aeBeforeSleepProc *aftersleep) {
+    eventLoop->aftersleep = aftersleep;
+}
@@ -46,6 +46,7 @@
 #define AE_TIME_EVENTS 2
 #define AE_ALL_EVENTS (AE_FILE_EVENTS|AE_TIME_EVENTS)
 #define AE_DONT_WAIT 4
+#define AE_CALL_AFTER_SLEEP 8

 #define AE_NOMORE -1
 #define AE_DELETED_EVENT_ID -1
@@ -98,6 +99,7 @@ typedef struct aeEventLoop {
    int stop;
    void *apidata; /* This is used for polling API specific data */
    aeBeforeSleepProc *beforesleep;
+    aeBeforeSleepProc *aftersleep;
 } aeEventLoop;

 /* Prototypes */
@@ -117,6 +119,7 @@ int aeWait(int fd, int mask, long long milliseconds);
 void aeMain(aeEventLoop *eventLoop);
 char *aeGetApiName(void);
 void aeSetBeforeSleepProc(aeEventLoop *eventLoop, aeBeforeSleepProc *beforesleep);
+void aeSetAfterSleepProc(aeEventLoop *eventLoop, aeBeforeSleepProc *aftersleep);
 int aeGetSetSize(aeEventLoop *eventLoop);
 int aeResizeSetSize(aeEventLoop *eventLoop, int setsize);

@@ -237,7 +237,7 @@ int anetResolveIP(char *err, char *host, char *ipbuf, size_t ipbuf_len) {

 static int anetSetReuseAddr(char *err, int fd) {
    int yes = 1;
-    /* Make sure connection-intensive things like the redis benckmark
+    /* Make sure connection-intensive things like the redis benchmark
     * will be able to close/open sockets a zillion of times */
    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1) {
        anetSetError(err, "setsockopt SO_REUSEADDR: %s", strerror(errno));
@@ -380,8 +380,10 @@ int anetUnixGenericConnect(char *err, char *path, int flags)
    sa.sun_family = AF_LOCAL;
    strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);
    if (flags & ANET_CONNECT_NONBLOCK) {
-        if (anetNonBlock(err,s) != ANET_OK)
+        if (anetNonBlock(err,s) != ANET_OK) {
+            close(s);
            return ANET_ERR;
+        }
    }
    if (connect(s,(struct sockaddr*)&sa,sizeof(sa)) == -1) {
        if (errno == EINPROGRESS &&
@@ -462,7 +464,7 @@ static int anetV6Only(char *err, int s) {

 static int _anetTcpServer(char *err, int port, char *bindaddr, int af, int backlog)
 {
-    int s, rv;
+    int s = -1, rv;
    char _port[6];  /* strlen("65535") */
    struct addrinfo hints, *servinfo, *p;

@@ -491,6 +493,7 @@ static int _anetTcpServer(char *err, int port, char *bindaddr, int af, int backl
    }

 error:
+    if (s != -1) close(s);
    s = ANET_ERR;
 end:
    freeaddrinfo(servinfo);
@@ -115,6 +115,7 @@ void aofChildWriteDiffData(aeEventLoop *el, int fd, void *privdata, int mask) {
            if (nwritten <= 0) return;
            memmove(block->buf,block->buf+nwritten,block->used-nwritten);
            block->used -= nwritten;
+            block->free += nwritten;
        }
        if (block->used == 0) listDelNode(server.aof_rewrite_buf_blocks,ln);
    }
@@ -236,11 +237,11 @@ void stopAppendOnly(void) {
 * at runtime using the CONFIG command. */
 int startAppendOnly(void) {
    char cwd[MAXPATHLEN]; /* Current working dir path for error messages. */
+    int newfd;

-    server.aof_last_fsync = server.unixtime;
-    server.aof_fd = open(server.aof_filename,O_WRONLY|O_APPEND|O_CREAT,0644);
+    newfd = open(server.aof_filename,O_WRONLY|O_APPEND|O_CREAT,0644);
    serverAssert(server.aof_state == AOF_OFF);
-    if (server.aof_fd == -1) {
+    if (newfd == -1) {
        char *cwdp = getcwd(cwd,MAXPATHLEN);

        serverLog(LL_WARNING,
@@ -255,16 +256,46 @@ int startAppendOnly(void) {
        server.aof_rewrite_scheduled = 1;
        serverLog(LL_WARNING,"AOF was enabled but there is already a child process saving an RDB file on disk. An AOF background was scheduled to start when possible.");
    } else if (rewriteAppendOnlyFileBackground() == C_ERR) {
-        close(server.aof_fd);
+        close(newfd);
        serverLog(LL_WARNING,"Redis needs to enable the AOF but can't trigger a background AOF rewrite operation. Check the above logs for more info about the error.");
        return C_ERR;
    }
    /* We correctly switched on AOF, now wait for the rewrite to be complete
     * in order to append data on disk. */
    server.aof_state = AOF_WAIT_REWRITE;
+    server.aof_last_fsync = server.unixtime;
+    server.aof_fd = newfd;
    return C_OK;
 }

+/* This is a wrapper to the write syscall in order to retry on short writes
+ * or if the syscall gets interrupted. It could look strange that we retry
+ * on short writes given that we are writing to a block device: normally if
+ * the first call is short, there is a end-of-space condition, so the next
+ * is likely to fail. However apparently in modern systems this is no longer
+ * true, and in general it looks just more resilient to retry the write. If
+ * there is an actual error condition we'll get it at the next try. */
+ssize_t aofWrite(int fd, const char *buf, size_t len) {
+    ssize_t nwritten = 0, totwritten = 0;
+
+    while(len) {
+        nwritten = write(fd, buf, len);
+
+        if (nwritten < 0) {
+            if (errno == EINTR) {
+                continue;
+            }
+            return totwritten ? totwritten : -1;
+        }
+
+        len -= nwritten;
+        buf += nwritten;
+        totwritten += nwritten;
+    }
+
+    return totwritten;
+}
+
 /* Write the append only file buffer on disk.
 *
 * Since we are required to write the AOF before replying to the client,
@@ -322,7 +353,7 @@ void flushAppendOnlyFile(int force) {
     * or alike */

    latencyStartMonitor(latency);
-    nwritten = write(server.aof_fd,server.aof_buf,sdslen(server.aof_buf));
+    nwritten = aofWrite(server.aof_fd,server.aof_buf,sdslen(server.aof_buf));
    latencyEndMonitor(latency);
    /* We want to capture different events for delayed writes:
     * when the delay happens with a pending fsync, or with a saving child
@@ -341,7 +372,7 @@ void flushAppendOnlyFile(int force) {
    /* We performed the write so reset the postponed flush sentinel to zero. */
    server.aof_flush_postponed_start = 0;

-    if (nwritten != (signed)sdslen(server.aof_buf)) {
+    if (nwritten != (ssize_t)sdslen(server.aof_buf)) {
        static time_t last_write_error_log = 0;
        int can_log = 0;

@@ -535,6 +566,22 @@ void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int a
        buf = catAppendOnlyGenericCommand(buf,3,tmpargv);
        decrRefCount(tmpargv[0]);
        buf = catAppendOnlyExpireAtCommand(buf,cmd,argv[1],argv[2]);
+    } else if (cmd->proc == setCommand && argc > 3) {
+        int i;
+        robj *exarg = NULL, *pxarg = NULL;
+        /* Translate SET [EX seconds][PX milliseconds] to SET and PEXPIREAT */
+        buf = catAppendOnlyGenericCommand(buf,3,argv);
+        for (i = 3; i < argc; i ++) {
+            if (!strcasecmp(argv[i]->ptr, "ex")) exarg = argv[i+1];
+            if (!strcasecmp(argv[i]->ptr, "px")) pxarg = argv[i+1];
+        }
+        serverAssert(!(exarg && pxarg));
+        if (exarg)
+            buf = catAppendOnlyExpireAtCommand(buf,server.expireCommand,argv[1],
+                                               exarg);
+        if (pxarg)
+            buf = catAppendOnlyExpireAtCommand(buf,server.pexpireCommand,argv[1],
+                                               pxarg);
    } else {
        /* All the other commands don't need translation or need the
         * same translation already operated in the command vector
@@ -653,7 +700,7 @@ int loadAppendOnlyFile(char *filename) {
        serverLog(LL_NOTICE,"Reading RDB preamble from AOF file...");
        if (fseek(fp,0,SEEK_SET) == -1) goto readerr;
        rioInitWithFile(&rdb,fp);
-        if (rdbLoadRio(&rdb) != C_OK) {
+        if (rdbLoadRio(&rdb,NULL) != C_OK) {
            serverLog(LL_WARNING,"Error reading the RDB preamble of the AOF file, AOF loading aborted");
            goto readerr;
        } else {
@@ -1014,6 +1061,37 @@ int rewriteHashObject(rio *r, robj *key, robj *o) {
    return 1;
 }

+/* Emit the commands needed to rebuild a stream object.
+ * The function returns 0 on error, 1 on success. */
+int rewriteStreamObject(rio *r, robj *key, robj *o) {
+    streamIterator si;
+    streamIteratorStart(&si,o->ptr,NULL,NULL,0);
+    streamID id;
+    int64_t numfields;
+
+    while(streamIteratorGetID(&si,&id,&numfields)) {
+        /* Emit a two elements array for each item. The first is
+         * the ID, the second is an array of field-value pairs. */
+
+        /* Emit the XADD <key> <id> ...fields... command. */
+        if (rioWriteBulkCount(r,'*',3+numfields*2) == 0) return 0;
+        if (rioWriteBulkString(r,"XADD",4) == 0) return 0;
+        if (rioWriteBulkObject(r,key) == 0) return 0;
+        sds replyid = sdscatfmt(sdsempty(),"%U.%U",id.ms,id.seq);
+        if (rioWriteBulkString(r,replyid,sdslen(replyid)) == 0) return 0;
+        sdsfree(replyid);
+        while(numfields--) {
+            unsigned char *field, *value;
+            int64_t field_len, value_len;
+            streamIteratorGetField(&si,&field,&value,&field_len,&value_len);
+            if (rioWriteBulkString(r,(char*)field,field_len) == 0) return 0;
+            if (rioWriteBulkString(r,(char*)value,value_len) == 0) return 0;
+        }
+    }
+    streamIteratorStop(&si);
+    return 1;
+}
+
 /* Call the module type callback in order to rewrite a data type
 * that is exported by a module and is not handled by Redis itself.
 * The function returns 0 on error, 1 on success. */
@@ -1094,6 +1172,8 @@ int rewriteAppendOnlyFileRio(rio *aof) {
                if (rewriteSortedSetObject(aof,&key,o) == 0) goto werr;
            } else if (o->type == OBJ_HASH) {
                if (rewriteHashObject(aof,&key,o) == 0) goto werr;
+            } else if (o->type == OBJ_STREAM) {
+                if (rewriteStreamObject(aof,&key,o) == 0) goto werr;
            } else if (o->type == OBJ_MODULE) {
                if (rewriteModuleObject(aof,&key,o) == 0) goto werr;
            } else {
@@ -1152,7 +1232,7 @@ int rewriteAppendOnlyFile(char *filename) {

    if (server.aof_use_rdb_preamble) {
        int error;
-        if (rdbSaveRio(&aof,&error,RDB_SAVE_AOF_PREAMBLE) == C_ERR) {
+        if (rdbSaveRio(&aof,&error,RDB_SAVE_AOF_PREAMBLE,NULL) == C_ERR) {
            errno = error;
            goto werr;
        }
@@ -1357,6 +1437,7 @@ int rewriteAppendOnlyFileBackground(void) {
            serverLog(LL_WARNING,
                "Can't rewrite append only file in background: fork: %s",
                strerror(errno));
+            aofClosePipes();
            return C_ERR;
        }
        serverLog(LL_NOTICE,
@@ -3,18 +3,29 @@
 *
 * The exported interaface is composed of three macros:
 *
- * atomicIncr(var,count,mutex) -- Increment the atomic counter
- * atomicDecr(var,count,mutex) -- Decrement the atomic counter
- * atomicGet(var,dstvar,mutex) -- Fetch the atomic counter value
+ * atomicIncr(var,count) -- Increment the atomic counter
+ * atomicGetIncr(var,oldvalue_var,count) -- Get and increment the atomic counter
+ * atomicDecr(var,count) -- Decrement the atomic counter
+ * atomicGet(var,dstvar) -- Fetch the atomic counter value
+ * atomicSet(var,value)  -- Set the atomic counter value
+ *
+ * The variable 'var' should also have a declared mutex with the same
+ * name and the "_mutex" postfix, for instance:
+ *
+ *  long myvar;
+ *  pthread_mutex_t myvar_mutex;
+ *  atomicSet(myvar,12345);
 *
 * If atomic primitives are availble (tested in config.h) the mutex
 * is not used.
 *
- * Never use return value from the macros. To update and get use instead:
+ * Never use return value from the macros, instead use the AtomicGetIncr()
+ * if you need to get the current value and increment it atomically, like
+ * in the followign example:
 *
- *  atomicIncr(mycounter,...);
- *  atomicGet(mycounter,newvalue);
- *  doSomethingWith(newvalue);
+ *  long oldvalue;
+ *  atomicGetIncr(myvar,oldvalue,1);
+ *  doSomethingWith(oldvalue);
 *
 * ----------------------------------------------------------------------------
 *
@@ -51,44 +62,72 @@
 #ifndef __ATOMIC_VAR_H
 #define __ATOMIC_VAR_H

-#if defined(__ATOMIC_RELAXED)
+/* To test Redis with Helgrind (a Valgrind tool) it is useful to define
+ * the following macro, so that __sync macros are used: those can be detected
+ * by Helgrind (even if they are less efficient) so that no false positive
+ * is reported. */
+// #define __ATOMIC_VAR_FORCE_SYNC_MACROS
+
+#if !defined(__ATOMIC_VAR_FORCE_SYNC_MACROS) && defined(__ATOMIC_RELAXED) && !defined(__sun) && (!defined(__clang__) || !defined(__APPLE__) || __apple_build_version__ > 4210057)
 /* Implementation using __atomic macros. */

-#define atomicIncr(var,count,mutex) __atomic_add_fetch(&var,(count),__ATOMIC_RELAXED)
-#define atomicDecr(var,count,mutex) __atomic_sub_fetch(&var,(count),__ATOMIC_RELAXED)
-#define atomicGet(var,dstvar,mutex) do { \
+#define atomicIncr(var,count) __atomic_add_fetch(&var,(count),__ATOMIC_RELAXED)
+#define atomicGetIncr(var,oldvalue_var,count) do { \
+    oldvalue_var = __atomic_fetch_add(&var,(count),__ATOMIC_RELAXED); \
+} while(0)
+#define atomicDecr(var,count) __atomic_sub_fetch(&var,(count),__ATOMIC_RELAXED)
+#define atomicGet(var,dstvar) do { \
    dstvar = __atomic_load_n(&var,__ATOMIC_RELAXED); \
 } while(0)
+#define atomicSet(var,value) __atomic_store_n(&var,value,__ATOMIC_RELAXED)
+#define REDIS_ATOMIC_API "atomic-builtin"

 #elif defined(HAVE_ATOMIC)
 /* Implementation using __sync macros. */

-#define atomicIncr(var,count,mutex) __sync_add_and_fetch(&var,(count))
-#define atomicDecr(var,count,mutex) __sync_sub_and_fetch(&var,(count))
-#define atomicGet(var,dstvar,mutex) do { \
+#define atomicIncr(var,count) __sync_add_and_fetch(&var,(count))
+#define atomicGetIncr(var,oldvalue_var,count) do { \
+    oldvalue_var = __sync_fetch_and_add(&var,(count)); \
+} while(0)
+#define atomicDecr(var,count) __sync_sub_and_fetch(&var,(count))
+#define atomicGet(var,dstvar) do { \
    dstvar = __sync_sub_and_fetch(&var,0); \
 } while(0)
+#define atomicSet(var,value) do { \
+    while(!__sync_bool_compare_and_swap(&var,var,value)); \
+} while(0)
+#define REDIS_ATOMIC_API "sync-builtin"

 #else
 /* Implementation using pthread mutex. */

-#define atomicIncr(var,count,mutex) do { \
-    pthread_mutex_lock(&mutex); \
+#define atomicIncr(var,count) do { \
+    pthread_mutex_lock(&var ## _mutex); \
    var += (count); \
-    pthread_mutex_unlock(&mutex); \
+    pthread_mutex_unlock(&var ## _mutex); \
 } while(0)
-
-#define atomicDecr(var,count,mutex) do { \
-    pthread_mutex_lock(&mutex); \
+#define atomicGetIncr(var,oldvalue_var,count) do { \
+    pthread_mutex_lock(&var ## _mutex); \
+    oldvalue_var = var; \
+    var += (count); \
+    pthread_mutex_unlock(&var ## _mutex); \
+} while(0)
+#define atomicDecr(var,count) do { \
+    pthread_mutex_lock(&var ## _mutex); \
    var -= (count); \
-    pthread_mutex_unlock(&mutex); \
+    pthread_mutex_unlock(&var ## _mutex); \
 } while(0)
-
-#define atomicGet(var,dstvar,mutex) do { \
-    pthread_mutex_lock(&mutex); \
+#define atomicGet(var,dstvar) do { \
+    pthread_mutex_lock(&var ## _mutex); \
    dstvar = var; \
-    pthread_mutex_unlock(&mutex); \
+    pthread_mutex_unlock(&var ## _mutex); \
 } while(0)
-#endif
+#define atomicSet(var,value) do { \
+    pthread_mutex_lock(&var ## _mutex); \
+    var = value; \
+    pthread_mutex_unlock(&var ## _mutex); \
+} while(0)
+#define REDIS_ATOMIC_API "pthread-mutex"

+#endif
 #endif /* __ATOMIC_VAR_H */
@@ -104,6 +104,7 @@ long redisBitpos(void *s, unsigned long count, int bit) {
    unsigned long skipval, word = 0, one;
    long pos = 0; /* Position of bit, to return to the caller. */
    unsigned long j;
+    int found;

    /* Process whole words first, seeking for first word that is not
     * all ones or all zeros respectively if we are lookig for zeros
@@ -117,21 +118,27 @@ long redisBitpos(void *s, unsigned long count, int bit) {
    /* Skip initial bits not aligned to sizeof(unsigned long) byte by byte. */
    skipval = bit ? 0 : UCHAR_MAX;
    c = (unsigned char*) s;
+    found = 0;
    while((unsigned long)c & (sizeof(*l)-1) && count) {
-        if (*c != skipval) break;
+        if (*c != skipval) {
+            found = 1;
+            break;
+        }
        c++;
        count--;
        pos += 8;
    }

    /* Skip bits with full word step. */
-    skipval = bit ? 0 : ULONG_MAX;
    l = (unsigned long*) c;
-    while (count >= sizeof(*l)) {
-        if (*l != skipval) break;
-        l++;
-        count -= sizeof(*l);
-        pos += sizeof(*l)*8;
+    if (!found) {
+        skipval = bit ? 0 : ULONG_MAX;
+        while (count >= sizeof(*l)) {
+            if (*l != skipval) break;
+            l++;
+            count -= sizeof(*l);
+            pos += sizeof(*l)*8;
+        }
    }

    /* Load bytes into "word" considering the first byte as the most significant
@@ -654,8 +661,11 @@ void bitopCommand(client *c) {

        /* Fast path: as far as we have data for all the input bitmaps we
         * can take a fast path that performs much better than the
-         * vanilla algorithm. */
+         * vanilla algorithm. On ARM we skip the fast path since it will
+         * result in GCC compiling the code using multiple-words load/store
+         * operations that are not supported even in ARM >= v6. */
        j = 0;
+        #ifndef USE_ALIGNED_ACCESS
        if (minlen >= sizeof(unsigned long)*4 && numkeys <= 16) {
            unsigned long *lp[16];
            unsigned long *lres = (unsigned long*) res;
@@ -716,6 +726,7 @@ void bitopCommand(client *c) {
                }
            }
        }
+        #endif

        /* j is set to the next byte to process by the previous loop. */
        for (; j < maxlen; j++) {
@@ -907,7 +918,7 @@ void bitfieldCommand(client *c) {
    struct bitfieldOp *ops = NULL; /* Array of ops to execute at end. */
    int owtype = BFOVERFLOW_WRAP; /* Overflow type. */
    int readonly = 1;
-    long higest_write_offset = 0;
+    size_t higest_write_offset = 0;

    for (j = 2; j < c->argc; j++) {
        int remargs = c->argc-j-1; /* Remaining args other than current. */
@@ -957,7 +968,8 @@ void bitfieldCommand(client *c) {

        if (opcode != BITFIELDOP_GET) {
            readonly = 0;
-            higest_write_offset = bitoffset + bits - 1;
+            if (higest_write_offset < bitoffset + bits - 1)
+                higest_write_offset = bitoffset + bits - 1;
            /* INCRBY and SET require another argument. */
            if (getLongLongFromObjectOrReply(c,c->argv[j+3],&i64,NULL) != C_OK){
                zfree(ops);
@@ -65,6 +65,8 @@

 #include "server.h"

+int serveClientBlockedOnList(client *receiver, robj *key, robj *dstkey, redisDb *db, robj *value, int where);
+
 /* Get a timeout value from an object and store it into 'timeout'.
 * The final timeout is always stored as milliseconds as a time where the
 * timeout will expire, however the parsing is performed according to
@@ -100,7 +102,8 @@ int getTimeoutFromObjectOrReply(client *c, robj *object, mstime_t *timeout, int
 void blockClient(client *c, int btype) {
    c->flags |= CLIENT_BLOCKED;
    c->btype = btype;
-    server.bpop_blocked_clients++;
+    server.blocked_clients++;
+    server.blocked_clients_by_type[btype]++;
 }

 /* This function is called in the beforeSleep() function of the event loop
@@ -132,18 +135,21 @@ void processUnblockedClients(void) {
 /* Unblock a client calling the right function depending on the kind
 * of operation the client is blocking for. */
 void unblockClient(client *c) {
-    if (c->btype == BLOCKED_LIST) {
+    if (c->btype == BLOCKED_LIST || c->btype == BLOCKED_STREAM) {
        unblockClientWaitingData(c);
    } else if (c->btype == BLOCKED_WAIT) {
        unblockClientWaitingReplicas(c);
+    } else if (c->btype == BLOCKED_MODULE) {
+        unblockClientFromModule(c);
    } else {
        serverPanic("Unknown btype in unblockClient().");
    }
    /* Clear the flags, and put the client in the unblocked list so that
     * we'll process new commands in its query buffer ASAP. */
+    server.blocked_clients--;
+    server.blocked_clients_by_type[c->btype]--;
    c->flags &= ~CLIENT_BLOCKED;
    c->btype = BLOCKED_NONE;
-    server.bpop_blocked_clients--;
    /* The client may already be into the unblocked list because of a previous
     * blocking operation, don't add back it into the list multiple times. */
    if (!(c->flags & CLIENT_UNBLOCKED)) {
@@ -153,12 +159,15 @@ void unblockClient(client *c) {
 }

 /* This function gets called when a blocked client timed out in order to
- * send it a reply of some kind. */
+ * send it a reply of some kind. After this function is called,
+ * unblockClient() will be called with the same client as argument. */
 void replyToBlockedClientTimedOut(client *c) {
-    if (c->btype == BLOCKED_LIST) {
+    if (c->btype == BLOCKED_LIST || c->btype == BLOCKED_STREAM) {
        addReply(c,shared.nullmultibulk);
    } else if (c->btype == BLOCKED_WAIT) {
        addReplyLongLong(c,replicationCountAcksByOffset(c->bpop.reploffset));
+    } else if (c->btype == BLOCKED_MODULE) {
+        moduleBlockedClientTimedOut(c);
    } else {
        serverPanic("Unknown btype in replyToBlockedClientTimedOut().");
    }
@@ -188,3 +197,283 @@ void disconnectAllBlockedClients(void) {
        }
    }
 }
+
+/* This function should be called by Redis every time a single command,
+ * a MULTI/EXEC block, or a Lua script, terminated its execution after
+ * being called by a client.
+ *
+ * All the keys with at least one client blocked that received at least
+ * one new element via some PUSH/XADD operation are accumulated into
+ * the server.ready_keys list. This function will run the list and will
+ * serve clients accordingly. Note that the function will iterate again and
+ * again as a result of serving BRPOPLPUSH we can have new blocking clients
+ * to serve because of the PUSH side of BRPOPLPUSH. */
+void handleClientsBlockedOnKeys(void) {
+    while(listLength(server.ready_keys) != 0) {
+        list *l;
+
+        /* Point server.ready_keys to a fresh list and save the current one
+         * locally. This way as we run the old list we are free to call
+         * signalKeyAsReady() that may push new elements in server.ready_keys
+         * when handling clients blocked into BRPOPLPUSH. */
+        l = server.ready_keys;
+        server.ready_keys = listCreate();
+
+        while(listLength(l) != 0) {
+            listNode *ln = listFirst(l);
+            readyList *rl = ln->value;
+
+            /* First of all remove this key from db->ready_keys so that
+             * we can safely call signalKeyAsReady() against this key. */
+            dictDelete(rl->db->ready_keys,rl->key);
+
+            /* Serve clients blocked on list key. */
+            robj *o = lookupKeyWrite(rl->db,rl->key);
+            if (o != NULL && o->type == OBJ_LIST) {
+                dictEntry *de;
+
+                /* We serve clients in the same order they blocked for
+                 * this key, from the first blocked to the last. */
+                de = dictFind(rl->db->blocking_keys,rl->key);
+                if (de) {
+                    list *clients = dictGetVal(de);
+                    int numclients = listLength(clients);
+
+                    while(numclients--) {
+                        listNode *clientnode = listFirst(clients);
+                        client *receiver = clientnode->value;
+
+                        if (receiver->btype != BLOCKED_LIST) {
+                            /* Put on the tail, so that at the next call
+                             * we'll not run into it again. */
+                            listDelNode(clients,clientnode);
+                            listAddNodeTail(clients,receiver);
+                            continue;
+                        }
+
+                        robj *dstkey = receiver->bpop.target;
+                        int where = (receiver->lastcmd &&
+                                     receiver->lastcmd->proc == blpopCommand) ?
+                                    LIST_HEAD : LIST_TAIL;
+                        robj *value = listTypePop(o,where);
+
+                        if (value) {
+                            /* Protect receiver->bpop.target, that will be
+                             * freed by the next unblockClient()
+                             * call. */
+                            if (dstkey) incrRefCount(dstkey);
+                            unblockClient(receiver);
+
+                            if (serveClientBlockedOnList(receiver,
+                                rl->key,dstkey,rl->db,value,
+                                where) == C_ERR)
+                            {
+                                /* If we failed serving the client we need
+                                 * to also undo the POP operation. */
+                                    listTypePush(o,value,where);
+                            }
+
+                            if (dstkey) decrRefCount(dstkey);
+                            decrRefCount(value);
+                        } else {
+                            break;
+                        }
+                    }
+                }
+
+                if (listTypeLength(o) == 0) {
+                    dbDelete(rl->db,rl->key);
+                }
+                /* We don't call signalModifiedKey() as it was already called
+                 * when an element was pushed on the list. */
+            }
+
+            /* Serve clients blocked on stream key. */
+            else if (o != NULL && o->type == OBJ_STREAM) {
+                dictEntry *de = dictFind(rl->db->blocking_keys,rl->key);
+                stream *s = o->ptr;
+
+                /* We need to provide the new data arrived on the stream
+                 * to all the clients that are waiting for an offset smaller
+                 * than the current top item. */
+                if (de) {
+                    list *clients = dictGetVal(de);
+                    listNode *ln;
+                    listIter li;
+                    listRewind(clients,&li);
+
+                    while((ln = listNext(&li))) {
+                        client *receiver = listNodeValue(ln);
+                        if (receiver->btype != BLOCKED_STREAM) continue;
+                        streamID *gt = dictFetchValue(receiver->bpop.keys,
+                                                      rl->key);
+                        if (s->last_id.ms > gt->ms ||
+                            (s->last_id.ms == gt->ms &&
+                             s->last_id.seq > gt->seq))
+                        {
+                            streamID start = *gt;
+                            start.seq++; /* Can't overflow, it's an uint64_t */
+                            /* Note that after we unblock the client, 'gt'
+                             * is no longer valid, so we must do it after
+                             * we copied the ID into the 'start' variable. */
+                            unblockClient(receiver);
+
+                            /* Emit the two elements sub-array consisting of
+                             * the name of the stream and the data we
+                             * extracted from it. Wrapped in a single-item
+                             * array, since we have just one key. */
+                            addReplyMultiBulkLen(receiver,1);
+                            addReplyMultiBulkLen(receiver,2);
+                            addReplyBulk(receiver,rl->key);
+                            streamReplyWithRange(receiver,s,&start,NULL,
+                                                 receiver->bpop.xread_count,0);
+                        }
+                    }
+                }
+            }
+
+            /* Free this item. */
+            decrRefCount(rl->key);
+            zfree(rl);
+            listDelNode(l,ln);
+        }
+        listRelease(l); /* We have the new list on place at this point. */
+    }
+}
+
+/* This is how the current blocking lists/streams work, we use BLPOP as
+ * example, but the concept is the same for other list ops and XREAD.
+ * - If the user calls BLPOP and the key exists and contains a non empty list
+ *   then LPOP is called instead. So BLPOP is semantically the same as LPOP
+ *   if blocking is not required.
+ * - If instead BLPOP is called and the key does not exists or the list is
+ *   empty we need to block. In order to do so we remove the notification for
+ *   new data to read in the client socket (so that we'll not serve new
+ *   requests if the blocking request is not served). Also we put the client
+ *   in a dictionary (db->blocking_keys) mapping keys to a list of clients
+ *   blocking for this keys.
+ * - If a PUSH operation against a key with blocked clients waiting is
+ *   performed, we mark this key as "ready", and after the current command,
+ *   MULTI/EXEC block, or script, is executed, we serve all the clients waiting
+ *   for this list, from the one that blocked first, to the last, accordingly
+ *   to the number of elements we have in the ready list.
+ */
+
+/* Set a client in blocking mode for the specified key (list or stream), with
+ * the specified timeout. The 'type' argument is BLOCKED_LIST or BLOCKED_STREAM
+ * depending on the kind of operation we are waiting for an empty key in
+ * order to awake the client. The client is blocked for all the 'numkeys'
+ * keys as in the 'keys' argument. When we block for stream keys, we also
+ * provide an array of streamID structures: clients will be unblocked only
+ * when items with an ID greater or equal to the specified one is appended
+ * to the stream. */
+void blockForKeys(client *c, int btype, robj **keys, int numkeys, mstime_t timeout, robj *target, streamID *ids) {
+    dictEntry *de;
+    list *l;
+    int j;
+
+    c->bpop.timeout = timeout;
+    c->bpop.target = target;
+
+    if (target != NULL) incrRefCount(target);
+
+    for (j = 0; j < numkeys; j++) {
+        /* The value associated with the key name in the bpop.keys dictionary
+         * is NULL for lists, or the stream ID for streams. */
+        void *key_data = NULL;
+        if (btype == BLOCKED_STREAM) {
+            key_data = zmalloc(sizeof(streamID));
+            memcpy(key_data,ids+j,sizeof(streamID));
+        }
+
+        /* If the key already exists in the dictionary ignore it. */
+        if (dictAdd(c->bpop.keys,keys[j],key_data) != DICT_OK) {
+            zfree(key_data);
+            continue;
+        }
+        incrRefCount(keys[j]);
+
+        /* And in the other "side", to map keys -> clients */
+        de = dictFind(c->db->blocking_keys,keys[j]);
+        if (de == NULL) {
+            int retval;
+
+            /* For every key we take a list of clients blocked for it */
+            l = listCreate();
+            retval = dictAdd(c->db->blocking_keys,keys[j],l);
+            incrRefCount(keys[j]);
+            serverAssertWithInfo(c,keys[j],retval == DICT_OK);
+        } else {
+            l = dictGetVal(de);
+        }
+        listAddNodeTail(l,c);
+    }
+    blockClient(c,btype);
+}
+
+/* Unblock a client that's waiting in a blocking operation such as BLPOP.
+ * You should never call this function directly, but unblockClient() instead. */
+void unblockClientWaitingData(client *c) {
+    dictEntry *de;
+    dictIterator *di;
+    list *l;
+
+    serverAssertWithInfo(c,NULL,dictSize(c->bpop.keys) != 0);
+    di = dictGetIterator(c->bpop.keys);
+    /* The client may wait for multiple keys, so unblock it for every key. */
+    while((de = dictNext(di)) != NULL) {
+        robj *key = dictGetKey(de);
+
+        /* Remove this client from the list of clients waiting for this key. */
+        l = dictFetchValue(c->db->blocking_keys,key);
+        serverAssertWithInfo(c,key,l != NULL);
+        listDelNode(l,listSearchKey(l,c));
+        /* If the list is empty we need to remove it to avoid wasting memory */
+        if (listLength(l) == 0)
+            dictDelete(c->db->blocking_keys,key);
+    }
+    dictReleaseIterator(di);
+
+    /* Cleanup the client structure */
+    dictEmpty(c->bpop.keys,NULL);
+    if (c->bpop.target) {
+        decrRefCount(c->bpop.target);
+        c->bpop.target = NULL;
+    }
+    if (c->bpop.xread_group) {
+        decrRefCount(c->bpop.xread_group);
+        c->bpop.xread_group = NULL;
+    }
+}
+
+/* If the specified key has clients blocked waiting for list pushes, this
+ * function will put the key reference into the server.ready_keys list.
+ * Note that db->ready_keys is a hash table that allows us to avoid putting
+ * the same key again and again in the list in case of multiple pushes
+ * made by a script or in the context of MULTI/EXEC.
+ *
+ * The list will be finally processed by handleClientsBlockedOnLists() */
+void signalKeyAsReady(redisDb *db, robj *key) {
+    readyList *rl;
+
+    /* No clients blocking for this key? No need to queue it. */
+    if (dictFind(db->blocking_keys,key) == NULL) return;
+
+    /* Key was already signaled? No need to queue it again. */
+    if (dictFind(db->ready_keys,key) != NULL) return;
+
+    /* Ok, we need to queue this key into server.ready_keys. */
+    rl = zmalloc(sizeof(*rl));
+    rl->key = key;
+    rl->db = db;
+    incrRefCount(key);
+    listAddNodeTail(server.ready_keys,rl);
+
+    /* We also add the key in the db->ready_keys dictionary in order
+     * to avoid adding it multiple times into a list with a simple O(1)
+     * check. */
+    incrRefCount(key);
+    serverAssert(dictAdd(db->ready_keys,key,NULL) == DICT_OK);
+}
+
+
@@ -37,7 +37,6 @@
 #include <arpa/inet.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/file.h>
 #include <math.h>
@@ -129,7 +128,7 @@ int clusterLoadConfig(char *filename) {
        /* Skip blank lines, they can be created either by users manually
         * editing nodes.conf or by the config writing process if stopped
         * before the truncate() call. */
-        if (line[0] == '\n') continue;
+        if (line[0] == '\n' || line[0] == '\0') continue;

        /* Split the line into arguments for processing. */
        argv = sdssplitargs(line,&argc);
@@ -244,6 +243,7 @@ int clusterLoadConfig(char *filename) {
                *p = '\0';
                direction = p[1]; /* Either '>' or '<' */
                slot = atoi(argv[j]+1);
+                if (slot < 0 || slot >= CLUSTER_SLOTS) goto fmterr;
                p += 3;
                cn = clusterLookupNode(p);
                if (!cn) {
@@ -263,6 +263,8 @@ int clusterLoadConfig(char *filename) {
            } else {
                start = stop = atoi(argv[j]);
            }
+            if (start < 0 || start >= CLUSTER_SLOTS) goto fmterr;
+            if (stop < 0 || stop >= CLUSTER_SLOTS) goto fmterr;
            while(start <= stop) clusterAddSlot(n, start++);
        }

@@ -423,8 +425,11 @@ void clusterInit(void) {
    server.cluster->failover_auth_epoch = 0;
    server.cluster->cant_failover_reason = CLUSTER_CANT_FAILOVER_NONE;
    server.cluster->lastVoteEpoch = 0;
-    server.cluster->stats_bus_messages_sent = 0;
-    server.cluster->stats_bus_messages_received = 0;
+    for (int i = 0; i < CLUSTERMSG_TYPE_COUNT; i++) {
+        server.cluster->stats_bus_messages_sent[i] = 0;
+        server.cluster->stats_bus_messages_received[i] = 0;
+    }
+    server.cluster->stats_pfail_nodes = 0;
    memset(server.cluster->slots,0, sizeof(server.cluster->slots));
    clusterCloseAllSlots();

@@ -476,8 +481,10 @@ void clusterInit(void) {
        }
    }

-    /* The slots -> keys map is a sorted set. Init it. */
-    server.cluster->slots_to_keys = zslCreate();
+    /* The slots -> keys map is a radix tree. Initialize it here. */
+    server.cluster->slots_to_keys = raxNew();
+    memset(server.cluster->slots_keys_count,0,
+           sizeof(server.cluster->slots_keys_count));

    /* Set myself->port / cport to my listening ports, we'll just need to
     * discover the IP address via MEET messages. */
@@ -646,7 +653,7 @@ unsigned int keyHashSlot(char *key, int keylen) {
    for (e = s+1; e < keylen; e++)
        if (key[e] == '}') break;

-    /* No '}' or nothing betweeen {} ? Hash the whole key. */
+    /* No '}' or nothing between {} ? Hash the whole key. */
    if (e == keylen || e == s+1) return crc16(key,keylen) & 0x3FFF;

    /* If we are here there is both a { and a } on its right. Hash
@@ -1319,14 +1326,16 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
        clusterNode *node;
        sds ci;

-        ci = representClusterNodeFlags(sdsempty(), flags);
-        serverLog(LL_DEBUG,"GOSSIP %.40s %s:%d@%d %s",
-            g->nodename,
-            g->ip,
-            ntohs(g->port),
-            ntohs(g->cport),
-            ci);
-        sdsfree(ci);
+        if (server.verbosity == LL_DEBUG) {
+            ci = representClusterNodeFlags(sdsempty(), flags);
+            serverLog(LL_DEBUG,"GOSSIP %.40s %s:%d@%d %s",
+                g->nodename,
+                g->ip,
+                ntohs(g->port),
+                ntohs(g->cport),
+                ci);
+            sdsfree(ci);
+        }

        /* Update our state accordingly to the gossip sections */
        node = clusterLookupNode(g->nodename);
@@ -1350,6 +1359,28 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
                }
            }

+            /* If from our POV the node is up (no failure flags are set),
+             * we have no pending ping for the node, nor we have failure
+             * reports for this node, update the last pong time with the
+             * one we see from the other nodes. */
+            if (!(flags & (CLUSTER_NODE_FAIL|CLUSTER_NODE_PFAIL)) &&
+                node->ping_sent == 0 &&
+                clusterNodeFailureReportsCount(node) == 0)
+            {
+                mstime_t pongtime = ntohl(g->pong_received);
+                pongtime *= 1000; /* Convert back to milliseconds. */
+
+                /* Replace the pong time with the received one only if
+                 * it's greater than our view but is not in the future
+                 * (with 500 milliseconds tolerance) from the POV of our
+                 * clock. */
+                if (pongtime <= (server.mstime+500) &&
+                    pongtime > node->pong_received)
+                {
+                    node->pong_received = pongtime;
+                }
+            }
+
            /* If we already know this node, but it is not reachable, and
             * we see a different address in the gossip section of a node that
             * can talk with this other node, update the address, disconnect
@@ -1581,7 +1612,8 @@ int clusterProcessPacket(clusterLink *link) {
    uint32_t totlen = ntohl(hdr->totlen);
    uint16_t type = ntohs(hdr->type);

-    server.cluster->stats_bus_messages_received++;
+    if (type < CLUSTERMSG_TYPE_COUNT)
+        server.cluster->stats_bus_messages_received[type]++;
    serverLog(LL_DEBUG,"--- Processing packet of type %d, %lu bytes",
        type, (unsigned long) totlen);

@@ -2128,7 +2160,12 @@ void clusterSendMessage(clusterLink *link, unsigned char *msg, size_t msglen) {
                    clusterWriteHandler,link);

    link->sndbuf = sdscatlen(link->sndbuf, msg, msglen);
-    server.cluster->stats_bus_messages_sent++;
+
+    /* Populate sent messages stats. */
+    clusterMsg *hdr = (clusterMsg*) msg;
+    uint16_t type = ntohs(hdr->type);
+    if (type < CLUSTERMSG_TYPE_COUNT)
+        server.cluster->stats_bus_messages_sent[type]++;
 }

 /* Send a message to all the nodes that are part of the cluster having
@@ -2229,6 +2266,33 @@ void clusterBuildMessageHdr(clusterMsg *hdr, int type) {
    /* For PING, PONG, and MEET, fixing the totlen field is up to the caller. */
 }

+/* Return non zero if the node is already present in the gossip section of the
+ * message pointed by 'hdr' and having 'count' gossip entries. Otherwise
+ * zero is returned. Helper for clusterSendPing(). */
+int clusterNodeIsInGossipSection(clusterMsg *hdr, int count, clusterNode *n) {
+    int j;
+    for (j = 0; j < count; j++) {
+        if (memcmp(hdr->data.ping.gossip[j].nodename,n->name,
+                CLUSTER_NAMELEN) == 0) break;
+    }
+    return j != count;
+}
+
+/* Set the i-th entry of the gossip section in the message pointed by 'hdr'
+ * to the info of the specified node 'n'. */
+void clusterSetGossipEntry(clusterMsg *hdr, int i, clusterNode *n) {
+    clusterMsgDataGossip *gossip;
+    gossip = &(hdr->data.ping.gossip[i]);
+    memcpy(gossip->nodename,n->name,CLUSTER_NAMELEN);
+    gossip->ping_sent = htonl(n->ping_sent/1000);
+    gossip->pong_received = htonl(n->pong_received/1000);
+    memcpy(gossip->ip,n->ip,sizeof(n->ip));
+    gossip->port = htons(n->port);
+    gossip->cport = htons(n->cport);
+    gossip->flags = htons(n->flags);
+    gossip->notused1 = 0;
+}
+
 /* Send a PING or PONG packet to the specified node, making sure to add enough
 * gossip informations. */
 void clusterSendPing(clusterLink *link, int type) {
@@ -2273,11 +2337,15 @@ void clusterSendPing(clusterLink *link, int type) {
    if (wanted < 3) wanted = 3;
    if (wanted > freshnodes) wanted = freshnodes;

+    /* Include all the nodes in PFAIL state, so that failure reports are
+     * faster to propagate to go from PFAIL to FAIL state. */
+    int pfail_wanted = server.cluster->stats_pfail_nodes;
+
    /* Compute the maxium totlen to allocate our buffer. We'll fix the totlen
     * later according to the number of gossip sections we really were able
     * to put inside the packet. */
    totlen = sizeof(clusterMsg)-sizeof(union clusterMsgData);
-    totlen += (sizeof(clusterMsgDataGossip)*wanted);
+    totlen += (sizeof(clusterMsgDataGossip)*(wanted+pfail_wanted));
    /* Note: clusterBuildMessageHdr() expects the buffer to be always at least
     * sizeof(clusterMsg) or more. */
    if (totlen < (int)sizeof(clusterMsg)) totlen = sizeof(clusterMsg);
@@ -2294,17 +2362,13 @@ void clusterSendPing(clusterLink *link, int type) {
    while(freshnodes > 0 && gossipcount < wanted && maxiterations--) {
        dictEntry *de = dictGetRandomKey(server.cluster->nodes);
        clusterNode *this = dictGetVal(de);
-        clusterMsgDataGossip *gossip;
-        int j;

        /* Don't include this node: the whole packet header is about us
         * already, so we just gossip about other nodes. */
        if (this == myself) continue;

-        /* Give a bias to FAIL/PFAIL nodes. */
-        if (maxiterations > wanted*2 &&
-            !(this->flags & (CLUSTER_NODE_PFAIL|CLUSTER_NODE_FAIL)))
-            continue;
+        /* PFAIL nodes will be added later. */
+        if (this->flags & CLUSTER_NODE_PFAIL) continue;

        /* In the gossip section don't include:
         * 1) Nodes in HANDSHAKE state.
@@ -2318,27 +2382,37 @@ void clusterSendPing(clusterLink *link, int type) {
            continue;
        }

-        /* Check if we already added this node */
-        for (j = 0; j < gossipcount; j++) {
-            if (memcmp(hdr->data.ping.gossip[j].nodename,this->name,
-                    CLUSTER_NAMELEN) == 0) break;
-        }
-        if (j != gossipcount) continue;
+        /* Do not add a node we already have. */
+        if (clusterNodeIsInGossipSection(hdr,gossipcount,this)) continue;

        /* Add it */
+        clusterSetGossipEntry(hdr,gossipcount,this);
        freshnodes--;
-        gossip = &(hdr->data.ping.gossip[gossipcount]);
-        memcpy(gossip->nodename,this->name,CLUSTER_NAMELEN);
-        gossip->ping_sent = htonl(this->ping_sent);
-        gossip->pong_received = htonl(this->pong_received);
-        memcpy(gossip->ip,this->ip,sizeof(this->ip));
-        gossip->port = htons(this->port);
-        gossip->cport = htons(this->cport);
-        gossip->flags = htons(this->flags);
-        gossip->notused1 = 0;
        gossipcount++;
    }

+    /* If there are PFAIL nodes, add them at the end. */
+    if (pfail_wanted) {
+        dictIterator *di;
+        dictEntry *de;
+
+        di = dictGetSafeIterator(server.cluster->nodes);
+        while((de = dictNext(di)) != NULL && pfail_wanted > 0) {
+            clusterNode *node = dictGetVal(de);
+            if (node->flags & CLUSTER_NODE_HANDSHAKE) continue;
+            if (node->flags & CLUSTER_NODE_NOADDR) continue;
+            if (!(node->flags & CLUSTER_NODE_PFAIL)) continue;
+            clusterSetGossipEntry(hdr,gossipcount,node);
+            freshnodes--;
+            gossipcount++;
+            /* We take the count of the slots we allocated, since the
+             * PFAIL stats may not match perfectly with the current number
+             * of PFAIL nodes. */
+            pfail_wanted--;
+        }
+        dictReleaseIterator(di);
+    }
+
    /* Ready to send... fix the totlen fiend and queue the message in the
     * output buffer. */
    totlen = sizeof(clusterMsg)-sizeof(union clusterMsgData);
@@ -2774,7 +2848,7 @@ void clusterHandleSlaveFailover(void) {
     * and wait for replies), and the failover retry time (the time to wait
     * before trying to get voted again).
     *
-     * Timeout is MIN(NODE_TIMEOUT*2,2000) milliseconds.
+     * Timeout is MAX(NODE_TIMEOUT*2,2000) milliseconds.
     * Retry is two times the Timeout.
     */
    auth_timeout = server.cluster_node_timeout*2;
@@ -3164,13 +3238,21 @@ void clusterCron(void) {
    handshake_timeout = server.cluster_node_timeout;
    if (handshake_timeout < 1000) handshake_timeout = 1000;

-    /* Check if we have disconnected nodes and re-establish the connection. */
+    /* Check if we have disconnected nodes and re-establish the connection.
+     * Also update a few stats while we are here, that can be used to make
+     * better decisions in other part of the code. */
    di = dictGetSafeIterator(server.cluster->nodes);
+    server.cluster->stats_pfail_nodes = 0;
    while((de = dictNext(di)) != NULL) {
        clusterNode *node = dictGetVal(de);

+        /* Not interested in reconnecting the link with myself or nodes
+         * for which we have no address. */
        if (node->flags & (CLUSTER_NODE_MYSELF|CLUSTER_NODE_NOADDR)) continue;

+        if (node->flags & CLUSTER_NODE_PFAIL)
+            server.cluster->stats_pfail_nodes++;
+
        /* A Node in HANDSHAKE state has a limited lifespan equal to the
         * configured node timeout. */
        if (nodeInHandshake(node) && now - node->ctime > handshake_timeout) {
@@ -3523,8 +3605,10 @@ int clusterDelNodeSlots(clusterNode *node) {
    int deleted = 0, j;

    for (j = 0; j < CLUSTER_SLOTS; j++) {
-        if (clusterNodeGetSlotBit(node,j)) clusterDelSlot(j);
-        deleted++;
+        if (clusterNodeGetSlotBit(node,j)) {
+            clusterDelSlot(j);
+            deleted++;
+        }
    }
    return deleted;
 }
@@ -3758,15 +3842,14 @@ static struct redisNodeFlags redisNodeFlagsTable[] = {
 /* Concatenate the comma separated list of node flags to the given SDS
 * string 'ci'. */
 sds representClusterNodeFlags(sds ci, uint16_t flags) {
-    if (flags == 0) {
-        ci = sdscat(ci,"noflags,");
-    } else {
-        int i, size = sizeof(redisNodeFlagsTable)/sizeof(struct redisNodeFlags);
-        for (i = 0; i < size; i++) {
-            struct redisNodeFlags *nodeflag = redisNodeFlagsTable + i;
-            if (flags & nodeflag->flag) ci = sdscat(ci, nodeflag->name);
-        }
+    size_t orig_len = sdslen(ci);
+    int i, size = sizeof(redisNodeFlagsTable)/sizeof(struct redisNodeFlags);
+    for (i = 0; i < size; i++) {
+        struct redisNodeFlags *nodeflag = redisNodeFlagsTable + i;
+        if (flags & nodeflag->flag) ci = sdscat(ci, nodeflag->name);
    }
+    /* If no flag was added, add the "noflags" special flag. */
+    if (sdslen(ci) == orig_len) ci = sdscat(ci,"noflags,");
    sdsIncrLen(ci,-1); /* Remove trailing comma. */
    return ci;
 }
@@ -3875,6 +3958,21 @@ sds clusterGenNodesDescription(int filter) {
 * CLUSTER command
 * -------------------------------------------------------------------------- */

+const char *clusterGetMessageTypeString(int type) {
+    switch(type) {
+    case CLUSTERMSG_TYPE_PING: return "ping";
+    case CLUSTERMSG_TYPE_PONG: return "pong";
+    case CLUSTERMSG_TYPE_MEET: return "meet";
+    case CLUSTERMSG_TYPE_FAIL: return "fail";
+    case CLUSTERMSG_TYPE_PUBLISH: return "publish";
+    case CLUSTERMSG_TYPE_FAILOVER_AUTH_REQUEST: return "auth-req";
+    case CLUSTERMSG_TYPE_FAILOVER_AUTH_ACK: return "auth-ack";
+    case CLUSTERMSG_TYPE_UPDATE: return "update";
+    case CLUSTERMSG_TYPE_MFSTART: return "mfstart";
+    }
+    return "unknown";
+}
+
 int getSlotOrReply(client *c, robj *o) {
    long long slot;

@@ -3967,7 +4065,34 @@ void clusterCommand(client *c) {
        return;
    }

-    if (!strcasecmp(c->argv[1]->ptr,"meet") && (c->argc == 4 || c->argc == 5)) {
+    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
+        const char *help[] = {
+"addslots <slot> [slot ...] -- Assign slots to current node.",
+"bumpepoch -- Advance the cluster config epoch.",
+"count-failure-reports <node-id> -- Return number of failure reports for <node-id>.",
+"countkeysinslot <slot> - Return the number of keys in <slot>.",
+"delslots <slot> [slot ...] -- Delete slots information from current node.",
+"failover [force|takeover] -- Promote current slave node to being a master.",
+"forget <node-id> -- Remove a node from the cluster.",
+"getkeysinslot <slot> <count> -- Return key names stored by current node in a slot.",
+"flushslots -- Delete current node own slots information.",
+"info - Return onformation about the cluster.",
+"keyslot <key> -- Return the hash slot for <key>.",
+"meet <ip> <port> [bus-port] -- Connect nodes into a working cluster.",
+"myid -- Return the node id.",
+"nodes -- Return cluster configuration seen by node. Output format:",
+"    <id> <ip:port> <flags> <master> <pings> <pongs> <epoch> <link> <slot> ... <slot>",
+"replicate <node-id> -- Configure current node as slave to <node-id>.",
+"reset [hard|soft] -- Reset current node (default: soft).",
+"set-config-epoch <epoch> - Set config epoch of current node.",
+"setslot <slot> (importing|migrating|stable|node <node-id>) -- Set slot state.",
+"slaves <node-id> -- Return <node-id> slaves.",
+"slots -- Return information about slots range mappings. Each range is made of:",
+"    start, end, master and replicas IP addresses, ports and ids",
+NULL
+        };
+        addReplyHelp(c, help);
+    } else if (!strcasecmp(c->argv[1]->ptr,"meet") && (c->argc == 4 || c->argc == 5)) {
        /* CLUSTER MEET <ip> <port> [cport] */
        long long port, cport;

@@ -4102,7 +4227,7 @@ void clusterCommand(client *c) {
            }
            if ((n = clusterLookupNode(c->argv[4]->ptr)) == NULL) {
                addReplyErrorFormat(c,"I don't know about node %s",
-                    (char*)c->argv[3]->ptr);
+                    (char*)c->argv[4]->ptr);
                return;
            }
            server.cluster->importing_slots_from[slot] = n;
@@ -4160,7 +4285,7 @@ void clusterCommand(client *c) {
            clusterAddSlot(n,slot);
        } else {
            addReplyError(c,
-                "Invalid CLUSTER SETSLOT action or number of arguments");
+                "Invalid CLUSTER SETSLOT action or number of arguments. Try CLUSTER HELP");
            return;
        }
        clusterDoBeforeSleep(CLUSTER_TODO_SAVE_CONFIG|CLUSTER_TODO_UPDATE_STATE);
@@ -4206,8 +4331,6 @@ void clusterCommand(client *c) {
            "cluster_size:%d\r\n"
            "cluster_current_epoch:%llu\r\n"
            "cluster_my_epoch:%llu\r\n"
-            "cluster_stats_messages_sent:%lld\r\n"
-            "cluster_stats_messages_received:%lld\r\n"
            , statestr[server.cluster->state],
            slots_assigned,
            slots_ok,
@@ -4216,10 +4339,36 @@ void clusterCommand(client *c) {
            dictSize(server.cluster->nodes),
            server.cluster->size,
            (unsigned long long) server.cluster->currentEpoch,
-            (unsigned long long) myepoch,
-            server.cluster->stats_bus_messages_sent,
-            server.cluster->stats_bus_messages_received
+            (unsigned long long) myepoch
        );
+
+        /* Show stats about messages sent and received. */
+        long long tot_msg_sent = 0;
+        long long tot_msg_received = 0;
+
+        for (int i = 0; i < CLUSTERMSG_TYPE_COUNT; i++) {
+            if (server.cluster->stats_bus_messages_sent[i] == 0) continue;
+            tot_msg_sent += server.cluster->stats_bus_messages_sent[i];
+            info = sdscatprintf(info,
+                "cluster_stats_messages_%s_sent:%lld\r\n",
+                clusterGetMessageTypeString(i),
+                server.cluster->stats_bus_messages_sent[i]);
+        }
+        info = sdscatprintf(info,
+            "cluster_stats_messages_sent:%lld\r\n", tot_msg_sent);
+
+        for (int i = 0; i < CLUSTERMSG_TYPE_COUNT; i++) {
+            if (server.cluster->stats_bus_messages_received[i] == 0) continue;
+            tot_msg_received += server.cluster->stats_bus_messages_received[i];
+            info = sdscatprintf(info,
+                "cluster_stats_messages_%s_received:%lld\r\n",
+                clusterGetMessageTypeString(i),
+                server.cluster->stats_bus_messages_received[i]);
+        }
+        info = sdscatprintf(info,
+            "cluster_stats_messages_received:%lld\r\n", tot_msg_received);
+
+        /* Produce the reply protocol. */
        addReplySds(c,sdscatprintf(sdsempty(),"$%lu\r\n",
            (unsigned long)sdslen(info)));
        addReplySds(c,info);
@@ -4264,6 +4413,11 @@ void clusterCommand(client *c) {
            return;
        }

+        /* Avoid allocating more than needed in case of large COUNT argument
+         * and smaller actual number of keys. */
+        unsigned int keys_in_slot = countKeysInSlot(slot);
+        if (maxkeys > keys_in_slot) maxkeys = keys_in_slot;
+
        keys = zmalloc(sizeof(robj*)*maxkeys);
        numkeys = getKeysInSlot(slot, keys, maxkeys);
        addReplyMultiBulkLen(c,numkeys);
@@ -4481,7 +4635,9 @@ void clusterCommand(client *c) {
        clusterReset(hard);
        addReply(c,shared.ok);
    } else {
-        addReplyError(c,"Wrong CLUSTER subcommand or number of arguments");
+         addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try CLUSTER HELP",
+            (char*)c->argv[1]->ptr);
+        return;
    }
 }

@@ -4617,7 +4773,7 @@ void restoreCommand(client *c) {

    /* Create the key and set the TTL if any */
    dbAdd(c->db,c->argv[1],obj);
-    if (ttl) setExpire(c->db,c->argv[1],mstime()+ttl);
+    if (ttl) setExpire(c,c->db,c->argv[1],mstime()+ttl);
    signalModifiedKey(c->db,c->argv[1]);
    addReply(c,shared.ok);
    server.dirty++;
@@ -4750,13 +4906,13 @@ void migrateCommand(client *c) {
    int copy, replace, j;
    long timeout;
    long dbid;
-    long long ttl, expireat;
    robj **ov = NULL; /* Objects to migrate. */
    robj **kv = NULL; /* Key names. */
    robj **newargv = NULL; /* Used to rewrite the command as DEL ... keys ... */
    rio cmd, payload;
    int may_retry = 1;
    int write_error = 0;
+    int argv_rewritten = 0;

    /* To support the KEYS option we need the following additional state. */
    int first_key = 3; /* Argument index of the first key. */
@@ -4765,7 +4921,6 @@ void migrateCommand(client *c) {
    /* Initialization */
    copy = 0;
    replace = 0;
-    ttl = 0;

    /* Parse additional options */
    for (j = 6; j < c->argc; j++) {
@@ -4841,7 +4996,9 @@ try_again:

    /* Create RESTORE payload and generate the protocol to call the command. */
    for (j = 0; j < num_keys; j++) {
-        expireat = getExpire(c->db,kv[j]);
+        long long ttl = 0;
+        long long expireat = getExpire(c->db,kv[j]);
+
        if (expireat != -1) {
            ttl = expireat-mstime();
            if (ttl < 1) ttl = 1;
@@ -4939,12 +5096,20 @@ try_again:
        goto socket_err; /* A retry is guaranteed because of tested conditions.*/
    }

+    /* On socket errors, close the migration socket now that we still have
+     * the original host/port in the ARGV. Later the original command may be
+     * rewritten to DEL and will be too later. */
+    if (socket_error) migrateCloseSocket(c->argv[1],c->argv[2]);
+
    if (!copy) {
-        /* Translate MIGRATE as DEL for replication/AOF. */
+        /* Translate MIGRATE as DEL for replication/AOF. Note that we do
+         * this only for the keys for which we received an acknowledgement
+         * from the receiving Redis server, by using the del_idx index. */
        if (del_idx > 1) {
            newargv[0] = createStringObject("DEL",3);
            /* Note that the following call takes ownership of newargv. */
            replaceClientCommandVector(c,del_idx,newargv);
+            argv_rewritten = 1;
        } else {
            /* No key transfer acknowledged, no need to rewrite as DEL. */
            zfree(newargv);
@@ -4953,8 +5118,8 @@ try_again:
    }

    /* If we are here and a socket error happened, we don't want to retry.
-     * Just signal the problem to the client, but only do it if we don't
-     * already queued a different error reported by the destination server. */
+     * Just signal the problem to the client, but only do it if we did not
+     * already queue a different error reported by the destination server. */
    if (!error_from_target && socket_error) {
        may_retry = 0;
        goto socket_err;
@@ -4962,7 +5127,11 @@ try_again:

    if (!error_from_target) {
        /* Success! Update the last_dbid in migrateCachedSocket, so that we can
-         * avoid SELECT the next time if the target DB is the same. Reply +OK. */
+         * avoid SELECT the next time if the target DB is the same. Reply +OK.
+         *
+         * Note: If we reached this point, even if socket_error is true
+         * still the SELECT command succeeded (otherwise the code jumps to
+         * socket_err label. */
        cs->last_dbid = dbid;
        addReply(c,shared.ok);
    } else {
@@ -4972,7 +5141,6 @@ try_again:

    sdsfree(cmd.io.buffer.ptr);
    zfree(ov); zfree(kv); zfree(newargv);
-    if (socket_error) migrateCloseSocket(c->argv[1],c->argv[2]);
    return;

 /* On socket errors we try to close the cached socket and try again.
@@ -4982,7 +5150,12 @@ socket_err:
    /* Cleanup we want to perform in both the retry and no retry case.
     * Note: Closing the migrate socket will also force SELECT next time. */
    sdsfree(cmd.io.buffer.ptr);
-    migrateCloseSocket(c->argv[1],c->argv[2]);
+
+    /* If the command was rewritten as DEL and there was a socket error,
+     * we already closed the socket earlier. While migrateCloseSocket()
+     * is idempotent, the host/port arguments are now gone, so don't do it
+     * again. */
+    if (!argv_rewritten) migrateCloseSocket(c->argv[1],c->argv[2]);
    zfree(newargv);
    newargv = NULL; /* This will get reallocated on retry. */

@@ -5219,7 +5392,8 @@ clusterNode *getNodeByQuery(client *c, struct redisCommand *cmd, robj **argv, in
     * node is a slave and the request is about an hash slot our master
     * is serving, we can reply without redirection. */
    if (c->flags & CLIENT_READONLY &&
-        cmd->flags & CMD_READONLY &&
+        (cmd->flags & CMD_READONLY || cmd->proc == evalCommand ||
+         cmd->proc == evalShaCommand) &&
        nodeIsSlave(myself) &&
        myself->slaveof == n)
    {
@@ -5285,8 +5459,9 @@ int clusterRedirectBlockedClientIfNeeded(client *c) {
            return 1;
        }

+        /* All keys must belong to the same slot, so check first key only. */
        di = dictGetIterator(c->bpop.keys);
-        while((de = dictNext(di)) != NULL) {
+        if ((de = dictNext(di)) != NULL) {
            robj *key = dictGetKey(de);
            int slot = keyHashSlot((char*)key->ptr, sdslen(key->ptr));
            clusterNode *node = server.cluster->slots[slot];
@@ -5304,6 +5479,7 @@ int clusterRedirectBlockedClientIfNeeded(client *c) {
                    clusterRedirectClient(c,node,slot,
                        CLUSTER_REDIR_MOVED);
                }
+                dictReleaseIterator(di);
                return 1;
            }
        }
@@ -73,6 +73,29 @@ typedef struct clusterLink {
 #define CLUSTER_CANT_FAILOVER_WAITING_VOTES 4
 #define CLUSTER_CANT_FAILOVER_RELOG_PERIOD (60*5) /* seconds. */

+/* clusterState todo_before_sleep flags. */
+#define CLUSTER_TODO_HANDLE_FAILOVER (1<<0)
+#define CLUSTER_TODO_UPDATE_STATE (1<<1)
+#define CLUSTER_TODO_SAVE_CONFIG (1<<2)
+#define CLUSTER_TODO_FSYNC_CONFIG (1<<3)
+
+/* Message types.
+ *
+ * Note that the PING, PONG and MEET messages are actually the same exact
+ * kind of packet. PONG is the reply to ping, in the exact format as a PING,
+ * while MEET is a special PING that forces the receiver to add the sender
+ * as a node (if it is not already in the list). */
+#define CLUSTERMSG_TYPE_PING 0          /* Ping */
+#define CLUSTERMSG_TYPE_PONG 1          /* Pong (reply to Ping) */
+#define CLUSTERMSG_TYPE_MEET 2          /* Meet "let's join" message */
+#define CLUSTERMSG_TYPE_FAIL 3          /* Mark node xxx as failing */
+#define CLUSTERMSG_TYPE_PUBLISH 4       /* Pub/Sub Publish propagation */
+#define CLUSTERMSG_TYPE_FAILOVER_AUTH_REQUEST 5 /* May I failover? */
+#define CLUSTERMSG_TYPE_FAILOVER_AUTH_ACK 6     /* Yes, you have my vote */
+#define CLUSTERMSG_TYPE_UPDATE 7        /* Another node slots configuration */
+#define CLUSTERMSG_TYPE_MFSTART 8       /* Pause clients for manual failover */
+#define CLUSTERMSG_TYPE_COUNT 9         /* Total number of message types. */
+
 /* This structure represent elements of node->fail_reports. */
 typedef struct clusterNodeFailReport {
    struct clusterNode *node;  /* Node reporting the failure condition. */
@@ -116,7 +139,8 @@ typedef struct clusterState {
    clusterNode *migrating_slots_to[CLUSTER_SLOTS];
    clusterNode *importing_slots_from[CLUSTER_SLOTS];
    clusterNode *slots[CLUSTER_SLOTS];
-    zskiplist *slots_to_keys;
+    uint64_t slots_keys_count[CLUSTER_SLOTS];
+    rax *slots_to_keys;
    /* The following fields are used to take the slave state on elections. */
    mstime_t failover_auth_time; /* Time of previous or next election. */
    int failover_auth_count;    /* Number of votes received so far. */
@@ -138,32 +162,15 @@ typedef struct clusterState {
    /* The followign fields are used by masters to take state on elections. */
    uint64_t lastVoteEpoch;     /* Epoch of the last vote granted. */
    int todo_before_sleep; /* Things to do in clusterBeforeSleep(). */
-    long long stats_bus_messages_sent;  /* Num of msg sent via cluster bus. */
-    long long stats_bus_messages_received; /* Num of msg rcvd via cluster bus.*/
+    /* Messages received and sent by type. */
+    long long stats_bus_messages_sent[CLUSTERMSG_TYPE_COUNT];
+    long long stats_bus_messages_received[CLUSTERMSG_TYPE_COUNT];
+    long long stats_pfail_nodes;    /* Number of nodes in PFAIL status,
+                                       excluding nodes without address. */
 } clusterState;

-/* clusterState todo_before_sleep flags. */
-#define CLUSTER_TODO_HANDLE_FAILOVER (1<<0)
-#define CLUSTER_TODO_UPDATE_STATE (1<<1)
-#define CLUSTER_TODO_SAVE_CONFIG (1<<2)
-#define CLUSTER_TODO_FSYNC_CONFIG (1<<3)
-
 /* Redis cluster messages header */

-/* Note that the PING, PONG and MEET messages are actually the same exact
- * kind of packet. PONG is the reply to ping, in the exact format as a PING,
- * while MEET is a special PING that forces the receiver to add the sender
- * as a node (if it is not already in the list). */
-#define CLUSTERMSG_TYPE_PING 0          /* Ping */
-#define CLUSTERMSG_TYPE_PONG 1          /* Pong (reply to Ping) */
-#define CLUSTERMSG_TYPE_MEET 2          /* Meet "let's join" message */
-#define CLUSTERMSG_TYPE_FAIL 3          /* Mark node xxx as failing */
-#define CLUSTERMSG_TYPE_PUBLISH 4       /* Pub/Sub Publish propagation */
-#define CLUSTERMSG_TYPE_FAILOVER_AUTH_REQUEST 5 /* May I failover? */
-#define CLUSTERMSG_TYPE_FAILOVER_AUTH_ACK 6     /* Yes, you have my vote */
-#define CLUSTERMSG_TYPE_UPDATE 7        /* Another node slots configuration */
-#define CLUSTERMSG_TYPE_MFSTART 8       /* Pause clients for manual failover */
-
 /* Initially we don't know our "name", but we'll find it once we connect
 * to the first node, using the getsockname() function. Then we'll use this
 * address for all the next messages. */
@@ -225,7 +232,7 @@ union clusterMsgData {
 typedef struct {
    char sig[4];        /* Siganture "RCmb" (Redis Cluster message bus). */
    uint32_t totlen;    /* Total length of this message */
-    uint16_t ver;       /* Protocol version, currently set to 0. */
+    uint16_t ver;       /* Protocol version, currently set to 1. */
    uint16_t port;      /* TCP base port number. */
    uint16_t type;      /* Message type */
    uint16_t count;     /* Only used for some kind of messages. */
@@ -283,6 +283,10 @@ void loadServerConfigFromString(char *config) {
                }
                fclose(logfp);
            }
+        } else if (!strcasecmp(argv[0],"always-show-logo") && argc == 2) {
+            if ((server.always_show_logo = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
        } else if (!strcasecmp(argv[0],"syslog-enabled") && argc == 2) {
            if ((server.syslog_enabled = yesnotoi(argv[1])) == -1) {
                err = "argument must be 'yes' or 'no'"; goto loaderr;
@@ -326,13 +330,13 @@ void loadServerConfigFromString(char *config) {
            }
        } else if (!strcasecmp(argv[0],"lfu-log-factor") && argc == 2) {
            server.lfu_log_factor = atoi(argv[1]);
-            if (server.maxmemory_samples < 0) {
+            if (server.lfu_log_factor < 0) {
                err = "lfu-log-factor must be 0 or greater";
                goto loaderr;
            }
        } else if (!strcasecmp(argv[0],"lfu-decay-time") && argc == 2) {
            server.lfu_decay_time = atoi(argv[1]);
-            if (server.maxmemory_samples < 1) {
+            if (server.lfu_decay_time < 0) {
                err = "lfu-decay-time must be 0 or greater";
                goto loaderr;
            }
@@ -419,6 +423,10 @@ void loadServerConfigFromString(char *config) {
            if ((server.repl_slave_lazy_flush = yesnotoi(argv[1])) == -1) {
                err = "argument must be 'yes' or 'no'"; goto loaderr;
            }
+        } else if (!strcasecmp(argv[0],"activedefrag") && argc == 2) {
+            if ((server.active_defrag_enabled = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
        } else if (!strcasecmp(argv[0],"daemonize") && argc == 2) {
            if ((server.daemonize = yesnotoi(argv[1])) == -1) {
                err = "argument must be 'yes' or 'no'"; goto loaderr;
@@ -495,6 +503,36 @@ void loadServerConfigFromString(char *config) {
            }
            zfree(server.rdb_filename);
            server.rdb_filename = zstrdup(argv[1]);
+        } else if (!strcasecmp(argv[0],"active-defrag-threshold-lower") && argc == 2) {
+            server.active_defrag_threshold_lower = atoi(argv[1]);
+            if (server.active_defrag_threshold_lower < 0) {
+                err = "active-defrag-threshold-lower must be 0 or greater";
+                goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"active-defrag-threshold-upper") && argc == 2) {
+            server.active_defrag_threshold_upper = atoi(argv[1]);
+            if (server.active_defrag_threshold_upper < 0) {
+                err = "active-defrag-threshold-upper must be 0 or greater";
+                goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"active-defrag-ignore-bytes") && argc == 2) {
+            server.active_defrag_ignore_bytes = memtoll(argv[1], NULL);
+            if (server.active_defrag_ignore_bytes <= 0) {
+                err = "active-defrag-ignore-bytes must above 0";
+                goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"active-defrag-cycle-min") && argc == 2) {
+            server.active_defrag_cycle_min = atoi(argv[1]);
+            if (server.active_defrag_cycle_min < 1 || server.active_defrag_cycle_min > 99) {
+                err = "active-defrag-cycle-min must be between 1 and 99";
+                goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"active-defrag-cycle-max") && argc == 2) {
+            server.active_defrag_cycle_max = atoi(argv[1]);
+            if (server.active_defrag_cycle_max < 1 || server.active_defrag_cycle_max > 99) {
+                err = "active-defrag-cycle-max must be between 1 and 99";
+                goto loaderr;
+            }
        } else if (!strcasecmp(argv[0],"hash-max-ziplist-entries") && argc == 2) {
            server.hash_max_ziplist_entries = memtoll(argv[1], NULL);
        } else if (!strcasecmp(argv[0],"hash-max-ziplist-value") && argc == 2) {
@@ -967,6 +1005,18 @@ void configSetCommand(client *c) {
      "slave-read-only",server.repl_slave_ro) {
    } config_set_bool_field(
      "activerehashing",server.activerehashing) {
+    } config_set_bool_field(
+      "activedefrag",server.active_defrag_enabled) {
+#ifndef HAVE_DEFRAG
+        if (server.active_defrag_enabled) {
+            server.active_defrag_enabled = 0;
+            addReplyError(c,
+                "Active defragmentation cannot be enabled: it requires a "
+                "Redis server compiled with a modified Jemalloc like the "
+                "one shipped by default with the Redis source distribution");
+            return;
+        }
+#endif
    } config_set_bool_field(
      "protected-mode",server.protected_mode) {
    } config_set_bool_field(
@@ -995,9 +1045,17 @@ void configSetCommand(client *c) {
    } config_set_numerical_field(
      "timeout",server.maxidletime,0,LONG_MAX) {
    } config_set_numerical_field(
-      "auto-aof-rewrite-percentage",server.aof_rewrite_perc,0,LLONG_MAX){
+      "active-defrag-threshold-lower",server.active_defrag_threshold_lower,0,1000) {
    } config_set_numerical_field(
-      "auto-aof-rewrite-min-size",server.aof_rewrite_min_size,0,LLONG_MAX) {
+      "active-defrag-threshold-upper",server.active_defrag_threshold_upper,0,1000) {
+    } config_set_memory_field(
+      "active-defrag-ignore-bytes",server.active_defrag_ignore_bytes) {
+    } config_set_numerical_field(
+      "active-defrag-cycle-min",server.active_defrag_cycle_min,1,99) {
+    } config_set_numerical_field(
+      "active-defrag-cycle-max",server.active_defrag_cycle_max,1,99) {
+    } config_set_numerical_field(
+      "auto-aof-rewrite-percentage",server.aof_rewrite_perc,0,LLONG_MAX){
    } config_set_numerical_field(
      "hash-max-ziplist-entries",server.hash_max_ziplist_entries,0,LLONG_MAX) {
    } config_set_numerical_field(
@@ -1076,6 +1134,8 @@ void configSetCommand(client *c) {
        }
    } config_set_memory_field("repl-backlog-size",ll) {
        resizeReplicationBacklog(ll);
+    } config_set_memory_field("auto-aof-rewrite-min-size",ll) {
+        server.aof_rewrite_min_size = ll;

    /* Enumeration fields.
     * config_set_enum_field(name,var,enum_var) */
@@ -1161,7 +1221,14 @@ void configGetCommand(client *c) {
    /* Numerical values */
    config_get_numerical_field("maxmemory",server.maxmemory);
    config_get_numerical_field("maxmemory-samples",server.maxmemory_samples);
+    config_get_numerical_field("lfu-log-factor",server.lfu_log_factor);
+    config_get_numerical_field("lfu-decay-time",server.lfu_decay_time);
    config_get_numerical_field("timeout",server.maxidletime);
+    config_get_numerical_field("active-defrag-threshold-lower",server.active_defrag_threshold_lower);
+    config_get_numerical_field("active-defrag-threshold-upper",server.active_defrag_threshold_upper);
+    config_get_numerical_field("active-defrag-ignore-bytes",server.active_defrag_ignore_bytes);
+    config_get_numerical_field("active-defrag-cycle-min",server.active_defrag_cycle_min);
+    config_get_numerical_field("active-defrag-cycle-max",server.active_defrag_cycle_max);
    config_get_numerical_field("auto-aof-rewrite-percentage",
            server.aof_rewrite_perc);
    config_get_numerical_field("auto-aof-rewrite-min-size",
@@ -1226,6 +1293,7 @@ void configGetCommand(client *c) {
    config_get_bool_field("rdbcompression", server.rdb_compression);
    config_get_bool_field("rdbchecksum", server.rdb_checksum);
    config_get_bool_field("activerehashing", server.activerehashing);
+    config_get_bool_field("activedefrag", server.active_defrag_enabled);
    config_get_bool_field("protected-mode", server.protected_mode);
    config_get_bool_field("repl-disable-tcp-nodelay",
            server.repl_disable_tcp_nodelay);
@@ -1357,7 +1425,7 @@ void configGetCommand(client *c) {
 /* We use the following dictionary type to store where a configuration
 * option is mentioned in the old configuration file, so it's
 * like "maxmemory" -> list of line numbers (first line is zero). */
-unsigned int dictSdsCaseHash(const void *key);
+uint64_t dictSdsCaseHash(const void *key);
 int dictSdsKeyCaseCompare(void *privdata, const void *key1, const void *key2);
 void dictSdsDestructor(void *privdata, void *val);
 void dictListDestructor(void *privdata, void *val);
@@ -1926,6 +1994,13 @@ int rewriteConfig(char *path) {
    rewriteConfigBytesOption(state,"maxmemory",server.maxmemory,CONFIG_DEFAULT_MAXMEMORY);
    rewriteConfigEnumOption(state,"maxmemory-policy",server.maxmemory_policy,maxmemory_policy_enum,CONFIG_DEFAULT_MAXMEMORY_POLICY);
    rewriteConfigNumericalOption(state,"maxmemory-samples",server.maxmemory_samples,CONFIG_DEFAULT_MAXMEMORY_SAMPLES);
+    rewriteConfigNumericalOption(state,"lfu-log-factor",server.lfu_log_factor,CONFIG_DEFAULT_LFU_LOG_FACTOR);
+    rewriteConfigNumericalOption(state,"lfu-decay-time",server.lfu_decay_time,CONFIG_DEFAULT_LFU_DECAY_TIME);
+    rewriteConfigNumericalOption(state,"active-defrag-threshold-lower",server.active_defrag_threshold_lower,CONFIG_DEFAULT_DEFRAG_THRESHOLD_LOWER);
+    rewriteConfigNumericalOption(state,"active-defrag-threshold-upper",server.active_defrag_threshold_upper,CONFIG_DEFAULT_DEFRAG_THRESHOLD_UPPER);
+    rewriteConfigBytesOption(state,"active-defrag-ignore-bytes",server.active_defrag_ignore_bytes,CONFIG_DEFAULT_DEFRAG_IGNORE_BYTES);
+    rewriteConfigNumericalOption(state,"active-defrag-cycle-min",server.active_defrag_cycle_min,CONFIG_DEFAULT_DEFRAG_CYCLE_MIN);
+    rewriteConfigNumericalOption(state,"active-defrag-cycle-max",server.active_defrag_cycle_max,CONFIG_DEFAULT_DEFRAG_CYCLE_MAX);
    rewriteConfigYesNoOption(state,"appendonly",server.aof_state != AOF_OFF,0);
    rewriteConfigStringOption(state,"appendfilename",server.aof_filename,CONFIG_DEFAULT_AOF_FILENAME);
    rewriteConfigEnumOption(state,"appendfsync",server.aof_fsync,aof_fsync_enum,CONFIG_DEFAULT_AOF_FSYNC);
@@ -1952,6 +2027,7 @@ int rewriteConfig(char *path) {
    rewriteConfigNumericalOption(state,"zset-max-ziplist-value",server.zset_max_ziplist_value,OBJ_ZSET_MAX_ZIPLIST_VALUE);
    rewriteConfigNumericalOption(state,"hll-sparse-max-bytes",server.hll_sparse_max_bytes,CONFIG_DEFAULT_HLL_SPARSE_MAX_BYTES);
    rewriteConfigYesNoOption(state,"activerehashing",server.activerehashing,CONFIG_DEFAULT_ACTIVE_REHASHING);
+    rewriteConfigYesNoOption(state,"activedefrag",server.active_defrag_enabled,CONFIG_DEFAULT_ACTIVE_DEFRAG);
    rewriteConfigYesNoOption(state,"protected-mode",server.protected_mode,CONFIG_DEFAULT_PROTECTED_MODE);
    rewriteConfigClientoutputbufferlimitOption(state);
    rewriteConfigNumericalOption(state,"hz",server.hz,CONFIG_DEFAULT_HZ);
@@ -1993,19 +2069,24 @@ void configCommand(client *c) {
        return;
    }

-    if (!strcasecmp(c->argv[1]->ptr,"set")) {
-        if (c->argc != 4) goto badarity;
+    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
+        const char *help[] = {
+"get <pattern> -- Return parameters matching the glob-like <pattern> and their values.",
+"set <parameter> <value> -- Set parameter to value.",
+"resetstat -- Reset statistics reported by INFO.",
+"rewrite -- Rewrite the configuration file.",
+NULL
+        };
+        addReplyHelp(c, help);
+    } else if (!strcasecmp(c->argv[1]->ptr,"set") && c->argc == 4) {
        configSetCommand(c);
-    } else if (!strcasecmp(c->argv[1]->ptr,"get")) {
-        if (c->argc != 3) goto badarity;
+    } else if (!strcasecmp(c->argv[1]->ptr,"get") && c->argc == 3) {
        configGetCommand(c);
-    } else if (!strcasecmp(c->argv[1]->ptr,"resetstat")) {
-        if (c->argc != 2) goto badarity;
+    } else if (!strcasecmp(c->argv[1]->ptr,"resetstat") && c->argc == 2) {
        resetServerStats();
        resetCommandTableStats();
        addReply(c,shared.ok);
-    } else if (!strcasecmp(c->argv[1]->ptr,"rewrite")) {
-        if (c->argc != 2) goto badarity;
+    } else if (!strcasecmp(c->argv[1]->ptr,"rewrite") && c->argc == 2) {
        if (server.configfile == NULL) {
            addReplyError(c,"The server is running without a config file");
            return;
@@ -2018,12 +2099,8 @@ void configCommand(client *c) {
            addReply(c,shared.ok);
        }
    } else {
-        addReplyError(c,
-            "CONFIG subcommand must be one of GET, SET, RESETSTAT, REWRITE");
+         addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try CONFIG HELP",
+            (char*)c->argv[1]->ptr);
+        return;
    }
-    return;
-
-badarity:
-    addReplyErrorFormat(c,"Wrong number of arguments for CONFIG %s",
-        (char*) c->argv[1]->ptr);
 }
@@ -206,4 +206,22 @@ void setproctitle(const char *fmt, ...);
 #endif
 #endif

+/* Make sure we can test for ARM just checking for __arm__, since sometimes
+ * __arm is defined but __arm__ is not. */
+#if defined(__arm) && !defined(__arm__)
+#define __arm__
+#endif
+#if defined (__aarch64__) && !defined(__arm64__)
+#define __arm64__
+#endif
+
+/* Make sure we can test for SPARC just checking for __sparc__. */
+#if defined(__sparc) && !defined(__sparc__)
+#define __sparc__
+#endif
+
+#if defined(__sparc__) || defined(__arm__)
+#define USE_ALIGNED_ACCESS
+#endif
+
 #endif
@@ -38,6 +38,15 @@
 * C-level DB API
 *----------------------------------------------------------------------------*/

+/* Update LFU when an object is accessed.
+ * Firstly, decrement the counter if the decrement time is reached.
+ * Then logarithmically increment the counter, and update the access time. */
+void updateLFU(robj *val) {
+    unsigned long counter = LFUDecrAndReturn(val);
+    counter = LFULogIncr(counter);
+    val->lru = (LFUGetTimeInMinutes()<<8) | counter;
+}
+
 /* Low level key lookup API, not actually called directly from commands
 * implementations that should instead rely on lookupKeyRead(),
 * lookupKeyWrite() and lookupKeyReadWithFlags(). */
@@ -54,9 +63,7 @@ robj *lookupKey(redisDb *db, robj *key, int flags) {
            !(flags & LOOKUP_NOTOUCH))
        {
            if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
-                unsigned long ldt = val->lru >> 8;
-                unsigned long counter = LFULogIncr(val->lru & 255);
-                val->lru = (ldt << 8) | counter;
+                updateLFU(val);
            } else {
                val->lru = LRU_CLOCK();
            }
@@ -93,7 +100,7 @@ robj *lookupKeyReadWithFlags(redisDb *db, robj *key, int flags) {

    if (expireIfNeeded(db,key) == 1) {
        /* Key expired. If we are in the context of a master, expireIfNeeded()
-         * returns 0 only when the key does not exist at all, so it's save
+         * returns 0 only when the key does not exist at all, so it's safe
         * to return NULL ASAP. */
        if (server.masterhost == NULL) return NULL;

@@ -162,9 +169,9 @@ void dbAdd(redisDb *db, robj *key, robj *val) {
    int retval = dictAdd(db->dict, copy, val);

    serverAssertWithInfo(NULL,key,retval == DICT_OK);
-    if (val->type == OBJ_LIST) signalListAsReady(db, key);
+    if (val->type == OBJ_LIST) signalKeyAsReady(db, key);
    if (server.cluster_enabled) slotToKeyAdd(key);
- }
+}

 /* Overwrite an existing key with a new value. Incrementing the reference
 * count of the new value is up to the caller.
@@ -180,6 +187,9 @@ void dbOverwrite(redisDb *db, robj *key, robj *val) {
        int saved_lru = old->lru;
        dictReplace(db->dict, key->ptr, val);
        val->lru = saved_lru;
+        /* LFU should be not only copied but also updated
+         * when a key is overwritten. */
+        updateLFU(val);
    } else {
        dictReplace(db->dict, key->ptr, val);
    }
@@ -190,7 +200,9 @@ void dbOverwrite(redisDb *db, robj *key, robj *val) {
 *
 * 1) The ref count of the value object is incremented.
 * 2) clients WATCHing for the destination key notified.
- * 3) The expire time of the key is reset (the key is made persistent). */
+ * 3) The expire time of the key is reset (the key is made persistent).
+ *
+ * All the new keys in the database should be craeted via this interface. */
 void setKey(redisDb *db, robj *key, robj *val) {
    if (lookupKeyWrite(db,key) == NULL) {
        dbAdd(db,key,val);
@@ -330,6 +342,7 @@ long long emptyDb(int dbnum, int flags, void(callback)(void*)) {
            slotToKeyFlush();
        }
    }
+    if (dbnum == -1) flushSlaveKeysWithExpireList();
    return removed;
 }

@@ -413,7 +426,9 @@ void flushallCommand(client *c) {
        /* Normally rdbSave() will reset dirty, but we don't want this here
         * as otherwise FLUSHALL will not be replicated nor put into the AOF. */
        int saved_dirty = server.dirty;
-        rdbSave(server.rdb_filename);
+        rdbSaveInfo rsi, *rsiptr;
+        rsiptr = rdbPopulateSaveInfo(&rsi);
+        rdbSave(server.rdb_filename,rsiptr);
        server.dirty = saved_dirty;
    }
    server.dirty++;
@@ -471,7 +486,7 @@ void selectCommand(client *c) {
        return;
    }
    if (selectDb(c,id) == C_ERR) {
-        addReplyError(c,"invalid DB index");
+        addReplyError(c,"DB index is out of range");
    } else {
        addReply(c,shared.ok);
    }
@@ -662,7 +677,7 @@ void scanGenericCommand(client *c, robj *o, unsigned long cursor) {
        privdata[0] = keys;
        privdata[1] = o;
        do {
-            cursor = dictScan(ht, cursor, scanCallback, privdata);
+            cursor = dictScan(ht, cursor, scanCallback, NULL, privdata);
        } while (cursor &&
              maxiterations-- &&
              listLength(keys) < (unsigned long)count);
@@ -783,6 +798,7 @@ void typeCommand(client *c) {
        case OBJ_SET: type = "set"; break;
        case OBJ_ZSET: type = "zset"; break;
        case OBJ_HASH: type = "hash"; break;
+        case OBJ_STREAM: type = "stream"; break;
        case OBJ_MODULE: {
            moduleValue *mv = o->ptr;
            type = mv->type->name;
@@ -851,7 +867,7 @@ void renameGenericCommand(client *c, int nx) {
        dbDelete(c->db,c->argv[2]);
    }
    dbAdd(c->db,c->argv[2],o);
-    if (expire != -1) setExpire(c->db,c->argv[2],expire);
+    if (expire != -1) setExpire(c,c->db,c->argv[2],expire);
    dbDelete(c->db,c->argv[1]);
    signalModifiedKey(c->db,c->argv[1]);
    signalModifiedKey(c->db,c->argv[2]);
@@ -917,7 +933,7 @@ void moveCommand(client *c) {
        return;
    }
    dbAdd(dst,c->argv[1],o);
-    if (expire != -1) setExpire(dst,c->argv[1],expire);
+    if (expire != -1) setExpire(c,dst,c->argv[1],expire);
    incrRefCount(o);

    /* OK! key moved, free the entry in the source DB */
@@ -926,6 +942,91 @@ void moveCommand(client *c) {
    addReply(c,shared.cone);
 }

+/* Helper function for dbSwapDatabases(): scans the list of keys that have
+ * one or more blocked clients for B[LR]POP or other list blocking commands
+ * and signal the keys are ready if they are lists. See the comment where
+ * the function is used for more info. */
+void scanDatabaseForReadyLists(redisDb *db) {
+    dictEntry *de;
+    dictIterator *di = dictGetSafeIterator(db->blocking_keys);
+    while((de = dictNext(di)) != NULL) {
+        robj *key = dictGetKey(de);
+        robj *value = lookupKey(db,key,LOOKUP_NOTOUCH);
+        if (value && (value->type == OBJ_LIST || value->type == OBJ_STREAM))
+            signalKeyAsReady(db, key);
+    }
+    dictReleaseIterator(di);
+}
+
+/* Swap two databases at runtime so that all clients will magically see
+ * the new database even if already connected. Note that the client
+ * structure c->db points to a given DB, so we need to be smarter and
+ * swap the underlying referenced structures, otherwise we would need
+ * to fix all the references to the Redis DB structure.
+ *
+ * Returns C_ERR if at least one of the DB ids are out of range, otherwise
+ * C_OK is returned. */
+int dbSwapDatabases(int id1, int id2) {
+    if (id1 < 0 || id1 >= server.dbnum ||
+        id2 < 0 || id2 >= server.dbnum) return C_ERR;
+    if (id1 == id2) return C_OK;
+    redisDb aux = server.db[id1];
+    redisDb *db1 = &server.db[id1], *db2 = &server.db[id2];
+
+    /* Swap hash tables. Note that we don't swap blocking_keys,
+     * ready_keys and watched_keys, since we want clients to
+     * remain in the same DB they were. */
+    db1->dict = db2->dict;
+    db1->expires = db2->expires;
+    db1->avg_ttl = db2->avg_ttl;
+
+    db2->dict = aux.dict;
+    db2->expires = aux.expires;
+    db2->avg_ttl = aux.avg_ttl;
+
+    /* Now we need to handle clients blocked on lists: as an effect
+     * of swapping the two DBs, a client that was waiting for list
+     * X in a given DB, may now actually be unblocked if X happens
+     * to exist in the new version of the DB, after the swap.
+     *
+     * However normally we only do this check for efficiency reasons
+     * in dbAdd() when a list is created. So here we need to rescan
+     * the list of clients blocked on lists and signal lists as ready
+     * if needed. */
+    scanDatabaseForReadyLists(db1);
+    scanDatabaseForReadyLists(db2);
+    return C_OK;
+}
+
+/* SWAPDB db1 db2 */
+void swapdbCommand(client *c) {
+    long id1, id2;
+
+    /* Not allowed in cluster mode: we have just DB 0 there. */
+    if (server.cluster_enabled) {
+        addReplyError(c,"SWAPDB is not allowed in cluster mode");
+        return;
+    }
+
+    /* Get the two DBs indexes. */
+    if (getLongFromObjectOrReply(c, c->argv[1], &id1,
+        "invalid first DB index") != C_OK)
+        return;
+
+    if (getLongFromObjectOrReply(c, c->argv[2], &id2,
+        "invalid second DB index") != C_OK)
+        return;
+
+    /* Swap... */
+    if (dbSwapDatabases(id1,id2) == C_ERR) {
+        addReplyError(c,"DB index is out of range");
+        return;
+    } else {
+        server.dirty++;
+        addReply(c,shared.ok);
+    }
+}
+
 /*-----------------------------------------------------------------------------
 * Expires API
 *----------------------------------------------------------------------------*/
@@ -937,7 +1038,11 @@ int removeExpire(redisDb *db, robj *key) {
    return dictDelete(db->expires,key->ptr) == DICT_OK;
 }

-void setExpire(redisDb *db, robj *key, long long when) {
+/* Set an expire to the specified key. If the expire is set in the context
+ * of an user calling a command 'c' is the client, otherwise 'c' is set
+ * to NULL. The 'when' parameter is the absolute unix time in milliseconds
+ * after which the key will no longer be considered valid. */
+void setExpire(client *c, redisDb *db, robj *key, long long when) {
    dictEntry *kde, *de;

    /* Reuse the sds from the main dict in the expire dict */
@@ -945,6 +1050,10 @@ void setExpire(redisDb *db, robj *key, long long when) {
    serverAssertWithInfo(NULL,key,kde != NULL);
    de = dictAddOrFind(db->expires,dictGetKey(kde));
    dictSetSignedIntegerVal(de,when);
+
+    int writable_slave = server.masterhost && server.repl_slave_ro == 0;
+    if (c && writable_slave && !(c->flags & CLIENT_MASTER))
+        rememberSlaveKeyWithExpire(db,key);
 }

 /* Return the expire time of the specified key, or -1 if no expire
@@ -1037,11 +1146,24 @@ int *getKeysUsingCommandTable(struct redisCommand *cmd,robj **argv, int argc, in
        *numkeys = 0;
        return NULL;
    }
+
    last = cmd->lastkey;
    if (last < 0) last = argc+last;
    keys = zmalloc(sizeof(int)*((last - cmd->firstkey)+1));
    for (j = cmd->firstkey; j <= last; j += cmd->keystep) {
-        serverAssert(j < argc);
+        if (j >= argc) {
+            /* Modules command do not have dispatch time arity checks, so
+             * we need to handle the case where the user passed an invalid
+             * number of arguments here. In this case we return no keys
+             * and expect the module command to report an arity error. */
+            if (cmd->flags & CMD_MODULE) {
+                zfree(keys);
+                *numkeys = 0;
+                return NULL;
+            } else {
+                serverPanic("Redis built-in command declared keys positions not matching the arity requirements.");
+            }
+        }
        keys[i++] = j;
    }
    *numkeys = i;
@@ -1203,92 +1325,155 @@ int *migrateGetKeys(struct redisCommand *cmd, robj **argv, int argc, int *numkey
    return keys;
 }

+/* Helper function to extract keys from following commands:
+ * GEORADIUS key x y radius unit [WITHDIST] [WITHHASH] [WITHCOORD] [ASC|DESC]
+ *                             [COUNT count] [STORE key] [STOREDIST key]
+ * GEORADIUSBYMEMBER key member radius unit ... options ... */
+int *georadiusGetKeys(struct redisCommand *cmd, robj **argv, int argc, int *numkeys) {
+    int i, num, *keys;
+    UNUSED(cmd);
+
+    /* Check for the presence of the stored key in the command */
+    int stored_key = -1;
+    for (i = 5; i < argc; i++) {
+        char *arg = argv[i]->ptr;
+        /* For the case when user specifies both "store" and "storedist" options, the
+         * second key specified would override the first key. This behavior is kept 
+         * the same as in georadiusCommand method.
+         */
+        if ((!strcasecmp(arg, "store") || !strcasecmp(arg, "storedist")) && ((i+1) < argc)) {
+            stored_key = i+1;
+            i++;
+        }
+    }
+    num = 1 + (stored_key == -1 ? 0 : 1);
+
+    /* Keys in the command come from two places:
+     * argv[1] = key,
+     * argv[5...n] = stored key if present
+     */
+    keys = zmalloc(sizeof(int) * num);
+
+    /* Add all key positions to keys[] */
+    keys[0] = 1;
+    if(num > 1) {
+         keys[1] = stored_key;
+    }
+    *numkeys = num; 
+    return keys;
+}
+
+/* XREAD [BLOCK <milliseconds>] [COUNT <count>] [GROUP <groupname> <ttl>]
+ *       [RETRY <milliseconds> <ttl>] STREAMS key_1 key_2 ... key_N
+ *       ID_1 ID_2 ... ID_N */
+int *xreadGetKeys(struct redisCommand *cmd, robj **argv, int argc, int *numkeys) {
+    int i, num, *keys;
+    UNUSED(cmd);
+
+    /* We need to seek the last argument that contains "STREAMS", because other
+     * arguments before may contain it (for example the group name). */
+    int streams_pos = -1;
+    for (i = 1; i < argc; i++) {
+        char *arg = argv[i]->ptr;
+        if (!strcasecmp(arg, "streams")) streams_pos = i;
+    }
+    if (streams_pos != -1) num = argc - streams_pos - 1;
+
+    /* Syntax error. */
+    if (streams_pos == -1 || num % 2 != 0) {
+        *numkeys = 0;
+        return NULL;
+    }
+    num /= 2; /* We have half the keys as there are arguments because
+                 there are also the IDs, one per key. */
+
+    keys = zmalloc(sizeof(int) * num);
+    for (i = streams_pos+1; i < argc; i++) keys[i-streams_pos-1] = i;
+    *numkeys = num;
+    return keys;
+}
+
 /* Slot to Key API. This is used by Redis Cluster in order to obtain in
 * a fast way a key that belongs to a specified hash slot. This is useful
- * while rehashing the cluster. */
-void slotToKeyAdd(robj *key) {
+ * while rehashing the cluster and in other conditions when we need to
+ * understand if we have keys for a given hash slot. */
+void slotToKeyUpdateKey(robj *key, int add) {
    unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
+    unsigned char buf[64];
+    unsigned char *indexed = buf;
+    size_t keylen = sdslen(key->ptr);

-    sds sdskey = sdsdup(key->ptr);
-    zslInsert(server.cluster->slots_to_keys,hashslot,sdskey);
+    server.cluster->slots_keys_count[hashslot] += add ? 1 : -1;
+    if (keylen+2 > 64) indexed = zmalloc(keylen+2);
+    indexed[0] = (hashslot >> 8) & 0xff;
+    indexed[1] = hashslot & 0xff;
+    memcpy(indexed+2,key->ptr,keylen);
+    if (add) {
+        raxInsert(server.cluster->slots_to_keys,indexed,keylen+2,NULL,NULL);
+    } else {
+        raxRemove(server.cluster->slots_to_keys,indexed,keylen+2,NULL);
+    }
+    if (indexed != buf) zfree(indexed);
+}
+
+void slotToKeyAdd(robj *key) {
+    slotToKeyUpdateKey(key,1);
 }

 void slotToKeyDel(robj *key) {
-    unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
-    zslDelete(server.cluster->slots_to_keys,hashslot,key->ptr,NULL);
+    slotToKeyUpdateKey(key,0);
 }

 void slotToKeyFlush(void) {
-    zslFree(server.cluster->slots_to_keys);
-    server.cluster->slots_to_keys = zslCreate();
+    raxFree(server.cluster->slots_to_keys);
+    server.cluster->slots_to_keys = raxNew();
+    memset(server.cluster->slots_keys_count,0,
+           sizeof(server.cluster->slots_keys_count));
 }

 /* Pupulate the specified array of objects with keys in the specified slot.
 * New objects are returned to represent keys, it's up to the caller to
 * decrement the reference count to release the keys names. */
 unsigned int getKeysInSlot(unsigned int hashslot, robj **keys, unsigned int count) {
-    zskiplistNode *n;
-    zrangespec range;
+    raxIterator iter;
    int j = 0;
+    unsigned char indexed[2];

-    range.min = range.max = hashslot;
-    range.minex = range.maxex = 0;
-
-    n = zslFirstInRange(server.cluster->slots_to_keys, &range);
-    while(n && n->score == hashslot && count--) {
-        keys[j++] = createStringObject(n->ele,sdslen(n->ele));
-        n = n->level[0].forward;
+    indexed[0] = (hashslot >> 8) & 0xff;
+    indexed[1] = hashslot & 0xff;
+    raxStart(&iter,server.cluster->slots_to_keys);
+    raxSeek(&iter,">=",indexed,2);
+    while(count-- && raxNext(&iter)) {
+        if (iter.key[0] != indexed[0] || iter.key[1] != indexed[1]) break;
+        keys[j++] = createStringObject((char*)iter.key+2,iter.key_len-2);
    }
+    raxStop(&iter);
    return j;
 }

 /* Remove all the keys in the specified hash slot.
 * The number of removed items is returned. */
 unsigned int delKeysInSlot(unsigned int hashslot) {
-    zskiplistNode *n;
-    zrangespec range;
+    raxIterator iter;
    int j = 0;
+    unsigned char indexed[2];

-    range.min = range.max = hashslot;
-    range.minex = range.maxex = 0;
+    indexed[0] = (hashslot >> 8) & 0xff;
+    indexed[1] = hashslot & 0xff;
+    raxStart(&iter,server.cluster->slots_to_keys);
+    while(server.cluster->slots_keys_count[hashslot]) {
+        raxSeek(&iter,">=",indexed,2);
+        raxNext(&iter);

-    n = zslFirstInRange(server.cluster->slots_to_keys, &range);
-    while(n && n->score == hashslot) {
-        sds sdskey = n->ele;
-        robj *key = createStringObject(sdskey,sdslen(sdskey));
-        n = n->level[0].forward; /* Go to the next item before freeing it. */
+        robj *key = createStringObject((char*)iter.key+2,iter.key_len-2);
        dbDelete(&server.db[0],key);
        decrRefCount(key);
        j++;
    }
+    raxStop(&iter);
    return j;
 }

 unsigned int countKeysInSlot(unsigned int hashslot) {
-    zskiplist *zsl = server.cluster->slots_to_keys;
-    zskiplistNode *zn;
-    zrangespec range;
-    int rank, count = 0;
-
-    range.min = range.max = hashslot;
-    range.minex = range.maxex = 0;
-
-    /* Find first element in range */
-    zn = zslFirstInRange(zsl, &range);
-
-    /* Use rank of first element, if any, to determine preliminary count */
-    if (zn != NULL) {
-        rank = zslGetRank(zsl, zn->score, zn->ele);
-        count = (zsl->length - (rank - 1));
-
-        /* Find last element in range */
-        zn = zslLastInRange(zsl, &range);
-
-        /* Use rank of last element, if any, to determine the actual count */
-        if (zn != NULL) {
-            rank = zslGetRank(zsl, zn->score, zn->ele);
-            count -= (zsl->length - rank);
-        }
-    }
-    return count;
+    return server.cluster->slots_keys_count[hashslot];
 }
@@ -126,7 +126,7 @@ void computeDatasetDigest(unsigned char *final) {
        redisDb *db = server.db+j;

        if (dictSize(db->dict) == 0) continue;
-        di = dictGetIterator(db->dict);
+        di = dictGetSafeIterator(db->dict);

        /* hash the DB id, so the same dataset moved in a different
         * DB will lead to a different digest */
@@ -239,6 +239,36 @@ void computeDatasetDigest(unsigned char *final) {
                    xorDigest(digest,eledigest,20);
                }
                hashTypeReleaseIterator(hi);
+            } else if (o->type == OBJ_STREAM) {
+                streamIterator si;
+                streamIteratorStart(&si,o->ptr,NULL,NULL,0);
+                streamID id;
+                int64_t numfields;
+
+                while(streamIteratorGetID(&si,&id,&numfields)) {
+                    sds itemid = sdscatfmt(sdsempty(),"%U.%U",id.ms,id.seq);
+                    mixDigest(digest,itemid,sdslen(itemid));
+                    sdsfree(itemid);
+
+                    while(numfields--) {
+                        unsigned char *field, *value;
+                        int64_t field_len, value_len;
+                        streamIteratorGetField(&si,&field,&value,
+                                                   &field_len,&value_len);
+                        mixDigest(digest,field,field_len);
+                        mixDigest(digest,value,value_len);
+                    }
+                }
+                streamIteratorStop(&si);
+            } else if (o->type == OBJ_MODULE) {
+                RedisModuleDigest md;
+                moduleValue *mv = o->ptr;
+                moduleType *mt = mv->type;
+                moduleInitDigestContext(md);
+                if (mt->digest) {
+                    mt->digest(&md,mv->value);
+                    xorDigest(digest,md.x,sizeof(md.x));
+                }
            } else {
                serverPanic("Unknown object type");
            }
@@ -253,51 +283,34 @@ void computeDatasetDigest(unsigned char *final) {
 }

 void debugCommand(client *c) {
-    if (c->argc == 1) {
-        addReplyError(c,"You must specify a subcommand for DEBUG. Try DEBUG HELP for info.");
-        return;
-    }
-
-    if (!strcasecmp(c->argv[1]->ptr,"help")) {
-        void *blenp = addDeferredMultiBulkLength(c);
-        int blen = 0;
-        blen++; addReplyStatus(c,
-        "DEBUG <subcommand> arg arg ... arg. Subcommands:");
-        blen++; addReplyStatus(c,
-        "segfault -- Crash the server with sigsegv.");
-        blen++; addReplyStatus(c,
-        "restart  -- Graceful restart: save config, db, restart.");
-        blen++; addReplyStatus(c,
-        "crash-and-recovery <milliseconds> -- Hard crash and restart after <milliseconds> delay.");
-        blen++; addReplyStatus(c,
-        "assert   -- Crash by assertion failed.");
-        blen++; addReplyStatus(c,
-        "reload   -- Save the RDB on disk and reload it back in memory.");
-        blen++; addReplyStatus(c,
-        "loadaof  -- Flush the AOF buffers on disk and reload the AOF in memory.");
-        blen++; addReplyStatus(c,
-        "object <key> -- Show low level info about key and associated value.");
-        blen++; addReplyStatus(c,
-        "sdslen <key> -- Show low level SDS string info representing key and value.");
-        blen++; addReplyStatus(c,
-        "populate <count> [prefix] -- Create <count> string keys named key:<num>. If a prefix is specified is used instead of the 'key' prefix.");
-        blen++; addReplyStatus(c,
-        "digest   -- Outputs an hex signature representing the current DB content.");
-        blen++; addReplyStatus(c,
-        "sleep <seconds> -- Stop the server for <seconds>. Decimals allowed.");
-        blen++; addReplyStatus(c,
-        "set-active-expire (0|1) -- Setting it to 0 disables expiring keys in background when they are not accessed (otherwise the Redis behavior). Setting it to 1 reenables back the default.");
-        blen++; addReplyStatus(c,
-        "lua-always-replicate-commands (0|1) -- Setting it to 1 makes Lua replication defaulting to replicating single commands, without the script having to enable effects replication.");
-        blen++; addReplyStatus(c,
-        "error <string> -- Return a Redis protocol error with <string> as message. Useful for clients unit tests to simulate Redis errors.");
-        blen++; addReplyStatus(c,
-        "structsize -- Return the size of different Redis core C structures.");
-        blen++; addReplyStatus(c,
-        "htstats <dbid> -- Return hash table statistics of the specified Redis database.");
-        setDeferredMultiBulkLength(c,blenp,blen);
+    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
+        const char *help[] = {
+"assert -- Crash by assertion failed.",
+"change-repl-id -- Change the replication IDs of the instance. Dangerous, should be used only for testing the replication subsystem.",
+"crash-and-recovery <milliseconds> -- Hard crash and restart after <milliseconds> delay.",
+"digest -- Outputs an hex signature representing the current DB content.",
+"htstats <dbid> -- Return hash table statistics of the specified Redis database.",
+"loadaof -- Flush the AOF buffers on disk and reload the AOF in memory.",
+"lua-always-replicate-commands (0|1) -- Setting it to 1 makes Lua replication defaulting to replicating single commands, without the script having to enable effects replication.",
+"object <key> -- Show low level info about key and associated value.",
+"panic -- Crash the server simulating a panic.",
+"populate <count> [prefix] [size] -- Create <count> string keys named key:<num>. If a prefix is specified is used instead of the 'key' prefix.",
+"reload -- Save the RDB on disk and reload it back in memory.",
+"restart -- Graceful restart: save config, db, restart.",
+"sdslen <key> -- Show low level SDS string info representing key and value.",
+"segfault -- Crash the server with sigsegv.",
+"set-active-expire (0|1) -- Setting it to 0 disables expiring keys in background when they are not accessed (otherwise the Redis behavior). Setting it to 1 reenables back the default.",
+"sleep <seconds> -- Stop the server for <seconds>. Decimals allowed.",
+"structsize -- Return the size of different Redis core C structures.",
+"ziplist <key> -- Show low level info about the ziplist encoding.",
+"error <string> -- Return a Redis protocol error with <string> as message. Useful for clients unit tests to simulate Redis errors.",
+NULL
+        };
+        addReplyHelp(c, help);
    } else if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
        *((char*)-1) = 'x';
+    } else if (!strcasecmp(c->argv[1]->ptr,"panic")) {
+        serverPanic("DEBUG PANIC called at Unix time %ld", time(NULL));
    } else if (!strcasecmp(c->argv[1]->ptr,"restart") ||
               !strcasecmp(c->argv[1]->ptr,"crash-and-recover"))
    {
@@ -320,12 +333,14 @@ void debugCommand(client *c) {
        if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
        serverAssertWithInfo(c,c->argv[0],1 == 2);
    } else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
-        if (rdbSave(server.rdb_filename) != C_OK) {
+        rdbSaveInfo rsi, *rsiptr;
+        rsiptr = rdbPopulateSaveInfo(&rsi);
+        if (rdbSave(server.rdb_filename,rsiptr) != C_OK) {
            addReply(c,shared.err);
            return;
        }
        emptyDb(-1,EMPTYDB_NO_FLAGS,NULL);
-        if (rdbLoad(server.rdb_filename) != C_OK) {
+        if (rdbLoad(server.rdb_filename,NULL) != C_OK) {
            addReplyError(c,"Error trying to load the RDB dump");
            return;
        }
@@ -353,13 +368,13 @@ void debugCommand(client *c) {
        val = dictGetVal(de);
        strenc = strEncoding(val->encoding);

-        char extra[128] = {0};
+        char extra[138] = {0};
        if (val->encoding == OBJ_ENCODING_QUICKLIST) {
            char *nextra = extra;
            int remaining = sizeof(extra);
            quicklist *ql = val->ptr;
            /* Add number of quicklist nodes */
-            int used = snprintf(nextra, remaining, " ql_nodes:%u", ql->len);
+            int used = snprintf(nextra, remaining, " ql_nodes:%lu", ql->len);
            nextra += used;
            remaining -= used;
            /* Add average quicklist fill factor */
@@ -418,8 +433,20 @@ void debugCommand(client *c) {
                (long long) sdsavail(val->ptr),
                (long long) getStringObjectSdsUsedMemory(val));
        }
+    } else if (!strcasecmp(c->argv[1]->ptr,"ziplist") && c->argc == 3) {
+        robj *o;
+
+        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nokeyerr))
+                == NULL) return;
+
+        if (o->encoding != OBJ_ENCODING_ZIPLIST) {
+            addReplyError(c,"Not an sds encoded string.");
+        } else {
+            ziplistRepr(o->ptr);
+            addReplyStatus(c,"Ziplist structure printed on stdout");
+        }
    } else if (!strcasecmp(c->argv[1]->ptr,"populate") &&
-               (c->argc == 3 || c->argc == 4)) {
+               c->argc >= 3 && c->argc <= 5) {
        long keys, j;
        robj *key, *val;
        char buf[128];
@@ -428,15 +455,25 @@ void debugCommand(client *c) {
            return;
        dictExpand(c->db->dict,keys);
        for (j = 0; j < keys; j++) {
+            long valsize = 0;
            snprintf(buf,sizeof(buf),"%s:%lu",
                (c->argc == 3) ? "key" : (char*)c->argv[3]->ptr, j);
            key = createStringObject(buf,strlen(buf));
+            if (c->argc == 5)
+                if (getLongFromObjectOrReply(c, c->argv[4], &valsize, NULL) != C_OK)
+                    return;
            if (lookupKeyWrite(c->db,key) != NULL) {
                decrRefCount(key);
                continue;
            }
            snprintf(buf,sizeof(buf),"value:%lu",j);
-            val = createStringObject(buf,strlen(buf));
+            if (valsize==0)
+                val = createStringObject(buf,strlen(buf));
+            else {
+                int buflen = strlen(buf);
+                val = createStringObject(NULL,valsize);
+                memcpy(val->ptr, buf, valsize<=buflen? valsize: buflen);
+            }
            dbAdd(c->db,key,val);
            signalModifiedKey(c->db,key);
            decrRefCount(key);
@@ -510,9 +547,15 @@ void debugCommand(client *c) {
        stats = sdscat(stats,buf);

        addReplyBulkSds(c,stats);
+    } else if (!strcasecmp(c->argv[1]->ptr,"change-repl-id") && c->argc == 2) {
+        serverLog(LL_WARNING,"Changing replication IDs after receiving DEBUG change-repl-id");
+        changeReplicationId();
+        clearReplicationId2();
+        addReply(c,shared.ok);
    } else {
-        addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
+        addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try DEBUG HELP",
            (char*)c->argv[1]->ptr);
+        return;
    }
 }

@@ -591,11 +634,17 @@ void _serverAssertWithInfo(const client *c, const robj *o, const char *estr, con
    _serverAssert(estr,file,line);
 }

-void _serverPanic(const char *msg, const char *file, int line) {
+void _serverPanic(const char *file, int line, const char *msg, ...) {
+    va_list ap;
+    va_start(ap,msg);
+    char fmtmsg[256];
+    vsnprintf(fmtmsg,sizeof(fmtmsg),msg,ap);
+    va_end(ap);
+
    bugReportStart();
    serverLog(LL_WARNING,"------------------------------------------------");
    serverLog(LL_WARNING,"!!! Software Failure. Press left mouse button to continue");
-    serverLog(LL_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
+    serverLog(LL_WARNING,"Guru Meditation: %s #%s:%d",fmtmsg,file,line);
 #ifdef HAVE_BACKTRACE
    serverLog(LL_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
 #endif
@@ -995,8 +1044,6 @@ void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
    /* Log INFO and CLIENT LIST */
    serverLogRaw(LL_WARNING|LL_RAW, "\n------ INFO OUTPUT ------\n");
    infostring = genRedisInfoString("all");
-    infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
-        dictGetHashFunctionSeed());
    serverLogRaw(LL_WARNING|LL_RAW, infostring);
    serverLogRaw(LL_WARNING|LL_RAW, "\n------ CLIENT LIST OUTPUT ------\n");
    clients = getAllClientsInfoString();
@@ -0,0 +1,579 @@
+/* 
+ * Active memory defragmentation
+ * Try to find key / value allocations that need to be re-allocated in order 
+ * to reduce external fragmentation.
+ * We do that by scanning the keyspace and for each pointer we have, we can try to
+ * ask the allocator if moving it to a new address will help reduce fragmentation.
+ *
+ * Copyright (c) 2017, Oran Agra
+ * Copyright (c) 2017, Redis Labs, Inc
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "server.h"
+#include <time.h>
+#include <assert.h>
+#include <stddef.h>
+
+#ifdef HAVE_DEFRAG
+
+/* this method was added to jemalloc in order to help us understand which
+ * pointers are worthwhile moving and which aren't */
+int je_get_defrag_hint(void* ptr, int *bin_util, int *run_util);
+
+/* Defrag helper for generic allocations.
+ *
+ * returns NULL in case the allocatoin wasn't moved.
+ * when it returns a non-null value, the old pointer was already released
+ * and should NOT be accessed. */
+void* activeDefragAlloc(void *ptr) {
+    int bin_util, run_util;
+    size_t size;
+    void *newptr;
+    if(!je_get_defrag_hint(ptr, &bin_util, &run_util)) {
+        server.stat_active_defrag_misses++;
+        return NULL;
+    }
+    /* if this run is more utilized than the average utilization in this bin
+     * (or it is full), skip it. This will eventually move all the allocations
+     * from relatively empty runs into relatively full runs. */
+    if (run_util > bin_util || run_util == 1<<16) {
+        server.stat_active_defrag_misses++;
+        return NULL;
+    }
+    /* move this allocation to a new allocation.
+     * make sure not to use the thread cache. so that we don't get back the same
+     * pointers we try to free */
+    size = zmalloc_size(ptr);
+    newptr = zmalloc_no_tcache(size);
+    memcpy(newptr, ptr, size);
+    zfree_no_tcache(ptr);
+    return newptr;
+}
+
+/*Defrag helper for sds strings
+ *
+ * returns NULL in case the allocatoin wasn't moved.
+ * when it returns a non-null value, the old pointer was already released
+ * and should NOT be accessed. */
+sds activeDefragSds(sds sdsptr) {
+    void* ptr = sdsAllocPtr(sdsptr);
+    void* newptr = activeDefragAlloc(ptr);
+    if (newptr) {
+        size_t offset = sdsptr - (char*)ptr;
+        sdsptr = (char*)newptr + offset;
+        return sdsptr;
+    }
+    return NULL;
+}
+
+/* Defrag helper for robj and/or string objects
+ *
+ * returns NULL in case the allocatoin wasn't moved.
+ * when it returns a non-null value, the old pointer was already released
+ * and should NOT be accessed. */
+robj *activeDefragStringOb(robj* ob, int *defragged) {
+    robj *ret = NULL;
+    if (ob->refcount!=1)
+        return NULL;
+
+    /* try to defrag robj (only if not an EMBSTR type (handled below). */
+    if (ob->type!=OBJ_STRING || ob->encoding!=OBJ_ENCODING_EMBSTR) {
+        if ((ret = activeDefragAlloc(ob))) {
+            ob = ret;
+            (*defragged)++;
+        }
+    }
+
+    /* try to defrag string object */
+    if (ob->type == OBJ_STRING) {
+        if(ob->encoding==OBJ_ENCODING_RAW) {
+            sds newsds = activeDefragSds((sds)ob->ptr);
+            if (newsds) {
+                ob->ptr = newsds;
+                (*defragged)++;
+            }
+        } else if (ob->encoding==OBJ_ENCODING_EMBSTR) {
+            /* The sds is embedded in the object allocation, calculate the
+             * offset and update the pointer in the new allocation. */
+            long ofs = (intptr_t)ob->ptr - (intptr_t)ob;
+            if ((ret = activeDefragAlloc(ob))) {
+                ret->ptr = (void*)((intptr_t)ret + ofs);
+                (*defragged)++;
+            }
+        } else if (ob->encoding!=OBJ_ENCODING_INT) {
+            serverPanic("Unknown string encoding");
+        }
+    }
+    return ret;
+}
+
+/* Defrag helper for dictEntries to be used during dict iteration (called on
+ * each step). Teturns a stat of how many pointers were moved. */
+int dictIterDefragEntry(dictIterator *iter) {
+    /* This function is a little bit dirty since it messes with the internals
+     * of the dict and it's iterator, but the benefit is that it is very easy
+     * to use, and require no other chagnes in the dict. */
+    int defragged = 0;
+    dictht *ht;
+    /* Handle the next entry (if there is one), and update the pointer in the
+     * current entry. */
+    if (iter->nextEntry) {
+        dictEntry *newde = activeDefragAlloc(iter->nextEntry);
+        if (newde) {
+            defragged++;
+            iter->nextEntry = newde;
+            iter->entry->next = newde;
+        }
+    }
+    /* handle the case of the first entry in the hash bucket. */
+    ht = &iter->d->ht[iter->table];
+    if (ht->table[iter->index] == iter->entry) {
+        dictEntry *newde = activeDefragAlloc(iter->entry);
+        if (newde) {
+            iter->entry = newde;
+            ht->table[iter->index] = newde;
+            defragged++;
+        }
+    }
+    return defragged;
+}
+
+/* Defrag helper for dict main allocations (dict struct, and hash tables).
+ * receives a pointer to the dict* and implicitly updates it when the dict
+ * struct itself was moved. Returns a stat of how many pointers were moved. */
+int dictDefragTables(dict** dictRef) {
+    dict *d = *dictRef;
+    dictEntry **newtable;
+    int defragged = 0;
+    /* handle the dict struct */
+    dict *newd = activeDefragAlloc(d);
+    if (newd)
+        defragged++, *dictRef = d = newd;
+    /* handle the first hash table */
+    newtable = activeDefragAlloc(d->ht[0].table);
+    if (newtable)
+        defragged++, d->ht[0].table = newtable;
+    /* handle the second hash table */
+    if (d->ht[1].table) {
+        newtable = activeDefragAlloc(d->ht[1].table);
+        if (newtable)
+            defragged++, d->ht[1].table = newtable;
+    }
+    return defragged;
+}
+
+/* Internal function used by zslDefrag */
+void zslUpdateNode(zskiplist *zsl, zskiplistNode *oldnode, zskiplistNode *newnode, zskiplistNode **update) {
+    int i;
+    for (i = 0; i < zsl->level; i++) {
+        if (update[i]->level[i].forward == oldnode)
+            update[i]->level[i].forward = newnode;
+    }
+    serverAssert(zsl->header!=oldnode);
+    if (newnode->level[0].forward) {
+        serverAssert(newnode->level[0].forward->backward==oldnode);
+        newnode->level[0].forward->backward = newnode;
+    } else {
+        serverAssert(zsl->tail==oldnode);
+        zsl->tail = newnode;
+    }
+}
+
+/* Defrag helper for sorted set.
+ * Update the robj pointer, defrag the skiplist struct and return the new score
+ * reference. We may not access oldele pointer (not even the pointer stored in
+ * the skiplist), as it was already freed. Newele may be null, in which case we
+ * only need to defrag the skiplist, but not update the obj pointer.
+ * When return value is non-NULL, it is the score reference that must be updated
+ * in the dict record. */
+double *zslDefrag(zskiplist *zsl, double score, sds oldele, sds newele) {
+    zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x, *newx;
+    int i;
+    sds ele = newele? newele: oldele;
+
+    /* find the skiplist node referring to the object that was moved,
+     * and all pointers that need to be updated if we'll end up moving the skiplist node. */
+    x = zsl->header;
+    for (i = zsl->level-1; i >= 0; i--) {
+        while (x->level[i].forward &&
+            x->level[i].forward->ele != oldele && /* make sure not to access the
+                                                     ->obj pointer if it matches
+                                                     oldele */
+            (x->level[i].forward->score < score ||
+                (x->level[i].forward->score == score &&
+                sdscmp(x->level[i].forward->ele,ele) < 0)))
+            x = x->level[i].forward;
+        update[i] = x;
+    }
+
+    /* update the robj pointer inside the skip list record. */
+    x = x->level[0].forward;
+    serverAssert(x && score == x->score && x->ele==oldele);
+    if (newele)
+        x->ele = newele;
+
+    /* try to defrag the skiplist record itself */
+    newx = activeDefragAlloc(x);
+    if (newx) {
+        zslUpdateNode(zsl, x, newx, update);
+        return &newx->score;
+    }
+    return NULL;
+}
+
+/* Utility function that replaces an old key pointer in the dictionary with a
+ * new pointer. Additionally, we try to defrag the dictEntry in that dict.
+ * Oldkey mey be a dead pointer and should not be accessed (we get a
+ * pre-calculated hash value). Newkey may be null if the key pointer wasn't
+ * moved. Return value is the the dictEntry if found, or NULL if not found.
+ * NOTE: this is very ugly code, but it let's us avoid the complication of
+ * doing a scan on another dict. */
+dictEntry* replaceSateliteDictKeyPtrAndOrDefragDictEntry(dict *d, sds oldkey, sds newkey, unsigned int hash, int *defragged) {
+    dictEntry **deref = dictFindEntryRefByPtrAndHash(d, oldkey, hash);
+    if (deref) {
+        dictEntry *de = *deref;
+        dictEntry *newde = activeDefragAlloc(de);
+        if (newde) {
+            de = *deref = newde;
+            (*defragged)++;
+        }
+        if (newkey)
+            de->key = newkey;
+        return de;
+    }
+    return NULL;
+}
+
+/* for each key we scan in the main dict, this function will attempt to defrag
+ * all the various pointers it has. Returns a stat of how many pointers were
+ * moved. */
+int defragKey(redisDb *db, dictEntry *de) {
+    sds keysds = dictGetKey(de);
+    robj *newob, *ob;
+    unsigned char *newzl;
+    dict *d;
+    dictIterator *di;
+    int defragged = 0;
+    sds newsds;
+
+    /* Try to defrag the key name. */
+    newsds = activeDefragSds(keysds);
+    if (newsds)
+        defragged++, de->key = newsds;
+    if (dictSize(db->expires)) {
+         /* Dirty code:
+          * I can't search in db->expires for that key after i already released
+          * the pointer it holds it won't be able to do the string compare */
+        uint64_t hash = dictGetHash(db->dict, de->key);
+        replaceSateliteDictKeyPtrAndOrDefragDictEntry(db->expires, keysds, newsds, hash, &defragged);
+    }
+
+    /* Try to defrag robj and / or string value. */
+    ob = dictGetVal(de);
+    if ((newob = activeDefragStringOb(ob, &defragged))) {
+        de->v.val = newob;
+        ob = newob;
+    }
+
+    if (ob->type == OBJ_STRING) {
+        /* Already handled in activeDefragStringOb. */
+    } else if (ob->type == OBJ_LIST) {
+        if (ob->encoding == OBJ_ENCODING_QUICKLIST) {
+            quicklist *ql = ob->ptr, *newql;
+            quicklistNode *node = ql->head, *newnode;
+            if ((newql = activeDefragAlloc(ql)))
+                defragged++, ob->ptr = ql = newql;
+            while (node) {
+                if ((newnode = activeDefragAlloc(node))) {
+                    if (newnode->prev)
+                        newnode->prev->next = newnode;
+                    else
+                        ql->head = newnode;
+                    if (newnode->next)
+                        newnode->next->prev = newnode;
+                    else
+                        ql->tail = newnode;
+                    node = newnode;
+                    defragged++;
+                }
+                if ((newzl = activeDefragAlloc(node->zl)))
+                    defragged++, node->zl = newzl;
+                node = node->next;
+            }
+        } else if (ob->encoding == OBJ_ENCODING_ZIPLIST) {
+            if ((newzl = activeDefragAlloc(ob->ptr)))
+                defragged++, ob->ptr = newzl;
+        } else {
+            serverPanic("Unknown list encoding");
+        }
+    } else if (ob->type == OBJ_SET) {
+        if (ob->encoding == OBJ_ENCODING_HT) {
+            d = ob->ptr;
+            di = dictGetIterator(d);
+            while((de = dictNext(di)) != NULL) {
+                sds sdsele = dictGetKey(de);
+                if ((newsds = activeDefragSds(sdsele)))
+                    defragged++, de->key = newsds;
+                defragged += dictIterDefragEntry(di);
+            }
+            dictReleaseIterator(di);
+            dictDefragTables((dict**)&ob->ptr);
+        } else if (ob->encoding == OBJ_ENCODING_INTSET) {
+            intset *is = ob->ptr;
+            intset *newis = activeDefragAlloc(is);
+            if (newis)
+                defragged++, ob->ptr = newis;
+        } else {
+            serverPanic("Unknown set encoding");
+        }
+    } else if (ob->type == OBJ_ZSET) {
+        if (ob->encoding == OBJ_ENCODING_ZIPLIST) {
+            if ((newzl = activeDefragAlloc(ob->ptr)))
+                defragged++, ob->ptr = newzl;
+        } else if (ob->encoding == OBJ_ENCODING_SKIPLIST) {
+            zset *zs = (zset*)ob->ptr;
+            zset *newzs;
+            zskiplist *newzsl;
+            struct zskiplistNode *newheader;
+            if ((newzs = activeDefragAlloc(zs)))
+                defragged++, ob->ptr = zs = newzs;
+            if ((newzsl = activeDefragAlloc(zs->zsl)))
+                defragged++, zs->zsl = newzsl;
+            if ((newheader = activeDefragAlloc(zs->zsl->header)))
+                defragged++, zs->zsl->header = newheader;
+            d = zs->dict;
+            di = dictGetIterator(d);
+            while((de = dictNext(di)) != NULL) {
+                double* newscore;
+                sds sdsele = dictGetKey(de);
+                if ((newsds = activeDefragSds(sdsele)))
+                    defragged++, de->key = newsds;
+                newscore = zslDefrag(zs->zsl, *(double*)dictGetVal(de), sdsele, newsds);
+                if (newscore) {
+                    dictSetVal(d, de, newscore);
+                    defragged++;
+                }
+                defragged += dictIterDefragEntry(di);
+            }
+            dictReleaseIterator(di);
+            dictDefragTables(&zs->dict);
+        } else {
+            serverPanic("Unknown sorted set encoding");
+        }
+    } else if (ob->type == OBJ_HASH) {
+        if (ob->encoding == OBJ_ENCODING_ZIPLIST) {
+            if ((newzl = activeDefragAlloc(ob->ptr)))
+                defragged++, ob->ptr = newzl;
+        } else if (ob->encoding == OBJ_ENCODING_HT) {
+            d = ob->ptr;
+            di = dictGetIterator(d);
+            while((de = dictNext(di)) != NULL) {
+                sds sdsele = dictGetKey(de);
+                if ((newsds = activeDefragSds(sdsele)))
+                    defragged++, de->key = newsds;
+                sdsele = dictGetVal(de);
+                if ((newsds = activeDefragSds(sdsele)))
+                    defragged++, de->v.val = newsds;
+                defragged += dictIterDefragEntry(di);
+            }
+            dictReleaseIterator(di);
+            dictDefragTables((dict**)&ob->ptr);
+        } else {
+            serverPanic("Unknown hash encoding");
+        }
+    } else if (ob->type == OBJ_MODULE) {
+        /* Currently defragmenting modules private data types
+         * is not supported. */
+    } else {
+        serverPanic("Unknown object type");
+    }
+    return defragged;
+}
+
+/* Defrag scan callback for the main db dictionary. */
+void defragScanCallback(void *privdata, const dictEntry *de) {
+    int defragged = defragKey((redisDb*)privdata, (dictEntry*)de);
+    server.stat_active_defrag_hits += defragged;
+    if(defragged)
+        server.stat_active_defrag_key_hits++;
+    else
+        server.stat_active_defrag_key_misses++;
+}
+
+/* Defrag scan callback for for each hash table bicket,
+ * used in order to defrag the dictEntry allocations. */
+void defragDictBucketCallback(void *privdata, dictEntry **bucketref) {
+    UNUSED(privdata);
+    while(*bucketref) {
+        dictEntry *de = *bucketref, *newde;
+        if ((newde = activeDefragAlloc(de))) {
+            *bucketref = newde;
+        }
+        bucketref = &(*bucketref)->next;
+    }
+}
+
+/* Utility function to get the fragmentation ratio from jemalloc.
+ * It is critical to do that by comparing only heap maps that belown to
+ * jemalloc, and skip ones the jemalloc keeps as spare. Since we use this
+ * fragmentation ratio in order to decide if a defrag action should be taken
+ * or not, a false detection can cause the defragmenter to waste a lot of CPU
+ * without the possibility of getting any results. */
+float getAllocatorFragmentation(size_t *out_frag_bytes) {
+    size_t epoch = 1, allocated = 0, resident = 0, active = 0, sz = sizeof(size_t);
+    /* Update the statistics cached by mallctl. */
+    je_mallctl("epoch", &epoch, &sz, &epoch, sz);
+    /* Unlike RSS, this does not include RSS from shared libraries and other non
+     * heap mappings. */
+    je_mallctl("stats.resident", &resident, &sz, NULL, 0);
+    /* Unlike resident, this doesn't not include the pages jemalloc reserves
+     * for re-use (purge will clean that). */
+    je_mallctl("stats.active", &active, &sz, NULL, 0);
+    /* Unlike zmalloc_used_memory, this matches the stats.resident by taking
+     * into account all allocations done by this process (not only zmalloc). */
+    je_mallctl("stats.allocated", &allocated, &sz, NULL, 0);
+    float frag_pct = ((float)active / allocated)*100 - 100;
+    size_t frag_bytes = active - allocated;
+    float rss_pct = ((float)resident / allocated)*100 - 100;
+    size_t rss_bytes = resident - allocated;
+    if(out_frag_bytes)
+        *out_frag_bytes = frag_bytes;
+    serverLog(LL_DEBUG,
+        "allocated=%zu, active=%zu, resident=%zu, frag=%.0f%% (%.0f%% rss), frag_bytes=%zu (%zu%% rss)",
+        allocated, active, resident, frag_pct, rss_pct, frag_bytes, rss_bytes);
+    return frag_pct;
+}
+
+#define INTERPOLATE(x, x1, x2, y1, y2) ( (y1) + ((x)-(x1)) * ((y2)-(y1)) / ((x2)-(x1)) )
+#define LIMIT(y, min, max) ((y)<(min)? min: ((y)>(max)? max: (y)))
+
+/* Perform incremental defragmentation work from the serverCron.
+ * This works in a similar way to activeExpireCycle, in the sense that
+ * we do incremental work across calls. */
+void activeDefragCycle(void) {
+    static int current_db = -1;
+    static unsigned long cursor = 0;
+    static redisDb *db = NULL;
+    static long long start_scan, start_stat;
+    unsigned int iterations = 0;
+    unsigned long long defragged = server.stat_active_defrag_hits;
+    long long start, timelimit;
+
+    if (server.aof_child_pid!=-1 || server.rdb_child_pid!=-1)
+        return; /* Defragging memory while there's a fork will just do damage. */
+
+    /* Once a second, check if we the fragmentation justfies starting a scan
+     * or making it more aggressive. */
+    run_with_period(1000) {
+        size_t frag_bytes;
+        float frag_pct = getAllocatorFragmentation(&frag_bytes);
+        /* If we're not already running, and below the threshold, exit. */
+        if (!server.active_defrag_running) {
+            if(frag_pct < server.active_defrag_threshold_lower || frag_bytes < server.active_defrag_ignore_bytes)
+                return;
+        }
+
+        /* Calculate the adaptive aggressiveness of the defrag */
+        int cpu_pct = INTERPOLATE(frag_pct,
+                server.active_defrag_threshold_lower,
+                server.active_defrag_threshold_upper,
+                server.active_defrag_cycle_min,
+                server.active_defrag_cycle_max);
+        cpu_pct = LIMIT(cpu_pct,
+                server.active_defrag_cycle_min,
+                server.active_defrag_cycle_max);
+         /* We allow increasing the aggressiveness during a scan, but don't
+          * reduce it. */
+        if (!server.active_defrag_running ||
+            cpu_pct > server.active_defrag_running)
+        {
+            server.active_defrag_running = cpu_pct;
+            serverLog(LL_VERBOSE,
+                "Starting active defrag, frag=%.0f%%, frag_bytes=%zu, cpu=%d%%",
+                frag_pct, frag_bytes, cpu_pct);
+        }
+    }
+    if (!server.active_defrag_running)
+        return;
+
+    /* See activeExpireCycle for how timelimit is handled. */
+    start = ustime();
+    timelimit = 1000000*server.active_defrag_running/server.hz/100;
+    if (timelimit <= 0) timelimit = 1;
+
+    do {
+        if (!cursor) {
+            /* Move on to next database, and stop if we reached the last one. */
+            if (++current_db >= server.dbnum) {
+                long long now = ustime();
+                size_t frag_bytes;
+                float frag_pct = getAllocatorFragmentation(&frag_bytes);
+                serverLog(LL_VERBOSE,
+                    "Active defrag done in %dms, reallocated=%d, frag=%.0f%%, frag_bytes=%zu",
+                    (int)((now - start_scan)/1000), (int)(server.stat_active_defrag_hits - start_stat), frag_pct, frag_bytes);
+
+                start_scan = now;
+                current_db = -1;
+                cursor = 0;
+                db = NULL;
+                server.active_defrag_running = 0;
+                return;
+            }
+            else if (current_db==0) {
+                /* Start a scan from the first database. */
+                start_scan = ustime();
+                start_stat = server.stat_active_defrag_hits;
+            }
+
+            db = &server.db[current_db];
+            cursor = 0;
+        }
+
+        do {
+            cursor = dictScan(db->dict, cursor, defragScanCallback, defragDictBucketCallback, db);
+            /* Once in 16 scan iterations, or 1000 pointer reallocations
+             * (if we have a lot of pointers in one hash bucket), check if we
+             * reached the tiem limit. */
+            if (cursor && (++iterations > 16 || server.stat_active_defrag_hits - defragged > 1000)) {
+                if ((ustime() - start) > timelimit) {
+                    return;
+                }
+                iterations = 0;
+                defragged = server.stat_active_defrag_hits;
+            }
+        } while(cursor);
+    } while(1);
+}
+
+#else /* HAVE_DEFRAG */
+
+void activeDefragCycle(void) {
+    /* Not implemented yet. */
+}
+
+#endif
@@ -37,11 +37,11 @@

 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include <string.h>
 #include <stdarg.h>
 #include <limits.h>
 #include <sys/time.h>
-#include <ctype.h>

 #include "dict.h"
 #include "zmalloc.h"
@@ -66,82 +66,33 @@ static unsigned int dict_force_resize_ratio = 5;

 static int _dictExpandIfNeeded(dict *ht);
 static unsigned long _dictNextPower(unsigned long size);
-static int _dictKeyIndex(dict *ht, const void *key, unsigned int hash, dictEntry **existing);
+static long _dictKeyIndex(dict *ht, const void *key, uint64_t hash, dictEntry **existing);
 static int _dictInit(dict *ht, dictType *type, void *privDataPtr);

 /* -------------------------- hash functions -------------------------------- */

-static uint32_t dict_hash_function_seed = 5381;
+static uint8_t dict_hash_function_seed[16];

-void dictSetHashFunctionSeed(uint32_t seed) {
-    dict_hash_function_seed = seed;
+void dictSetHashFunctionSeed(uint8_t *seed) {
+    memcpy(dict_hash_function_seed,seed,sizeof(dict_hash_function_seed));
 }

-uint32_t dictGetHashFunctionSeed(void) {
+uint8_t *dictGetHashFunctionSeed(void) {
    return dict_hash_function_seed;
 }

-/* MurmurHash2, by Austin Appleby
- * Note - This code makes a few assumptions about how your machine behaves -
- * 1. We can read a 4-byte value from any address without crashing
- * 2. sizeof(int) == 4
- *
- * And it has a few limitations -
- *
- * 1. It will not work incrementally.
- * 2. It will not produce the same results on little-endian and big-endian
- *    machines.
- */
-unsigned int dictGenHashFunction(const void *key, int len) {
-    /* 'm' and 'r' are mixing constants generated offline.
-     They're not really 'magic', they just happen to work well.  */
-    uint32_t seed = dict_hash_function_seed;
-    const uint32_t m = 0x5bd1e995;
-    const int r = 24;
+/* The default hashing function uses SipHash implementation
+ * in siphash.c. */

-    /* Initialize the hash to a 'random' value */
-    uint32_t h = seed ^ len;
+uint64_t siphash(const uint8_t *in, const size_t inlen, const uint8_t *k);
+uint64_t siphash_nocase(const uint8_t *in, const size_t inlen, const uint8_t *k);

-    /* Mix 4 bytes at a time into the hash */
-    const unsigned char *data = (const unsigned char *)key;
-
-    while(len >= 4) {
-        uint32_t k = *(uint32_t*)data;
-
-        k *= m;
-        k ^= k >> r;
-        k *= m;
-
-        h *= m;
-        h ^= k;
-
-        data += 4;
-        len -= 4;
-    }
-
-    /* Handle the last few bytes of the input array  */
-    switch(len) {
-    case 3: h ^= data[2] << 16;
-    case 2: h ^= data[1] << 8;
-    case 1: h ^= data[0]; h *= m;
-    };
-
-    /* Do a few final mixes of the hash to ensure the last few
-     * bytes are well-incorporated. */
-    h ^= h >> 13;
-    h *= m;
-    h ^= h >> 15;
-
-    return (unsigned int)h;
+uint64_t dictGenHashFunction(const void *key, int len) {
+    return siphash(key,len,dict_hash_function_seed);
 }

-/* And a case insensitive hash function (based on djb hash) */
-unsigned int dictGenCaseHashFunction(const unsigned char *buf, int len) {
-    unsigned int hash = (unsigned int)dict_hash_function_seed;
-
-    while (len--)
-        hash = ((hash << 5) + hash) + (tolower(*buf++)); /* hash * 33 + c */
-    return hash;
+uint64_t dictGenCaseHashFunction(const unsigned char *buf, int len) {
+    return siphash_nocase(buf,len,dict_hash_function_seed);
 }

 /* ----------------------------- API implementation ------------------------- */
@@ -251,7 +202,7 @@ int dictRehash(dict *d, int n) {
        de = d->ht[0].table[d->rehashidx];
        /* Move all the keys in this bucket from the old to the new hash HT */
        while(de) {
-            unsigned int h;
+            uint64_t h;

            nextde = de->next;
            /* Get the index in the new hash table */
@@ -340,7 +291,7 @@ int dictAdd(dict *d, void *key, void *val)
 */
 dictEntry *dictAddRaw(dict *d, void *key, dictEntry **existing)
 {
-    int index;
+    long index;
    dictEntry *entry;
    dictht *ht;

@@ -411,7 +362,7 @@ dictEntry *dictAddOrFind(dict *d, void *key) {
 * dictDelete() and dictUnlink(), please check the top comment
 * of those functions. */
 static dictEntry *dictGenericDelete(dict *d, const void *key, int nofree) {
-    unsigned int h, idx;
+    uint64_t h, idx;
    dictEntry *he, *prevHe;
    int table;

@@ -525,7 +476,7 @@ void dictRelease(dict *d)
 dictEntry *dictFind(dict *d, const void *key)
 {
    dictEntry *he;
-    unsigned int h, idx, table;
+    uint64_t h, idx, table;

    if (d->ht[0].used + d->ht[1].used == 0) return NULL; /* dict is empty */
    if (dictIsRehashing(d)) _dictRehashStep(d);
@@ -659,7 +610,7 @@ void dictReleaseIterator(dictIterator *iter)
 dictEntry *dictGetRandomKey(dict *d)
 {
    dictEntry *he, *orighe;
-    unsigned int h;
+    unsigned long h;
    int listlen, listele;

    if (dictSize(d) == 0) return NULL;
@@ -885,6 +836,7 @@ static unsigned long rev(unsigned long v) {
 unsigned long dictScan(dict *d,
                       unsigned long v,
                       dictScanFunction *fn,
+                       dictScanBucketFunction* bucketfn,
                       void *privdata)
 {
    dictht *t0, *t1;
@@ -898,6 +850,7 @@ unsigned long dictScan(dict *d,
        m0 = t0->sizemask;

        /* Emit entries at cursor */
+        if (bucketfn) bucketfn(privdata, &t0->table[v & m0]);
        de = t0->table[v & m0];
        while (de) {
            next = de->next;
@@ -919,6 +872,7 @@ unsigned long dictScan(dict *d,
        m1 = t1->sizemask;

        /* Emit entries at cursor */
+        if (bucketfn) bucketfn(privdata, &t0->table[v & m0]);
        de = t0->table[v & m0];
        while (de) {
            next = de->next;
@@ -930,6 +884,7 @@ unsigned long dictScan(dict *d,
         * of the index pointed to by the cursor in the smaller table */
        do {
            /* Emit entries at cursor */
+            if (bucketfn) bucketfn(privdata, &t1->table[v & m1]);
            de = t1->table[v & m1];
            while (de) {
                next = de->next;
@@ -985,7 +940,7 @@ static unsigned long _dictNextPower(unsigned long size)
 {
    unsigned long i = DICT_HT_INITIAL_SIZE;

-    if (size >= LONG_MAX) return LONG_MAX;
+    if (size >= LONG_MAX) return LONG_MAX + 1LU;
    while(1) {
        if (i >= size)
            return i;
@@ -1000,9 +955,9 @@ static unsigned long _dictNextPower(unsigned long size)
 *
 * Note that if we are in the process of rehashing the hash table, the
 * index is always returned in the context of the second (new) hash table. */
-static int _dictKeyIndex(dict *d, const void *key, unsigned int hash, dictEntry **existing)
+static long _dictKeyIndex(dict *d, const void *key, uint64_t hash, dictEntry **existing)
 {
-    unsigned int idx, table;
+    unsigned long idx, table;
    dictEntry *he;
    if (existing) *existing = NULL;

@@ -1040,6 +995,35 @@ void dictDisableResize(void) {
    dict_can_resize = 0;
 }

+uint64_t dictGetHash(dict *d, const void *key) {
+    return dictHashKey(d, key);
+}
+
+/* Finds the dictEntry reference by using pointer and pre-calculated hash.
+ * oldkey is a dead pointer and should not be accessed.
+ * the hash value should be provided using dictGetHash.
+ * no string / key comparison is performed.
+ * return value is the reference to the dictEntry if found, or NULL if not found. */
+dictEntry **dictFindEntryRefByPtrAndHash(dict *d, const void *oldptr, uint64_t hash) {
+    dictEntry *he, **heref;
+    unsigned long idx, table;
+
+    if (d->ht[0].used + d->ht[1].used == 0) return NULL; /* dict is empty */
+    for (table = 0; table <= 1; table++) {
+        idx = hash & d->ht[table].sizemask;
+        heref = &d->ht[table].table[idx];
+        he = *heref;
+        while(he) {
+            if (oldptr==he->key)
+                return heref;
+            heref = &he->next;
+            he = *heref;
+        }
+        if (!dictIsRehashing(d)) return NULL;
+    }
+    return NULL;
+}
+
 /* ------------------------------- Debugging ---------------------------------*/

 #define DICT_STATS_VECTLEN 50
@@ -1125,7 +1109,7 @@ void dictGetStats(char *buf, size_t bufsize, dict *d) {

 #include "sds.h"

-unsigned int hashCallback(const void *key) {
+uint64_t hashCallback(const void *key) {
    return dictGenHashFunction((unsigned char*)key, sdslen((char*)key));
 }

@@ -56,7 +56,7 @@ typedef struct dictEntry {
 } dictEntry;

 typedef struct dictType {
-    unsigned int (*hashFunction)(const void *key);
+    uint64_t (*hashFunction)(const void *key);
    void *(*keyDup)(void *privdata, const void *key);
    void *(*valDup)(void *privdata, const void *obj);
    int (*keyCompare)(void *privdata, const void *key1, const void *key2);
@@ -95,6 +95,7 @@ typedef struct dictIterator {
 } dictIterator;

 typedef void (dictScanFunction)(void *privdata, const dictEntry *de);
+typedef void (dictScanBucketFunction)(void *privdata, dictEntry **bucketref);

 /* This is the initial size of every hash table */
 #define DICT_HT_INITIAL_SIZE     4
@@ -167,16 +168,18 @@ void dictReleaseIterator(dictIterator *iter);
 dictEntry *dictGetRandomKey(dict *d);
 unsigned int dictGetSomeKeys(dict *d, dictEntry **des, unsigned int count);
 void dictGetStats(char *buf, size_t bufsize, dict *d);
-unsigned int dictGenHashFunction(const void *key, int len);
-unsigned int dictGenCaseHashFunction(const unsigned char *buf, int len);
+uint64_t dictGenHashFunction(const void *key, int len);
+uint64_t dictGenCaseHashFunction(const unsigned char *buf, int len);
 void dictEmpty(dict *d, void(callback)(void*));
 void dictEnableResize(void);
 void dictDisableResize(void);
 int dictRehash(dict *d, int n);
 int dictRehashMilliseconds(dict *d, int ms);
-void dictSetHashFunctionSeed(unsigned int initval);
-unsigned int dictGetHashFunctionSeed(void);
-unsigned long dictScan(dict *d, unsigned long v, dictScanFunction *fn, void *privdata);
+void dictSetHashFunctionSeed(uint8_t *seed);
+uint8_t *dictGetHashFunctionSeed(void);
+unsigned long dictScan(dict *d, unsigned long v, dictScanFunction *fn, dictScanBucketFunction *bucketfn, void *privdata);
+uint64_t dictGetHash(dict *d, const void *key);
+dictEntry **dictFindEntryRefByPtrAndHash(dict *d, const void *oldptr, uint64_t hash);

 /* Hash table types */
 extern dictType dictTypeHeapStringCopyKey;
@@ -32,6 +32,7 @@

 #include "server.h"
 #include "bio.h"
+#include "atomicvar.h"

 /* ----------------------------------------------------------------------------
 * Data structures
@@ -59,8 +60,6 @@ struct evictionPoolEntry {

 static struct evictionPoolEntry *EvictionPoolLRU;

-unsigned long LFUDecrAndReturn(robj *o);
-
 /* ----------------------------------------------------------------------------
 * Implementation of eviction, aging and LRU
 * --------------------------------------------------------------------------*/
@@ -72,6 +71,20 @@ unsigned int getLRUClock(void) {
    return (mstime()/LRU_CLOCK_RESOLUTION) & LRU_CLOCK_MAX;
 }

+/* This function is used to obtain the current LRU clock.
+ * If the current resolution is lower than the frequency we refresh the
+ * LRU clock (as it should be in production servers) we return the
+ * precomputed value, otherwise we need to resort to a system call. */
+unsigned int LRU_CLOCK(void) {
+    unsigned int lruclock;
+    if (1000/server.hz <= LRU_CLOCK_RESOLUTION) {
+        atomicGet(server.lruclock,lruclock);
+    } else {
+        lruclock = getLRUClock();
+    }
+    return lruclock;
+}
+
 /* Given an object returns the min number of milliseconds the object was never
 * requested, using an approximated LRU algorithm. */
 unsigned long long estimateObjectIdleTime(robj *o) {
@@ -287,8 +300,8 @@ unsigned long LFUGetTimeInMinutes(void) {
    return (server.unixtime/60) & 65535;
 }

-/* Given an object last decrement time, compute the minimum number of minutes
- * that elapsed since the last decrement. Handle overflow (ldt greater than
+/* Given an object last access time, compute the minimum number of minutes
+ * that elapsed since the last access. Handle overflow (ldt greater than
 * the current 16 bits minutes time) considering the time as wrapping
 * exactly once. */
 unsigned long LFUTimeElapsed(unsigned long ldt) {
@@ -309,25 +322,22 @@ uint8_t LFULogIncr(uint8_t counter) {
    return counter;
 }

-/* If the object decrement time is reached, decrement the LFU counter and
- * update the decrement time field. Return the object frequency counter.
+/* If the object decrement time is reached decrement the LFU counter but
+ * do not update LFU fields of the object, we update the access time
+ * and counter in an explicit way when the object is really accessed.
+ * And we will times halve the counter according to the times of
+ * elapsed time than server.lfu_decay_time.
+ * Return the object frequency counter.
 *
 * This function is used in order to scan the dataset for the best object
 * to fit: as we check for the candidate, we incrementally decrement the
 * counter of the scanned objects if needed. */
-#define LFU_DECR_INTERVAL 1
 unsigned long LFUDecrAndReturn(robj *o) {
    unsigned long ldt = o->lru >> 8;
    unsigned long counter = o->lru & 255;
-    if (LFUTimeElapsed(ldt) >= server.lfu_decay_time && counter) {
-        if (counter > LFU_INIT_VAL*2) {
-            counter /= 2;
-            if (counter < LFU_INIT_VAL*2) counter = LFU_INIT_VAL*2;
-        } else {
-            counter--;
-        }
-        o->lru = (LFUGetTimeInMinutes()<<8) | counter;
-    }
+    unsigned long num_periods = server.lfu_decay_time ? LFUTimeElapsed(ldt) / server.lfu_decay_time : 0;
+    if (num_periods)
+        counter = (num_periods > counter) ? 0 : counter - num_periods;
    return counter;
 }

@@ -336,11 +346,39 @@ unsigned long LFUDecrAndReturn(robj *o) {
 * server when there is data to add in order to make space if needed.
 * --------------------------------------------------------------------------*/

+/* We don't want to count AOF buffers and slaves output buffers as
+ * used memory: the eviction should use mostly data size. This function
+ * returns the sum of AOF and slaves buffer. */
+size_t freeMemoryGetNotCountedMemory(void) {
+    size_t overhead = 0;
+    int slaves = listLength(server.slaves);
+
+    if (slaves) {
+        listIter li;
+        listNode *ln;
+
+        listRewind(server.slaves,&li);
+        while((ln = listNext(&li))) {
+            client *slave = listNodeValue(ln);
+            overhead += getClientOutputBufferMemoryUsage(slave);
+        }
+    }
+    if (server.aof_state != AOF_OFF) {
+        overhead += sdslen(server.aof_buf)+aofRewriteBufferSize();
+    }
+    return overhead;
+}
+
 int freeMemoryIfNeeded(void) {
    size_t mem_reported, mem_used, mem_tofree, mem_freed;
-    int slaves = listLength(server.slaves);
    mstime_t latency, eviction_latency;
    long long delta;
+    int slaves = listLength(server.slaves);
+
+    /* When clients are paused the dataset should be static not just from the
+     * POV of clients not being able to write, but also from the POV of
+     * expires and evictions of keys not being performed. */
+    if (clientsArePaused()) return C_OK;

    /* Check if we are over the memory usage limit. If we are not, no need
     * to subtract the slaves output buffers. We can just return ASAP. */
@@ -350,24 +388,8 @@ int freeMemoryIfNeeded(void) {
    /* Remove the size of slaves output buffers and AOF buffer from the
     * count of used memory. */
    mem_used = mem_reported;
-    if (slaves) {
-        listIter li;
-        listNode *ln;
-
-        listRewind(server.slaves,&li);
-        while((ln = listNext(&li))) {
-            client *slave = listNodeValue(ln);
-            unsigned long obuf_bytes = getClientOutputBufferMemoryUsage(slave);
-            if (obuf_bytes > mem_used)
-                mem_used = 0;
-            else
-                mem_used -= obuf_bytes;
-        }
-    }
-    if (server.aof_state != AOF_OFF) {
-        mem_used -= sdslen(server.aof_buf);
-        mem_used -= aofRewriteBufferSize();
-    }
+    size_t overhead = freeMemoryGetNotCountedMemory();
+    mem_used = (mem_used > overhead) ? mem_used-overhead : 0;

    /* Check if we are still over the memory limit. */
    if (mem_used <= server.maxmemory) return C_OK;
@@ -498,6 +520,22 @@ int freeMemoryIfNeeded(void) {
             * deliver data to the slaves fast enough, so we force the
             * transmission here inside the loop. */
            if (slaves) flushSlavesOutputBuffers();
+
+            /* Normally our stop condition is the ability to release
+             * a fixed, pre-computed amount of memory. However when we
+             * are deleting objects in another thread, it's better to
+             * check, from time to time, if we already reached our target
+             * memory, since the "mem_freed" amount is computed only
+             * across the dbAsyncDelete() call, while the thread can
+             * release the memory all the time. */
+            if (server.lazyfree_lazy_eviction && !(keys_freed % 16)) {
+                overhead = freeMemoryGetNotCountedMemory();
+                mem_used = zmalloc_used_memory();
+                mem_used = (mem_used > overhead) ? mem_used-overhead : 0;
+                if (mem_used <= server.maxmemory) {
+                    mem_freed = mem_tofree;
+                }
+            }
        }

        if (!keys_freed) {
@@ -92,7 +92,7 @@ int activeExpireCycleTryExpire(redisDb *db, dictEntry *de, long long now) {
 *
 * If type is ACTIVE_EXPIRE_CYCLE_SLOW, that normal expire cycle is
 * executed, where the time limit is a percentage of the REDIS_HZ period
- * as specified by the REDIS_EXPIRELOOKUPS_TIME_PERC define. */
+ * as specified by the ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC define. */

 void activeExpireCycle(int type) {
    /* This function has some global state in order to continue the work
@@ -103,7 +103,12 @@ void activeExpireCycle(int type) {

    int j, iteration = 0;
    int dbs_per_call = CRON_DBS_PER_CALL;
-    long long start = ustime(), timelimit;
+    long long start = ustime(), timelimit, elapsed;
+
+    /* When clients are paused the dataset should be static not just from the
+     * POV of clients not being able to write, but also from the POV of
+     * expires and evictions of keys not being performed. */
+    if (clientsArePaused()) return;

    if (type == ACTIVE_EXPIRE_CYCLE_FAST) {
        /* Don't start a fast cycle if the previous cycle did not exited
@@ -135,7 +140,7 @@ void activeExpireCycle(int type) {
    if (type == ACTIVE_EXPIRE_CYCLE_FAST)
        timelimit = ACTIVE_EXPIRE_CYCLE_FAST_DURATION; /* in microseconds. */

-    for (j = 0; j < dbs_per_call; j++) {
+    for (j = 0; j < dbs_per_call && timelimit_exit == 0; j++) {
        int expired;
        redisDb *db = server.db+(current_db % server.dbnum);

@@ -150,6 +155,7 @@ void activeExpireCycle(int type) {
            unsigned long num, slots;
            long long now, ttl_sum;
            int ttl_samples;
+            iteration++;

            /* If there is nothing to expire try next DB ASAP. */
            if ((num = dictSize(db->expires)) == 0) {
@@ -202,18 +208,168 @@ void activeExpireCycle(int type) {
            /* We can't block forever here even if there are many keys to
             * expire. So after a given amount of milliseconds return to the
             * caller waiting for the other active expire cycle. */
-            iteration++;
            if ((iteration & 0xf) == 0) { /* check once every 16 iterations. */
-                long long elapsed = ustime()-start;
-
-                latencyAddSampleIfNeeded("expire-cycle",elapsed/1000);
-                if (elapsed > timelimit) timelimit_exit = 1;
+                elapsed = ustime()-start;
+                if (elapsed > timelimit) {
+                    timelimit_exit = 1;
+                    break;
+                }
            }
-            if (timelimit_exit) return;
            /* We don't repeat the cycle if there are less than 25% of keys
             * found expired in the current DB. */
        } while (expired > ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP/4);
    }
+
+    elapsed = ustime()-start;
+    latencyAddSampleIfNeeded("expire-cycle",elapsed/1000);
+}
+
+/*-----------------------------------------------------------------------------
+ * Expires of keys created in writable slaves
+ *
+ * Normally slaves do not process expires: they wait the masters to synthesize
+ * DEL operations in order to retain consistency. However writable slaves are
+ * an exception: if a key is created in the slave and an expire is assigned
+ * to it, we need a way to expire such a key, since the master does not know
+ * anything about such a key.
+ *
+ * In order to do so, we track keys created in the slave side with an expire
+ * set, and call the expireSlaveKeys() function from time to time in order to
+ * reclaim the keys if they already expired.
+ *
+ * Note that the use case we are trying to cover here, is a popular one where
+ * slaves are put in writable mode in order to compute slow operations in
+ * the slave side that are mostly useful to actually read data in a more
+ * processed way. Think at sets intersections in a tmp key, with an expire so
+ * that it is also used as a cache to avoid intersecting every time.
+ *
+ * This implementation is currently not perfect but a lot better than leaking
+ * the keys as implemented in 3.2.
+ *----------------------------------------------------------------------------*/
+
+/* The dictionary where we remember key names and database ID of keys we may
+ * want to expire from the slave. Since this function is not often used we
+ * don't even care to initialize the database at startup. We'll do it once
+ * the feature is used the first time, that is, when rememberSlaveKeyWithExpire()
+ * is called.
+ *
+ * The dictionary has an SDS string representing the key as the hash table
+ * key, while the value is a 64 bit unsigned integer with the bits corresponding
+ * to the DB where the keys may exist set to 1. Currently the keys created
+ * with a DB id > 63 are not expired, but a trivial fix is to set the bitmap
+ * to the max 64 bit unsigned value when we know there is a key with a DB
+ * ID greater than 63, and check all the configured DBs in such a case. */
+dict *slaveKeysWithExpire = NULL;
+
+/* Check the set of keys created by the master with an expire set in order to
+ * check if they should be evicted. */
+void expireSlaveKeys(void) {
+    if (slaveKeysWithExpire == NULL ||
+        dictSize(slaveKeysWithExpire) == 0) return;
+
+    int cycles = 0, noexpire = 0;
+    mstime_t start = mstime();
+    while(1) {
+        dictEntry *de = dictGetRandomKey(slaveKeysWithExpire);
+        sds keyname = dictGetKey(de);
+        uint64_t dbids = dictGetUnsignedIntegerVal(de);
+        uint64_t new_dbids = 0;
+
+        /* Check the key against every database corresponding to the
+         * bits set in the value bitmap. */
+        int dbid = 0;
+        while(dbids && dbid < server.dbnum) {
+            if ((dbids & 1) != 0) {
+                redisDb *db = server.db+dbid;
+                dictEntry *expire = dictFind(db->expires,keyname);
+                int expired = 0;
+
+                if (expire &&
+                    activeExpireCycleTryExpire(server.db+dbid,expire,start))
+                {
+                    expired = 1;
+                }
+
+                /* If the key was not expired in this DB, we need to set the
+                 * corresponding bit in the new bitmap we set as value.
+                 * At the end of the loop if the bitmap is zero, it means we
+                 * no longer need to keep track of this key. */
+                if (expire && !expired) {
+                    noexpire++;
+                    new_dbids |= (uint64_t)1 << dbid;
+                }
+            }
+            dbid++;
+            dbids >>= 1;
+        }
+
+        /* Set the new bitmap as value of the key, in the dictionary
+         * of keys with an expire set directly in the writable slave. Otherwise
+         * if the bitmap is zero, we no longer need to keep track of it. */
+        if (new_dbids)
+            dictSetUnsignedIntegerVal(de,new_dbids);
+        else
+            dictDelete(slaveKeysWithExpire,keyname);
+
+        /* Stop conditions: found 3 keys we cna't expire in a row or
+         * time limit was reached. */
+        cycles++;
+        if (noexpire > 3) break;
+        if ((cycles % 64) == 0 && mstime()-start > 1) break;
+        if (dictSize(slaveKeysWithExpire) == 0) break;
+    }
+}
+
+/* Track keys that received an EXPIRE or similar command in the context
+ * of a writable slave. */
+void rememberSlaveKeyWithExpire(redisDb *db, robj *key) {
+    if (slaveKeysWithExpire == NULL) {
+        static dictType dt = {
+            dictSdsHash,                /* hash function */
+            NULL,                       /* key dup */
+            NULL,                       /* val dup */
+            dictSdsKeyCompare,          /* key compare */
+            dictSdsDestructor,          /* key destructor */
+            NULL                        /* val destructor */
+        };
+        slaveKeysWithExpire = dictCreate(&dt,NULL);
+    }
+    if (db->id > 63) return;
+
+    dictEntry *de = dictAddOrFind(slaveKeysWithExpire,key->ptr);
+    /* If the entry was just created, set it to a copy of the SDS string
+     * representing the key: we don't want to need to take those keys
+     * in sync with the main DB. The keys will be removed by expireSlaveKeys()
+     * as it scans to find keys to remove. */
+    if (de->key == key->ptr) {
+        de->key = sdsdup(key->ptr);
+        dictSetUnsignedIntegerVal(de,0);
+    }
+
+    uint64_t dbids = dictGetUnsignedIntegerVal(de);
+    dbids |= (uint64_t)1 << db->id;
+    dictSetUnsignedIntegerVal(de,dbids);
+}
+
+/* Return the number of keys we are tracking. */
+size_t getSlaveKeyWithExpireCount(void) {
+    if (slaveKeysWithExpire == NULL) return 0;
+    return dictSize(slaveKeysWithExpire);
+}
+
+/* Remove the keys in the hash table. We need to do that when data is
+ * flushed from the server. We may receive new keys from the master with
+ * the same name/db and it is no longer a good idea to expire them.
+ *
+ * Note: technically we should handle the case of a single DB being flushed
+ * but it is not worth it since anyway race conditions using the same set
+ * of key names in a wriatable slave and in its master will lead to
+ * inconsistencies. This is just a best-effort thing we do. */
+void flushSlaveKeysWithExpireList(void) {
+    if (slaveKeysWithExpire) {
+        dictRelease(slaveKeysWithExpire);
+        slaveKeysWithExpire = NULL;
+    }
 }

 /*-----------------------------------------------------------------------------
@@ -265,7 +421,7 @@ void expireGenericCommand(client *c, long long basetime, int unit) {
        addReply(c, shared.cone);
        return;
    } else {
-        setExpire(c->db,key,when);
+        setExpire(c,c->db,key,when);
        addReply(c,shared.cone);
        signalModifiedKey(c->db,key);
        notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",key,c->db->id);
@@ -329,18 +485,15 @@ void pttlCommand(client *c) {

 /* PERSIST key */
 void persistCommand(client *c) {
-    dictEntry *de;
-
-    de = dictFind(c->db->dict,c->argv[1]->ptr);
-    if (de == NULL) {
-        addReply(c,shared.czero);
-    } else {
+    if (lookupKeyWrite(c->db,c->argv[1])) {
        if (removeExpire(c->db,c->argv[1])) {
            addReply(c,shared.cone);
            server.dirty++;
        } else {
            addReply(c,shared.czero);
        }
+    } else {
+        addReply(c,shared.czero);
    }
 }

@@ -161,7 +161,7 @@ double extractDistanceOrReply(client *c, robj **argv,
        addReplyError(c,"radius cannot be negative");
        return -1;
    }
-    
+
    double to_meters = extractUnitOrReply(c,argv[1]);
    if (to_meters < 0) {
        return -1;
@@ -326,6 +326,7 @@ int membersOfGeoHashBox(robj *zobj, GeoHashBits hash, geoArray *ga, double lon,
 int membersOfAllNeighbors(robj *zobj, GeoHashRadius n, double lon, double lat, double radius, geoArray *ga) {
    GeoHashBits neighbors[9];
    unsigned int i, count = 0, last_processed = 0;
+    int debugmsg = 0;

    neighbors[0] = n.hash;
    neighbors[1] = n.neighbors.north;
@@ -340,8 +341,26 @@ int membersOfAllNeighbors(robj *zobj, GeoHashRadius n, double lon, double lat, d
    /* For each neighbor (*and* our own hashbox), get all the matching
     * members and add them to the potential result list. */
    for (i = 0; i < sizeof(neighbors) / sizeof(*neighbors); i++) {
-        if (HASHISZERO(neighbors[i]))
+        if (HASHISZERO(neighbors[i])) {
+            if (debugmsg) D("neighbors[%d] is zero",i);
            continue;
+        }
+
+        /* Debugging info. */
+        if (debugmsg) {
+            GeoHashRange long_range, lat_range;
+            geohashGetCoordRange(&long_range,&lat_range);
+            GeoHashArea myarea = {{0}};
+            geohashDecode(long_range, lat_range, neighbors[i], &myarea);
+
+            /* Dump center square. */
+            D("neighbors[%d]:\n",i);
+            D("area.longitude.min: %f\n", myarea.longitude.min);
+            D("area.longitude.max: %f\n", myarea.longitude.max);
+            D("area.latitude.min: %f\n", myarea.latitude.min);
+            D("area.latitude.max: %f\n", myarea.latitude.max);
+            D("\n");
+        }

        /* When a huge Radius (in the 5000 km range or more) is used,
         * adjacent neighbors can be the same, leading to duplicated
@@ -350,7 +369,11 @@ int membersOfAllNeighbors(robj *zobj, GeoHashRadius n, double lon, double lat, d
        if (last_processed &&
            neighbors[i].bits == neighbors[last_processed].bits &&
            neighbors[i].step == neighbors[last_processed].step)
+        {
+            if (debugmsg)
+                D("Skipping processing of %d, same as previous\n",i);
            continue;
+        }
        count += membersOfGeoHashBox(zobj, neighbors[i], ga, lon, lat, radius);
        last_processed = i;
    }
@@ -429,13 +452,14 @@ void geoaddCommand(client *c) {
 #define SORT_ASC 1
 #define SORT_DESC 2

-#define RADIUS_COORDS 1
-#define RADIUS_MEMBER 2
+#define RADIUS_COORDS (1<<0)    /* Search around coordinates. */
+#define RADIUS_MEMBER (1<<1)    /* Search around member. */
+#define RADIUS_NOSTORE (1<<2)   /* Do not acceot STORE/STOREDIST option. */

 /* GEORADIUS key x y radius unit [WITHDIST] [WITHHASH] [WITHCOORD] [ASC|DESC]
 *                               [COUNT count] [STORE key] [STOREDIST key]
 * GEORADIUSBYMEMBER key member radius unit ... options ... */
-void georadiusGeneric(client *c, int type) {
+void georadiusGeneric(client *c, int flags) {
    robj *key = c->argv[1];
    robj *storekey = NULL;
    int storedist = 0; /* 0 for STORE, 1 for STOREDIST. */
@@ -450,11 +474,11 @@ void georadiusGeneric(client *c, int type) {
    /* Find long/lat to use for radius search based on inquiry type */
    int base_args;
    double xy[2] = { 0 };
-    if (type == RADIUS_COORDS) {
+    if (flags & RADIUS_COORDS) {
        base_args = 6;
        if (extractLongLatOrReply(c, c->argv + 2, xy) == C_ERR)
            return;
-    } else if (type == RADIUS_MEMBER) {
+    } else if (flags & RADIUS_MEMBER) {
        base_args = 5;
        robj *member = c->argv[2];
        if (longLatFromMember(zobj, member, xy) == C_ERR) {
@@ -462,7 +486,7 @@ void georadiusGeneric(client *c, int type) {
            return;
        }
    } else {
-        addReplyError(c, "unknown georadius search type");
+        addReplyError(c, "Unknown georadius search type");
        return;
    }

@@ -499,11 +523,17 @@ void georadiusGeneric(client *c, int type) {
                    return;
                }
                i++;
-            } else if (!strcasecmp(arg, "store") && (i+1) < remaining) {
+            } else if (!strcasecmp(arg, "store") &&
+                       (i+1) < remaining &&
+                       !(flags & RADIUS_NOSTORE))
+            {
                storekey = c->argv[base_args+i+1];
                storedist = 0;
                i++;
-            } else if (!strcasecmp(arg, "storedist") && (i+1) < remaining) {
+            } else if (!strcasecmp(arg, "storedist") &&
+                       (i+1) < remaining &&
+                       !(flags & RADIUS_NOSTORE))
+            {
                storekey = c->argv[base_args+i+1];
                storedist = 1;
                i++;
@@ -648,10 +678,20 @@ void georadiusCommand(client *c) {
 }

 /* GEORADIUSBYMEMBER wrapper function. */
-void georadiusByMemberCommand(client *c) {
+void georadiusbymemberCommand(client *c) {
    georadiusGeneric(c, RADIUS_MEMBER);
 }

+/* GEORADIUS_RO wrapper function. */
+void georadiusroCommand(client *c) {
+    georadiusGeneric(c, RADIUS_COORDS|RADIUS_NOSTORE);
+}
+
+/* GEORADIUSBYMEMBER_RO wrapper function. */
+void georadiusbymemberroCommand(client *c) {
+    georadiusGeneric(c, RADIUS_MEMBER|RADIUS_NOSTORE);
+}
+
 /* GEOHASH key ele1 ele2 ... eleN
 *
 * Returns an array with an 11 characters geohash representation of the
@@ -661,16 +701,15 @@ void geohashCommand(client *c) {
    int j;

    /* Look up the requested zset */
-    robj *zobj = NULL;
-    if ((zobj = lookupKeyReadOrReply(c, c->argv[1], shared.emptymultibulk))
-        == NULL || checkType(c, zobj, OBJ_ZSET)) return;
+    robj *zobj = lookupKeyRead(c->db, c->argv[1]);
+    if (zobj && checkType(c, zobj, OBJ_ZSET)) return;

    /* Geohash elements one after the other, using a null bulk reply for
     * missing elements. */
    addReplyMultiBulkLen(c,c->argc-2);
    for (j = 2; j < c->argc; j++) {
        double score;
-        if (zsetScore(zobj, c->argv[j]->ptr, &score) == C_ERR) {
+        if (!zobj || zsetScore(zobj, c->argv[j]->ptr, &score) == C_ERR) {
            addReply(c,shared.nullbulk);
        } else {
            /* The internal format we use for geocoding is a bit different
@@ -715,16 +754,15 @@ void geoposCommand(client *c) {
    int j;

    /* Look up the requested zset */
-    robj *zobj = NULL;
-    if ((zobj = lookupKeyReadOrReply(c, c->argv[1], shared.emptymultibulk))
-        == NULL || checkType(c, zobj, OBJ_ZSET)) return;
+    robj *zobj = lookupKeyRead(c->db, c->argv[1]);
+    if (zobj && checkType(c, zobj, OBJ_ZSET)) return;

    /* Report elements one after the other, using a null bulk reply for
     * missing elements. */
    addReplyMultiBulkLen(c,c->argc-2);
    for (j = 2; j < c->argc; j++) {
        double score;
-        if (zsetScore(zobj, c->argv[j]->ptr, &score) == C_ERR) {
+        if (!zobj || zsetScore(zobj, c->argv[j]->ptr, &score) == C_ERR) {
            addReply(c,shared.nullmultibulk);
        } else {
            /* Decode... */
@@ -759,7 +797,7 @@ void geodistCommand(client *c) {

    /* Look up the requested zset */
    robj *zobj = NULL;
-    if ((zobj = lookupKeyReadOrReply(c, c->argv[1], shared.emptybulk))
+    if ((zobj = lookupKeyReadOrReply(c, c->argv[1], shared.nullbulk))
        == NULL || checkType(c, zobj, OBJ_ZSET)) return;

    /* Get the scores. We need both otherwise NULL is returned. */
@@ -82,30 +82,32 @@ uint8_t geohashEstimateStepsByRadius(double range_meters, double lat) {
    return step;
 }

+/* Return the bounding box of the search area centered at latitude,longitude
+ * having a radius of radius_meter. bounds[0] - bounds[2] is the minimum
+ * and maxium longitude, while bounds[1] - bounds[3] is the minimum and
+ * maximum latitude.
+ *
+ * This function does not behave correctly with very large radius values, for
+ * instance for the coordinates 81.634948934258375 30.561509253718668 and a
+ * radius of 7083 kilometers, it reports as bounding boxes:
+ *
+ * min_lon 7.680495, min_lat -33.119473, max_lon 155.589402, max_lat 94.242491
+ *
+ * However, for instance, a min_lon of 7.680495 is not correct, because the
+ * point -1.27579540014266968 61.33421815228281559 is at less than 7000
+ * kilometers away.
+ *
+ * Since this function is currently only used as an optimization, the
+ * optimization is not used for very big radiuses, however the function
+ * should be fixed. */
 int geohashBoundingBox(double longitude, double latitude, double radius_meters,
                       double *bounds) {
    if (!bounds) return 0;

-    double lonr, latr;
-    lonr = deg_rad(longitude);
-    latr = deg_rad(latitude);
-
-    if (radius_meters > EARTH_RADIUS_IN_METERS)
-        radius_meters = EARTH_RADIUS_IN_METERS;
-    double distance = radius_meters / EARTH_RADIUS_IN_METERS;
-    double min_latitude = latr - distance;
-    double max_latitude = latr + distance;
-
-    /* Note: we're being lazy and not accounting for coordinates near poles */
-    double min_longitude, max_longitude;
-    double difference_longitude = asin(sin(distance) / cos(latr));
-    min_longitude = lonr - difference_longitude;
-    max_longitude = lonr + difference_longitude;
-
-    bounds[0] = rad_deg(min_longitude);
-    bounds[1] = rad_deg(min_latitude);
-    bounds[2] = rad_deg(max_longitude);
-    bounds[3] = rad_deg(max_latitude);
+    bounds[0] = longitude - rad_deg(radius_meters/EARTH_RADIUS_IN_METERS/cos(deg_rad(latitude)));
+    bounds[2] = longitude + rad_deg(radius_meters/EARTH_RADIUS_IN_METERS/cos(deg_rad(latitude)));
+    bounds[1] = latitude - rad_deg(radius_meters/EARTH_RADIUS_IN_METERS);
+    bounds[3] = latitude + rad_deg(radius_meters/EARTH_RADIUS_IN_METERS);
    return 1;
 }

@@ -158,55 +160,35 @@ GeoHashRadius geohashGetAreasByRadius(double longitude, double latitude, double
            < radius_meters) decrease_step = 1;
    }

-    if (decrease_step) {
+    if (steps > 1 && decrease_step) {
        steps--;
        geohashEncode(&long_range,&lat_range,longitude,latitude,steps,&hash);
        geohashNeighbors(&hash,&neighbors);
        geohashDecode(long_range,lat_range,hash,&area);
    }

-    /* Example debug info. This turns to be very useful every time there is
-     * to investigate radius search potential bugs. So better to leave it
-     * here. */
-    if (0) {
-        GeoHashArea myarea = {{0}};
-        geohashDecode(long_range, lat_range, neighbors.west, &myarea);
-
-        /* Dump West. */
-        D("Neighbors");
-        D("area.longitude.min: %f\n", myarea.longitude.min);
-        D("area.longitude.max: %f\n", myarea.longitude.max);
-        D("area.latitude.min: %f\n", myarea.latitude.min);
-        D("area.latitude.max: %f\n", myarea.latitude.max);
-
-        /* Dump center square. */
-        D("Area");
-        D("area.longitude.min: %f\n", area.longitude.min);
-        D("area.longitude.max: %f\n", area.longitude.max);
-        D("area.latitude.min: %f\n", area.latitude.min);
-        D("area.latitude.max: %f\n", area.latitude.max);
-    }
-
    /* Exclude the search areas that are useless. */
-    if (area.latitude.min < min_lat) {
-        GZERO(neighbors.south);
-        GZERO(neighbors.south_west);
-        GZERO(neighbors.south_east);
-    }
-    if (area.latitude.max > max_lat) {
-        GZERO(neighbors.north);
-        GZERO(neighbors.north_east);
-        GZERO(neighbors.north_west);
-    }
-    if (area.longitude.min < min_lon) {
-        GZERO(neighbors.west);
-        GZERO(neighbors.south_west);
-        GZERO(neighbors.north_west);
-    }
-    if (area.longitude.max > max_lon) {
-        GZERO(neighbors.east);
-        GZERO(neighbors.south_east);
-        GZERO(neighbors.north_east);
+    if (steps >= 2) {
+        if (area.latitude.min < min_lat) {
+            GZERO(neighbors.south);
+            GZERO(neighbors.south_west);
+            GZERO(neighbors.south_east);
+        }
+        if (area.latitude.max > max_lat) {
+            GZERO(neighbors.north);
+            GZERO(neighbors.north_east);
+            GZERO(neighbors.north_west);
+        }
+        if (area.longitude.min < min_lon) {
+            GZERO(neighbors.west);
+            GZERO(neighbors.south_west);
+            GZERO(neighbors.north_west);
+        }
+        if (area.longitude.max > max_lon) {
+            GZERO(neighbors.east);
+            GZERO(neighbors.south_east);
+            GZERO(neighbors.north_east);
+        }
    }
    radius.hash = hash;
    radius.neighbors = neighbors;
@@ -401,7 +401,11 @@ uint64_t MurmurHash64A (const void * key, int len, unsigned int seed) {
        uint64_t k;

 #if (BYTE_ORDER == LITTLE_ENDIAN)
+	#ifdef USE_ALIGNED_ACCESS
+	memcpy(&k,data,sizeof(uint64_t));
+	#else
        k = *((uint64_t*)data);
+	#endif
 #else
        k = (uint64_t) data[0];
        k |= (uint64_t) data[1] << 8;
@@ -994,32 +998,21 @@ uint64_t hllCount(struct hllhdr *hdr, int *invalid) {
        serverPanic("Unknown HyperLogLog encoding in hllCount()");
    }

-    /* Muliply the inverse of E for alpha_m * m^2 to have the raw estimate. */
-    E = (1/E)*alpha*m*m;
+    /* Apply loglog-beta to the raw estimate. See:
+     * "LogLog-Beta and More: A New Algorithm for Cardinality Estimation
+     * Based on LogLog Counting" Jason Qin, Denys Kim, Yumei Tung
+     * arXiv:1612.02284 */
+    double zl = log(ez + 1);
+    double beta = -0.370393911*ez +
+                   0.070471823*zl +
+                   0.17393686*pow(zl,2) +
+                   0.16339839*pow(zl,3) +
+                  -0.09237745*pow(zl,4) +
+                   0.03738027*pow(zl,5) +
+                  -0.005384159*pow(zl,6) +
+                   0.00042419*pow(zl,7);

-    /* Use the LINEARCOUNTING algorithm for small cardinalities.
-     * For larger values but up to 72000 HyperLogLog raw approximation is
-     * used since linear counting error starts to increase. However HyperLogLog
-     * shows a strong bias in the range 2.5*16384 - 72000, so we try to
-     * compensate for it. */
-    if (E < m*2.5 && ez != 0) {
-        E = m*log(m/ez); /* LINEARCOUNTING() */
-    } else if (m == 16384 && E < 72000) {
-        /* We did polynomial regression of the bias for this range, this
-         * way we can compute the bias for a given cardinality and correct
-         * according to it. Only apply the correction for P=14 that's what
-         * we use and the value the correction was verified with. */
-        double bias = 5.9119*1.0e-18*(E*E*E*E)
-                      -1.4253*1.0e-12*(E*E*E)+
-                      1.2940*1.0e-7*(E*E)
-                      -5.2921*1.0e-3*E+
-                      83.3216;
-        E -= E*(bias/100);
-    }
-    /* We don't apply the correction for E > 1/30 of 2^32 since we use
-     * a 64 bit function and 6 bit counters. To apply the correction for
-     * 1/30 of 2^64 is not needed since it would require a huge set
-     * to approach such a value. */
+    E  = llroundl(alpha*m*(m-ez)*(1/(E+beta)));
    return (uint64_t) E;
 }

@@ -1128,6 +1121,7 @@ int isHLLObjectOrReply(client *c, robj *o) {
    if (checkType(c,o,OBJ_STRING))
        return C_ERR; /* Error already sent. */

+    if (!sdsEncodedObject(o)) goto invalid;
    if (stringObjectLen(o) < sizeof(*hdr)) goto invalid;
    hdr = o->ptr;

@@ -261,7 +261,7 @@ int64_t intsetRandom(intset *is) {
    return _intsetGet(is,rand()%intrev32ifbe(is->length));
 }

-/* Sets the value to the value at the given position. When this position is
+/* Get the value at the given position. When this position is
 * out of range the function returns 0, when in range it returns 1. */
 uint8_t intsetGet(intset *is, uint32_t pos, int64_t *value) {
    if (pos < intrev32ifbe(is->length)) {
@@ -41,7 +41,7 @@ int dictStringKeyCompare(void *privdata, const void *key1, const void *key2) {
    return strcmp(key1,key2) == 0;
 }

-unsigned int dictStringHash(const void *key) {
+uint64_t dictStringHash(const void *key) {
    return dictGenHashFunction(key, strlen(key));
 }

@@ -8,7 +8,9 @@ pthread_mutex_t lazyfree_objects_mutex = PTHREAD_MUTEX_INITIALIZER;

 /* Return the number of currently pending objects to free. */
 size_t lazyfreeGetPendingObjectsCount(void) {
-    return lazyfree_objects;
+    size_t aux;
+    atomicGet(lazyfree_objects,aux);
+    return aux;
 }

 /* Return the amount of work needed in order to free an object.
@@ -65,7 +67,7 @@ int dbAsyncDelete(redisDb *db, robj *key) {
        /* If releasing the object is too much work, let's put it into the
         * lazy free list. */
        if (free_effort > LAZYFREE_THRESHOLD) {
-            atomicIncr(lazyfree_objects,1,lazyfree_objects_mutex);
+            atomicIncr(lazyfree_objects,1);
            bioCreateBackgroundJob(BIO_LAZY_FREE,val,NULL,NULL);
            dictSetVal(db->dict,de,NULL);
        }
@@ -89,26 +91,27 @@ void emptyDbAsync(redisDb *db) {
    dict *oldht1 = db->dict, *oldht2 = db->expires;
    db->dict = dictCreate(&dbDictType,NULL);
    db->expires = dictCreate(&keyptrDictType,NULL);
-    atomicIncr(lazyfree_objects,dictSize(oldht1),
-        lazyfree_objects_mutex);
+    atomicIncr(lazyfree_objects,dictSize(oldht1));
    bioCreateBackgroundJob(BIO_LAZY_FREE,NULL,oldht1,oldht2);
 }

 /* Empty the slots-keys map of Redis CLuster by creating a new empty one
 * and scheduiling the old for lazy freeing. */
 void slotToKeyFlushAsync(void) {
-    zskiplist *oldsl = server.cluster->slots_to_keys;
-    server.cluster->slots_to_keys = zslCreate();
-    atomicIncr(lazyfree_objects,oldsl->length,
-        lazyfree_objects_mutex);
-    bioCreateBackgroundJob(BIO_LAZY_FREE,NULL,NULL,oldsl);
+    rax *old = server.cluster->slots_to_keys;
+
+    server.cluster->slots_to_keys = raxNew();
+    memset(server.cluster->slots_keys_count,0,
+           sizeof(server.cluster->slots_keys_count));
+    atomicIncr(lazyfree_objects,old->numele);
+    bioCreateBackgroundJob(BIO_LAZY_FREE,NULL,NULL,old);
 }

 /* Release objects from the lazyfree thread. It's just decrRefCount()
 * updating the count of objects to release. */
 void lazyfreeFreeObjectFromBioThread(robj *o) {
    decrRefCount(o);
-    atomicDecr(lazyfree_objects,1,lazyfree_objects_mutex);
+    atomicDecr(lazyfree_objects,1);
 }

 /* Release a database from the lazyfree thread. The 'db' pointer is the
@@ -120,13 +123,13 @@ void lazyfreeFreeDatabaseFromBioThread(dict *ht1, dict *ht2) {
    size_t numkeys = dictSize(ht1);
    dictRelease(ht1);
    dictRelease(ht2);
-    atomicDecr(lazyfree_objects,numkeys,lazyfree_objects_mutex);
+    atomicDecr(lazyfree_objects,numkeys);
 }

 /* Release the skiplist mapping Redis Cluster keys to slots in the
 * lazyfree thread. */
-void lazyfreeFreeSlotsMapFromBioThread(zskiplist *sl) {
-    size_t len = sl->length;
-    zslFree(sl);
-    atomicDecr(lazyfree_objects,len,lazyfree_objects_mutex);
+void lazyfreeFreeSlotsMapFromBioThread(rax *rt) {
+    size_t len = rt->numele;
+    raxFree(rt);
+    atomicDecr(lazyfree_objects,len);
 }
@@ -0,0 +1,783 @@
+/* Listpack -- A lists of strings serialization format
+ *
+ * This file implements the specification you can find at:
+ *
+ *  https://github.com/antirez/listpack
+ *
+ * Copyright (c) 2017, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "listpack.h"
+#include "listpack_malloc.h"
+
+#define LP_HDR_SIZE 6       /* 32 bit total len + 16 bit number of elements. */
+#define LP_HDR_NUMELE_UNKNOWN UINT16_MAX
+#define LP_MAX_INT_ENCODING_LEN 9
+#define LP_MAX_BACKLEN_SIZE 5
+#define LP_MAX_ENTRY_BACKLEN 34359738367ULL
+#define LP_ENCODING_INT 0
+#define LP_ENCODING_STRING 1
+
+#define LP_ENCODING_7BIT_UINT 0
+#define LP_ENCODING_7BIT_UINT_MASK 0x80
+#define LP_ENCODING_IS_7BIT_UINT(byte) (((byte)&LP_ENCODING_7BIT_UINT_MASK)==LP_ENCODING_7BIT_UINT)
+
+#define LP_ENCODING_6BIT_STR 0x80
+#define LP_ENCODING_6BIT_STR_MASK 0xC0
+#define LP_ENCODING_IS_6BIT_STR(byte) (((byte)&LP_ENCODING_6BIT_STR_MASK)==LP_ENCODING_6BIT_STR)
+
+#define LP_ENCODING_13BIT_INT 0xC0
+#define LP_ENCODING_13BIT_INT_MASK 0xE0
+#define LP_ENCODING_IS_13BIT_INT(byte) (((byte)&LP_ENCODING_13BIT_INT_MASK)==LP_ENCODING_13BIT_INT)
+
+#define LP_ENCODING_12BIT_STR 0xE0
+#define LP_ENCODING_12BIT_STR_MASK 0xF0
+#define LP_ENCODING_IS_12BIT_STR(byte) (((byte)&LP_ENCODING_12BIT_STR_MASK)==LP_ENCODING_12BIT_STR)
+
+#define LP_ENCODING_16BIT_INT 0xF1
+#define LP_ENCODING_16BIT_INT_MASK 0xFF
+#define LP_ENCODING_IS_16BIT_INT(byte) (((byte)&LP_ENCODING_16BIT_INT_MASK)==LP_ENCODING_16BIT_INT)
+
+#define LP_ENCODING_24BIT_INT 0xF2
+#define LP_ENCODING_24BIT_INT_MASK 0xFF
+#define LP_ENCODING_IS_24BIT_INT(byte) (((byte)&LP_ENCODING_24BIT_INT_MASK)==LP_ENCODING_24BIT_INT)
+
+#define LP_ENCODING_32BIT_INT 0xF3
+#define LP_ENCODING_32BIT_INT_MASK 0xFF
+#define LP_ENCODING_IS_32BIT_INT(byte) (((byte)&LP_ENCODING_32BIT_INT_MASK)==LP_ENCODING_32BIT_INT)
+
+#define LP_ENCODING_64BIT_INT 0xF4
+#define LP_ENCODING_64BIT_INT_MASK 0xFF
+#define LP_ENCODING_IS_64BIT_INT(byte) (((byte)&LP_ENCODING_64BIT_INT_MASK)==LP_ENCODING_64BIT_INT)
+
+#define LP_ENCODING_32BIT_STR 0xF0
+#define LP_ENCODING_32BIT_STR_MASK 0xFF
+#define LP_ENCODING_IS_32BIT_STR(byte) (((byte)&LP_ENCODING_32BIT_STR_MASK)==LP_ENCODING_32BIT_STR)
+
+#define LP_EOF 0xFF
+
+#define LP_ENCODING_6BIT_STR_LEN(p) ((p)[0] & 0x3F)
+#define LP_ENCODING_12BIT_STR_LEN(p) ((((p)[0] & 0xF) << 8) | (p)[1])
+#define LP_ENCODING_32BIT_STR_LEN(p) (((uint32_t)(p)[1]<<0) | \
+                                      ((uint32_t)(p)[2]<<8) | \
+                                      ((uint32_t)(p)[3]<<16) | \
+                                      ((uint32_t)(p)[4]<<24))
+
+#define lpGetTotalBytes(p)           (((uint32_t)(p)[0]<<0) | \
+                                      ((uint32_t)(p)[1]<<8) | \
+                                      ((uint32_t)(p)[2]<<16) | \
+                                      ((uint32_t)(p)[3]<<24))
+
+#define lpGetNumElements(p)          (((uint32_t)(p)[4]<<0) | \
+                                      ((uint32_t)(p)[5]<<8))
+#define lpSetTotalBytes(p,v) do { \
+    (p)[0] = (v)&0xff; \
+    (p)[1] = ((v)>>8)&0xff; \
+    (p)[2] = ((v)>>16)&0xff; \
+    (p)[3] = ((v)>>24)&0xff; \
+} while(0)
+
+#define lpSetNumElements(p,v) do { \
+    (p)[4] = (v)&0xff; \
+    (p)[5] = ((v)>>8)&0xff; \
+} while(0)
+
+/* Convert a string into a signed 64 bit integer.
+ * The function returns 1 if the string could be parsed into a (non-overflowing)
+ * signed 64 bit int, 0 otherwise. The 'value' will be set to the parsed value
+ * when the function returns success.
+ *
+ * Note that this function demands that the string strictly represents
+ * a int64 value: no spaces or other characters before or after the string
+ * representing the number are accepted, nor zeroes at the start if not
+ * for the string "0" representing the zero number.
+ *
+ * Because of its strictness, it is safe to use this function to check if
+ * you can convert a string into a long long, and obtain back the string
+ * from the number without any loss in the string representation. *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Credits: this function was adapted from the Redis source code, file
+ * "utils.c", function string2ll(), and is copyright:
+ *
+ * Copyright(C) 2011, Pieter Noordhuis
+ * Copyright(C) 2011, Salvatore Sanfilippo
+ *
+ * The function is released under the BSD 3-clause license.
+ */
+int lpStringToInt64(const char *s, unsigned long slen, int64_t *value) {
+    const char *p = s;
+    unsigned long plen = 0;
+    int negative = 0;
+    uint64_t v;
+
+    if (plen == slen)
+        return 0;
+
+    /* Special case: first and only digit is 0. */
+    if (slen == 1 && p[0] == '0') {
+        if (value != NULL) *value = 0;
+        return 1;
+    }
+
+    if (p[0] == '-') {
+        negative = 1;
+        p++; plen++;
+
+        /* Abort on only a negative sign. */
+        if (plen == slen)
+            return 0;
+    }
+
+    /* First digit should be 1-9, otherwise the string should just be 0. */
+    if (p[0] >= '1' && p[0] <= '9') {
+        v = p[0]-'0';
+        p++; plen++;
+    } else if (p[0] == '0' && slen == 1) {
+        *value = 0;
+        return 1;
+    } else {
+        return 0;
+    }
+
+    while (plen < slen && p[0] >= '0' && p[0] <= '9') {
+        if (v > (UINT64_MAX / 10)) /* Overflow. */
+            return 0;
+        v *= 10;
+
+        if (v > (UINT64_MAX - (p[0]-'0'))) /* Overflow. */
+            return 0;
+        v += p[0]-'0';
+
+        p++; plen++;
+    }
+
+    /* Return if not all bytes were used. */
+    if (plen < slen)
+        return 0;
+
+    if (negative) {
+        if (v > ((uint64_t)(-(INT64_MIN+1))+1)) /* Overflow. */
+            return 0;
+        if (value != NULL) *value = -v;
+    } else {
+        if (v > INT64_MAX) /* Overflow. */
+            return 0;
+        if (value != NULL) *value = v;
+    }
+    return 1;
+}
+
+/* Create a new, empty listpack.
+ * On success the new listpack is returned, otherwise an error is returned. */
+unsigned char *lpNew(void) {
+    unsigned char *lp = lp_malloc(LP_HDR_SIZE+1);
+    if (lp == NULL) return NULL;
+    lpSetTotalBytes(lp,LP_HDR_SIZE+1);
+    lpSetNumElements(lp,0);
+    lp[LP_HDR_SIZE] = LP_EOF;
+    return lp;
+}
+
+/* Free the specified listpack. */
+void lpFree(unsigned char *lp) {
+    lp_free(lp);
+}
+
+/* Given an element 'ele' of size 'size', determine if the element can be
+ * represented inside the listpack encoded as integer, and returns
+ * LP_ENCODING_INT if so. Otherwise returns LP_ENCODING_STR if no integer
+ * encoding is possible.
+ *
+ * If the LP_ENCODING_INT is returned, the function stores the integer encoded
+ * representation of the element in the 'intenc' buffer.
+ *
+ * Regardless of the returned encoding, 'enclen' is populated by reference to
+ * the number of bytes that the string or integer encoded element will require
+ * in order to be represented. */
+int lpEncodeGetType(unsigned char *ele, uint32_t size, unsigned char *intenc, uint64_t *enclen) {
+    int64_t v;
+    if (lpStringToInt64((const char*)ele, size, &v)) {
+        if (v >= 0 && v <= 127) {
+            /* Single byte 0-127 integer. */
+            intenc[0] = v;
+            *enclen = 1;
+        } else if (v >= -4096 && v <= 4095) {
+            /* 13 bit integer. */
+            if (v < 0) v = ((int64_t)1<<13)+v;
+            intenc[0] = (v>>8)|LP_ENCODING_13BIT_INT;
+            intenc[1] = v&0xff;
+            *enclen = 2;
+        } else if (v >= -32768 && v <= 32767) {
+            /* 16 bit integer. */
+            if (v < 0) v = ((int64_t)1<<16)+v;
+            intenc[0] = LP_ENCODING_16BIT_INT;
+            intenc[1] = v&0xff;
+            intenc[2] = v>>8;
+            *enclen = 3;
+        } else if (v >= -8388608 && v <= 8388607) {
+            /* 24 bit integer. */
+            if (v < 0) v = ((int64_t)1<<24)+v;
+            intenc[0] = LP_ENCODING_24BIT_INT;
+            intenc[1] = v&0xff;
+            intenc[2] = (v>>8)&0xff;
+            intenc[3] = v>>16;
+            *enclen = 4;
+        } else if (v >= -2147483648 && v <= 2147483647) {
+            /* 32 bit integer. */
+            if (v < 0) v = ((int64_t)1<<32)+v;
+            intenc[0] = LP_ENCODING_32BIT_INT;
+            intenc[1] = v&0xff;
+            intenc[2] = (v>>8)&0xff;
+            intenc[3] = (v>>16)&0xff;
+            intenc[4] = v>>24;
+            *enclen = 5;
+        } else {
+            /* 64 bit integer. */
+            uint64_t uv = v;
+            intenc[0] = LP_ENCODING_64BIT_INT;
+            intenc[1] = uv&0xff;
+            intenc[2] = (uv>>8)&0xff;
+            intenc[3] = (uv>>16)&0xff;
+            intenc[4] = (uv>>24)&0xff;
+            intenc[5] = (uv>>32)&0xff;
+            intenc[6] = (uv>>40)&0xff;
+            intenc[7] = (uv>>48)&0xff;
+            intenc[8] = uv>>56;
+            *enclen = 9;
+        }
+        return LP_ENCODING_INT;
+    } else {
+        if (size < 64) *enclen = 1+size;
+        else if (size < 4096) *enclen = 2+size;
+        else *enclen = 5+size;
+        return LP_ENCODING_STRING;
+    }
+}
+
+/* Store a reverse-encoded variable length field, representing the length
+ * of the previous element of size 'l', in the target buffer 'buf'.
+ * The function returns the number of bytes used to encode it, from
+ * 1 to 5. If 'buf' is NULL the funciton just returns the number of bytes
+ * needed in order to encode the backlen. */
+unsigned long lpEncodeBacklen(unsigned char *buf, uint64_t l) {
+    if (l <= 127) {
+        if (buf) buf[0] = l;
+        return 1;
+    } else if (l < 16383) {
+        if (buf) {
+            buf[0] = l>>7;
+            buf[1] = (l&127)|128;
+        }
+        return 2;
+    } else if (l < 2097151) {
+        if (buf) {
+            buf[0] = l>>14;
+            buf[1] = ((l>>7)&127)|128;
+            buf[2] = (l&127)|128;
+        }
+        return 3;
+    } else if (l < 268435455) {
+        if (buf) {
+            buf[0] = l>>21;
+            buf[1] = ((l>>14)&127)|128;
+            buf[2] = ((l>>7)&127)|128;
+            buf[3] = (l&127)|128;
+        }
+        return 4;
+    } else {
+        if (buf) {
+            buf[0] = l>>28;
+            buf[1] = ((l>>21)&127)|128;
+            buf[2] = ((l>>14)&127)|128;
+            buf[3] = ((l>>7)&127)|128;
+            buf[4] = (l&127)|128;
+        }
+        return 5;
+    }
+}
+
+/* Decode the backlen and returns it. If the encoding looks invalid (more than
+ * 5 bytes are used), UINT64_MAX is returned to report the problem. */
+uint64_t lpDecodeBacklen(unsigned char *p) {
+    uint64_t val = 0;
+    uint64_t shift = 0;
+    do {
+        val |= (uint64_t)(p[0] & 127) << shift;
+        if (!(p[0] & 128)) break;
+        shift += 7;
+        p--;
+        if (shift > 28) return UINT64_MAX;
+    } while(1);
+    return val;
+}
+
+/* Encode the string element pointed by 's' of size 'len' in the target
+ * buffer 's'. The function should be called with 'buf' having always enough
+ * space for encoding the string. This is done by calling lpEncodeGetType()
+ * before calling this function. */
+void lpEncodeString(unsigned char *buf, unsigned char *s, uint32_t len) {
+    if (len < 64) {
+        buf[0] = len | LP_ENCODING_6BIT_STR;
+        memcpy(buf+1,s,len);
+    } else if (len < 4096) {
+        buf[0] = (len >> 8) | LP_ENCODING_12BIT_STR;
+        buf[1] = len & 0xff;
+        memcpy(buf+2,s,len);
+    } else {
+        buf[0] = LP_ENCODING_32BIT_STR;
+        buf[1] = len & 0xff;
+        buf[2] = (len >> 8) & 0xff;
+        buf[3] = (len >> 16) & 0xff;
+        buf[4] = (len >> 24) & 0xff;
+        memcpy(buf+5,s,len);
+    }
+}
+
+/* Return the encoded length of the listpack element pointed by 'p'. If the
+ * element encoding is wrong then 0 is returned. */
+uint32_t lpCurrentEncodedSize(unsigned char *p) {
+    if (LP_ENCODING_IS_7BIT_UINT(p[0])) return 1;
+    if (LP_ENCODING_IS_6BIT_STR(p[0])) return 1+LP_ENCODING_6BIT_STR_LEN(p);
+    if (LP_ENCODING_IS_13BIT_INT(p[0])) return 2;
+    if (LP_ENCODING_IS_16BIT_INT(p[0])) return 3;
+    if (LP_ENCODING_IS_24BIT_INT(p[0])) return 4;
+    if (LP_ENCODING_IS_32BIT_INT(p[0])) return 5;
+    if (LP_ENCODING_IS_64BIT_INT(p[0])) return 9;
+    if (LP_ENCODING_IS_12BIT_STR(p[0])) return 2+LP_ENCODING_12BIT_STR_LEN(p);
+    if (LP_ENCODING_IS_32BIT_STR(p[0])) return 5+LP_ENCODING_32BIT_STR_LEN(p);
+    if (p[0] == LP_EOF) return 1;
+    return 0;
+}
+
+/* Skip the current entry returning the next. It is invalid to call this
+ * function if the current element is the EOF element at the end of the
+ * listpack, however, while this function is used to implement lpNext(),
+ * it does not return NULL when the EOF element is encountered. */
+unsigned char *lpSkip(unsigned char *p) {
+    unsigned long entrylen = lpCurrentEncodedSize(p);
+    entrylen += lpEncodeBacklen(NULL,entrylen);
+    p += entrylen;
+    return p;
+}
+
+/* If 'p' points to an element of the listpack, calling lpNext() will return
+ * the pointer to the next element (the one on the right), or NULL if 'p'
+ * already pointed to the last element of the listpack. */
+unsigned char *lpNext(unsigned char *lp, unsigned char *p) {
+    ((void) lp); /* lp is not used for now. However lpPrev() uses it. */
+    p = lpSkip(p);
+    if (p[0] == LP_EOF) return NULL;
+    return p;
+}
+
+/* If 'p' points to an element of the listpack, calling lpPrev() will return
+ * the pointer to the preivous element (the one on the left), or NULL if 'p'
+ * already pointed to the first element of the listpack. */
+unsigned char *lpPrev(unsigned char *lp, unsigned char *p) {
+    if (p-lp == LP_HDR_SIZE) return NULL;
+    p--; /* Seek the first backlen byte of the last element. */
+    uint64_t prevlen = lpDecodeBacklen(p);
+    prevlen += lpEncodeBacklen(NULL,prevlen);
+    return p-prevlen+1; /* Seek the first byte of the previous entry. */
+}
+
+/* Return a pointer to the first element of the listpack, or NULL if the
+ * listpack has no elements. */
+unsigned char *lpFirst(unsigned char *lp) {
+    lp += LP_HDR_SIZE; /* Skip the header. */
+    if (lp[0] == LP_EOF) return NULL;
+    return lp;
+}
+
+/* Return a pointer to the last element of the listpack, or NULL if the
+ * listpack has no elements. */
+unsigned char *lpLast(unsigned char *lp) {
+    unsigned char *p = lp+lpGetTotalBytes(lp)-1; /* Seek EOF element. */
+    return lpPrev(lp,p); /* Will return NULL if EOF is the only element. */
+}
+
+/* Return the number of elements inside the listpack. This function attempts
+ * to use the cached value when within range, otherwise a full scan is
+ * needed. As a side effect of calling this function, the listpack header
+ * could be modified, because if the count is found to be already within
+ * the 'numele' header field range, the new value is set. */
+uint32_t lpLength(unsigned char *lp) {
+    uint32_t numele = lpGetNumElements(lp);
+    if (numele != LP_HDR_NUMELE_UNKNOWN) return numele;
+
+    /* Too many elements inside the listpack. We need to scan in order
+     * to get the total number. */
+    uint32_t count = 0;
+    unsigned char *p = lpFirst(lp);
+    while(p) {
+        count++;
+        p = lpNext(lp,p);
+    }
+
+    /* If the count is again within range of the header numele field,
+     * set it. */
+    if (count < LP_HDR_NUMELE_UNKNOWN) lpSetNumElements(lp,count);
+    return count;
+}
+
+/* Return the listpack element pointed by 'p'.
+ *
+ * The function changes behavior depending on the passed 'intbuf' value.
+ * Specifically, if 'intbuf' is NULL:
+ *
+ * If the element is internally encoded as an integer, the function returns
+ * NULL and populates the integer value by reference in 'count'. Otherwise if
+ * the element is encoded as a string a pointer to the string (pointing inside
+ * the listpack itself) is returned, and 'count' is set to the length of the
+ * string.
+ *
+ * If instead 'intbuf' points to a buffer passed by the caller, that must be
+ * at least LP_INTBUF_SIZE bytes, the function always returns the element as
+ * it was a string (returning the pointer to the string and setting the
+ * 'count' argument to the string length by reference). However if the element
+ * is encoded as an integer, the 'intbuf' buffer is used in order to store
+ * the string representation.
+ *
+ * The user should use one or the other form depending on what the value will
+ * be used for. If there is immediate usage for an integer value returned
+ * by the function, than to pass a buffer (and convert it back to a number)
+ * is of course useless.
+ *
+ * If the function is called against a badly encoded ziplist, so that there
+ * is no valid way to parse it, the function returns like if there was an
+ * integer encoded with value 12345678900000000 + <unrecognized byte>, this may
+ * be an hint to understand that something is wrong. To crash in this case is
+ * not sensible because of the different requirements of the application using
+ * this lib.
+ *
+ * Similarly, there is no error returned since the listpack normally can be
+ * assumed to be valid, so that would be a very high API cost. However a function
+ * in order to check the integrity of the listpack at load time is provided,
+ * check lpIsValid(). */
+unsigned char *lpGet(unsigned char *p, int64_t *count, unsigned char *intbuf) {
+    int64_t val;
+    uint64_t uval, negstart, negmax;
+
+    if (LP_ENCODING_IS_7BIT_UINT(p[0])) {
+        negstart = UINT64_MAX; /* 7 bit ints are always positive. */
+        negmax = 0;
+        uval = p[0] & 0x7f;
+    } else if (LP_ENCODING_IS_6BIT_STR(p[0])) {
+        *count = LP_ENCODING_6BIT_STR_LEN(p);
+        return p+1;
+    } else if (LP_ENCODING_IS_13BIT_INT(p[0])) {
+        uval = ((p[0]&0x1f)<<8) | p[1];
+        negstart = (uint64_t)1<<12;
+        negmax = 8191;
+    } else if (LP_ENCODING_IS_16BIT_INT(p[0])) {
+        uval = (uint64_t)p[1] |
+               (uint64_t)p[2]<<8;
+        negstart = (uint64_t)1<<15;
+        negmax = UINT16_MAX;
+    } else if (LP_ENCODING_IS_24BIT_INT(p[0])) {
+        uval = (uint64_t)p[1] |
+               (uint64_t)p[2]<<8 |
+               (uint64_t)p[3]<<16;
+        negstart = (uint64_t)1<<23;
+        negmax = UINT32_MAX>>8;
+    } else if (LP_ENCODING_IS_32BIT_INT(p[0])) {
+        uval = (uint64_t)p[1] |
+               (uint64_t)p[2]<<8 |
+               (uint64_t)p[3]<<16 |
+               (uint64_t)p[4]<<24;
+        negstart = (uint64_t)1<<31;
+        negmax = UINT32_MAX;
+    } else if (LP_ENCODING_IS_64BIT_INT(p[0])) {
+        uval = (uint64_t)p[1] |
+               (uint64_t)p[2]<<8 |
+               (uint64_t)p[3]<<16 |
+               (uint64_t)p[4]<<24 |
+               (uint64_t)p[5]<<32 |
+               (uint64_t)p[6]<<40 |
+               (uint64_t)p[7]<<48 |
+               (uint64_t)p[8]<<56;
+        negstart = (uint64_t)1<<63;
+        negmax = UINT64_MAX;
+    } else if (LP_ENCODING_IS_12BIT_STR(p[0])) {
+        *count = LP_ENCODING_12BIT_STR_LEN(p);
+        return p+2;
+    } else if (LP_ENCODING_IS_32BIT_STR(p[0])) {
+        *count = LP_ENCODING_32BIT_STR_LEN(p);
+        return p+5;
+    } else {
+        uval = 12345678900000000ULL + p[0];
+        negstart = UINT64_MAX;
+        negmax = 0;
+    }
+
+    /* We reach this code path only for integer encodings.
+     * Convert the unsigned value to the signed one using two's complement
+     * rule. */
+    if (uval >= negstart) {
+        /* This three steps conversion should avoid undefined behaviors
+         * in the unsigned -> signed conversion. */
+        uval = negmax-uval;
+        val = uval;
+        val = -val-1;
+    } else {
+        val = uval;
+    }
+
+    /* Return the string representation of the integer or the value itself
+     * depending on intbuf being NULL or not. */
+    if (intbuf) {
+        *count = snprintf((char*)intbuf,LP_INTBUF_SIZE,"%lld",val);
+        return intbuf;
+    } else {
+        *count = val;
+        return NULL;
+    }
+}
+
+/* Insert, delete or replace the specified element 'ele' of lenght 'len' at
+ * the specified position 'p', with 'p' being a listpack element pointer
+ * obtained with lpFirst(), lpLast(), lpIndex(), lpNext(), lpPrev() or
+ * lpSeek().
+ *
+ * The element is inserted before, after, or replaces the element pointed
+ * by 'p' depending on the 'where' argument, that can be LP_BEFORE, LP_AFTER
+ * or LP_REPLACE.
+ *
+ * If 'ele' is set to NULL, the function removes the element pointed by 'p'
+ * instead of inserting one.
+ *
+ * Returns NULL on out of memory or when the listpack total length would exceed
+ * the max allowed size of 2^32-1, otherwise the new pointer to the listpack
+ * holding the new element is returned (and the old pointer passed is no longer
+ * considered valid)
+ *
+ * If 'newp' is not NULL, at the end of a successful call '*newp' will be set
+ * to the address of the element just added, so that it will be possible to
+ * continue an interation with lpNext() and lpPrev().
+ *
+ * For deletion operations ('ele' set to NULL) 'newp' is set to the next
+ * element, on the right of the deleted one, or to NULL if the deleted element
+ * was the last one. */
+unsigned char *lpInsert(unsigned char *lp, unsigned char *ele, uint32_t size, unsigned char *p, int where, unsigned char **newp) {
+    unsigned char intenc[LP_MAX_INT_ENCODING_LEN];
+    unsigned char backlen[LP_MAX_BACKLEN_SIZE];
+
+    uint64_t enclen; /* The length of the encoded element. */
+
+    /* An element pointer set to NULL means deletion, which is conceptually
+     * replacing the element with a zero-length element. So whatever we
+     * get passed as 'where', set it to LP_REPLACE. */
+    if (ele == NULL) where = LP_REPLACE;
+
+    /* If we need to insert after the current element, we just jump to the
+     * next element (that could be the EOF one) and handle the case of
+     * inserting before. So the function will actually deal with just two
+     * cases: LP_BEFORE and LP_REPLACE. */
+    if (where == LP_AFTER) {
+        p = lpSkip(p);
+        where = LP_BEFORE;
+    }
+
+    /* Store the offset of the element 'p', so that we can obtain its
+     * address again after a reallocation. */
+    unsigned long poff = p-lp;
+
+    /* Calling lpEncodeGetType() results into the encoded version of the
+     * element to be stored into 'intenc' in case it is representable as
+     * an integer: in that case, the function returns LP_ENCODING_INT.
+     * Otherwise if LP_ENCODING_STR is returned, we'll have to call
+     * lpEncodeString() to actually write the encoded string on place later.
+     *
+     * Whatever the returned encoding is, 'enclen' is populated with the
+     * length of the encoded element. */
+    int enctype;
+    if (ele) {
+        enctype = lpEncodeGetType(ele,size,intenc,&enclen);
+    } else {
+        enctype = -1;
+        enclen = 0;
+    }
+
+    /* We need to also encode the backward-parsable length of the element
+     * and append it to the end: this allows to traverse the listpack from
+     * the end to the start. */
+    unsigned long backlen_size = ele ? lpEncodeBacklen(backlen,enclen) : 0;
+    uint64_t old_listpack_bytes = lpGetTotalBytes(lp);
+    uint32_t replaced_len  = 0;
+    if (where == LP_REPLACE) {
+        replaced_len = lpCurrentEncodedSize(p);
+        replaced_len += lpEncodeBacklen(NULL,replaced_len);
+    }
+
+    uint64_t new_listpack_bytes = old_listpack_bytes + enclen + backlen_size
+                                  - replaced_len;
+    if (new_listpack_bytes > UINT32_MAX) return NULL;
+
+    /* We now need to reallocate in order to make space or shrink the
+     * allocation (in case 'when' value is LP_REPLACE and the new element is
+     * smaller). However we do that before memmoving the memory to
+     * make room for the new element if the final allocation will get
+     * larger, or we do it after if the final allocation will get smaller. */
+
+    unsigned char *dst = lp + poff; /* May be updated after reallocation. */
+
+    /* Realloc before: we need more room. */
+    if (new_listpack_bytes > old_listpack_bytes) {
+        if ((lp = lp_realloc(lp,new_listpack_bytes)) == NULL) return NULL;
+        dst = lp + poff;
+    }
+
+    /* Setup the listpack relocating the elements to make the exact room
+     * we need to store the new one. */
+    if (where == LP_BEFORE) {
+        memmove(dst+enclen+backlen_size,dst,old_listpack_bytes-poff);
+    } else { /* LP_REPLACE. */
+        long lendiff = (enclen+backlen_size)-replaced_len;
+        memmove(dst+replaced_len+lendiff,
+                dst+replaced_len,
+                old_listpack_bytes-poff-replaced_len);
+    }
+
+    /* Realloc after: we need to free space. */
+    if (new_listpack_bytes < old_listpack_bytes) {
+        if ((lp = lp_realloc(lp,new_listpack_bytes)) == NULL) return NULL;
+        dst = lp + poff;
+    }
+
+    /* Store the entry. */
+    if (newp) {
+        *newp = dst;
+        /* In case of deletion, set 'newp' to NULL if the next element is
+         * the EOF element. */
+        if (!ele && dst[0] == LP_EOF) *newp = NULL;
+    }
+    if (ele) {
+        if (enctype == LP_ENCODING_INT) {
+            memcpy(dst,intenc,enclen);
+        } else {
+            lpEncodeString(dst,ele,size);
+        }
+        dst += enclen;
+        memcpy(dst,backlen,backlen_size);
+        dst += backlen_size;
+    }
+
+    /* Update header. */
+    if (where != LP_REPLACE || ele == NULL) {
+        uint32_t num_elements = lpGetNumElements(lp);
+        if (num_elements != LP_HDR_NUMELE_UNKNOWN) {
+            if (ele)
+                lpSetNumElements(lp,num_elements+1);
+            else
+                lpSetNumElements(lp,num_elements-1);
+        }
+    }
+    lpSetTotalBytes(lp,new_listpack_bytes);
+    return lp;
+}
+
+/* Append the specified element 'ele' of lenght 'len' at the end of the
+ * listpack. It is implemented in terms of lpInsert(), so the return value is
+ * the same as lpInsert(). */
+unsigned char *lpAppend(unsigned char *lp, unsigned char *ele, uint32_t size) {
+    uint64_t listpack_bytes = lpGetTotalBytes(lp);
+    unsigned char *eofptr = lp + listpack_bytes - 1;
+    return lpInsert(lp,ele,size,eofptr,LP_BEFORE,NULL);
+}
+
+/* Remove the element pointed by 'p', and return the resulting listpack.
+ * If 'newp' is not NULL, the next element pointer (to the right of the
+ * deleted one) is returned by reference. If the deleted element was the
+ * last one, '*newp' is set to NULL. */
+unsigned char *lpDelete(unsigned char *lp, unsigned char *p, unsigned char **newp) {
+    return lpInsert(lp,NULL,0,p,LP_REPLACE,newp);
+}
+
+/* Return the total number of bytes the listpack is composed of. */
+uint32_t lpBytes(unsigned char *lp) {
+    return lpGetTotalBytes(lp);
+}
+
+/* Seek the specified element and returns the pointer to the seeked element.
+ * Positive indexes specify the zero-based element to seek from the head to
+ * the tail, negative indexes specify elements starting from the tail, where
+ * -1 means the last element, -2 the penultimate and so forth. If the index
+ * is out of range, NULL is returned. */
+unsigned char *lpSeek(unsigned char *lp, long index) {
+    int forward = 1; /* Seek forward by default. */
+
+    /* We want to seek from left to right or the other way around
+     * depending on the listpack length and the element position.
+     * However if the listpack length cannot be obtained in constant time,
+     * we always seek from left to right. */
+    uint32_t numele = lpGetNumElements(lp);
+    if (numele != LP_HDR_NUMELE_UNKNOWN) {
+        if (index < 0) index = (long)numele+index;
+        if (index < 0) return NULL; /* Index still < 0 means out of range. */
+        if (index >= numele) return NULL; /* Out of range the other side. */
+        /* We want to scan right-to-left if the element we are looking for
+         * is past the half of the listpack. */
+        if (index > numele/2) {
+            forward = 0;
+            /* Left to right scanning always expects a negative index. Convert
+             * our index to negative form. */
+            index -= numele;
+        }
+    } else {
+        /* If the listpack length is unspecified, for negative indexes we
+         * want to always scan left-to-right. */
+        if (index < 0) forward = 0;
+    }
+
+    /* Forward and backward scanning is trivially based on lpNext()/lpPrev(). */
+    if (forward) {
+        unsigned char *ele = lpFirst(lp);
+        while (index > 0 && ele) {
+            ele = lpNext(lp,ele);
+            index--;
+        }
+        return ele;
+    } else {
+        unsigned char *ele = lpLast(lp);
+        while (index < -1 && ele) {
+            ele = lpPrev(lp,ele);
+            index++;
+        }
+        return ele;
+    }
+}
+
@@ -0,0 +1,61 @@
+/* Listpack -- A lists of strings serialization format
+ *
+ * This file implements the specification you can find at:
+ *
+ *  https://github.com/antirez/listpack
+ *
+ * Copyright (c) 2017, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __LISTPACK_H
+#define __LISTPACK_H
+
+#include <stdint.h>
+
+#define LP_INTBUF_SIZE 21 /* 20 digits of -2^63 + 1 null term = 21. */
+
+/* lpInsert() where argument possible values: */
+#define LP_BEFORE 0
+#define LP_AFTER 1
+#define LP_REPLACE 2
+
+unsigned char *lpNew(void);
+void lpFree(unsigned char *lp);
+unsigned char *lpInsert(unsigned char *lp, unsigned char *ele, uint32_t size, unsigned char *p, int where, unsigned char **newp);
+unsigned char *lpAppend(unsigned char *lp, unsigned char *ele, uint32_t size);
+unsigned char *lpDelete(unsigned char *lp, unsigned char *p, unsigned char **newp);
+uint32_t lpLength(unsigned char *lp);
+unsigned char *lpGet(unsigned char *p, int64_t *count, unsigned char *intbuf);
+unsigned char *lpFirst(unsigned char *lp);
+unsigned char *lpLast(unsigned char *lp);
+unsigned char *lpNext(unsigned char *lp, unsigned char *p);
+unsigned char *lpPrev(unsigned char *lp, unsigned char *p);
+uint32_t lpBytes(unsigned char *lp);
+unsigned char *lpSeek(unsigned char *lp, long index);
+
+#endif
@@ -0,0 +1,45 @@
+/* Listpack -- A lists of strings serialization format
+ * https://github.com/antirez/listpack
+ *
+ * Copyright (c) 2017, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* Allocator selection.
+ *
+ * This file is used in order to change the Rax allocator at compile time.
+ * Just define the following defines to what you want to use. Also add
+ * the include of your alternate allocator if needed (not needed in order
+ * to use the default libc allocator). */
+
+#ifndef LISTPACK_ALLOC_H
+#define LISTPACK_ALLOC_H
+#include "zmalloc.h"
+#define lp_malloc zmalloc
+#define lp_realloc zrealloc
+#define lp_free zfree
+#endif
@@ -79,7 +79,11 @@
 * Unconditionally aligning does not cost very much, so do it if unsure
 */
 #ifndef STRICT_ALIGN
-# define STRICT_ALIGN !(defined(__i386) || defined (__amd64))
+# if !(defined(__i386) || defined (__amd64))
+#  define STRICT_ALIGN 1
+# else
+#  define STRICT_ALIGN 0
+# endif
 #endif

 /*
@@ -1,856 +0,0 @@
-Redis Modules: an introduction to the API
-===
-
-The modules documentation is composed of the following files:
-
-* `INTRO.md` (this file). An overview about Redis Modules system and API. It's a good idea to start your reading here.
-* `API.md` is generated from module.c top comments of RedisMoule functions. It is a good reference in order to understand how each function works.
-* `TYPES.md` covers the implementation of native data types into modules.
-
-Redis modules make possible to extend Redis functionality using external
-modules, implementing new Redis commands at a speed and with features
-similar to what can be done inside the core itself.
-
-Redis modules are dynamic libraries, that can be loaded into Redis at
-startup or using the `MODULE LOAD` command. Redis exports a C API, in the
-form of a single C header file called `redismodule.h`. Modules are meant
-to be written in C, however it will be possible to use C++ or other languages
-that have C binding functionalities.
-
-Modules are designed in order to be loaded into different versions of Redis,
-so a given module does not need to be designed, or recompiled, in order to
-run with a specific version of Redis. For this reason, the module will
-register to the Redis core using a specific API version. The current API
-version is "1".
-
-This document is about an alpha version of Redis modules. API, functionalities
-and other details may change in the future.
-
-# Loading modules
-
-In order to test the module you are developing, you can load the module
-using the following `redis.conf` configuration directive:
-
-    loadmodule /path/to/mymodule.so
-
-It is also possible to load a module at runtime using the following command:
-
-    MODULE LOAD /path/to/mymodule.so
-
-In order to list all loaded modules, use:
-
-    MODULE LIST
-
-Finally, you can unload (and later reload if you wish) a module using the
-following command:
-
-    MODULE UNLOAD mymodule
-
-Note that `mymodule` above is not the filename without the `.so` suffix, but
-instead, the name the module used to register itself into the Redis core.
-The name can be obtained using `MODULE LIST`. However it is good practice
-that the filename of the dynamic library is the same as the name the module
-uses to register itself into the Redis core.
-
-# The simplest module you can write
-
-In order to show the different parts of a module, here we'll show a very
-simple module that implements a command that outputs a random number.
-
-    #include "redismodule.h"
-    #include <stdlib.h>
-
-    int HelloworldRand_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
-        RedisModule_ReplyWithLongLong(ctx,rand());
-        return REDISMODULE_OK;
-    }
-
-    int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
-        if (RedisModule_Init(ctx,"helloworld",1,REDISMODULE_APIVER_1)
-            == REDISMODULE_ERR) return REDISMODULE_ERR;
-
-        if (RedisModule_CreateCommand(ctx,"helloworld.rand",
-            HelloworldRand_RedisCommand) == REDISMODULE_ERR)
-            return REDISMODULE_ERR;
-
-        return REDISMODULE_OK;
-    }
-
-The example module has two functions. One implements a command called
-HELLOWORLD.RAND. This function is specific of that module. However the
-other function called `RedisModule_OnLoad()` must be present in each
-Redis module. It is the entry point for the module to be initialized,
-register its commands, and potentially other private data structures
-it uses.
-
-Note that it is a good idea for modules to call commands with the
-name of the module followed by a dot, and finally the command name,
-like in the case of `HELLOWORLD.RAND`. This way it is less likely to
-have collisions.
-
-Note that if different modules have colliding commands, they'll not be
-able to work in Redis at the same time, since the function
-`RedisModule_CreateCommand` will fail in one of the modules, so the module
-loading will abort returning an error condition.
-
-# Module initialization
-
-The above example shows the usage of the function `RedisModule_Init()`.
-It should be the first function called by the module `OnLoad` function.
-The following is the function prototype:
-
-    int RedisModule_Init(RedisModuleCtx *ctx, const char *modulename,
-                         int module_version, int api_version);
-
-The `Init` function announces the Redis core that the module has a given
-name, its version (that is reported by `MODULE LIST`), and that is willing
-to use a specific version of the API.
-
-If the API version is wrong, the name is already taken, or there are other
-similar errors, the function will return `REDISMODULE_ERR`, and the module
-`OnLoad` function should return ASAP with an error.
-
-Before the `Init` function is called, no other API function can be called,
-otherwise the module will segfault and the Redis instance will crash.
-
-The second function called, `RedisModule_CreateCommand`, is used in order
-to register commands into the Redis core. The following is the prototype:
-
-    int RedisModule_CreateCommand(RedisModuleCtx *ctx, const char *cmdname,
-                                  RedisModuleCmdFunc cmdfunc);
-
-As you can see, most Redis modules API calls all take as first argument
-the `context` of the module, so that they have a reference to the module
-calling it, to the command and client executing a given command, and so forth.
-
-To create a new command, the above function needs the context, the command
-name, and the function pointer of the function implementing the command,
-which must have the following prototype:
-
-
-    int mycommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc);
-
-The command function arguments are just the context, that will be passed
-to all the other API calls, the command argument vector, and total number
-of arguments, as passed by the user.
-
-As you can see, the arguments are provided as pointers to a specific data
-type, the `RedisModuleString`. This is an opaque data type you have API
-functions to access and use, direct access to its fields is never needed.
-
-Zooming into the example command implementation, we can find another call:
-
-    int RedisModule_ReplyWithLongLong(RedisModuleCtx *ctx, long long integer);
-
-This function returns an integer to the client that invoked the command,
-exactly like other Redis commands do, like for example `INCR` or `SCARD`.
-
-# Setup and dependencies of a Redis module
-
-Redis modules don't depend on Redis or some other library, nor they
-need to be compiled with a specific `redismodule.h` file. In order
-to create a new module, just copy a recent version of `redismodule.h`
-in your source tree, link all the libraries you want, and create
-a dynamic library having the `RedisModule_OnLoad()` function symbol
-exported.
-
-The module will be able to load into different versions of Redis.
-
-# Passing configuration parameters to Redis modules
-
-When the module is loaded with the `MODULE LOAD` command, or using the
-`loadmodule` directive in the `redis.conf` file, the user is able to pass
-configuration parameters to the module by adding arguments after the module
-file name:
-
-    loadmodule mymodule.so foo bar 1234
-
-In the above example the strings `foo`, `bar` and `123` will be passed
-to the module `OnLoad()` function in the `argv` argument as an array
-of RedisModuleString pointers. The number of arguments passed is into `argc`.
-
-The way you can access those strings will be explained in the rest of this
-document. Normally the module will store the module configuration parameters
-in some `static` global variable that can be accessed module wide, so that
-the configuration can change the behavior of different commands.
-
-# Working with RedisModuleString objects
-
-The command argument vector `argv` passed to module commands, and the
-return value of other module APIs functions, are of type `RedisModuleString`.
-
-Usually you directly pass module strings to other API calls, however sometimes
-you may need to directly access the string object.
-
-There are a few functions in order to work with string objects:
-
-    const char *RedisModule_StringPtrLen(RedisModuleString *string, size_t *len);
-
-The above function accesses a string by returning its pointer and setting its
-length in `len`.
-You should never write to a string object pointer, as you can see from the
-`const` pointer qualifier.
-
-However, if you want, you can create new string objects using the following
-API:
-
-    RedisModuleString *RedisModule_CreateString(RedisModuleCtx *ctx, const char *ptr, size_t len);
-
-The string returned by the above command must be freed using a corresponding
-call to `RedisModule_FreeString()`:
-
-    void RedisModule_FreeString(RedisModuleString *str);
-
-However if you want to avoid having to free strings, the automatic memory
-management, covered later in this document, can be a good alternative, by
-doing it for you.
-
-Note that the strings provided via the argument vector `argv` never need
-to be freed. You only need to free new strings you create, or new strings
-returned by other APIs, where it is specified that the returned string must
-be freed.
-
-## Creating strings from numbers or parsing strings as numbers
-
-Creating a new string from an integer is a very common operation, so there
-is a function to do this:
-
-    RedisModuleString *mystr = RedisModule_CreateStringFromLongLong(ctx,10);
-
-Similarly in order to parse a string as a number:
-
-    long long myval;
-    if (RedisModule_StringToLongLong(ctx,argv[1],&myval) == REDISMODULE_OK) {
-        /* Do something with 'myval' */
-    }
-
-## Accessing Redis keys from modules
-
-Most Redis modules, in order to be useful, have to interact with the Redis
-data space (this is not always true, for example an ID generator may
-never touch Redis keys). Redis modules have two different APIs in order to
-access the Redis data space, one is a low level API that provides very
-fast access and a set of functions to manipulate Redis data structures.
-The other API is more high level, and allows to call Redis commands and
-fetch the result, similarly to how Lua scripts access Redis.
-
-The high level API is also useful in order to access Redis functionalities
-that are not available as APIs.
-
-In general modules developers should prefer the low level API, because commands
-implemented using the low level API run at a speed comparable to the speed
-of native Redis commands. However there are definitely use cases for the
-higher level API. For example often the bottleneck could be processing the
-data and not accessing it.
-
-Also note that sometimes using the low level API is not harder compared to
-the higher level one.
-
-# Calling Redis commands
-
-The high level API to access Redis is the sum of the `RedisModule_Call()`
-function, together with the functions needed in order to access the
-reply object returned by `Call()`.
-
-`RedisModule_Call` uses a special calling convention, with a format specifier
-that is used to specify what kind of objects you are passing as arguments
-to the function.
-
-Redis commands are invoked just using a command name and a list of arguments.
-However when calling commands, the arguments may originate from different
-kind of strings: null-terminated C strings, RedisModuleString objects as
-received from the `argv` parameter in the command implementation, binary
-safe C buffers with a pointer and a length, and so forth.
-
-For example if I want to call `INCRBY` using a first argument (the key)
-a string received in the argument vector `argv`, which is an array
-of RedisModuleString object pointers, and a C string representing the
-number "10" as second argument (the increment), I'll use the following
-function call:
-
-    RedisModuleCallReply *reply;
-    reply = RedisModule_Call(ctx,"INCR","sc",argv[1],"10");
-
-The first argument is the context, and the second is always a null terminated
-C string with the command name. The third argument is the format specifier
-where each character corresponds to the type of the arguments that will follow.
-In the above case `"sc"` means a RedisModuleString object, and a null
-terminated C string. The other arguments are just the two arguments as
-specified. In fact `argv[1]` is a RedisModuleString and `"10"` is a null
-terminated C string.
-
-This is the full list of format specifiers:
-
-* **c** -- Null terminated C string pointer.
-* **b** -- C buffer, two arguments needed: C string pointer and `size_t` length.
-* **s** -- RedisModuleString as received in `argv` or by other Redis module APIs returning a RedisModuleString object.
-* **l** -- Long long integer.
-* **v** -- Array of RedisModuleString objects.
-* **!** -- This modifier just tells the function to replicate the command to slaves and AOF. It is ignored from the point of view of arguments parsing.
-
-The function returns a `RedisModuleCallReply` object on success, on
-error NULL is returned.
-
-NULL is returned when the command name is invalid, the format specifier uses
-characters that are not recognized, or when the command is called with the
-wrong number of arguments. In the above cases the `errno` var is set to `EINVAL`. NULL is also returned when, in an instance with Cluster enabled, the target
-keys are about non local hash slots. In this case `errno` is set to `EPERM`.
-
-## Working with RedisModuleCallReply objects.
-
-`RedisModuleCall` returns reply objects that can be accessed using the
-`RedisModule_CallReply*` family of functions.
-
-In order to obtain the type or reply (corresponding to one of the data types
-supported by the Redis protocol), the function `RedisModule_CallReplyType()`
-is used:
-
-    reply = RedisModule_Call(ctx,"INCR","sc",argv[1],"10");
-    if (RedisModule_CallReplyType(reply) == REDISMODULE_REPLY_INTEGER) {
-        long long myval = RedisModule_CallReplyInteger(reply);
-        /* Do something with myval. */
-    }
-
-Valid reply types are:
-
-* `REDISMODULE_REPLY_STRING` Bulk string or status replies.
-* `REDISMODULE_REPLY_ERROR` Errors.
-* `REDISMODULE_REPLY_INTEGER` Signed 64 bit integers.
-* `REDISMODULE_REPLY_ARRAY` Array of replies.
-* `REDISMODULE_REPLY_NULL` NULL reply.
-
-Strings, errors and arrays have an associated length. For strings and errors
-the length corresponds to the length of the string. For arrays the length
-is the number of elements. To obtain the reply length the following function
-is used:
-
-    size_t reply_len = RedisModule_CallReplyLength(reply);
-
-In order to obtain the value of an integer reply, the following function is used, as already shown in the example above:
-
-    long long reply_integer_val = RedisModule_CallReplyInteger(reply);
-
-Called with a reply object of the wrong type, the above function always
-returns `LLONG_MIN`.
-
-Sub elements of array replies are accessed this way:
-
-    RedisModuleCallReply *subreply;
-    subreply = RedisModule_CallReplyArrayElement(reply,idx);
-
-The above function returns NULL if you try to access out of range elements.
-
-Strings and errors (which are like strings but with a different type) can
-be accessed using in the following way, making sure to never write to
-the resulting pointer (that is returned as as `const` pointer so that
-misusing must be pretty explicit):
-
-    size_t len;
-    char *ptr = RedisModule_CallReplyStringPtr(reply,&len);
-
-If the reply type is not a string or an error, NULL is returned.
-
-RedisCallReply objects are not the same as module string objects
-(RedisModuleString types). However sometimes you may need to pass replies
-of type string or integer, to API functions expecting a module string.
-
-When this is the case, you may want to evaluate if using the low level
-API could be a simpler way to implement your command, or you can use
-the following function in order to create a new string object from a
-call reply of type string, error or integer:
-
-    RedisModuleString *mystr = RedisModule_CreateStringFromCallReply(myreply);
-
-If the reply is not of the right type, NULL is returned.
-The returned string object should be released with `RedisModule_FreeString()`
-as usually, or by enabling automatic memory management (see corresponding
-section).
-
-# Releasing call reply objects
-
-Reply objects must be freed using `RedisModule_FreeCallReply`. For arrays,
-you need to free only the top level reply, not the nested replies.
-Currently the module implementation provides a protection in order to avoid
-crashing if you free a nested reply object for error, however this feature
-is not guaranteed to be here forever, so should not be considered part
-of the API.
-
-If you use automatic memory management (explained later in this document)
-you don't need to free replies (but you still could if you wish to release
-memory ASAP).
-
-## Returning values from Redis commands
-
-Like normal Redis commands, new commands implemented via modules must be
-able to return values to the caller. The API exports a set of functions for
-this goal, in order to return the usual types of the Redis protocol, and
-arrays of such types as elemented. Also errors can be returned with any
-error string and code (the error code is the initial uppercase letters in
-the error message, like the "BUSY" string in the "BUSY the sever is busy" error
-message).
-
-All the functions to send a reply to the client are called
-`RedisModule_ReplyWith<something>`.
-
-To return an error, use:
-
-    RedisModule_ReplyWithError(RedisModuleCtx *ctx, const char *err);
-
-There is a predefined error string for key of wrong type errors:
-
-    REDISMODULE_ERRORMSG_WRONGTYPE
-
-Example usage:
-
-    RedisModule_ReplyWithError(ctx,"ERR invalid arguments");
-
-We already saw how to reply with a long long in the examples above:
-
-    RedisModule_ReplyWithLongLong(ctx,12345);
-
-To reply with a simple string, that can't contain binary values or newlines,
-(so it's suitable to send small words, like "OK") we use:
-
-    RedisModule_ReplyWithSimpleString(ctx,"OK");
-
-It's possible to reply with "bulk strings" that are binary safe, using
-two different functions:
-
-    int RedisModule_ReplyWithStringBuffer(RedisModuleCtx *ctx, const char *buf, size_t len);
-
-    int RedisModule_ReplyWithString(RedisModuleCtx *ctx, RedisModuleString *str);
-
-The first function gets a C pointer and length. The second a RedisMoudleString
-object. Use one or the other depending on the source type you have at hand.
-
-In order to reply with an array, you just need to use a function to emit the
-array length, followed by as many calls to the above functions as the number
-of elements of the array are:
-
-    RedisModule_ReplyWithArray(ctx,2);
-    RedisModule_ReplyWithStringBuffer(ctx,"age",3);
-    RedisModule_ReplyWithLongLong(ctx,22);
-
-To return nested arrays is easy, your nested array element just uses another
-call to `RedisModule_ReplyWithArray()` followed by the calls to emit the
-sub array elements.
-
-## Returning arrays with dynamic length
-
-Sometimes it is not possible to know beforehand the number of items of
-an array. As an example, think of a Redis module implementing a FACTOR
-command that given a number outputs the prime factors. Instead of
-factorializing the number, storing the prime factors into an array, and
-later produce the command reply, a better solution is to start an array
-reply where the length is not known, and set it later. This is accomplished
-with a special argument to `RedisModule_ReplyWithArray()`:
-
-    RedisModule_ReplyWithArray(ctx, REDISMODULE_POSTPONED_ARRAY_LEN);
-
-The above call starts an array reply so we can use other `ReplyWith` calls
-in order to produce the array items. Finally in order to set the length
-se use the following call:
-
-    RedisModule_ReplySetArrayLength(ctx, number_of_items);
-
-In the case of the FACTOR command, this translates to some code similar
-to this:
-
-    RedisModule_ReplyWithArray(ctx, REDISMODULE_POSTPONED_ARRAY_LEN);
-    number_of_factors = 0;
-    while(still_factors) {
-        RedisModule_ReplyWithLongLong(ctx, some_factor);
-        number_of_factors++;
-    }
-    RedisModule_ReplySetArrayLength(ctx, number_of_factors);
-
-Another common use case for this feature is iterating over the arrays of
-some collection and only returning the ones passing some kind of filtering.
-
-It is possible to have multiple nested arrays with postponed reply.
-Each call to `SetArray()` will set the length of the latest corresponding
-call to `ReplyWithArray()`:
-
-    RedisModule_ReplyWithArray(ctx, REDISMODULE_POSTPONED_ARRAY_LEN);
-    ... generate 100 elements ...
-    RedisModule_ReplyWithArray(ctx, REDISMODULE_POSTPONED_ARRAY_LEN);
-    ... generate 10 elements ...
-    RedisModule_ReplySetArrayLength(ctx, 10);
-    RedisModule_ReplySetArrayLength(ctx, 100);
-
-This creates a 100 items array having as last element a 10 items array.
-
-# Arity and type checks
-
-Often commands need to check that the number of arguments and type of the key
-is correct. In order to report a wrong arity, there is a specific function
-called `RedisModule_WrongArity()`. The usage is trivial:
-
-    if (argc != 2) return RedisModule_WrongArity(ctx);
-
-Checking for the wrong type involves opening the key and checking the type:
-
-    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
-        REDISMODULE_READ|REDISMODULE_WRITE);
-
-    int keytype = RedisModule_KeyType(key);
-    if (keytype != REDISMODULE_KEYTYPE_STRING &&
-        keytype != REDISMODULE_KEYTYPE_EMPTY)
-    {
-        RedisModule_CloseKey(key);
-        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
-    }
-
-Note that you often want to proceed with a command both if the key
-is of the expected type, or if it's empty.
-
-## Low level access to keys
-
-Low level access to keys allow to perform operations on value objects associated
-to keys directly, with a speed similar to what Redis uses internally to
-implement the built-in commands.
-
-Once a key is opened, a key pointer is returned that will be used with all the
-other low level API calls in order to perform operations on the key or its
-associated value.
-
-Because the API is meant to be very fast, it cannot do too many run-time
-checks, so the user must be aware of certain rules to follow:
-
-* Opening the same key multiple times where at least one instance is opened for writing, is undefined and may lead to crashes.
-* While a key is open, it should only be accessed via the low level key API. For example opening a key, then calling DEL on the same key using the `RedisModule_Call()` API will result into a crash. However it is safe to open a key, perform some operation with the low level API, closing it, then using other APIs to manage the same key, and later opening it again to do some more work.
-
-In order to open a key the `RedisModule_OpenKey` function is used. It returns
-a key pointer, that we'll use with all the next calls to access and modify
-the value:
-
-    RedisModuleKey *key;
-    key = RedisModule_OpenKey(ctx,argv[1],REDISMODULE_READ);
-
-The second argument is the key name, that must be a `RedisModuleString` object.
-The third argument is the mode: `REDISMODULE_READ` or `REDISMODULE_WRITE`.
-It is possible to use `|` to bitwise OR the two modes to open the key in
-both modes. Currently a key opened for writing can also be accessed for reading
-but this is to be considered an implementation detail. The right mode should
-be used in sane modules.
-
-You can open non exisitng keys for writing, since the keys will be created
-when an attempt to write to the key is performed. However when opening keys
-just for reading, `RedisModule_OpenKey` will return NULL if the key does not
-exist.
-
-Once you are done using a key, you can close it with:
-
-    RedisModule_CloseKey(key);
-
-Note that if automatic memory management is enabled, you are not forced to
-close keys. When the module function returns, Redis will take care to close
-all the keys which are still open.
-
-## Getting the key type
-
-In order to obtain the value of a key, use the `RedisModule_KeyType()` function:
-
-    int keytype = RedisModule_KeyType(key);
-
-It returns one of the following values:
-
-    REDISMODULE_KEYTYPE_EMPTY
-    REDISMODULE_KEYTYPE_STRING
-    REDISMODULE_KEYTYPE_LIST
-    REDISMODULE_KEYTYPE_HASH
-    REDISMODULE_KEYTYPE_SET
-    REDISMODULE_KEYTYPE_ZSET
-
-The above are just the usual Redis key types, with the addition of an empty
-type, that signals the key pointer is associated with an empty key that
-does not yet exists.
-
-## Creating new keys
-
-To create a new key, open it for writing and then write to it using one
-of the key writing functions. Example:
-
-    RedisModuleKey *key;
-    key = RedisModule_OpenKey(ctx,argv[1],REDISMODULE_READ);
-    if (RedisModule_KeyType(key) == REDISMODULE_KEYTYPE_EMPTY) {
-        RedisModule_StringSet(key,argv[2]);
-    }
-
-## Deleting keys
-
-Just use:
-
-    RedisModule_DeleteKey(key);
-
-The function returns `REDISMODULE_ERR` if the key is not open for writing.
-Note that after a key gets deleted, it is setup in order to be targeted
-by new key commands. For example `RedisModule_KeyType()` will return it is
-an empty key, and writing to it will create a new key, possibly of another
-type (depending on the API used).
-
-## Managing key expires (TTLs)
-
-To control key expires two functions are provided, that are able to set,
-modify, get, and unset the time to live associated with a key.
-
-One function is used in order to query the current expire of an open key:
-
-    mstime_t RedisModule_GetExpire(RedisModuleKey *key);
-
-The function returns the time to live of the key in milliseconds, or
-`REDISMODULE_NO_EXPIRE` as a special value to signal the key has no associated
-expire or does not exist at all (you can differentiate the two cases checking
-if the key type is `REDISMODULE_KEYTYPE_EMPTY`).
-
-In order to change the expire of a key the following function is used instead:
-
-    int RedisModule_SetExpire(RedisModuleKey *key, mstime_t expire);
-
-When called on a non existing key, `REDISMODULE_ERR` is returned, because
-the function can only associate expires to existing open keys (non existing
-open keys are only useful in order to create new values with data type
-specific write operations).
-
-Again the `expire` time is specified in milliseconds. If the key has currently
-no expire, a new expire is set. If the key already have an expire, it is
-replaced with the new value.
-
-If the key has an expire, and the special value `REDISMODULE_NO_EXPIRE` is
-used as a new expire, the expire is removed, similarly to the Redis
-`PERSIST` command. In case the key was already persistent, no operation is
-performed.
-
-## Obtaining the length of values
-
-There is a single function in order to retrieve the length of the value
-associated to an open key. The returned length is value-specific, and is
-the string length for strings, and the number of elements for the aggregated
-data types (how many elements there is in a list, set, sorted set, hash).
-
-    size_t len = RedisModule_ValueLength(key);
-
-If the key does not exist, 0 is returned by the function:
-
-## String type API
-
-Setting a new string value, like the Redis `SET` command does, is performed
-using:
-
-    int RedisModule_StringSet(RedisModuleKey *key, RedisModuleString *str);
-
-The function works exactly like the Redis `SET` command itself, that is, if
-there is a prior value (of any type) it will be deleted.
-
-Accessing existing string values is performed using DMA (direct memory
-access) for speed. The API will return a pointer and a length, so that's
-possible to access and, if needed, modify the string directly.
-
-    size_t len, j;
-    char *myptr = RedisModule_StringDMA(key,&len,REDISMODULE_WRITE);
-    for (j = 0; j < len; j++) myptr[j] = 'A';
-
-In the above example we write directly on the string. Note that if you want
-to write, you must be sure to ask for `WRITE` mode.
-
-DMA pointers are only valid if no other operations are performed with the key
-before using the pointer, after the DMA call.
-
-Sometimes when we want to manipulate strings directly, we need to change
-their size as well. For this scope, the `RedisModule_StringTruncate` function
-is used. Example:
-
-    RedisModule_StringTruncate(mykey,1024);
-
-The function truncates, or enlarges the string as needed, padding it with
-zero bytes if the previos length is smaller than the new length we request.
-If the string does not exist since `key` is associated to an open empty key,
-a string value is created and associated to the key.
-
-Note that every time `StringTruncate()` is called, we need to re-obtain
-the DMA pointer again, since the old may be invalid.
-
-## List type API
-
-It's possible to push and pop values from list values:
-
-    int RedisModule_ListPush(RedisModuleKey *key, int where, RedisModuleString *ele);
-    RedisModuleString *RedisModule_ListPop(RedisModuleKey *key, int where);
-
-In both the APIs the `where` argument specifies if to push or pop from tail
-or head, using the following macros:
-
-    REDISMODULE_LIST_HEAD
-    REDISMODULE_LIST_TAIL
-
-Elements returned by `RedisModule_ListPop()` are like strings craeted with
-`RedisModule_CreateString()`, they must be released with
-`RedisModule_FreeString()` or by enabling automatic memory management.
-
-## Set type API
-
-Work in progress.
-
-## Sorted set type API
-
-Documentation missing, please refer to the top comments inside `module.c`
-for the following functions:
-
-* `RedisModule_ZsetAdd`
-* `RedisModule_ZsetIncrby`
-* `RedisModule_ZsetScore`
-* `RedisModule_ZsetRem`
-
-And for the sorted set iterator:
-
-* `RedisModule_ZsetRangeStop`
-* `RedisModule_ZsetFirstInScoreRange`
-* `RedisModule_ZsetLastInScoreRange`
-* `RedisModule_ZsetFirstInLexRange`
-* `RedisModule_ZsetLastInLexRange`
-* `RedisModule_ZsetRangeCurrentElement`
-* `RedisModule_ZsetRangeNext`
-* `RedisModule_ZsetRangePrev`
-* `RedisModule_ZsetRangeEndReached`
-
-## Hash type API
-
-Documentation missing, please refer to the top comments inside `module.c`
-for the following functions:
-
-* `RedisModule_HashSet`
-* `RedisModule_HashGet`
-
-## Iterating aggregated values
-
-Work in progress.
-
-# Replicating commands
-
-If you want to use module commands exactly like normal Redis commands, in the
-context of replicated Redis instances, or using the AOF file for persistence,
-it is important for module commands to handle their replication in a consistent
-way.
-
-When using the higher level APIs to invoke commands, replication happens
-automatically if you use the "!" modifier in the format string of
-`RedisModule_Call()` as in the following example:
-
-    reply = RedisModule_Call(ctx,"INCR","!sc",argv[1],"10");
-
-As you can see the format specifier is `"!sc"`. The bang is not parsed as a
-format specifier, but it internally flags the command as "must replicate".
-
-If you use the above programming style, there are no problems.
-However sometimes things are more complex than that, and you use the low level
-API. In this case, if there are no side effects in the command execution, and
-it consistently always performs the same work, what is possible to do is to
-replicate the command verbatim as the user executed it. To do that, you just
-need to call the following function:
-
-    RedisModule_ReplicateVerbatim(ctx);
-
-When you use the above API, you should not use any other replication function
-since they are not guaranteed to mix well.
-
-However this is not the only option. It's also possible to exactly tell
-Redis what commands to replicate as the effect of the command execution, using
-an API similar to `RedisModule_Call()` but that instead of calling the command
-sends it to the AOF / slaves stream. Example:
-
-    RedisModule_Replicate(ctx,"INCRBY","cl","foo",my_increment);
-
-It's possible to call `RedisModule_Replicate` multiple times, and each
-will emit a command. All the sequence emitted is wrapped between a
-`MULTI/EXEC` transaction, so that the AOF and replication effects are the
-same as executing a single command.
-
-Note that `Call()` replication and `Replicate()` replication have a rule,
-in case you want to mix both forms of replication (not necessarily a good
-idea if there are simpler approaches). Commands replicated with `Call()`
-are always the first emitted in the final `MULTI/EXEC` block, while all
-the commands emitted with `Replicate()` will follow.
-
-# Automatic memory management
-
-Normally when writing programs in the C language, programmers need to manage
-memory manually. This is why the Redis modules API has functions to release
-strings, close open keys, free replies, and so forth.
-
-However given that commands are executed in a contained environment and
-with a set of strict APIs, Redis is able to provide automatic memory management
-to modules, at the cost of some performance (most of the time, a very low
-cost).
-
-When automatic memory management is enabled:
-
-1. You don't need to close open keys.
-2. You don't need to free replies.
-3. You don't need to free RedisModuleString objects.
-
-However you can still do it, if you want. For example, automatic memory
-management may be active, but inside a loop allocating a lot of strings,
-you may still want to free strings no longer used.
-
-In order to enable automatic memory management, just call the following
-function at the start of the command implementation:
-
-    RedisModule_AutoMemory(ctx);
-
-Automatic memory management is usually the way to go, however experienced
-C programmers may not use it in order to gain some speed and memory usage
-benefit.
-
-# Allocating memory into modules
-
-Normal C programs use `malloc()` and `free()` in order to allocate and
-release memory dynamically. While in Redis modules the use of malloc is
-not technically forbidden, it is a lot better to use the Redis Modules
-specific functions, that are exact replacements for `malloc`, `free`,
-`realloc` and `strdup`. These functions are:
-
-    void *RedisModule_Alloc(size_t bytes);
-    void* RedisModule_Realloc(void *ptr, size_t bytes);
-    void RedisModule_Free(void *ptr);
-    void RedisModule_Calloc(size_t nmemb, size_t size);
-    char *RedisModule_Strdup(const char *str);
-
-They work exactly like their `libc` equivalent calls, however they use
-the same allocator Redis uses, and the memory allocated using these
-functions is reported by the `INFO` command in the memory section, is
-accounted when enforcing the `maxmemory` policy, and in general is
-a first citizen of the Redis executable. On the contrar, the method
-allocated inside modules with libc `malloc()` is transparent to Redis.
-
-Another reason to use the modules functions in order to allocate memory
-is that, when creating native data types inside modules, the RDB loading
-functions can return deserialized strings (from the RDB file) directly
-as `RedisModule_Alloc()` allocations, so they can be used directly to
-populate data structures after loading, instead of having to copy them
-to the data structure.
-
-## Pool allocator
-
-Sometimes in commands implementations, it is required to perform many
-small allocations that will be not retained at the end of the command
-execution, but are just functional to execute the command itself.
-
-This work can be more easily accomplished using the Redis pool allocator:
-
-    void *RedisModule_PoolAlloc(RedisModuleCtx *ctx, size_t bytes);
-
-It works similarly to `malloc()`, and returns memory aligned to the
-next power of two of greater or equal to `bytes` (for a maximum alignment
-of 8 bytes). However it allocates memory in blocks, so it the overhead
-of the allocations is small, and more important, the memory allocated
-is automatically released when the command returns.
-
-So in general short living allocations are a good candidates for the pool
-allocator.
-
-# Writing commands compatible with Redis Cluster
-
-Documentation missing, please check the following functions inside `module.c`:
-
-    RedisModule_IsKeysPositionRequest(ctx);
-    RedisModule_KeyAtPos(ctx,pos);
@@ -4,16 +4,16 @@ uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')

 # Compile flags for linux / osx
 ifeq ($(uname_S),Linux)
-	SHOBJ_CFLAGS ?= -fno-common -g -ggdb -std=c99 -O2
+	SHOBJ_CFLAGS ?= -W -Wall -fno-common -g -ggdb -std=c99 -O2
 	SHOBJ_LDFLAGS ?= -shared
 else
-	SHOBJ_CFLAGS ?= -dynamic -fno-common -g -ggdb -std=c99 -O2
+	SHOBJ_CFLAGS ?= -W -Wall -dynamic -fno-common -g -ggdb -std=c99 -O2
 	SHOBJ_LDFLAGS ?= -bundle -undefined dynamic_lookup
 endif

 .SUFFIXES: .c .so .xo .o

-all: helloworld.so hellotype.so testmodule.so
+all: helloworld.so hellotype.so helloblock.so testmodule.so

 .c.xo:
 	$(CC) -I. $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@
@@ -28,6 +28,11 @@ hellotype.xo: ../redismodule.h
 hellotype.so: hellotype.xo
 	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc

+helloblock.xo: ../redismodule.h
+
+helloblock.so: helloblock.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lpthread -lc
+
 testmodule.xo: ../redismodule.h

 testmodule.so: testmodule.xo
@@ -1,371 +0,0 @@
-Native types in Redis modules
-===
-
-Redis modules can access Redis built-in data structures both at high level,
-by calling Redis commands, and at low level, by manipulating the data structures
-directly.
-
-By using these capabilities in order to build new abstractions on top of existing
-Redis data structures, or by using strings DMA in order to encode modules
-data structures into Redis strings, it is possible to create modules that
-*feel like* they are exporting new data types. However, for more complex
-problems, this is not enough, and the implementation of new data structures
-inside the module is needed.
-
-We call the ability of Redis modules to implement new data structures that
-feel like native Redis ones **native types support**. This document describes
-the API exported by the Redis modules system in order to create new data
-structures and handle the serialization in RDB files, the rewriting process
-in AOF, the type reporting via the `TYPE` command, and so forth.
-
-Overview of native types
---
-
-A module exporting a native type is composed of the following main parts:
-
-* The implementation of some kind of new data structure and of commands operating on the new data structure.
-* A set of callbacks that handle: RDB saving, RDB loading, AOF rewriting, releasing of a value associated with a key, calculation of a value digest (hash) to be used with the `DEBUG DIGEST` command.
-* A 9 characters name that is unique to each module native data type.
-* An encoding version, used to persist into RDB files a module-specific data version, so that a module will be able to load older representations from RDB files.
-
-While to handle RDB loading, saving and AOF rewriting may look complex as a first glance, the modules API provide very high level function for handling all this, without requiring the user to handle read/write errors, so in practical terms, writing a new data structure for Redis is a simple task.
-
-A **very easy** to understand but complete example of native type implementation
-is available inside the Redis distribution in the `/modules/hellotype.c` file.
-The reader is encouraged to read the documentation by looking at this example
-implementation to see how things are applied in the practice.
-
-Registering a new data type
-===
-
-In order to register a new native type into the Redis core, the module needs
-to declare a global variable that will hold a reference to the data type.
-The API to register the data type will return a data type reference that will
-be stored in the global variable.
-
-    static RedisModuleType *MyType;
-    #define MYTYPE_ENCODING_VERSION 0
-
-    int RedisModule_OnLoad(RedisModuleCtx *ctx) {
-        MyType = RedisModule_CreateDataType("MyType-AZ", MYTYPE_ENCODING_VERSION,
-            MyTypeRDBLoad, MyTypeRDBSave, MyTypeAOFRewrite, MyTypeDigest,
-            MyTypeFree);
-        if (MyType == NULL) return REDISMODULE_ERR;
-    }
-
-As you can see from the example above, a single API call is needed in order to
-register the new type. However a number of function pointers are passed as
-arguments. The prototype of `RedisModule_CreateDataType` is the following:
-
-    moduleType *RedisModule_CreateDataType(RedisModuleCtx *ctx,
-               const char *name, int encver,
-               moduleTypeLoadFunc rdb_load,
-               moduleTypeSaveFunc rdb_save,
-               moduleTypeRewriteFunc aof_rewrite,
-               moduleTypeDigestFunc digest,
-               moduleTypeFreeFunc free);
-
-The `ctx` argument is the context that we receive in the `OnLoad` function.
-The type `name` is a 9 character name in the character set that includes
-from `A-Z`, `a-z`, `0-9`, plus the underscore `_` and minus `-` characters.
-
-Note that **this name must be unique** for each data type in the Redis
-ecosystem, so be creative, use both lower-case and upper case if it makes
-sense, and try to use the convention of mixing the type name with the name
-of the author of the module, to create a 9 character unique name.
-
-For example if I'm building a *b-tree* data structure and my name is *antirez*
-I'll call my type **btree1-az**. The name, converted to a 64 bit integer,
-is stored inside the RDB file when saving the type, and will be used when the
-RDB data is loaded in order to resolve what module can load the data. If Redis
-finds no matching module, the integer is converted back to a name in order to
-provide some clue to the user about what module is missing in order to load
-the data.
-
-The type name is also used as a reply for the `TYPE` command when called
-with a key holding the registered type.
-
-The `encver` argument is the encoding version used by the module to store data
-inside the RDB file. For example I can start with an encoding version of 0,
-but later when I release version 2.0 of my module, I can switch encoding to
-something better. The new module will register with an encoding version of 1,
-so when it saves new RDB files, the new version will be stored on disk. However
-when loading RDB files, the module `rdb_load` method will be called even if
-there is data found for a different encoding version (and the encoding version
-is passed as argument to `rdb_load`), so that the module can still load old
-RDB files.
-
-The remaining arguments `rdb_load`, `rdb_save`, `aof_rewrite`, `digest` and
-`free` are all callbacks with the following prototypes and uses:
-
-    typedef void *(*RedisModuleTypeLoadFunc)(RedisModuleIO *rdb, int encver);
-    typedef void (*RedisModuleTypeSaveFunc)(RedisModuleIO *rdb, void *value);
-    typedef void (*RedisModuleTypeRewriteFunc)(RedisModuleIO *aof, RedisModuleString *key, void *value);
-    typedef void (*RedisModuleTypeDigestFunc)(RedisModuleDigest *digest, void *value);
-    typedef void (*RedisModuleTypeFreeFunc)(void *value);
-
-* `rdb_load` is called when loading data from the RDB file. It loads data in the same format as `rdb_save` produces.
-* `rdb_save` is called when saving data to the RDB file.
-* `aof_rewrite` is called when the AOF is being rewritten, and the module needs to tell Redis what is the sequence of commands to recreate the content of a given key.
-* `digest` is called when `DEBUG DIGEST` is executed and a key holding this module type is found. Currently this is not yet implemented so the function ca be left empty.
-* `free` is called when a key with the module native type is deleted via `DEL` or in any other mean, in order to let the module reclaim the memory associated with such a value.
-
-Ok, but *why* modules types require a 9 characters name?
---
-
-Oh, I understand you need to understand this, so here is a very specific
-explanation.
-
-When Redis persists to RDB files, modules specific data types require to
-be persisted as well. Now RDB files are sequences of key-value pairs
-like the following:
-
-    [1 byte type] [key] [a type specific value]
-
-The 1 byte type identifies strings, lists, sets, and so forth. In the case
-of modules data, it is set to a special value of `module data`, but of
-course this is not enough, we need the information needed to link a specific
-value with a specific module type that is able to load and handle it.
-
-So when we save a `type specific value` about a module, we prefix it with
-a 64 bit integer. 64 bits is large enough to store the informations needed
-in order to lookup the module that can handle that specific type, but is
-short enough that we can prefix each module value we store inside the RDB
-without making the final RDB file too big. At the same time, this solution
-of prefixing the value with a 64 bit *signature* does not require to do
-strange things like defining in the RDB header a list of modules specific
-types. Everything is pretty simple.
-
-So, what you can store in 64 bits in order to identify a given module in
-a reliable way? Well if you build a character set of 64 symbols, you can
-easily store 9 characters of 6 bits, and you are left with 10 bits, that
-are used in order to store the *encoding version* of the type, so that
-the same type can evolve in the future and provide a different and more
-efficient or updated serialization format for RDB files.
-
-So the 64 bit prefix stored before each module value is like the following:
-
-    6|6|6|6|6|6|6|6|6|10
-
-The first 9 elements are 6-bits characters, the final 10 bits is the
-encoding version.
-
-When the RDB file is loaded back, it reads the 64 bit value, masks the final
-10 bits, and searches for a matching module in the modules types cache.
-When a matching one is found, the method to load the RDB file value is called
-with the 10 bits encoding version as argument, so that the module knows
-what version of the data layout to load, if it can support multiple versions.
-
-Now the interesting thing about all this is that, if instead the module type
-cannot be resolved, since there is no loaded module having this signature,
-we can convert back the 64 bit value into a 9 characters name, and print
-an error to the user that includes the module type name! So that she or he
-immediately realizes what's wrong.
-
-Setting and getting keys
---
-
-After registering our new data type in the `RedisModule_OnLoad()` function,
-we also need to be able to set Redis keys having as value our native type.
-
-This normally happens in the context of commands that write data to a key.
-The native types API allow to set and get keys to module native data types,
-and to test if a given key is already associated to a value of a specific data
-type.
-
-The API uses the normal modules `RedisModule_OpenKey()` low level key access
-interface in order to deal with this. This is an eaxmple of setting a
-native type private data structure to a Redis key:
-
-    RedisModuleKey *key = RedisModule_OpenKey(ctx,keyname,REDISMODULE_WRITE);
-    struct some_private_struct *data = createMyDataStructure();
-    RedisModule_ModuleTypeSetValue(key,MyType,data);
-
-The function `RedisModule_ModuleTypeSetValue()` is used with a key handle open
-for writing, and gets three arguments: the key handle, the reference to the
-native type, as obtained during the type registration, and finally a `void*`
-pointer that contains the private data implementing the module native type.
-
-Note that Redis has no clues at all about what your data contains. It will
-just call the callbacks you provided during the method registration in order
-to perform operations on the type.
-
-Similarly we can retrieve the private data from a key using this function:
-
-    struct some_private_struct *data;
-    data = RedisModule_ModuleTypeGetValue(key);
-
-We can also test for a key to have our native type as value:
-
-    if (RedisModule_ModuleTypeGetType(key) == MyType) {
-        /* ... do something ... */
-    }
-
-However for the calls to do the right thing, we need to check if the key
-is empty, if it contains a value of the right kind, and so forth. So
-the idiomatic code to implement a command writing to our native type
-is along these lines:
-
-    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
-        REDISMODULE_READ|REDISMODULE_WRITE);
-    int type = RedisModule_KeyType(key);
-    if (type != REDISMODULE_KEYTYPE_EMPTY &&
-        RedisModule_ModuleTypeGetType(key) != MyType)
-    {
-        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
-    }
-
-Then if we successfully verified the key is not of the wrong type, and
-we are going to write to it, we usually want to create a new data structure if
-the key is empty, or retrieve the reference to the value associated to the
-key if there is already one:
-
-    /* Create an empty value object if the key is currently empty. */
-    struct some_private_struct *data;
-    if (type == REDISMODULE_KEYTYPE_EMPTY) {
-        data = createMyDataStructure();
-        RedisModule_ModuleTypeSetValue(key,MyTyke,data);
-    } else {
-        data = RedisModule_ModuleTypeGetValue(key);
-    }
-    /* Do something with 'data'... */
-
-Free method
---
-
-As already mentioned, when Redis needs to free a key holding a native type
-value, it needs help from the module in order to release the memory. This
-is the reason why we pass a `free` callback during the type registration:
-
-    typedef void (*RedisModuleTypeFreeFunc)(void *value);
-
-A trivial implementation of the free method can be something like this,
-assuming our data structure is composed of a single allocation:
-
-    void MyTypeFreeCallback(void *value) {
-        RedisModule_Free(value);
-    }
-
-However a more real world one will call some function that performs a more
-complex memory reclaiming, by casting the void pointer to some structure
-and freeing all the resources composing the value.
-
-RDB load and save methods
---
-
-The RDB saving and loading callbacks need to create (and load back) a
-representation of the data type on disk. Redis offers an high level API
-that can automatically store inside the RDB file the following types:
-
-* Unsigned 64 bit integers.
-* Signed 64 bit integers.
-* Doubles.
-* Strings.
-
-It is up to the module to find a viable representation using the above base
-types. However note that while the integer and double values are stored
-and loaded in an architecture and *endianess* agnostic way, if you use
-the raw string saving API to, for example, save a structure on disk, you
-have to care those details yourself.
-
-This is the list of functions performing RDB saving and loading:
-
-    void RedisModule_SaveUnsigned(RedisModuleIO *io, uint64_t value);
-    uint64_t RedisModule_LoadUnsigned(RedisModuleIO *io);
-    void RedisModule_SaveSigned(RedisModuleIO *io, int64_t value);
-    int64_t RedisModule_LoadSigned(RedisModuleIO *io);
-    void RedisModule_SaveString(RedisModuleIO *io, RedisModuleString *s);
-    void RedisModule_SaveStringBuffer(RedisModuleIO *io, const char *str, size_t len);
-    RedisModuleString *RedisModule_LoadString(RedisModuleIO *io);
-    char *RedisModule_LoadStringBuffer(RedisModuleIO *io, size_t *lenptr);
-    void RedisModule_SaveDouble(RedisModuleIO *io, double value);
-    double RedisModule_LoadDouble(RedisModuleIO *io);
-
-The functions don't require any error checking from the module, that can
-always assume calls succeed.
-
-As an example, imagine I've a native type that implements an array of
-double values, with the following structure:
-
-    struct double_array {
-        size_t count;
-        double *values;
-    };
-
-My `rdb_save` method may look like the following:
-
-    void DoubleArrayRDBSave(RedisModuleIO *io, void *ptr) {
-        struct dobule_array *da = ptr;
-        RedisModule_SaveUnsigned(io,da->count);
-        for (size_t j = 0; j < da->count; j++)
-            RedisModule_SaveDouble(io,da->values[j]);
-    }
-
-What we did was to store the number of elements followed by each double
-value. So when later we'll have to load the structure in the `rdb_load`
-method we'll do something like this:
-
-    void *DoubleArrayRDBLoad(RedisModuleIO *io, int encver) {
-        if (encver != DOUBLE_ARRAY_ENC_VER) {
-            /* We should actually log an error here, or try to implement
-               the ability to load older versions of our data structure. */
-            return NULL;
-        }
-
-        struct double_array *da;
-        da = RedisModule_Alloc(sizeof(*da));
-        da->count = RedisModule_LoadUnsigned(io);
-        da->values = RedisModule_Alloc(da->count * sizeof(double));
-        for (size_t j = 0; j < da->count; j++)
-            da->values = RedisModule_LoadDouble(io);
-        return da;
-    }
-
-The load callback just reconstruct back the data structure from the data
-we stored in the RDB file.
-
-Note that while there is no error handling on the API that writes and reads
-from disk, still the load callback can return NULL on errors in case what
-it reads does not look correct. Redis will just panic in that case.
-
-AOF rewriting
---
-
-    void RedisModule_EmitAOF(RedisModuleIO *io, const char *cmdname, const char *fmt, ...);
-
-Handling multiple encodings
---
-
-    WORK IN PROGRESS
-
-Allocating memory
---
-
-Modules data types should try to use `RedisModule_Alloc()` functions family
-in order to allocate, reallocate and release heap memory used to implement the native data structures (see the other Redis Modules documentation for detailed information).
-
-This is not just useful in order for Redis to be able to account for the memory used by the module, but there are also more advantages:
-
-* Redis uses the `jemalloc` allcator, that often prevents fragmentation problems that could be caused by using the libc allocator.
-* When loading strings from the RDB file, the native types API is able to return strings allocated directly with `RedisModule_Alloc()`, so that the module can directly link this memory into the data structure representation, avoiding an useless copy of the data.
-
-Even if you are using external libraries implementing your data structures, the
-allocation functions provided by the module API is exactly compatible with
-`malloc()`, `realloc()`, `free()` and `strdup()`, so converting the libraries
-in order to use these functions should be trivial.
-
-In case you have an external library that uses libc `malloc()`, and you want
-to avoid replacing manually all the calls with the Redis Modules API calls,
-an approach could be to use simple macros in order to replace the libc calls
-with the Redis API calls. Something like this could work:
-
-    #define malloc RedisModule_Alloc
-    #define realloc RedisModule_Realloc
-    #define free RedisModule_Free
-    #define strdup RedisModule_Strdup
-
-However take in mind that mixing libc calls with Redis API calls will result
-into troubles and crashes, so if you replace calls using macros, you need to
-make sure that all the calls are correctly replaced, and that the code with
-the substituted calls will never, for example, attempt to call
-`RedisModule_Free()` with a pointer allocated using libc `malloc()`.
@@ -6,21 +6,29 @@ def markdown(s)
    s = s.gsub(/\*\/$/,"")
    s = s.gsub(/^ \* {0,1}/,"")
    s = s.gsub(/^\/\* /,"")
-    if s[0] != ' '
-        s = s.gsub(/RM_[A-z()]+/){|x| "`#{x}`"}
-        s = s.gsub(/RedisModule_[A-z()]+/){|x| "`#{x}`"}
-        s = s.gsub(/REDISMODULE_[A-z]+/){|x| "`#{x}`"}
-    end
    s.chop! while s[-1] == "\n" || s[-1] == " "
-    return s
+    lines = s.split("\n")
+    newlines = []
+    lines.each{|l|
+        if l[0] != ' '
+            l = l.gsub(/RM_[A-z()]+/){|x| "`#{x}`"}
+            l = l.gsub(/RedisModule_[A-z()]+/){|x| "`#{x}`"}
+            l = l.gsub(/REDISMODULE_[A-z]+/){|x| "`#{x}`"}
+        end
+        newlines << l
+    }
+    return newlines.join("\n")
 end

 # Given the source code array and the index at which an exported symbol was
 # detected, extracts and outputs the documentation.
 def docufy(src,i)
    m = /RM_[A-z0-9]+/.match(src[i])
+    name = m[0]
+    name = name.sub("RM_","RedisModule_")
    proto = src[i].sub("{","").strip+";\n"
-    puts "## `#{m[0]}`\n\n"
+    proto = proto.sub("RM_","RedisModule_")
+    puts "## `#{name}`\n\n"
    puts "    #{proto}\n"
    comment = ""
    while true
@@ -0,0 +1,196 @@
+/* Helloblock module -- An example of blocking command implementation
+ * with threads.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2016, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define REDISMODULE_EXPERIMENTAL_API
+#include "../redismodule.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
+
+/* Reply callback for blocking command HELLO.BLOCK */
+int HelloBlock_Reply(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+    int *myint = RedisModule_GetBlockedClientPrivateData(ctx);
+    return RedisModule_ReplyWithLongLong(ctx,*myint);
+}
+
+/* Timeout callback for blocking command HELLO.BLOCK */
+int HelloBlock_Timeout(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+    return RedisModule_ReplyWithSimpleString(ctx,"Request timedout");
+}
+
+/* Private data freeing callback for HELLO.BLOCK command. */
+void HelloBlock_FreeData(void *privdata) {
+    RedisModule_Free(privdata);
+}
+
+/* The thread entry point that actually executes the blocking part
+ * of the command HELLO.BLOCK. */
+void *HelloBlock_ThreadMain(void *arg) {
+    void **targ = arg;
+    RedisModuleBlockedClient *bc = targ[0];
+    long long delay = (unsigned long)targ[1];
+    RedisModule_Free(targ);
+
+    sleep(delay);
+    int *r = RedisModule_Alloc(sizeof(int));
+    *r = rand();
+    RedisModule_UnblockClient(bc,r);
+    return NULL;
+}
+
+/* HELLO.BLOCK <delay> <timeout> -- Block for <count> seconds, then reply with
+ * a random number. Timeout is the command timeout, so that you can test
+ * what happens when the delay is greater than the timeout. */
+int HelloBlock_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+    long long delay;
+    long long timeout;
+
+    if (RedisModule_StringToLongLong(argv[1],&delay) != REDISMODULE_OK) {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid count");
+    }
+
+    if (RedisModule_StringToLongLong(argv[2],&timeout) != REDISMODULE_OK) {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid count");
+    }
+
+    pthread_t tid;
+    RedisModuleBlockedClient *bc = RedisModule_BlockClient(ctx,HelloBlock_Reply,HelloBlock_Timeout,HelloBlock_FreeData,timeout);
+
+    /* Now that we setup a blocking client, we need to pass the control
+     * to the thread. However we need to pass arguments to the thread:
+     * the delay and a reference to the blocked client handle. */
+    void **targ = RedisModule_Alloc(sizeof(void*)*2);
+    targ[0] = bc;
+    targ[1] = (void*)(unsigned long) delay;
+
+    if (pthread_create(&tid,NULL,HelloBlock_ThreadMain,targ) != 0) {
+        RedisModule_AbortBlock(bc);
+        return RedisModule_ReplyWithError(ctx,"-ERR Can't start thread");
+    }
+    return REDISMODULE_OK;
+}
+
+/* The thread entry point that actually executes the blocking part
+ * of the command HELLO.KEYS.
+ *
+ * Note: this implementation is very simple on purpose, so no duplicated
+ * keys (returned by SCAN) are filtered. However adding such a functionality
+ * would be trivial just using any data structure implementing a dictionary
+ * in order to filter the duplicated items. */
+void *HelloKeys_ThreadMain(void *arg) {
+    RedisModuleBlockedClient *bc = arg;
+    RedisModuleCtx *ctx = RedisModule_GetThreadSafeContext(bc);
+    long long cursor = 0;
+    size_t replylen = 0;
+
+    RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
+    do {
+        RedisModule_ThreadSafeContextLock(ctx);
+        RedisModuleCallReply *reply = RedisModule_Call(ctx,
+            "SCAN","l",(long long)cursor);
+        RedisModule_ThreadSafeContextUnlock(ctx);
+
+        RedisModuleCallReply *cr_cursor =
+            RedisModule_CallReplyArrayElement(reply,0);
+        RedisModuleCallReply *cr_keys =
+            RedisModule_CallReplyArrayElement(reply,1);
+
+        RedisModuleString *s = RedisModule_CreateStringFromCallReply(cr_cursor);
+        RedisModule_StringToLongLong(s,&cursor);
+        RedisModule_FreeString(ctx,s);
+
+        size_t items = RedisModule_CallReplyLength(cr_keys);
+        for (size_t j = 0; j < items; j++) {
+            RedisModuleCallReply *ele =
+                RedisModule_CallReplyArrayElement(cr_keys,j);
+            RedisModule_ReplyWithCallReply(ctx,ele);
+            replylen++;
+        }
+        RedisModule_FreeCallReply(reply);
+    } while (cursor != 0);
+    RedisModule_ReplySetArrayLength(ctx,replylen);
+
+    RedisModule_FreeThreadSafeContext(ctx);
+    RedisModule_UnblockClient(bc,NULL);
+    return NULL;
+}
+
+/* HELLO.KEYS -- Return all the keys in the current database without blocking
+ * the server. The keys do not represent a point-in-time state so only the keys
+ * that were in the database from the start to the end are guaranteed to be
+ * there. */
+int HelloKeys_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    if (argc != 1) return RedisModule_WrongArity(ctx);
+
+    pthread_t tid;
+
+    /* Note that when blocking the client we do not set any callback: no
+     * timeout is possible since we passed '0', nor we need a reply callback
+     * because we'll use the thread safe context to accumulate a reply. */
+    RedisModuleBlockedClient *bc = RedisModule_BlockClient(ctx,NULL,NULL,NULL,0);
+
+    /* Now that we setup a blocking client, we need to pass the control
+     * to the thread. However we need to pass arguments to the thread:
+     * the reference to the blocked client handle. */
+    if (pthread_create(&tid,NULL,HelloKeys_ThreadMain,bc) != 0) {
+        RedisModule_AbortBlock(bc);
+        return RedisModule_ReplyWithError(ctx,"-ERR Can't start thread");
+    }
+    return REDISMODULE_OK;
+}
+
+/* This function must be present on each Redis module. It is used in order to
+ * register the commands into the Redis server. */
+int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
+    if (RedisModule_Init(ctx,"helloblock",1,REDISMODULE_APIVER_1)
+        == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.block",
+        HelloBlock_RedisCommand,"",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+    if (RedisModule_CreateCommand(ctx,"hello.keys",
+        HelloKeys_RedisCommand,"",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    return REDISMODULE_OK;
+}
@@ -226,21 +226,48 @@ void HelloTypeAofRewrite(RedisModuleIO *aof, RedisModuleString *key, void *value
    }
 }

-void HelloTypeDigest(RedisModuleDigest *digest, void *value) {
-    /* TODO: The DIGEST module interface is yet not implemented. */
+/* The goal of this function is to return the amount of memory used by
+ * the HelloType value. */
+size_t HelloTypeMemUsage(const void *value) {
+    const struct HelloTypeObject *hto = value;
+    struct HelloTypeNode *node = hto->head;
+    return sizeof(*hto) + sizeof(*node)*hto->len;
 }

 void HelloTypeFree(void *value) {
    HelloTypeReleaseObject(value);
 }

+void HelloTypeDigest(RedisModuleDigest *md, void *value) {
+    struct HelloTypeObject *hto = value;
+    struct HelloTypeNode *node = hto->head;
+    while(node) {
+        RedisModule_DigestAddLongLong(md,node->value);
+        node = node->next;
+    }
+    RedisModule_DigestEndSequence(md);
+}
+
 /* This function must be present on each Redis module. It is used in order to
 * register the commands into the Redis server. */
 int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
    if (RedisModule_Init(ctx,"hellotype",1,REDISMODULE_APIVER_1)
        == REDISMODULE_ERR) return REDISMODULE_ERR;

-    HelloType = RedisModule_CreateDataType(ctx,"hellotype",0,HelloTypeRdbLoad,HelloTypeRdbSave,HelloTypeAofRewrite,HelloTypeDigest,HelloTypeFree);
+    RedisModuleTypeMethods tm = {
+        .version = REDISMODULE_TYPE_METHOD_VERSION,
+        .rdb_load = HelloTypeRdbLoad,
+        .rdb_save = HelloTypeRdbSave,
+        .aof_rewrite = HelloTypeAofRewrite,
+        .mem_usage = HelloTypeMemUsage,
+        .free = HelloTypeFree,
+        .digest = HelloTypeDigest
+    };
+
+    HelloType = RedisModule_CreateDataType(ctx,"hellotype",0,&tm);
    if (HelloType == NULL) return REDISMODULE_ERR;

    if (RedisModule_CreateCommand(ctx,"hellotype.insert",
@@ -46,6 +46,8 @@
 * fetch the currently selected DB, the other in order to send the client
 * an integer reply as response. */
 int HelloSimple_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
    RedisModule_ReplyWithLongLong(ctx,RedisModule_GetSelectedDb(ctx));
    return REDISMODULE_OK;
 }
@@ -237,7 +239,8 @@ int HelloRandArray_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, i
 * comments the function implementation). */
 int HelloRepl1_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
 {
-    RedisModuleCallReply *reply;
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
    RedisModule_AutoMemory(ctx);

    /* This will be replicated *after* the two INCR statements, since
@@ -254,8 +257,8 @@ int HelloRepl1_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int a

    /* Using the "!" modifier we replicate the command if it
     * modified the dataset in some way. */
-    reply = RedisModule_Call(ctx,"INCR","c!","foo");
-    reply = RedisModule_Call(ctx,"INCR","c!","bar");
+    RedisModule_Call(ctx,"INCR","c!","foo");
+    RedisModule_Call(ctx,"INCR","c!","bar");

    RedisModule_ReplyWithLongLong(ctx,0);

@@ -519,7 +522,7 @@ int HelloLeftPad_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int

    /* If the string is already larger than the target len, just return
     * the string itself. */
-    if (strlen >= padlen)
+    if (strlen >= (size_t)padlen)
        return RedisModule_ReplyWithString(ctx,argv[1]);

    /* Padding must be a single character in this simple implementation. */
@@ -530,7 +533,7 @@ int HelloLeftPad_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int
    /* Here we use our pool allocator, for our throw-away allocation. */
    padlen -= strlen;
    char *buf = RedisModule_PoolAlloc(ctx,padlen+strlen);
-    for (size_t j = 0; j < padlen; j++) buf[j] = *ch;
+    for (long long j = 0; j < padlen; j++) buf[j] = *ch;
    memcpy(buf+padlen,str,strlen);

    RedisModule_ReplyWithStringBuffer(ctx,buf,padlen+strlen);
@@ -48,6 +48,9 @@ int TestMatchReply(RedisModuleCallReply *reply, char *str) {

 /* TEST.CALL -- Test Call() API. */
 int TestCall(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
    RedisModule_AutoMemory(ctx);
    RedisModuleCallReply *reply;

@@ -75,6 +78,9 @@ fail:

 /* TEST.STRING.APPEND -- Test appending to an existing string object. */
 int TestStringAppend(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
    RedisModuleString *s = RedisModule_CreateString(ctx,"foo",3);
    RedisModule_StringAppendBuffer(ctx,s,"bar",3);
    RedisModule_ReplyWithString(ctx,s);
@@ -84,6 +90,9 @@ int TestStringAppend(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {

 /* TEST.STRING.APPEND.AM -- Test append with retain when auto memory is on. */
 int TestStringAppendAM(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
    RedisModule_AutoMemory(ctx);
    RedisModuleString *s = RedisModule_CreateString(ctx,"foo",3);
    RedisModule_RetainString(ctx,s);
@@ -112,6 +121,81 @@ int TestStringPrintf(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
 }


+/* TEST.CTXFLAGS -- Test GetContextFlags. */
+int TestCtxFlags(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argc);
+    REDISMODULE_NOT_USED(argv);
+  
+    RedisModule_AutoMemory(ctx);
+  
+    int ok = 1;
+    const char *errString = NULL;
+  
+  #define FAIL(msg)    \
+    {                  \
+      ok = 0;          \
+      errString = msg; \
+      goto end;        \
+    }
+  
+    int flags = RedisModule_GetContextFlags(ctx);
+    if (flags == 0) {
+      FAIL("Got no flags");
+    }
+  
+    if (flags & REDISMODULE_CTX_FLAGS_LUA) FAIL("Lua flag was set");
+    if (flags & REDISMODULE_CTX_FLAGS_MULTI) FAIL("Multi flag was set");
+  
+    if (flags & REDISMODULE_CTX_FLAGS_AOF) FAIL("AOF Flag was set")
+    /* Enable AOF to test AOF flags */
+    RedisModule_Call(ctx, "config", "ccc", "set", "appendonly", "yes");
+    flags = RedisModule_GetContextFlags(ctx);
+    if (!(flags & REDISMODULE_CTX_FLAGS_AOF))
+      FAIL("AOF Flag not set after config set");
+  
+    if (flags & REDISMODULE_CTX_FLAGS_RDB) FAIL("RDB Flag was set");
+    /* Enable RDB to test RDB flags */
+    RedisModule_Call(ctx, "config", "ccc", "set", "save", "900 1");
+    flags = RedisModule_GetContextFlags(ctx);
+    if (!(flags & REDISMODULE_CTX_FLAGS_RDB))
+      FAIL("RDB Flag was not set after config set");
+  
+    if (!(flags & REDISMODULE_CTX_FLAGS_MASTER)) FAIL("Master flag was not set");
+    if (flags & REDISMODULE_CTX_FLAGS_SLAVE) FAIL("Slave flag was set");
+    if (flags & REDISMODULE_CTX_FLAGS_READONLY) FAIL("Read-only flag was set");
+    if (flags & REDISMODULE_CTX_FLAGS_CLUSTER) FAIL("Cluster flag was set");
+  
+    if (flags & REDISMODULE_CTX_FLAGS_MAXMEMORY) FAIL("Maxmemory flag was set");
+    ;
+    RedisModule_Call(ctx, "config", "ccc", "set", "maxmemory", "100000000");
+    flags = RedisModule_GetContextFlags(ctx);
+    if (!(flags & REDISMODULE_CTX_FLAGS_MAXMEMORY))
+      FAIL("Maxmemory flag was not set after config set");
+  
+    if (flags & REDISMODULE_CTX_FLAGS_EVICT) FAIL("Eviction flag was set");
+    RedisModule_Call(ctx, "config", "ccc", "set", "maxmemory-policy",
+                     "allkeys-lru");
+    flags = RedisModule_GetContextFlags(ctx);
+    if (!(flags & REDISMODULE_CTX_FLAGS_EVICT))
+      FAIL("Eviction flag was not set after config set");
+  
+  end:
+    /* Revert config changes */
+    RedisModule_Call(ctx, "config", "ccc", "set", "appendonly", "no");
+    RedisModule_Call(ctx, "config", "ccc", "set", "save", "");
+    RedisModule_Call(ctx, "config", "ccc", "set", "maxmemory", "0");
+    RedisModule_Call(ctx, "config", "ccc", "set", "maxmemory-policy", "noeviction");
+  
+    if (!ok) {
+      RedisModule_Log(ctx, "warning", "Failed CTXFLAGS Test. Reason: %s",
+                      errString);
+      return RedisModule_ReplyWithSimpleString(ctx, "ERR");
+    }
+  
+    return RedisModule_ReplyWithSimpleString(ctx, "OK");
+  }
+
+
 /* ----------------------------- Test framework ----------------------------- */

 /* Return 1 if the reply matches the specified string, otherwise log errors
@@ -163,6 +247,9 @@ int TestAssertIntegerReply(RedisModuleCtx *ctx, RedisModuleCallReply *reply, lon

 /* TEST.IT -- Run all the tests. */
 int TestIt(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
    RedisModule_AutoMemory(ctx);
    RedisModuleCallReply *reply;

@@ -176,6 +263,9 @@ int TestIt(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
    T("test.call","");
    if (!TestAssertStringReply(ctx,reply,"OK",2)) goto fail;

+    T("test.ctxflags","");
+    if (!TestAssertStringReply(ctx,reply,"OK",2)) goto fail;
+
    T("test.string.append","");
    if (!TestAssertStringReply(ctx,reply,"foobar",6)) goto fail;

@@ -195,6 +285,9 @@ fail:
 }

 int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
    if (RedisModule_Init(ctx,"test",1,REDISMODULE_APIVER_1)
        == REDISMODULE_ERR) return REDISMODULE_ERR;

@@ -214,6 +307,10 @@ int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
        TestStringPrintf,"write deny-oom",1,1,1) == REDISMODULE_ERR)
        return REDISMODULE_ERR;

+    if (RedisModule_CreateCommand(ctx,"test.ctxflags",
+        TestCtxFlags,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
    if (RedisModule_CreateCommand(ctx,"test.it",
        TestIt,"readonly",1,1,1) == REDISMODULE_ERR)
        return REDISMODULE_ERR;
@@ -117,6 +117,7 @@ void execCommand(client *c) {
    int orig_argc;
    struct redisCommand *orig_cmd;
    int must_propagate = 0; /* Need to propagate MULTI/EXEC to AOF / slaves? */
+    int was_master = server.masterhost == NULL;

    if (!(c->flags & CLIENT_MULTI)) {
        addReplyError(c,"EXEC without MULTI");
@@ -147,11 +148,12 @@ void execCommand(client *c) {
        c->argv = c->mstate.commands[j].argv;
        c->cmd = c->mstate.commands[j].cmd;

-        /* Propagate a MULTI request once we encounter the first write op.
+        /* Propagate a MULTI request once we encounter the first command which
+         * is not readonly nor an administrative one.
         * This way we'll deliver the MULTI/..../EXEC block as a whole and
         * both the AOF and the replication link will have the same consistency
         * and atomicity guarantees. */
-        if (!must_propagate && !(c->cmd->flags & CMD_READONLY)) {
+        if (!must_propagate && !(c->cmd->flags & (CMD_READONLY|CMD_ADMIN))) {
            execCommandPropagateMulti(c);
            must_propagate = 1;
        }
@@ -167,9 +169,22 @@ void execCommand(client *c) {
    c->argc = orig_argc;
    c->cmd = orig_cmd;
    discardTransaction(c);
+
    /* Make sure the EXEC command will be propagated as well if MULTI
     * was already propagated. */
-    if (must_propagate) server.dirty++;
+    if (must_propagate) {
+        int is_master = server.masterhost == NULL;
+        server.dirty++;
+        /* If inside the MULTI/EXEC block this instance was suddenly
+         * switched from master to slave (using the SLAVEOF command), the
+         * initial MULTI was propagated into the replication backlog, but the
+         * rest was not. We need to make sure to at least terminate the
+         * backlog with the final EXEC. */
+        if (server.repl_backlog && was_master && !is_master) {
+            char *execcmd = "*1\r\n$4\r\nEXEC\r\n";
+            feedReplicationBacklog(execcmd,strlen(execcmd));
+        }
+    }

 handle_monitor:
    /* Send EXEC to clients waiting data from MONITOR. We do it here
@@ -28,10 +28,12 @@
 */

 #include "server.h"
+#include "atomicvar.h"
 #include <sys/uio.h>
 #include <math.h>
+#include <ctype.h>

-static void setProtocolError(client *c, int pos);
+static void setProtocolError(const char *errstr, client *c, int pos);

 /* Return the size consumed from the allocator, for the specified SDS string,
 * including internal fragmentation. This function is used in order to compute
@@ -65,6 +67,16 @@ int listMatchObjects(void *a, void *b) {
    return equalStringObjects(a,b);
 }

+/* This function links the client to the global linked list of clients.
+ * unlinkClient() does the opposite, among other things. */
+void linkClient(client *c) {
+    listAddNodeTail(server.clients,c);
+    /* Note that we remember the linked list node where the client is stored,
+     * this way removing the client in unlinkClient() will not require
+     * a linear scan, but just a constant time operation. */
+    c->client_list_node = listLast(server.clients);
+}
+
 client *createClient(int fd) {
    client *c = zmalloc(sizeof(client));

@@ -87,11 +99,14 @@ client *createClient(int fd) {
    }

    selectDb(c,0);
-    c->id = server.next_client_id++;
+    uint64_t client_id;
+    atomicGetIncr(server.next_client_id,client_id,1);
+    c->id = client_id;
    c->fd = fd;
    c->name = NULL;
    c->bufpos = 0;
    c->querybuf = sdsempty();
+    c->pending_querybuf = sdsempty();
    c->querybuf_peak = 0;
    c->reqtype = 0;
    c->argc = 0;
@@ -106,6 +121,7 @@ client *createClient(int fd) {
    c->replstate = REPL_STATE_NONE;
    c->repl_put_online_on_ack = 0;
    c->reploff = 0;
+    c->read_reploff = 0;
    c->repl_ack_off = 0;
    c->repl_ack_time = 0;
    c->slave_listening_port = 0;
@@ -118,8 +134,9 @@ client *createClient(int fd) {
    listSetDupMethod(c->reply,dupClientReplyValue);
    c->btype = BLOCKED_NONE;
    c->bpop.timeout = 0;
-    c->bpop.keys = dictCreate(&objectKeyPointerValueDictType,NULL);
+    c->bpop.keys = dictCreate(&objectKeyHeapPointerValueDictType,NULL);
    c->bpop.target = NULL;
+    c->bpop.xread_group = NULL;
    c->bpop.numreplicas = 0;
    c->bpop.reploffset = 0;
    c->woff = 0;
@@ -127,9 +144,10 @@ client *createClient(int fd) {
    c->pubsub_channels = dictCreate(&objectKeyPointerValueDictType,NULL);
    c->pubsub_patterns = listCreate();
    c->peerid = NULL;
+    c->client_list_node = NULL;
    listSetFreeMethod(c->pubsub_patterns,decrRefCountVoid);
    listSetMatchMethod(c->pubsub_patterns,listMatchObjects);
-    if (fd != -1) listAddNodeTail(server.clients,c);
+    if (fd != -1) linkClient(c);
    initClientMultiState(c);
    return c;
 }
@@ -352,6 +370,14 @@ void addReplySds(client *c, sds s) {
    }
 }

+/* This low level function just adds whatever protocol you send it to the
+ * client buffer, trying the static buffer initially, and using the string
+ * of objects if not possible.
+ *
+ * It is efficient because does not create an SDS object nor an Redis object
+ * if not needed. The object will only be created by calling
+ * _addReplyStringToList() if we fail to extend the existing tail object
+ * in the list of objects. */
 void addReplyString(client *c, const char *s, size_t len) {
    if (prepareClientToWrite(c) != C_OK) return;
    if (_addReplyToBuffer(c,s,len) != C_OK)
@@ -547,13 +573,12 @@ void addReplyBulkCBuffer(client *c, const void *p, size_t len) {

 /* Add sds to reply (takes ownership of sds and frees it) */
 void addReplyBulkSds(client *c, sds s)  {
-    addReplySds(c,sdscatfmt(sdsempty(),"$%u\r\n",
-        (unsigned long)sdslen(s)));
+    addReplyLongLongWithPrefix(c,sdslen(s),'$');
    addReplySds(c,s);
    addReply(c,shared.crlf);
 }

-/* Add a C nul term string as bulk reply */
+/* Add a C null term string as bulk reply */
 void addReplyBulkCString(client *c, const char *s) {
    if (s == NULL) {
        addReply(c,shared.nullbulk);
@@ -571,6 +596,26 @@ void addReplyBulkLongLong(client *c, long long ll) {
    addReplyBulkCBuffer(c,buf,len);
 }

+/* Add an array of C strings as status replies with a heading.
+ * This function is typically invoked by from commands that support
+ * subcommands in response to the 'help' subcommand. The help array
+ * is terminated by NULL sentinel. */
+void addReplyHelp(client *c, const char **help) {
+    sds cmd = sdsnew((char*) c->argv[0]->ptr);
+    void *blenp = addDeferredMultiBulkLength(c);
+    int blen = 0;
+
+    sdstoupper(cmd);
+    addReplyStatusFormat(c,
+        "%s <subcommand> arg arg ... arg. Subcommands are:",cmd);
+    sdsfree(cmd);
+
+    while (help[blen]) addReplyStatus(c,help[blen++]);
+
+    blen++;  /* Account for the header line(s). */
+    setDeferredMultiBulkLength(c,blenp,blen);
+}
+
 /* Copy 'src' client output buffers into 'dst' client output buffers.
 * The function takes care of freeing the old output buffers of the
 * destination client. */
@@ -730,9 +775,10 @@ void unlinkClient(client *c) {
     * fd is already set to -1. */
    if (c->fd != -1) {
        /* Remove from the list of active clients. */
-        ln = listSearchKey(server.clients,c);
-        serverAssert(ln != NULL);
-        listDelNode(server.clients,ln);
+        if (c->client_list_node) {
+            listDelNode(server.clients,c->client_list_node);
+            c->client_list_node = NULL;
+        }

        /* Unregister async I/O handlers and close the socket. */
        aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
@@ -787,6 +833,7 @@ void freeClient(client *c) {

    /* Free the query buffer */
    sdsfree(c->querybuf);
+    sdsfree(c->pending_querybuf);
    c->querybuf = NULL;

    /* Deallocate structures used to block on blocking ops. */
@@ -912,6 +959,10 @@ int writeToClient(int fd, client *c, int handler_installed) {
                listDelNode(c->reply,listFirst(c->reply));
                c->sentlen = 0;
                c->reply_bytes -= objlen;
+                /* If there are no longer objects in the list, we expect
+                 * the count of reply bytes to be exactly zero. */
+                if (listLength(c->reply) == 0)
+                    serverAssert(c->reply_bytes == 0);
            }
        }
        /* Note that we avoid to send more than NET_MAX_WRITES_PER_EVENT
@@ -922,11 +973,11 @@ int writeToClient(int fd, client *c, int handler_installed) {
         *
         * However if we are over the maxmemory limit we ignore that and
         * just deliver as much data as it is possible to deliver. */
-        server.stat_net_output_bytes += totwritten;
        if (totwritten > NET_MAX_WRITES_PER_EVENT &&
            (server.maxmemory == 0 ||
             zmalloc_used_memory() < server.maxmemory)) break;
    }
+    server.stat_net_output_bytes += totwritten;
    if (nwritten == -1) {
        if (errno == EAGAIN) {
            nwritten = 0;
@@ -1018,6 +1069,13 @@ void resetClient(client *c) {
    }
 }

+/* Like processMultibulkBuffer(), but for the inline protocol instead of RESP,
+ * this function consumes the client query buffer and creates a command ready
+ * to be executed inside the client structure. Returns C_OK if the command
+ * is ready to be executed, or C_ERR if there is still protocol to read to
+ * have a well formed command. The function also returns C_ERR when there is
+ * a protocol error: in such a case the client structure is setup to reply
+ * with the error and close the connection. */
 int processInlineBuffer(client *c) {
    char *newline;
    int argc, j;
@@ -1031,7 +1089,7 @@ int processInlineBuffer(client *c) {
    if (newline == NULL) {
        if (sdslen(c->querybuf) > PROTO_INLINE_MAX_SIZE) {
            addReplyError(c,"Protocol error: too big inline request");
-            setProtocolError(c,0);
+            setProtocolError("too big inline request",c,0);
        }
        return C_ERR;
    }
@@ -1047,7 +1105,7 @@ int processInlineBuffer(client *c) {
    sdsfree(aux);
    if (argv == NULL) {
        addReplyError(c,"Protocol error: unbalanced quotes in request");
-        setProtocolError(c,0);
+        setProtocolError("unbalanced quotes in inline request",c,0);
        return C_ERR;
    }

@@ -1081,17 +1139,46 @@ int processInlineBuffer(client *c) {

 /* Helper function. Trims query buffer to make the function that processes
 * multi bulk requests idempotent. */
-static void setProtocolError(client *c, int pos) {
+#define PROTO_DUMP_LEN 128
+static void setProtocolError(const char *errstr, client *c, int pos) {
    if (server.verbosity <= LL_VERBOSE) {
        sds client = catClientInfoString(sdsempty(),c);
+
+        /* Sample some protocol to given an idea about what was inside. */
+        char buf[256];
+        if (sdslen(c->querybuf) < PROTO_DUMP_LEN) {
+            snprintf(buf,sizeof(buf),"Query buffer during protocol error: '%s'", c->querybuf);
+        } else {
+            snprintf(buf,sizeof(buf),"Query buffer during protocol error: '%.*s' (... more %zu bytes ...) '%.*s'", PROTO_DUMP_LEN/2, c->querybuf, sdslen(c->querybuf)-PROTO_DUMP_LEN, PROTO_DUMP_LEN/2, c->querybuf+sdslen(c->querybuf)-PROTO_DUMP_LEN/2);
+        }
+
+        /* Remove non printable chars. */
+        char *p = buf;
+        while (*p != '\0') {
+            if (!isprint(*p)) *p = '.';
+            p++;
+        }
+
+        /* Log all the client and protocol info. */
        serverLog(LL_VERBOSE,
-            "Protocol error from client: %s", client);
+            "Protocol error (%s) from client: %s. %s", errstr, client, buf);
        sdsfree(client);
    }
    c->flags |= CLIENT_CLOSE_AFTER_REPLY;
    sdsrange(c->querybuf,pos,-1);
 }

+/* Process the query buffer for client 'c', setting up the client argument
+ * vector for command execution. Returns C_OK if after running the function
+ * the client has a well-formed ready to be processed command, otherwise
+ * C_ERR if there is still to read more buffer to get the full command.
+ * The function also returns C_ERR when there is a protocol error: in such a
+ * case the client structure is setup to reply with the error and close
+ * the connection.
+ *
+ * This function is called if processInputBuffer() detects that the next
+ * command is in RESP format, so the first byte in the command is found
+ * to be '*'. Otherwise for inline commands processInlineBuffer() is called. */
 int processMultibulkBuffer(client *c) {
    char *newline = NULL;
    int pos = 0, ok;
@@ -1106,7 +1193,7 @@ int processMultibulkBuffer(client *c) {
        if (newline == NULL) {
            if (sdslen(c->querybuf) > PROTO_INLINE_MAX_SIZE) {
                addReplyError(c,"Protocol error: too big mbulk count string");
-                setProtocolError(c,0);
+                setProtocolError("too big mbulk count string",c,0);
            }
            return C_ERR;
        }
@@ -1121,7 +1208,7 @@ int processMultibulkBuffer(client *c) {
        ok = string2ll(c->querybuf+1,newline-(c->querybuf+1),&ll);
        if (!ok || ll > 1024*1024) {
            addReplyError(c,"Protocol error: invalid multibulk length");
-            setProtocolError(c,pos);
+            setProtocolError("invalid mbulk count",c,pos);
            return C_ERR;
        }

@@ -1147,7 +1234,7 @@ int processMultibulkBuffer(client *c) {
                if (sdslen(c->querybuf) > PROTO_INLINE_MAX_SIZE) {
                    addReplyError(c,
                        "Protocol error: too big bulk count string");
-                    setProtocolError(c,0);
+                    setProtocolError("too big bulk count string",c,0);
                    return C_ERR;
                }
                break;
@@ -1161,14 +1248,14 @@ int processMultibulkBuffer(client *c) {
                addReplyErrorFormat(c,
                    "Protocol error: expected '$', got '%c'",
                    c->querybuf[pos]);
-                setProtocolError(c,pos);
+                setProtocolError("expected $ but got something else",c,pos);
                return C_ERR;
            }

            ok = string2ll(c->querybuf+pos+1,newline-(c->querybuf+pos+1),&ll);
            if (!ok || ll < 0 || ll > 512*1024*1024) {
                addReplyError(c,"Protocol error: invalid bulk length");
-                setProtocolError(c,pos);
+                setProtocolError("invalid bulk length",c,pos);
                return C_ERR;
            }

@@ -1226,10 +1313,14 @@ int processMultibulkBuffer(client *c) {
    /* We're done when c->multibulk == 0 */
    if (c->multibulklen == 0) return C_OK;

-    /* Still not read to process the command */
+    /* Still not ready to process the command */
    return C_ERR;
 }

+/* This function is called every time, in the client structure 'c', there is
+ * more query buffer to process, because we read more data from the socket
+ * or because a client was blocked and later reactivated, so there could be
+ * pending query buffer, already representing a full command, to process. */
 void processInputBuffer(client *c) {
    server.current_client = c;
    /* Keep processing while there is something in the input buffer */
@@ -1269,10 +1360,22 @@ void processInputBuffer(client *c) {
            resetClient(c);
        } else {
            /* Only reset the client when the command was executed. */
-            if (processCommand(c) == C_OK)
-                resetClient(c);
-            /* freeMemoryIfNeeded may flush slave output buffers. This may result
-             * into a slave, that may be the active client, to be freed. */
+            if (processCommand(c) == C_OK) {
+                if (c->flags & CLIENT_MASTER && !(c->flags & CLIENT_MULTI)) {
+                    /* Update the applied replication offset of our master. */
+                    c->reploff = c->read_reploff - sdslen(c->querybuf);
+                }
+
+                /* Don't reset the client structure for clients blocked in a
+                 * module blocking command, so that the reply callback will
+                 * still be able to access the client argv and argc field.
+                 * The client will be reset in unblockClientFromModule(). */
+                if (!(c->flags & CLIENT_BLOCKED) || c->btype != BLOCKED_MODULE)
+                    resetClient(c);
+            }
+            /* freeMemoryIfNeeded may flush slave output buffers. This may
+             * result into a slave, that may be the active client, to be
+             * freed. */
            if (server.current_client == NULL) break;
        }
    }
@@ -1317,11 +1420,17 @@ void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask) {
        serverLog(LL_VERBOSE, "Client closed connection");
        freeClient(c);
        return;
+    } else if (c->flags & CLIENT_MASTER) {
+        /* Append the query buffer to the pending (not applied) buffer
+         * of the master. We'll use this buffer later in order to have a
+         * copy of the string applied by the last command executed. */
+        c->pending_querybuf = sdscatlen(c->pending_querybuf,
+                                        c->querybuf+qblen,nread);
    }

    sdsIncrLen(c->querybuf,nread);
    c->lastinteraction = server.unixtime;
-    if (c->flags & CLIENT_MASTER) c->reploff += nread;
+    if (c->flags & CLIENT_MASTER) c->read_reploff += nread;
    server.stat_net_input_bytes += nread;
    if (sdslen(c->querybuf) > server.client_max_querybuf_len) {
        sds ci = catClientInfoString(sdsempty(),c), bytes = sdsempty();
@@ -1333,7 +1442,25 @@ void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask) {
        freeClient(c);
        return;
    }
-    processInputBuffer(c);
+
+    /* Time to process the buffer. If the client is a master we need to
+     * compute the difference between the applied offset before and after
+     * processing the buffer, to understand how much of the replication stream
+     * was actually applied to the master state: this quantity, and its
+     * corresponding part of the replication stream, will be propagated to
+     * the sub-slaves and to the replication backlog. */
+    if (!(c->flags & CLIENT_MASTER)) {
+        processInputBuffer(c);
+    } else {
+        size_t prev_offset = c->reploff;
+        processInputBuffer(c);
+        size_t applied = c->reploff - prev_offset;
+        if (applied) {
+            replicationFeedSlavesFromMasterStream(server.slaves,
+                    c->pending_querybuf, applied);
+            sdsrange(c->pending_querybuf,applied,-1);
+        }
+    }
 }

 void getClientsMaxBuffers(unsigned long *longest_output_list,
@@ -1462,7 +1589,22 @@ void clientCommand(client *c) {
    listIter li;
    client *client;

-    if (!strcasecmp(c->argv[1]->ptr,"list") && c->argc == 2) {
+    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
+        const char *help[] = {
+"getname -- Return the name of the current connection.",
+"kill <ip:port> -- Kill connection made from <ip:port>.",
+"kill <option> <value> [option value ...] -- Kill connections. Options are:",
+"     addr <ip:port> -- Kill connection made from <ip:port>.",
+"     type (normal|master|slave|pubsub) -- Kill connections by type.",
+"     skipme (yes|no) -- Skip killing current connection (default: yes).",
+"list -- Return information about client connections.",
+"pause <timeout> -- Suspend all Redis clients for <timout> milliseconds.",
+"reply (on|off|skip) -- Control the replies sent to the current connection.",
+"setname <name> -- Assign the name <name> to the current connection.",
+NULL
+        };
+        addReplyHelp(c, help);
+    } else if (!strcasecmp(c->argv[1]->ptr,"list") && c->argc == 2) {
        /* CLIENT LIST */
        sds o = getAllClientsInfoString();
        addReplyBulkCBuffer(c,o,sdslen(o));
@@ -1608,7 +1750,7 @@ void clientCommand(client *c) {
        pauseClients(duration);
        addReply(c,shared.ok);
    } else {
-        addReplyError(c, "Syntax error, try CLIENT (LIST | KILL | GETNAME | SETNAME | PAUSE | REPLY)");
+        addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try CLIENT HELP", (char*)c->argv[1]->ptr);
    }
 }

@@ -54,6 +54,7 @@ int keyspaceEventsStringToFlags(char *classes) {
        case 'e': flags |= NOTIFY_EVICTED; break;
        case 'K': flags |= NOTIFY_KEYSPACE; break;
        case 'E': flags |= NOTIFY_KEYEVENT; break;
+        case 't': flags |= NOTIFY_STREAM; break;
        default: return -1;
        }
    }
@@ -79,6 +80,7 @@ sds keyspaceEventsFlagsToString(int flags) {
        if (flags & NOTIFY_ZSET) res = sdscatlen(res,"z",1);
        if (flags & NOTIFY_EXPIRED) res = sdscatlen(res,"x",1);
        if (flags & NOTIFY_EVICTED) res = sdscatlen(res,"e",1);
+        if (flags & NOTIFY_STREAM) res = sdscatlen(res,"t",1);
    }
    if (flags & NOTIFY_KEYSPACE) res = sdscatlen(res,"K",1);
    if (flags & NOTIFY_KEYEVENT) res = sdscatlen(res,"E",1);
@@ -232,6 +232,13 @@ robj *createZsetZiplistObject(void) {
    return o;
 }

+robj *createStreamObject(void) {
+    stream *s = streamNew();
+    robj *o = createObject(OBJ_STREAM,s);
+    o->encoding = OBJ_ENCODING_STREAM;
+    return o;
+}
+
 robj *createModuleObject(moduleType *mt, void *value) {
    moduleValue *mv = zmalloc(sizeof(*mv));
    mv->type = mt;
@@ -246,11 +253,9 @@ void freeStringObject(robj *o) {
 }

 void freeListObject(robj *o) {
-    switch (o->encoding) {
-    case OBJ_ENCODING_QUICKLIST:
+    if (o->encoding == OBJ_ENCODING_QUICKLIST) {
        quicklistRelease(o->ptr);
-        break;
-    default:
+    } else {
        serverPanic("Unknown list encoding type");
    }
 }
@@ -305,6 +310,10 @@ void freeModuleObject(robj *o) {
    zfree(mv);
 }

+void freeStreamObject(robj *o) {
+    freeStream(o->ptr);
+}
+
 void incrRefCount(robj *o) {
    if (o->refcount != OBJ_SHARED_REFCOUNT) o->refcount++;
 }
@@ -318,6 +327,7 @@ void decrRefCount(robj *o) {
        case OBJ_ZSET: freeZsetObject(o); break;
        case OBJ_HASH: freeHashObject(o); break;
        case OBJ_MODULE: freeModuleObject(o); break;
+        case OBJ_STREAM: freeStreamObject(o); break;
        default: serverPanic("Unknown object type"); break;
        }
        zfree(o);
@@ -560,11 +570,11 @@ int getDoubleFromObject(const robj *o, double *target) {
        if (sdsEncodedObject(o)) {
            errno = 0;
            value = strtod(o->ptr, &eptr);
-            if (isspace(((const char*)o->ptr)[0]) ||
-                eptr[0] != '\0' ||
+            if (sdslen(o->ptr) == 0 ||
+                isspace(((const char*)o->ptr)[0]) ||
+                (size_t)(eptr-(char*)o->ptr) != sdslen(o->ptr) ||
                (errno == ERANGE &&
                    (value == HUGE_VAL || value == -HUGE_VAL || value == 0)) ||
-                errno == EINVAL ||
                isnan(value))
                return C_ERR;
        } else if (o->encoding == OBJ_ENCODING_INT) {
@@ -602,8 +612,12 @@ int getLongDoubleFromObject(robj *o, long double *target) {
        if (sdsEncodedObject(o)) {
            errno = 0;
            value = strtold(o->ptr, &eptr);
-            if (isspace(((char*)o->ptr)[0]) || eptr[0] != '\0' ||
-                errno == ERANGE || isnan(value))
+            if (sdslen(o->ptr) == 0 ||
+                isspace(((const char*)o->ptr)[0]) ||
+                (size_t)(eptr-(char*)o->ptr) != sdslen(o->ptr) ||
+                (errno == ERANGE &&
+                    (value == HUGE_VAL || value == -HUGE_VAL || value == 0)) ||
+                isnan(value))
                return C_ERR;
        } else if (o->encoding == OBJ_ENCODING_INT) {
            value = (long)o->ptr;
@@ -786,6 +800,57 @@ size_t objectComputeSize(robj *o, size_t sample_size) {
        } else {
            serverPanic("Unknown hash encoding");
        }
+    } else if (o->type == OBJ_STREAM) {
+        stream *s = o->ptr;
+        /* Note: to guess the size of the radix tree is not trivial, so we
+         * approximate it considering 64 bytes of data overhead for each
+         * key (the ID), and then adding the number of bare nodes, plus some
+         * overhead due by the data and child pointers. This secret recipe
+         * was obtained by checking the average radix tree created by real
+         * workloads, and then adjusting the constants to get numbers that
+         * more or less match the real memory usage.
+         *
+         * Actually the number of nodes and keys may be different depending
+         * on the insertion speed and thus the ability of the radix tree
+         * to compress prefixes. */
+        asize = sizeof(*o);
+        asize += s->rax->numele * 64;
+        asize += s->rax->numnodes * sizeof(raxNode);
+        asize += s->rax->numnodes * 32*7; /* Add a few child pointers... */
+
+        /* Now we have to add the listpacks. The last listpack is often non
+         * complete, so we estimate the size of the first N listpacks, and
+         * use the average to compute the size of the first N-1 listpacks, and
+         * finally add the real size of the last node. */
+        raxIterator ri;
+        raxStart(&ri,s->rax);
+        raxSeek(&ri,"^",NULL,0);
+        size_t lpsize = 0, samples = 0;
+        while(samples < sample_size && raxNext(&ri)) {
+            unsigned char *lp = ri.data;
+            lpsize += lpBytes(lp);
+            samples++;
+        }
+        if (s->rax->numele <= samples) {
+            asize += lpsize;
+        } else {
+            if (samples) lpsize /= samples; /* Compute the average. */
+            asize += lpsize * (s->rax->numele-1);
+            /* No need to check if seek succeeded, we enter this branch only
+             * if there are a few elements in the radix tree. */
+            raxSeek(&ri,"$",NULL,0);
+            raxNext(&ri);
+            asize += lpBytes(ri.data);
+        }
+        raxStop(&ri);
+    } else if (o->type == OBJ_MODULE) {
+        moduleValue *mv = o->ptr;
+        moduleType *mt = mv->type;
+        if (mt->mem_usage != NULL) {
+            asize = mt->mem_usage(mv->value);
+        } else {
+            asize = 0;
+        }
    } else {
        serverPanic("Unknown object type");
    }
@@ -828,9 +893,9 @@ struct redisMemOverhead *getMemoryOverheadData(void) {

        listRewind(server.slaves,&li);
        while((ln = listNext(&li))) {
-            client *client = listNodeValue(ln);
-            mem += getClientOutputBufferMemoryUsage(client);
-            mem += sdsAllocSize(client->querybuf);
+            client *c = listNodeValue(ln);
+            mem += getClientOutputBufferMemoryUsage(c);
+            mem += sdsAllocSize(c->querybuf);
            mem += sizeof(client);
        }
    }
@@ -844,11 +909,11 @@ struct redisMemOverhead *getMemoryOverheadData(void) {

        listRewind(server.clients,&li);
        while((ln = listNext(&li))) {
-            client *client = listNodeValue(ln);
-            if (client->flags & CLIENT_SLAVE)
+            client *c = listNodeValue(ln);
+            if (c->flags & CLIENT_SLAVE)
                continue;
-            mem += getClientOutputBufferMemoryUsage(client);
-            mem += sdsAllocSize(client->querybuf);
+            mem += getClientOutputBufferMemoryUsage(c);
+            mem += sdsAllocSize(c->querybuf);
            mem += sizeof(client);
        }
    }
@@ -945,7 +1010,7 @@ sds getMemoryDoctorReport(void) {
        }

        /* Slaves using more than 10 MB each? */
-        if (mh->clients_slaves / numslaves > (1024*1024*10)) {
+        if (numslaves > 0 && mh->clients_slaves / numslaves > (1024*1024*10)) {
            big_slave_buf = 1;
            num_reports++;
        }
@@ -955,14 +1020,14 @@ sds getMemoryDoctorReport(void) {
    if (num_reports == 0) {
        s = sdsnew(
        "Hi Sam, I can't find any memory issue in your instance. "
-        "I can only account for what occurs on this base.");
+        "I can only account for what occurs on this base.\n");
    } else if (empty == 1) {
        s = sdsnew(
        "Hi Sam, this instance is empty or is using very little memory, "
        "my issues detector can't be used in these conditions. "
        "Please, leave for your mission on Earth and fill it with some data. "
        "The new Sam and I will be back to our programming as soon as I "
-        "finished rebooting.");
+        "finished rebooting.\n");
    } else {
        s = sdsnew("Sam, I detected a few issues in this Redis instance memory implants:\n\n");
        if (big_peak) {
@@ -1002,11 +1067,20 @@ robj *objectCommandLookupOrReply(client *c, robj *key, robj *reply) {
 }

 /* Object command allows to inspect the internals of an Redis Object.
- * Usage: OBJECT <refcount|encoding|idletime> <key> */
+ * Usage: OBJECT <refcount|encoding|idletime|freq> <key> */
 void objectCommand(client *c) {
    robj *o;

-    if (!strcasecmp(c->argv[1]->ptr,"refcount") && c->argc == 3) {
+    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
+        const char *help[] = {
+"encoding <key> -- Return the kind of internal representation used in order to store the value associated with a key.",
+"freq <key> -- Return the access frequency index of the key. The returned integer is proportional to the logarithm of the recent access frequency of the key.",
+"idletime <key> -- Return the idle time of the key, that is the approximated number of seconds elapsed since the last access to the key.",
+"refcount <key> -- Return the number of references of the value associated with the specified key.",
+NULL
+        };
+        addReplyHelp(c, help);
+    } else if (!strcasecmp(c->argv[1]->ptr,"refcount") && c->argc == 3) {
        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
                == NULL) return;
        addReplyLongLong(c,o->refcount);
@@ -1025,13 +1099,17 @@ void objectCommand(client *c) {
    } else if (!strcasecmp(c->argv[1]->ptr,"freq") && c->argc == 3) {
        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
                == NULL) return;
-        if (server.maxmemory_policy & MAXMEMORY_FLAG_LRU) {
-            addReplyError(c,"An LRU maxmemory policy is selected, access frequency not tracked. Please note that when switching between policies at runtime LRU and LFU data will take some time to adjust.");
+        if (!(server.maxmemory_policy & MAXMEMORY_FLAG_LFU)) {
+            addReplyError(c,"An LFU maxmemory policy is not selected, access frequency not tracked. Please note that when switching between policies at runtime LRU and LFU data will take some time to adjust.");
            return;
        }
-        addReplyLongLong(c,o->lru&255);
+        /* LFUDecrAndReturn should be called
+         * in case of the key has not been accessed for a long time,
+         * because we update the access time only
+         * when the key is read or overwritten. */
+        addReplyLongLong(c,LFUDecrAndReturn(o));
    } else {
-        addReplyError(c,"Syntax error. Try OBJECT (refcount|encoding|idletime|freq)");
+        addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try OBJECT help", (char *)c->argv[1]->ptr);
    }
 }

@@ -1064,7 +1142,7 @@ void memoryCommand(client *c) {
        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
                == NULL) return;
        size_t usage = objectComputeSize(o,samples);
-        usage += sdsAllocSize(c->argv[1]->ptr);
+        usage += sdsAllocSize(c->argv[2]->ptr);
        usage += sizeof(dictEntry);
        addReplyLongLong(c,usage);
    } else if (!strcasecmp(c->argv[1]->ptr,"stats") && c->argc == 2) {
@@ -1157,7 +1235,9 @@ void memoryCommand(client *c) {
        /* Nothing to do for other allocators. */
 #endif
    } else if (!strcasecmp(c->argv[1]->ptr,"help") && c->argc == 2) {
-        addReplyMultiBulkLen(c,4);
+        addReplyMultiBulkLen(c,5);
+        addReplyBulkCString(c,
+"MEMORY DOCTOR                        - Outputs memory problems report");
        addReplyBulkCString(c,
 "MEMORY USAGE <key> [SAMPLES <count>] - Estimate memory usage of key");
        addReplyBulkCString(c,
@@ -325,8 +325,16 @@ void publishCommand(client *c) {

 /* PUBSUB command for Pub/Sub introspection. */
 void pubsubCommand(client *c) {
-    if (!strcasecmp(c->argv[1]->ptr,"channels") &&
-        (c->argc == 2 || c->argc ==3))
+    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
+        const char *help[] = {
+"channels [<pattern>] -- Return the currently active channels matching a pattern (default: all).",
+"numpat -- Return number of subscriptions to patterns.",
+"numsub [channel-1 .. channel-N] -- Returns the number of subscribers for the specified channels (excluding patterns, default: none).",
+NULL
+        };
+        addReplyHelp(c, help);
+    } else if (!strcasecmp(c->argv[1]->ptr,"channels") &&
+        (c->argc == 2 || c->argc == 3))
    {
        /* PUBSUB CHANNELS [<pattern>] */
        sds pat = (c->argc == 2) ? NULL : c->argv[2]->ptr;
@@ -364,8 +372,7 @@ void pubsubCommand(client *c) {
        /* PUBSUB NUMPAT */
        addReplyLongLong(c,listLength(server.pubsub_patterns));
    } else {
-        addReplyErrorFormat(c,
-            "Unknown PUBSUB subcommand or wrong number of arguments for '%s'",
+        addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try PUBSUB HELP",
            (char*)c->argv[1]->ptr);
    }
 }
@@ -149,7 +149,7 @@ REDIS_STATIC quicklistNode *quicklistCreateNode(void) {
 }

 /* Return cached quicklist count */
-unsigned int quicklistCount(const quicklist *ql) { return ql->count; }
+unsigned long quicklistCount(const quicklist *ql) { return ql->count; }

 /* Free entire quicklist. */
 void quicklistRelease(quicklist *quicklist) {
@@ -1192,12 +1192,12 @@ quicklist *quicklistDup(quicklist *orig) {
         current = current->next) {
        quicklistNode *node = quicklistCreateNode();

-        if (node->encoding == QUICKLIST_NODE_ENCODING_LZF) {
-            quicklistLZF *lzf = (quicklistLZF *)node->zl;
+        if (current->encoding == QUICKLIST_NODE_ENCODING_LZF) {
+            quicklistLZF *lzf = (quicklistLZF *)current->zl;
            size_t lzf_sz = sizeof(*lzf) + lzf->sz;
            node->zl = zmalloc(lzf_sz);
            memcpy(node->zl, current->zl, lzf_sz);
-        } else if (node->encoding == QUICKLIST_NODE_ENCODING_RAW) {
+        } else if (current->encoding == QUICKLIST_NODE_ENCODING_RAW) {
            node->zl = zmalloc(current->sz);
            memcpy(node->zl, current->zl, current->sz);
        }
@@ -64,7 +64,7 @@ typedef struct quicklistLZF {
    char compressed[];
 } quicklistLZF;

-/* quicklist is a 32 byte struct (on 64-bit systems) describing a quicklist.
+/* quicklist is a 40 byte struct (on 64-bit systems) describing a quicklist.
 * 'count' is the number of total entries.
 * 'len' is the number of quicklist nodes.
 * 'compress' is: -1 if compression disabled, otherwise it's the number
@@ -74,7 +74,7 @@ typedef struct quicklist {
    quicklistNode *head;
    quicklistNode *tail;
    unsigned long count;        /* total count of all entries in all ziplists */
-    unsigned int len;           /* number of quicklistNodes */
+    unsigned long len;          /* number of quicklistNodes */
    int fill : 16;              /* fill factor for individual nodes */
    unsigned int compress : 16; /* depth of end nodes not to compress;0=off */
 } quicklist;
@@ -154,7 +154,7 @@ int quicklistPopCustom(quicklist *quicklist, int where, unsigned char **data,
                       void *(*saver)(unsigned char *data, unsigned int sz));
 int quicklistPop(quicklist *quicklist, int where, unsigned char **data,
                 unsigned int *sz, long long *slong);
-unsigned int quicklistCount(const quicklist *ql);
+unsigned long quicklistCount(const quicklist *ql);
 int quicklistCompare(unsigned char *p1, unsigned char *p2, int p2_len);
 size_t quicklistGetLzf(const quicklistNode *node, void **data);

@@ -0,0 +1,163 @@
+#ifndef RAX_H
+#define RAX_H
+
+#include <stdint.h>
+
+/* Representation of a radix tree as implemented in this file, that contains
+ * the strings "foo", "foobar" and "footer" after the insertion of each
+ * word. When the node represents a key inside the radix tree, we write it
+ * between [], otherwise it is written between ().
+ *
+ * This is the vanilla representation:
+ *
+ *              (f) ""
+ *                \
+ *                (o) "f"
+ *                  \
+ *                  (o) "fo"
+ *                    \
+ *                  [t   b] "foo"
+ *                  /     \
+ *         "foot" (e)     (a) "foob"
+ *                /         \
+ *      "foote" (r)         (r) "fooba"
+ *              /             \
+ *    "footer" []             [] "foobar"
+ *
+ * However, this implementation implements a very common optimization where
+ * successive nodes having a single child are "compressed" into the node
+ * itself as a string of characters, each representing a next-level child,
+ * and only the link to the node representing the last character node is
+ * provided inside the representation. So the above representation is turend
+ * into:
+ *
+ *                  ["foo"] ""
+ *                     |
+ *                  [t   b] "foo"
+ *                  /     \
+ *        "foot" ("er")    ("ar") "foob"
+ *                 /          \
+ *       "footer" []          [] "foobar"
+ *
+ * However this optimization makes the implementation a bit more complex.
+ * For instance if a key "first" is added in the above radix tree, a
+ * "node splitting" operation is needed, since the "foo" prefix is no longer
+ * composed of nodes having a single child one after the other. This is the
+ * above tree and the resulting node splitting after this event happens:
+ *
+ *
+ *                    (f) ""
+ *                    /
+ *                 (i o) "f"
+ *                 /   \
+ *    "firs"  ("rst")  (o) "fo"
+ *              /        \
+ *    "first" []       [t   b] "foo"
+ *                     /     \
+ *           "foot" ("er")    ("ar") "foob"
+ *                    /          \
+ *          "footer" []          [] "foobar"
+ *
+ * Similarly after deletion, if a new chain of nodes having a single child
+ * is created (the chain must also not include nodes that represent keys),
+ * it must be compressed back into a single node.
+ *
+ */
+
+#define RAX_NODE_MAX_SIZE ((1<<29)-1)
+typedef struct raxNode {
+    uint32_t iskey:1;     /* Does this node contain a key? */
+    uint32_t isnull:1;    /* Associated value is NULL (don't store it). */
+    uint32_t iscompr:1;   /* Node is compressed. */
+    uint32_t size:29;     /* Number of children, or compressed string len. */
+    /* Data layout is as follows:
+     *
+     * If node is not compressed we have 'size' bytes, one for each children
+     * character, and 'size' raxNode pointers, point to each child node.
+     * Note how the character is not stored in the children but in the
+     * edge of the parents:
+     *
+     * [header strlen=0][abc][a-ptr][b-ptr][c-ptr](value-ptr?)
+     *
+     * if node is compressed (strlen != 0) the node has 1 children.
+     * In that case the 'size' bytes of the string stored immediately at
+     * the start of the data section, represent a sequence of successive
+     * nodes linked one after the other, for which only the last one in
+     * the sequence is actually represented as a node, and pointed to by
+     * the current compressed node.
+     *
+     * [header strlen=3][xyz][z-ptr](value-ptr?)
+     *
+     * Both compressed and not compressed nodes can represent a key
+     * with associated data in the radix tree at any level (not just terminal
+     * nodes).
+     *
+     * If the node has an associated key (iskey=1) and is not NULL
+     * (isnull=0), then after the raxNode pointers poiting to the
+     * childen, an additional value pointer is present (as you can see
+     * in the representation above as "value-ptr" field).
+     */
+    unsigned char data[];
+} raxNode;
+
+typedef struct rax {
+    raxNode *head;
+    uint64_t numele;
+    uint64_t numnodes;
+} rax;
+
+/* Stack data structure used by raxLowWalk() in order to, optionally, return
+ * a list of parent nodes to the caller. The nodes do not have a "parent"
+ * field for space concerns, so we use the auxiliary stack when needed. */
+#define RAX_STACK_STATIC_ITEMS 32
+typedef struct raxStack {
+    void **stack; /* Points to static_items or an heap allocated array. */
+    size_t items, maxitems; /* Number of items contained and total space. */
+    /* Up to RAXSTACK_STACK_ITEMS items we avoid to allocate on the heap
+     * and use this static array of pointers instead. */
+    void *static_items[RAX_STACK_STATIC_ITEMS];
+    int oom; /* True if pushing into this stack failed for OOM at some point. */
+} raxStack;
+
+/* Radix tree iterator state is encapsulated into this data structure. */
+#define RAX_ITER_STATIC_LEN 128
+#define RAX_ITER_JUST_SEEKED (1<<0) /* Iterator was just seeked. Return current
+                                       element for the first iteration and
+                                       clear the flag. */
+#define RAX_ITER_EOF (1<<1)    /* End of iteration reached. */
+#define RAX_ITER_SAFE (1<<2)   /* Safe iterator, allows operations while
+                                  iterating. But it is slower. */
+typedef struct raxIterator {
+    int flags;
+    rax *rt;                /* Radix tree we are iterating. */
+    unsigned char *key;     /* The current string. */
+    void *data;             /* Data associated to this key. */
+    size_t key_len;         /* Current key length. */
+    size_t key_max;         /* Max key len the current key buffer can hold. */
+    unsigned char key_static_string[RAX_ITER_STATIC_LEN];
+    raxNode *node;          /* Current node. Only for unsafe iteration. */
+    raxStack stack;         /* Stack used for unsafe iteration. */
+} raxIterator;
+
+/* A special pointer returned for not found items. */
+extern void *raxNotFound;
+
+/* Exported API. */
+rax *raxNew(void);
+int raxInsert(rax *rax, unsigned char *s, size_t len, void *data, void **old);
+int raxRemove(rax *rax, unsigned char *s, size_t len, void **old);
+void *raxFind(rax *rax, unsigned char *s, size_t len);
+void raxFree(rax *rax);
+void raxFreeWithCallback(rax *rax, void (*free_callback)(void*));
+void raxStart(raxIterator *it, rax *rt);
+int raxSeek(raxIterator *it, const char *op, unsigned char *ele, size_t len);
+int raxNext(raxIterator *it);
+int raxPrev(raxIterator *it);
+int raxRandomWalk(raxIterator *it, size_t steps);
+int raxCompare(raxIterator *iter, const char *op, unsigned char *key, size_t key_len);
+void raxStop(raxIterator *it);
+int raxEOF(raxIterator *it);
+void raxShow(rax *rax);
+uint64_t raxSize(rax *rax);
+
+#endif
@@ -0,0 +1,44 @@
+/* Rax -- A radix tree implementation.
+ *
+ * Copyright (c) 2017, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* Allocator selection.
+ *
+ * This file is used in order to change the Rax allocator at compile time.
+ * Just define the following defines to what you want to use. Also add
+ * the include of your alternate allocator if needed (not needed in order
+ * to use the default libc allocator). */
+
+#ifndef RAX_ALLOC_H
+#define RAX_ALLOC_H
+#include "zmalloc.h"
+#define rax_malloc zmalloc
+#define rax_realloc zrealloc
+#define rax_free zfree
+#endif
@@ -31,6 +31,7 @@
 #include "lzf.h"    /* LZF compression library */
 #include "zipmap.h"
 #include "endianconv.h"
+#include "stream.h"

 #include <math.h>
 #include <sys/types.h>
@@ -61,7 +62,7 @@ void rdbCheckThenExit(int linenum, char *reason, ...) {
    if (!rdbCheckMode) {
        serverLog(LL_WARNING, "%s", msg);
        char *argv[2] = {"",server.rdb_filename};
-        redis_check_rdb_main(2,argv);
+        redis_check_rdb_main(2,argv,NULL);
    } else {
        rdbCheckError("%s",msg);
    }
@@ -622,8 +623,10 @@ int rdbSaveObjectType(rio *rdb, robj *o) {
            return rdbSaveType(rdb,RDB_TYPE_HASH);
        else
            serverPanic("Unknown hash encoding");
+    case OBJ_STREAM:
+        return rdbSaveType(rdb,RDB_TYPE_STREAM_LISTPACKS);
    case OBJ_MODULE:
-        return rdbSaveType(rdb,RDB_TYPE_MODULE);
+        return rdbSaveType(rdb,RDB_TYPE_MODULE_2);
    default:
        serverPanic("Unknown object type");
    }
@@ -656,7 +659,7 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
            if ((n = rdbSaveLen(rdb,ql->len)) == -1) return -1;
            nwritten += n;

-            do {
+            while(node) {
                if (quicklistNodeIsCompressed(node)) {
                    void *data;
                    size_t compress_len = quicklistGetLzf(node, &data);
@@ -666,7 +669,8 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
                    if ((n = rdbSaveRawString(rdb,node->zl,node->sz)) == -1) return -1;
                    nwritten += n;
                }
-            } while ((node = node->next));
+                node = node->next;
+            }
        } else {
            serverPanic("Unknown list encoding");
        }
@@ -704,23 +708,30 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
            nwritten += n;
        } else if (o->encoding == OBJ_ENCODING_SKIPLIST) {
            zset *zs = o->ptr;
-            dictIterator *di = dictGetIterator(zs->dict);
-            dictEntry *de;
+            zskiplist *zsl = zs->zsl;

-            if ((n = rdbSaveLen(rdb,dictSize(zs->dict))) == -1) return -1;
+            if ((n = rdbSaveLen(rdb,zsl->length)) == -1) return -1;
            nwritten += n;

-            while((de = dictNext(di)) != NULL) {
-                sds ele = dictGetKey(de);
-                double *score = dictGetVal(de);
-
-                if ((n = rdbSaveRawString(rdb,(unsigned char*)ele,sdslen(ele)))
-                    == -1) return -1;
+            /* We save the skiplist elements from the greatest to the smallest
+             * (that's trivial since the elements are already ordered in the
+             * skiplist): this improves the load process, since the next loaded
+             * element will always be the smaller, so adding to the skiplist
+             * will always immediately stop at the head, making the insertion
+             * O(1) instead of O(log(N)). */
+            zskiplistNode *zn = zsl->tail;
+            while (zn != NULL) {
+                if ((n = rdbSaveRawString(rdb,
+                    (unsigned char*)zn->ele,sdslen(zn->ele))) == -1)
+                {
+                    return -1;
+                }
                nwritten += n;
-                if ((n = rdbSaveBinaryDoubleValue(rdb,*score)) == -1) return -1;
+                if ((n = rdbSaveBinaryDoubleValue(rdb,zn->score)) == -1)
+                    return -1;
                nwritten += n;
+                zn = zn->backward;
            }
-            dictReleaseIterator(di);
        } else {
            serverPanic("Unknown sorted set encoding");
        }
@@ -754,7 +765,39 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
        } else {
            serverPanic("Unknown hash encoding");
        }
+    } else if (o->type == OBJ_STREAM) {
+        /* Store how many listpacks we have inside the radix tree. */
+        stream *s = o->ptr;
+        rax *rax = s->rax;
+        if ((n = rdbSaveLen(rdb,raxSize(rax))) == -1) return -1;
+        nwritten += n;

+        /* Serialize all the listpacks inside the radix tree as they are,
+         * when loading back, we'll use the first entry of each listpack
+         * to insert it back into the radix tree. */
+        raxIterator ri;
+        raxStart(&ri,rax);
+        raxSeek(&ri,"^",NULL,0);
+        while (raxNext(&ri)) {
+            unsigned char *lp = ri.data;
+            size_t lp_bytes = lpBytes(lp);
+            if ((n = rdbSaveRawString(rdb,ri.key,ri.key_len)) == -1) return -1;
+            nwritten += n;
+            if ((n = rdbSaveRawString(rdb,lp,lp_bytes)) == -1) return -1;
+            nwritten += n;
+        }
+        raxStop(&ri);
+
+        /* Save the number of elements inside the stream. We cannot obtain
+         * this easily later, since our macro nodes should be checked for
+         * number of items: not a great CPU / space tradeoff. */
+        if ((n = rdbSaveLen(rdb,s->length)) == -1) return -1;
+        nwritten += n;
+        /* Save the last entry ID. */
+        if ((n = rdbSaveLen(rdb,s->last_id.ms)) == -1) return -1;
+        nwritten += n;
+        if ((n = rdbSaveLen(rdb,s->last_id.seq)) == -1) return -1;
+        nwritten += n;
    } else if (o->type == OBJ_MODULE) {
        /* Save a module-specific value. */
        RedisModuleIO io;
@@ -768,8 +811,12 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
        if (retval == -1) return -1;
        io.bytes += retval;

-        /* Then write the module-specific representation. */
+        /* Then write the module-specific representation + EOF marker. */
        mt->rdb_save(&io,mv->value);
+        retval = rdbSaveLen(rdb,RDB_MODULE_OPCODE_EOF);
+        if (retval == -1) return -1;
+        io.bytes += retval;
+
        if (io.ctx) {
            moduleFreeContext(io.ctx);
            zfree(io.ctx);
@@ -835,7 +882,7 @@ int rdbSaveAuxFieldStrInt(rio *rdb, char *key, long long val) {
 }

 /* Save a few default AUX fields with information about the RDB generated. */
-int rdbSaveInfoAuxFields(rio *rdb, int flags) {
+int rdbSaveInfoAuxFields(rio *rdb, int flags, rdbSaveInfo *rsi) {
    int redis_bits = (sizeof(void*) == 8) ? 64 : 32;
    int aof_preamble = (flags & RDB_SAVE_AOF_PREAMBLE) != 0;

@@ -844,6 +891,16 @@ int rdbSaveInfoAuxFields(rio *rdb, int flags) {
    if (rdbSaveAuxFieldStrInt(rdb,"redis-bits",redis_bits) == -1) return -1;
    if (rdbSaveAuxFieldStrInt(rdb,"ctime",time(NULL)) == -1) return -1;
    if (rdbSaveAuxFieldStrInt(rdb,"used-mem",zmalloc_used_memory()) == -1) return -1;
+
+    /* Handle saving options that generate aux fields. */
+    if (rsi) {
+        if (rdbSaveAuxFieldStrInt(rdb,"repl-stream-db",rsi->repl_stream_db)
+            == -1) return -1;
+        if (rdbSaveAuxFieldStrStr(rdb,"repl-id",server.replid)
+            == -1) return -1;
+        if (rdbSaveAuxFieldStrInt(rdb,"repl-offset",server.master_repl_offset)
+            == -1) return -1;
+    }
    if (rdbSaveAuxFieldStrInt(rdb,"aof-preamble",aof_preamble) == -1) return -1;
    return 1;
 }
@@ -856,7 +913,7 @@ int rdbSaveInfoAuxFields(rio *rdb, int flags) {
 * When the function returns C_ERR and if 'error' is not NULL, the
 * integer pointed by 'error' is set to the value of errno just after the I/O
 * error. */
-int rdbSaveRio(rio *rdb, int *error, int flags) {
+int rdbSaveRio(rio *rdb, int *error, int flags, rdbSaveInfo *rsi) {
    dictIterator *di = NULL;
    dictEntry *de;
    char magic[10];
@@ -869,7 +926,7 @@ int rdbSaveRio(rio *rdb, int *error, int flags) {
        rdb->update_cksum = rioGenericUpdateChecksum;
    snprintf(magic,sizeof(magic),"REDIS%04d",RDB_VERSION);
    if (rdbWriteRaw(rdb,magic,9) == -1) goto werr;
-    if (rdbSaveInfoAuxFields(rdb,flags) == -1) goto werr;
+    if (rdbSaveInfoAuxFields(rdb,flags,rsi) == -1) goto werr;

    for (j = 0; j < server.dbnum; j++) {
        redisDb *db = server.db+j;
@@ -921,6 +978,20 @@ int rdbSaveRio(rio *rdb, int *error, int flags) {
    }
    di = NULL; /* So that we don't release it again on error. */

+    /* If we are storing the replication information on disk, persist
+     * the script cache as well: on successful PSYNC after a restart, we need
+     * to be able to process any EVALSHA inside the replication backlog the
+     * master will send us. */
+    if (rsi && dictSize(server.lua_scripts)) {
+        di = dictGetIterator(server.lua_scripts);
+        while((de = dictNext(di)) != NULL) {
+            robj *body = dictGetVal(de);
+            if (rdbSaveAuxField(rdb,"lua",3,body->ptr,sdslen(body->ptr)) == -1)
+                goto werr;
+        }
+        dictReleaseIterator(di);
+    }
+
    /* EOF opcode */
    if (rdbSaveType(rdb,RDB_OPCODE_EOF) == -1) goto werr;

@@ -945,7 +1016,7 @@ werr:
 * While the suffix is the 40 bytes hex string we announced in the prefix.
 * This way processes receiving the payload can understand when it ends
 * without doing any processing of the content. */
-int rdbSaveRioWithEOFMark(rio *rdb, int *error) {
+int rdbSaveRioWithEOFMark(rio *rdb, int *error, rdbSaveInfo *rsi) {
    char eofmark[RDB_EOF_MARK_SIZE];

    getRandomHexChars(eofmark,RDB_EOF_MARK_SIZE);
@@ -953,7 +1024,7 @@ int rdbSaveRioWithEOFMark(rio *rdb, int *error) {
    if (rioWrite(rdb,"$EOF:",5) == 0) goto werr;
    if (rioWrite(rdb,eofmark,RDB_EOF_MARK_SIZE) == 0) goto werr;
    if (rioWrite(rdb,"\r\n",2) == 0) goto werr;
-    if (rdbSaveRio(rdb,error,RDB_SAVE_NONE) == C_ERR) goto werr;
+    if (rdbSaveRio(rdb,error,RDB_SAVE_NONE,rsi) == C_ERR) goto werr;
    if (rioWrite(rdb,eofmark,RDB_EOF_MARK_SIZE) == 0) goto werr;
    return C_OK;

@@ -964,7 +1035,7 @@ werr: /* Write error. */
 }

 /* Save the DB on disk. Return C_ERR on error, C_OK on success. */
-int rdbSave(char *filename) {
+int rdbSave(char *filename, rdbSaveInfo *rsi) {
    char tmpfile[256];
    char cwd[MAXPATHLEN]; /* Current working dir path for error messages. */
    FILE *fp;
@@ -985,7 +1056,7 @@ int rdbSave(char *filename) {
    }

    rioInitWithFile(&rdb,fp);
-    if (rdbSaveRio(&rdb,&error,RDB_SAVE_NONE) == C_ERR) {
+    if (rdbSaveRio(&rdb,&error,RDB_SAVE_NONE,rsi) == C_ERR) {
        errno = error;
        goto werr;
    }
@@ -1023,7 +1094,7 @@ werr:
    return C_ERR;
 }

-int rdbSaveBackground(char *filename) {
+int rdbSaveBackground(char *filename, rdbSaveInfo *rsi) {
    pid_t childpid;
    long long start;

@@ -1040,7 +1111,7 @@ int rdbSaveBackground(char *filename) {
        /* Child */
        closeListeningSockets(0);
        redisSetProcTitle("redis-rdb-bgsave");
-        retval = rdbSave(filename);
+        retval = rdbSave(filename,rsi);
        if (retval == C_OK) {
            size_t private_dirty = zmalloc_get_private_dirty(-1);

@@ -1083,6 +1154,45 @@ void rdbRemoveTempFile(pid_t childpid) {
    unlink(tmpfile);
 }

+/* This function is called by rdbLoadObject() when the code is in RDB-check
+ * mode and we find a module value of type 2 that can be parsed without
+ * the need of the actual module. The value is parsed for errors, finally
+ * a dummy redis object is returned just to conform to the API. */
+robj *rdbLoadCheckModuleValue(rio *rdb, char *modulename) {
+    uint64_t opcode;
+    while((opcode = rdbLoadLen(rdb,NULL)) != RDB_MODULE_OPCODE_EOF) {
+        if (opcode == RDB_MODULE_OPCODE_SINT ||
+            opcode == RDB_MODULE_OPCODE_UINT)
+        {
+            uint64_t len;
+            if (rdbLoadLenByRef(rdb,NULL,&len) == -1) {
+                rdbExitReportCorruptRDB(
+                    "Error reading integer from module %s value", modulename);
+            }
+        } else if (opcode == RDB_MODULE_OPCODE_STRING) {
+            robj *o = rdbGenericLoadStringObject(rdb,RDB_LOAD_NONE,NULL);
+            if (o == NULL) {
+                rdbExitReportCorruptRDB(
+                    "Error reading string from module %s value", modulename);
+            }
+            decrRefCount(o);
+        } else if (opcode == RDB_MODULE_OPCODE_FLOAT) {
+            float val;
+            if (rdbLoadBinaryFloatValue(rdb,&val) == -1) {
+                rdbExitReportCorruptRDB(
+                    "Error reading float from module %s value", modulename);
+            }
+        } else if (opcode == RDB_MODULE_OPCODE_DOUBLE) {
+            double val;
+            if (rdbLoadBinaryDoubleValue(rdb,&val) == -1) {
+                rdbExitReportCorruptRDB(
+                    "Error reading double from module %s value", modulename);
+            }
+        }
+    }
+    return createStringObject("module-dummy-value",18);
+}
+
 /* Load a Redis object of the specified type from the specified file.
 * On success a newly allocated object is returned, otherwise NULL. */
 robj *rdbLoadObject(int rdbtype, rio *rdb) {
@@ -1334,11 +1444,53 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
                rdbExitReportCorruptRDB("Unknown RDB encoding type %d",rdbtype);
                break;
        }
-    } else if (rdbtype == RDB_TYPE_MODULE) {
+    } else if (rdbtype == RDB_TYPE_STREAM_LISTPACKS) {
+        o = createStreamObject();
+        stream *s = o->ptr;
+        uint64_t listpacks = rdbLoadLen(rdb,NULL);
+
+        while(listpacks--) {
+            /* Get the master ID, the one we'll use as key of the radix tree
+             * node: the entries inside the listpack itself are delta-encoded
+             * relatively to this ID. */
+            sds nodekey = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL);
+            if (sdslen(nodekey) != sizeof(streamID)) {
+                rdbExitReportCorruptRDB("Stream node key entry is not the "
+                                        "size of a stream ID");
+            }
+
+            /* Load the listpack. */
+            unsigned char *lp =
+                rdbGenericLoadStringObject(rdb,RDB_LOAD_PLAIN,NULL);
+            if (lp == NULL) return NULL;
+            unsigned char *first = lpFirst(lp);
+            if (first == NULL) {
+                /* Serialized listpacks should never be empty, since on
+                 * deletion we should remove the radix tree key if the
+                 * resulting listpack is emtpy. */
+                rdbExitReportCorruptRDB("Empty listpack inside stream");
+            }
+
+            /* Insert the key in the radix tree. */
+            int retval = raxInsert(s->rax,
+                (unsigned char*)nodekey,sizeof(streamID),lp,NULL);
+            sdsfree(nodekey);
+            if (!retval)
+                rdbExitReportCorruptRDB("Listpack re-added with existing key");
+        }
+        /* Load total number of items inside the stream. */
+        s->length = rdbLoadLen(rdb,NULL);
+        /* Load the last entry ID. */
+        s->last_id.ms = rdbLoadLen(rdb,NULL);
+        s->last_id.seq = rdbLoadLen(rdb,NULL);
+    } else if (rdbtype == RDB_TYPE_MODULE || rdbtype == RDB_TYPE_MODULE_2) {
        uint64_t moduleid = rdbLoadLen(rdb,NULL);
        moduleType *mt = moduleTypeLookupModuleByID(moduleid);
        char name[10];

+        if (rdbCheckMode && rdbtype == RDB_TYPE_MODULE_2)
+            return rdbLoadCheckModuleValue(rdb,name);
+
        if (mt == NULL) {
            moduleTypeNameByID(name,moduleid);
            serverLog(LL_WARNING,"The RDB file contains module data I can't load: no matching module '%s'", name);
@@ -1346,9 +1498,24 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
        }
        RedisModuleIO io;
        moduleInitIOContext(io,mt,rdb);
+        io.ver = (rdbtype == RDB_TYPE_MODULE) ? 1 : 2;
        /* Call the rdb_load method of the module providing the 10 bit
         * encoding version in the lower 10 bits of the module ID. */
        void *ptr = mt->rdb_load(&io,moduleid&1023);
+        if (io.ctx) {
+            moduleFreeContext(io.ctx);
+            zfree(io.ctx);
+        }
+
+        /* Module v2 serialization has an EOF mark at the end. */
+        if (io.ver == 2) {
+            uint64_t eof = rdbLoadLen(rdb,NULL);
+            if (eof != RDB_MODULE_OPCODE_EOF) {
+                serverLog(LL_WARNING,"The RDB file contains module data for the module '%s' that is not terminated by the proper module value EOF marker", name);
+                exit(1);
+            }
+        }
+
        if (ptr == NULL) {
            moduleTypeNameByID(name,moduleid);
            serverLog(LL_WARNING,"The RDB file contains module data for the module type '%s', that the responsible module is not able to load. Check for modules log above for additional clues.", name);
@@ -1410,7 +1577,7 @@ void rdbLoadProgressCallback(rio *r, const void *buf, size_t len) {

 /* Load an RDB file from the rio stream 'rdb'. On success C_OK is returned,
 * otherwise C_ERR is returned and 'errno' is set accordingly. */
-int rdbLoadRio(rio *rdb) {
+int rdbLoadRio(rio *rdb, rdbSaveInfo *rsi) {
    uint64_t dbid;
    int type, rdbver;
    redisDb *db = server.db+0;
@@ -1501,6 +1668,22 @@ int rdbLoadRio(rio *rdb) {
                serverLog(LL_NOTICE,"RDB '%s': %s",
                    (char*)auxkey->ptr,
                    (char*)auxval->ptr);
+            } else if (!strcasecmp(auxkey->ptr,"repl-stream-db")) {
+                if (rsi) rsi->repl_stream_db = atoi(auxval->ptr);
+            } else if (!strcasecmp(auxkey->ptr,"repl-id")) {
+                if (rsi && sdslen(auxval->ptr) == CONFIG_RUN_ID_SIZE) {
+                    memcpy(rsi->repl_id,auxval->ptr,CONFIG_RUN_ID_SIZE+1);
+                    rsi->repl_id_is_set = 1;
+                }
+            } else if (!strcasecmp(auxkey->ptr,"repl-offset")) {
+                if (rsi) rsi->repl_offset = strtoll(auxval->ptr,NULL,10);
+            } else if (!strcasecmp(auxkey->ptr,"lua")) {
+                /* Load the script back in memory. */
+                if (luaCreateFunction(NULL,server.lua,auxval) == NULL) {
+                    rdbExitReportCorruptRDB(
+                        "Can't load Lua script from RDB file! "
+                        "BODY: %s", auxval->ptr);
+                }
            } else {
                /* We ignore fields we don't understand, as by AUX field
                 * contract. */
@@ -1531,7 +1714,7 @@ int rdbLoadRio(rio *rdb) {
        dbAdd(db,key,val);

        /* Set the expire time if needed */
-        if (expiretime != -1) setExpire(db,key,expiretime);
+        if (expiretime != -1) setExpire(NULL,db,key,expiretime);

        decrRefCount(key);
    }
@@ -1559,8 +1742,11 @@ eoferr: /* unexpected end of file is handled here with a fatal exit */
 /* Like rdbLoadRio() but takes a filename instead of a rio stream. The
 * filename is open for reading and a rio stream object created in order
 * to do the actual loading. Moreover the ETA displayed in the INFO
- * output is initialized and finalized. */
-int rdbLoad(char *filename) {
+ * output is initialized and finalized.
+ *
+ * If you pass an 'rsi' structure initialied with RDB_SAVE_OPTION_INIT, the
+ * loading code will fiil the information fields in the structure. */
+int rdbLoad(char *filename, rdbSaveInfo *rsi) {
    FILE *fp;
    rio rdb;
    int retval;
@@ -1568,7 +1754,7 @@ int rdbLoad(char *filename) {
    if ((fp = fopen(filename,"r")) == NULL) return C_ERR;
    startLoading(fp);
    rioInitWithFile(&rdb,fp);
-    retval = rdbLoadRio(&rdb);
+    retval = rdbLoadRio(&rdb,rsi);
    fclose(fp);
    stopLoading();
    return retval;
@@ -1721,7 +1907,7 @@ void backgroundSaveDoneHandler(int exitcode, int bysignal) {

 /* Spawn an RDB child that writes the RDB to the sockets of the slaves
 * that are currently in SLAVE_STATE_WAIT_BGSAVE_START state. */
-int rdbSaveToSlavesSockets(void) {
+int rdbSaveToSlavesSockets(rdbSaveInfo *rsi) {
    int *fds;
    uint64_t *clientids;
    int numfds;
@@ -1779,7 +1965,7 @@ int rdbSaveToSlavesSockets(void) {
        closeListeningSockets(0);
        redisSetProcTitle("redis-rdb-to-slaves");

-        retval = rdbSaveRioWithEOFMark(&slave_sockets,NULL);
+        retval = rdbSaveRioWithEOFMark(&slave_sockets,NULL,rsi);
        if (retval == C_OK && rioFlush(&slave_sockets) == 0)
            retval = C_ERR;

@@ -1839,9 +2025,6 @@ int rdbSaveToSlavesSockets(void) {
        exitFromChild((retval == C_OK) ? 0 : 1);
    } else {
        /* Parent */
-        server.stat_fork_time = ustime()-start;
-        server.stat_fork_rate = (double) zmalloc_used_memory() * 1000000 / server.stat_fork_time / (1024*1024*1024); /* GB per second. */
-        latencyAddSampleIfNeeded("fork",server.stat_fork_time/1000);
        if (childpid == -1) {
            serverLog(LL_WARNING,"Can't save in background: fork: %s",
                strerror(errno));
@@ -1865,6 +2048,10 @@ int rdbSaveToSlavesSockets(void) {
            close(pipefds[1]);
            closeChildInfoPipe();
        } else {
+            server.stat_fork_time = ustime()-start;
+            server.stat_fork_rate = (double) zmalloc_used_memory() * 1000000 / server.stat_fork_time / (1024*1024*1024); /* GB per second. */
+            latencyAddSampleIfNeeded("fork",server.stat_fork_time/1000);
+
            serverLog(LL_NOTICE,"Background RDB transfer started by pid %d",
                childpid);
            server.rdb_save_time_start = time(NULL);
@@ -1884,7 +2071,9 @@ void saveCommand(client *c) {
        addReplyError(c,"Background save already in progress");
        return;
    }
-    if (rdbSave(server.rdb_filename) == C_OK) {
+    rdbSaveInfo rsi, *rsiptr;
+    rsiptr = rdbPopulateSaveInfo(&rsi);
+    if (rdbSave(server.rdb_filename,rsiptr) == C_OK) {
        addReply(c,shared.ok);
    } else {
        addReply(c,shared.err);
@@ -1906,6 +2095,9 @@ void bgsaveCommand(client *c) {
        }
    }

+    rdbSaveInfo rsi, *rsiptr;
+    rsiptr = rdbPopulateSaveInfo(&rsi);
+
    if (server.rdb_child_pid != -1) {
        addReplyError(c,"Background save already in progress");
    } else if (server.aof_child_pid != -1) {
@@ -1915,12 +2107,61 @@ void bgsaveCommand(client *c) {
        } else {
            addReplyError(c,
                "An AOF log rewriting in progress: can't BGSAVE right now. "
-                "Use BGSAVE SCHEDULE in order to schedule a BGSAVE whenver "
+                "Use BGSAVE SCHEDULE in order to schedule a BGSAVE whenever "
                "possible.");
        }
-    } else if (rdbSaveBackground(server.rdb_filename) == C_OK) {
+    } else if (rdbSaveBackground(server.rdb_filename,rsiptr) == C_OK) {
        addReplyStatus(c,"Background saving started");
    } else {
        addReply(c,shared.err);
    }
 }
+
+/* Populate the rdbSaveInfo structure used to persist the replication
+ * information inside the RDB file. Currently the structure explicitly
+ * contains just the currently selected DB from the master stream, however
+ * if the rdbSave*() family functions receive a NULL rsi structure also
+ * the Replication ID/offset is not saved. The function popultes 'rsi'
+ * that is normally stack-allocated in the caller, returns the populated
+ * pointer if the instance has a valid master client, otherwise NULL
+ * is returned, and the RDB saving will not persist any replication related
+ * information. */
+rdbSaveInfo *rdbPopulateSaveInfo(rdbSaveInfo *rsi) {
+    rdbSaveInfo rsi_init = RDB_SAVE_INFO_INIT;
+    *rsi = rsi_init;
+
+    /* If the instance is a master, we can populate the replication info
+     * only when repl_backlog is not NULL. If the repl_backlog is NULL,
+     * it means that the instance isn't in any replication chains. In this
+     * scenario the replication info is useless, because when a slave
+     * connects to us, the NULL repl_backlog will trigger a full
+     * synchronization, at the same time we will use a new replid and clear
+     * replid2. */
+    if (!server.masterhost && server.repl_backlog) {
+        /* Note that when server.slaveseldb is -1, it means that this master
+         * didn't apply any write commands after a full synchronization.
+         * So we can let repl_stream_db be 0, this allows a restarted slave
+         * to reload replication ID/offset, it's safe because the next write
+         * command must generate a SELECT statement. */
+        rsi->repl_stream_db = server.slaveseldb == -1 ? 0 : server.slaveseldb;
+        return rsi;
+    }
+
+    /* If the instance is a slave we need a connected master
+     * in order to fetch the currently selected DB. */
+    if (server.master) {
+        rsi->repl_stream_db = server.master->db->id;
+        return rsi;
+    }
+
+    /* If we have a cached master we can use it in order to populate the
+     * replication selected DB info inside the RDB file: the slave can
+     * increment the master_repl_offset only from data arriving from the
+     * master, so if we are disconnected the offset in the cached master
+     * is valid. */
+    if (server.cached_master) {
+        rsi->repl_stream_db = server.cached_master->db->id;
+        return rsi;
+    }
+    return NULL;
+}
@@ -69,8 +69,9 @@
 #define RDB_ENC_INT32 2       /* 32 bit signed integer */
 #define RDB_ENC_LZF 3         /* string compressed with FASTLZ */

-/* Dup object types to RDB object types. Only reason is readability (are we
- * dealing with RDB types or with in-memory object types?). */
+/* Map object types to RDB object types. Macros starting with OBJ_ are for
+ * memory storage and may change. Instead RDB types must be fixed because
+ * we store them on disk. */
 #define RDB_TYPE_STRING 0
 #define RDB_TYPE_LIST   1
 #define RDB_TYPE_SET    2
@@ -78,6 +79,8 @@
 #define RDB_TYPE_HASH   4
 #define RDB_TYPE_ZSET_2 5 /* ZSET version 2 with doubles stored in binary. */
 #define RDB_TYPE_MODULE 6
+#define RDB_TYPE_MODULE_2 7 /* Module value with annotations for parsing without
+                               the generating module being loaded. */
 /* NOTE: WHEN ADDING NEW RDB TYPE, UPDATE rdbIsObjectType() BELOW */

 /* Object types for encoded objects. */
@@ -87,10 +90,11 @@
 #define RDB_TYPE_ZSET_ZIPLIST  12
 #define RDB_TYPE_HASH_ZIPLIST  13
 #define RDB_TYPE_LIST_QUICKLIST 14
+#define RDB_TYPE_STREAM_LISTPACKS 15
 /* NOTE: WHEN ADDING NEW RDB TYPE, UPDATE rdbIsObjectType() BELOW */

 /* Test if a type is an object type. */
-#define rdbIsObjectType(t) ((t >= 0 && t <= 6) || (t >= 9 && t <= 14))
+#define rdbIsObjectType(t) ((t >= 0 && t <= 7) || (t >= 9 && t <= 15))

 /* Special RDB opcodes (saved/loaded with rdbSaveType/rdbLoadType). */
 #define RDB_OPCODE_AUX        250
@@ -100,6 +104,14 @@
 #define RDB_OPCODE_SELECTDB   254
 #define RDB_OPCODE_EOF        255

+/* Module serialized values sub opcodes */
+#define RDB_MODULE_OPCODE_EOF   0   /* End of module value. */
+#define RDB_MODULE_OPCODE_SINT  1   /* Signed integer. */
+#define RDB_MODULE_OPCODE_UINT  2   /* Unsigned integer. */
+#define RDB_MODULE_OPCODE_FLOAT 3   /* Float. */
+#define RDB_MODULE_OPCODE_DOUBLE 4  /* Double. */
+#define RDB_MODULE_OPCODE_STRING 5  /* String. */
+
 /* rdbLoad...() functions flags. */
 #define RDB_LOAD_NONE   0
 #define RDB_LOAD_ENC    (1<<0)
@@ -118,11 +130,11 @@ uint64_t rdbLoadLen(rio *rdb, int *isencoded);
 int rdbLoadLenByRef(rio *rdb, int *isencoded, uint64_t *lenptr);
 int rdbSaveObjectType(rio *rdb, robj *o);
 int rdbLoadObjectType(rio *rdb);
-int rdbLoad(char *filename);
-int rdbSaveBackground(char *filename);
-int rdbSaveToSlavesSockets(void);
+int rdbLoad(char *filename, rdbSaveInfo *rsi);
+int rdbSaveBackground(char *filename, rdbSaveInfo *rsi);
+int rdbSaveToSlavesSockets(rdbSaveInfo *rsi);
 void rdbRemoveTempFile(pid_t childpid);
-int rdbSave(char *filename);
+int rdbSave(char *filename, rdbSaveInfo *rsi);
 ssize_t rdbSaveObject(rio *rdb, robj *o);
 size_t rdbSavedObjectLen(robj *o);
 robj *rdbLoadObject(int type, rio *rdb);
@@ -136,6 +148,7 @@ int rdbSaveBinaryDoubleValue(rio *rdb, double val);
 int rdbLoadBinaryDoubleValue(rio *rdb, double *val);
 int rdbSaveBinaryFloatValue(rio *rdb, float val);
 int rdbLoadBinaryFloatValue(rio *rdb, float *val);
-int rdbLoadRio(rio *rdb);
+int rdbLoadRio(rio *rdb, rdbSaveInfo *rsi);
+rdbSaveInfo *rdbPopulateSaveInfo(rdbSaveInfo *rsi);

 #endif
@@ -565,15 +565,15 @@ invalid:

 usage:
    printf(
-"Usage: redis-benchmark [-h <host>] [-p <port>] [-c <clients>] [-n <requests]> [-k <boolean>]\n\n"
+"Usage: redis-benchmark [-h <host>] [-p <port>] [-c <clients>] [-n <requests>] [-k <boolean>]\n\n"
 " -h <hostname>      Server hostname (default 127.0.0.1)\n"
 " -p <port>          Server port (default 6379)\n"
 " -s <socket>        Server socket (overrides host and port)\n"
 " -a <password>      Password for Redis Auth\n"
 " -c <clients>       Number of parallel connections (default 50)\n"
 " -n <requests>      Total number of requests (default 100000)\n"
-" -d <size>          Data size of SET/GET value in bytes (default 2)\n"
-" -dbnum <db>        SELECT the specified db number (default 0)\n"
+" -d <size>          Data size of SET/GET value in bytes (default 3)\n"
+" --dbnum <db>       SELECT the specified db number (default 0)\n"
 " -k <boolean>       1=keep alive 0=reconnect (default 1)\n"
 " -r <keyspacelen>   Use random keys for SET/GET/INCR, random values for SADD\n"
 "  Using this option the benchmark will expand the string __rand_int__\n"
@@ -779,6 +779,13 @@ int main(int argc, const char **argv) {
            free(cmd);
        }

+        if (test_is_selected("hset")) {
+            len = redisFormatCommand(&cmd,
+                "HSET myset:__rand_int__ element:__rand_int__ %s",data);
+            benchmark("HSET",cmd,len);
+            free(cmd);
+        }
+
        if (test_is_selected("spop")) {
            len = redisFormatCommand(&cmd,"SPOP myset");
            benchmark("SPOP",cmd,len);
@@ -28,13 +28,8 @@
 * POSSIBILITY OF SUCH DAMAGE.
 */

-#include "fmacros.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
+#include "server.h"
 #include <sys/stat.h>
-#include "config.h"

 #define ERROR(...) { \
    char __buf[1024]; \
@@ -60,7 +55,7 @@ int readLong(FILE *fp, char prefix, long *target) {
        return 0;
    }
    if (buf[0] != prefix) {
-        ERROR("Expected prefix '%c', got: '%c'",buf[0],prefix);
+        ERROR("Expected prefix '%c', got: '%c'",prefix,buf[0]);
        return 0;
    }
    *target = strtol(buf+1,&eptr,10);
@@ -87,7 +82,7 @@ int readString(FILE *fp, char** target) {

    /* Increase length to also consume \r\n */
    len += 2;
-    *target = (char*)malloc(len);
+    *target = (char*)zmalloc(len);
    if (!readBytes(fp,*target,len)) {
        return 0;
    }
@@ -127,12 +122,12 @@ off_t process(FILE *fp) {
                    }
                }
            }
-            free(str);
+            zfree(str);
        }

        /* Stop if the loop did not finish */
        if (i < argc) {
-            if (str) free(str);
+            if (str) zfree(str);
            break;
        }
    }
@@ -146,7 +141,7 @@ off_t process(FILE *fp) {
    return pos;
 }

-int main(int argc, char **argv) {
+int redis_check_aof_main(int argc, char **argv) {
    char *filename;
    int fix = 0;

@@ -185,6 +180,25 @@ int main(int argc, char **argv) {
        exit(1);
    }

+    /* This AOF file may have an RDB preamble. Check this to start, and if this
+     * is the case, start processing the RDB part. */
+    if (size >= 8) {    /* There must be at least room for the RDB header. */
+        char sig[5];
+        int has_preamble = fread(sig,sizeof(sig),1,fp) == 1 &&
+                            memcmp(sig,"REDIS",sizeof(sig)) == 0;
+        rewind(fp);
+        if (has_preamble) {
+            printf("The AOF appears to start with an RDB preamble.\n"
+                   "Checking the RDB preamble to start:\n");
+            if (redis_check_rdb_main(argc,argv,fp) == C_ERR) {
+                printf("RDB preamble of AOF file is not sane, aborting.\n");
+                exit(1);
+            } else {
+                printf("RDB preamble is OK, proceeding with AOF tail...\n");
+            }
+        }
+    }
+
    off_t pos = process(fp);
    off_t diff = size-pos;
    printf("AOF analyzed: size=%lld, ok_up_to=%lld, diff=%lld\n",
@@ -206,7 +220,8 @@ int main(int argc, char **argv) {
                printf("Successfully truncated AOF\n");
            }
        } else {
-            printf("AOF is not valid\n");
+            printf("AOF is not valid. "
+                   "Use the --fix option to try fixing it.\n");
            exit(1);
        }
    } else {
@@ -214,5 +229,5 @@ int main(int argc, char **argv) {
    }

    fclose(fp);
-    return 0;
+    exit(0);
 }
@@ -173,16 +173,18 @@ void rdbCheckSetupSignals(void) {
 }

 /* Check the specified RDB file. Return 0 if the RDB looks sane, otherwise
- * 1 is returned. */
-int redis_check_rdb(char *rdbfilename) {
+ * 1 is returned.
+ * The file is specified as a filename in 'rdbfilename' if 'fp' is not NULL,
+ * otherwise the already open file 'fp' is checked. */
+int redis_check_rdb(char *rdbfilename, FILE *fp) {
    uint64_t dbid;
    int type, rdbver;
    char buf[1024];
    long long expiretime, now = mstime();
-    FILE *fp;
    static rio rdb; /* Pointed by global struct riostate. */

-    if ((fp = fopen(rdbfilename,"r")) == NULL) return 1;
+    int closefile = (fp == NULL);
+    if (fp == NULL && (fp = fopen(rdbfilename,"r")) == NULL) return 1;

    rioInitWithFile(&rdb,fp);
    rdbstate.rio = &rdb;
@@ -191,12 +193,12 @@ int redis_check_rdb(char *rdbfilename) {
    buf[9] = '\0';
    if (memcmp(buf,"REDIS",5) != 0) {
        rdbCheckError("Wrong signature trying to load DB from file");
-        return 1;
+        goto err;
    }
    rdbver = atoi(buf+5);
    if (rdbver < 1 || rdbver > RDB_VERSION) {
        rdbCheckError("Can't handle RDB format version %d",rdbver);
-        return 1;
+        goto err;
    }

    startLoading(fp);
@@ -268,7 +270,7 @@ int redis_check_rdb(char *rdbfilename) {
        } else {
            if (!rdbIsObjectType(type)) {
                rdbCheckError("Invalid object type: %d", type);
-                return 1;
+                goto err;
            }
            rdbstate.key_type = type;
        }
@@ -305,12 +307,13 @@ int redis_check_rdb(char *rdbfilename) {
            rdbCheckInfo("RDB file was saved with checksum disabled: no check performed.");
        } else if (cksum != expected) {
            rdbCheckError("RDB CRC error");
+            goto err;
        } else {
            rdbCheckInfo("Checksum OK");
        }
    }

-    fclose(fp);
+    if (closefile) fclose(fp);
    return 0;

 eoferr: /* unexpected end of file is handled here with a fatal exit */
@@ -319,16 +322,25 @@ eoferr: /* unexpected end of file is handled here with a fatal exit */
    } else {
        rdbCheckError("Unexpected EOF reading RDB file");
    }
+err:
+    if (closefile) fclose(fp);
    return 1;
 }

 /* RDB check main: called form redis.c when Redis is executed with the
- * redis-check-rdb alias.
+ * redis-check-rdb alias, on during RDB loading errors.
 *
- * The function never returns, but exits with the status code according
- * to success (RDB is sane) or error (RDB is corrupted). */
-int redis_check_rdb_main(int argc, char **argv) {
-    if (argc != 2) {
+ * The function works in two ways: can be called with argc/argv as a
+ * standalone executable, or called with a non NULL 'fp' argument if we
+ * already have an open file to check. This happens when the function
+ * is used to check an RDB preamble inside an AOF file.
+ *
+ * When called with fp = NULL, the function never returns, but exits with the
+ * status code according to success (RDB is sane) or error (RDB is corrupted).
+ * Otherwise if called with a non NULL fp, the function returns C_OK or
+ * C_ERR depending on the success or failure. */
+int redis_check_rdb_main(int argc, char **argv, FILE *fp) {
+    if (argc != 2 && fp == NULL) {
        fprintf(stderr, "Usage: %s <rdb-file-name>\n", argv[0]);
        exit(1);
    }
@@ -341,10 +353,11 @@ int redis_check_rdb_main(int argc, char **argv) {
    rdbCheckMode = 1;
    rdbCheckInfo("Checking RDB file %s", argv[1]);
    rdbCheckSetupSignals();
-    int retval = redis_check_rdb(argv[1]);
+    int retval = redis_check_rdb(argv[1],fp);
    if (retval == 0) {
        rdbCheckInfo("\\o/ RDB looks OK! \\o/");
        rdbShowGenericInfo();
    }
+    if (fp) return (retval == 0) ? C_OK : C_ERR;
    exit(retval);
 }
@@ -107,6 +107,7 @@ static struct config {
    char *pattern;
    char *rdb_filename;
    int bigkeys;
+    int hotkeys;
    int stdinarg; /* get last arg from stdin. (-x option) */
    char *auth;
    int output; /* output mode, see OUTPUT_* defines */
@@ -198,6 +199,92 @@ static sds getDotfilePath(char *envoverride, char *dotfilename) {
    return dotPath;
 }

+/* URL-style percent decoding. */
+#define isHexChar(c) (isdigit(c) || (c >= 'a' && c <= 'f'))
+#define decodeHexChar(c) (isdigit(c) ? c - '0' : c - 'a' + 10)
+#define decodeHex(h, l) ((decodeHexChar(h) << 4) + decodeHexChar(l))
+
+static sds percentDecode(const char *pe, size_t len) {
+    const char *end = pe + len;
+    sds ret = sdsempty();
+    const char *curr = pe;
+
+    while (curr < end) {
+        if (*curr == '%') {
+            if ((end - curr) < 2) {
+                fprintf(stderr, "Incomplete URI encoding\n");
+                exit(1);
+            }
+
+            char h = tolower(*(++curr));
+            char l = tolower(*(++curr));
+            if (!isHexChar(h) || !isHexChar(l)) {
+                fprintf(stderr, "Illegal character in URI encoding\n");
+                exit(1);
+            }
+            char c = decodeHex(h, l);
+            ret = sdscatlen(ret, &c, 1);
+            curr++;
+        } else {
+            ret = sdscatlen(ret, curr++, 1);
+        }
+    }
+
+    return ret;
+}
+
+/* Parse a URI and extract the server connection information.
+ * URI scheme is based on the the provisional specification[1] excluding support
+ * for query parameters. Valid URIs are:
+ *   scheme:    "redis://"
+ *   authority: [<username> ":"] <password> "@"] [<hostname> [":" <port>]]
+ *   path:      ["/" [<db>]]
+ *
+ *  [1]: https://www.iana.org/assignments/uri-schemes/prov/redis */
+static void parseRedisUri(const char *uri) {
+
+    const char *scheme = "redis://";
+    const char *curr = uri;
+    const char *end = uri + strlen(uri);
+    const char *userinfo, *username, *port, *host, *path;
+
+    /* URI must start with a valid scheme. */
+    if (strncasecmp(scheme, curr, strlen(scheme))) {
+        fprintf(stderr,"Invalid URI scheme\n");
+        exit(1);
+    }
+    curr += strlen(scheme);
+    if (curr == end) return;
+
+    /* Extract user info. */
+    if ((userinfo = strchr(curr,'@'))) {
+        if ((username = strchr(curr, ':')) && username < userinfo) {
+            /* If provided, username is ignored. */
+            curr = username + 1;
+        }
+
+        config.auth = percentDecode(curr, userinfo - curr);
+        curr = userinfo + 1;
+    }
+    if (curr == end) return;
+
+    /* Extract host and port. */
+    path = strchr(curr, '/');
+    if (*curr != '/') {
+        host = path ? path - 1 : end;
+        if ((port = strchr(curr, ':'))) {
+            config.hostport = atoi(port + 1);
+            host = port - 1;
+        }
+        config.hostip = sdsnewlen(curr, host - curr + 1);
+    }
+    curr = path ? path + 1 : end;
+    if (curr == end) return;
+
+    /* Extract database number. */
+    config.dbnum = atoi(curr);
+}
+
 /*------------------------------------------------------------------------------
 * Help functions
 *--------------------------------------------------------------------------- */
@@ -275,6 +362,10 @@ static void cliIntegrateHelp(void) {
     * don't already match what we have. */
    for (size_t j = 0; j < reply->elements; j++) {
        redisReply *entry = reply->element[j];
+        if (entry->type != REDIS_REPLY_ARRAY || entry->elements < 4 ||
+            entry->element[0]->type != REDIS_REPLY_STRING ||
+            entry->element[1]->type != REDIS_REPLY_INTEGER ||
+            entry->element[3]->type != REDIS_REPLY_INTEGER) return;
        char *cmdname = entry->element[0]->str;
        int i;

@@ -336,7 +427,7 @@ static void cliOutputGenericHelp(void) {
        "      \"help <tab>\" to get a list of possible help topics\n"
        "      \"quit\" to exit\n"
        "\n"
-        "To set redis-cli perferences:\n"
+        "To set redis-cli preferences:\n"
        "      \":set hints\" enable online hints\n"
        "      \":set nohints\" disable online hints\n"
        "Set your preferences in ~/.redisclirc\n",
@@ -620,7 +711,7 @@ int isColorTerm(void) {
    return t != NULL && strstr(t,"xterm") != NULL;
 }

-/* Helpe  function for sdsCatColorizedLdbReply() appending colorize strings
+/* Helper  function for sdsCatColorizedLdbReply() appending colorize strings
 * to an SDS string. */
 sds sdscatcolor(sds o, char *s, size_t len, char *color) {
    if (!isColorTerm()) return sdscatlen(o,s,len);
@@ -628,7 +719,6 @@ sds sdscatcolor(sds o, char *s, size_t len, char *color) {
    int bold = strstr(color,"bold") != NULL;
    int ccode = 37; /* Defaults to white. */
    if (strstr(color,"red")) ccode = 31;
-    else if (strstr(color,"red")) ccode = 31;
    else if (strstr(color,"green")) ccode = 32;
    else if (strstr(color,"yellow")) ccode = 33;
    else if (strstr(color,"blue")) ccode = 34;
@@ -999,6 +1089,8 @@ static int parseOptions(int argc, char **argv) {
            config.dbnum = atoi(argv[++i]);
        } else if (!strcmp(argv[i],"-a") && !lastarg) {
            config.auth = argv[++i];
+        } else if (!strcmp(argv[i],"-u") && !lastarg) {
+            parseRedisUri(argv[++i]);
        } else if (!strcmp(argv[i],"--raw")) {
            config.output = OUTPUT_RAW;
        } else if (!strcmp(argv[i],"--no-raw")) {
@@ -1038,6 +1130,8 @@ static int parseOptions(int argc, char **argv) {
            config.pipe_timeout = atoi(argv[++i]);
        } else if (!strcmp(argv[i],"--bigkeys")) {
            config.bigkeys = 1;
+        } else if (!strcmp(argv[i],"--hotkeys")) {
+            config.hotkeys = 1;
        } else if (!strcmp(argv[i],"--eval") && !lastarg) {
            config.eval = argv[++i];
        } else if (!strcmp(argv[i],"--ldb")) {
@@ -1106,6 +1200,7 @@ static void usage(void) {
 "  -p <port>          Server port (default: 6379).\n"
 "  -s <socket>        Server socket (overrides hostname and port).\n"
 "  -a <password>      Password to use when connecting to the server.\n"
+"  -u <uri>           Server URI.\n"
 "  -r <repeat>        Execute specified command N times.\n"
 "  -i <interval>      When -r is used, waits <interval> seconds per command.\n"
 "                     It is possible to specify sub-second times like -i 0.1.\n"
@@ -1119,6 +1214,12 @@ static void usage(void) {
 "  --csv              Output in CSV format.\n"
 "  --stat             Print rolling stats about server: mem, clients, ...\n"
 "  --latency          Enter a special mode continuously sampling latency.\n"
+"                     If you use this mode in an interactive session it runs\n"
+"                     forever displaying real-time stats. Otherwise if --raw or\n"
+"                     --csv is specified, or if you redirect the output to a non\n"
+"                     TTY, it samples the latency for 1 second (you can use\n"
+"                     -i to change the interval), then produces a single output\n"
+"                     and exits.\n"
 "  --latency-history  Like --latency but tracking latency changes over time.\n"
 "                     Default time interval is 15 sec. Change it using -i.\n"
 "  --latency-dist     Shows latency as a spectrum, requires xterm 256 colors.\n"
@@ -1131,6 +1232,8 @@ static void usage(void) {
 "                     no reply is received within <n> seconds.\n"
 "                     Default timeout: %d. Use 0 to wait forever.\n"
 "  --bigkeys          Sample Redis keys looking for big keys.\n"
+"  --hotkeys          Sample Redis keys looking for hot keys.\n"
+"                     only works when maxmemory-policy is *lfu.\n"
 "  --scan             List all keys using the SCAN command.\n"
 "  --pattern <pat>    Useful with --scan to specify a SCAN pattern.\n"
 "  --intrinsic-latency <sec> Run a test to measure intrinsic system latency.\n"
@@ -1222,7 +1325,7 @@ static sds *cliSplitArgs(char *line, int *argc) {
    }
 }

-/* Set the CLI perferences. This function is invoked when an interactive
+/* Set the CLI preferences. This function is invoked when an interactive
 * ":command" is called, or when reading ~/.redisclirc file, in order to
 * set user preferences. */
 void cliSetPreferences(char **argv, int argc, int interactive) {
@@ -1257,6 +1360,7 @@ void cliLoadPreferences(void) {
            if (argc > 0) cliSetPreferences(argv,argc,0);
            sdsfreesplitres(argv,argc);
        }
+        fclose(fp);
    }
    sdsfree(rcfile);
 }
@@ -1268,6 +1372,11 @@ static void repl(void) {
    int argc;
    sds *argv;

+    /* Initialize the help and, if possible, use the COMMAND command in order
+     * to retrieve missing entries. */
+    cliInitHelp();
+    cliIntegrateHelp();
+
    config.interactive = 1;
    linenoiseSetMultiLine(1);
    linenoiseSetCompletionCallback(completionCallback);
@@ -1277,8 +1386,9 @@ static void repl(void) {
    /* Only use history and load the rc file when stdin is a tty. */
    if (isatty(fileno(stdin))) {
        historyfile = getDotfilePath(REDIS_CLI_HISTFILE_ENV,REDIS_CLI_HISTFILE_DEFAULT);
+        //keep in-memory history always regardless if history file can be determined
+        history = 1;
        if (historyfile != NULL) {
-            history = 1;
            linenoiseHistoryLoad(historyfile);
        }
        cliLoadPreferences();
@@ -1322,9 +1432,10 @@ static void repl(void) {
                } else {
                    long long start_time = mstime(), elapsed;
                    int repeat, skipargs = 0;
+                    char *endptr;

-                    repeat = atoi(argv[0]);
-                    if (argc > 1 && repeat) {
+                    repeat = strtol(argv[0], &endptr, 10);
+                    if (argc > 1 && *endptr == '\0' && repeat) {
                        skipargs = 1;
                    } else {
                        repeat = 1;
@@ -1343,7 +1454,9 @@ static void repl(void) {
                    }

                    elapsed = mstime()-start_time;
-                    if (elapsed >= 500) {
+                    if (elapsed >= 500 &&
+                        config.output == OUTPUT_STANDARD)
+                    {
                        printf("(%.2fs)\n",(double)elapsed/1000);
                    }
                }
@@ -1460,6 +1573,18 @@ static int evalMode(int argc, char **argv) {
 * Latency and latency history modes
 *--------------------------------------------------------------------------- */

+static void latencyModePrint(long long min, long long max, double avg, long long count) {
+    if (config.output == OUTPUT_STANDARD) {
+        printf("min: %lld, max: %lld, avg: %.2f (%lld samples)",
+                min, max, avg, count);
+        fflush(stdout);
+    } else if (config.output == OUTPUT_CSV) {
+        printf("%lld,%lld,%.2f,%lld\n", min, max, avg, count);
+    } else if (config.output == OUTPUT_RAW) {
+        printf("%lld %lld %.2f %lld\n", min, max, avg, count);
+    }
+}
+
 #define LATENCY_SAMPLE_RATE 10 /* milliseconds. */
 #define LATENCY_HISTORY_DEFAULT_INTERVAL 15000 /* milliseconds. */
 static void latencyMode(void) {
@@ -1471,6 +1596,14 @@ static void latencyMode(void) {
    double avg;
    long long history_start = mstime();

+    /* Set a default for the interval in case of --latency option
+     * with --raw, --csv or when it is redirected to non tty. */
+    if (config.interval == 0) {
+        config.interval = 1000;
+    } else {
+        config.interval /= 1000; /* We need to convert to milliseconds. */
+    }
+
    if (!context) exit(1);
    while(1) {
        start = mstime();
@@ -1491,9 +1624,19 @@ static void latencyMode(void) {
            tot += latency;
            avg = (double) tot/count;
        }
-        printf("\x1b[0G\x1b[2Kmin: %lld, max: %lld, avg: %.2f (%lld samples)",
-            min, max, avg, count);
-        fflush(stdout);
+
+        if (config.output == OUTPUT_STANDARD) {
+            printf("\x1b[0G\x1b[2K"); /* Clear the line. */
+            latencyModePrint(min,max,avg,count);
+        } else {
+            if (config.latency_history) {
+                latencyModePrint(min,max,avg,count);
+            } else if (mstime()-history_start > config.interval) {
+                latencyModePrint(min,max,avg,count);
+                exit(0);
+            }
+        }
+
        if (config.latency_history && mstime()-history_start > history_interval)
        {
            printf(" -- %.2f seconds range\n", (float)(mstime()-history_start)/1000);
@@ -1758,6 +1901,7 @@ static void getRDB(void) {
    }
    close(s); /* Close the file descriptor ASAP as fsync() may take time. */
    fsync(fd);
+    close(fd);
    fprintf(stderr,"Transfer finished with success.\n");
    exit(0);
 }
@@ -1931,7 +2075,8 @@ static void pipeMode(void) {
 #define TYPE_SET    2
 #define TYPE_HASH   3
 #define TYPE_ZSET   4
-#define TYPE_NONE   5
+#define TYPE_STREAM 5
+#define TYPE_NONE   6

 static redisReply *sendScan(unsigned long long *it) {
    redisReply *reply = redisCommand(context, "SCAN %llu", *it);
@@ -1990,6 +2135,8 @@ static int toIntType(char *key, char *type) {
        return TYPE_HASH;
    } else if(!strcmp(type, "zset")) {
        return TYPE_ZSET;
+    } else if(!strcmp(type, "stream")) {
+        return TYPE_STREAM;
    } else if(!strcmp(type, "none")) {
        return TYPE_NONE;
    } else {
@@ -2014,8 +2161,13 @@ static void getKeyTypes(redisReply *keys, int *types) {
                keys->element[i]->str, context->err, context->errstr);
            exit(1);
        } else if(reply->type != REDIS_REPLY_STATUS) {
-            fprintf(stderr, "Invalid reply type (%d) for TYPE on key '%s'!\n",
-                reply->type, keys->element[i]->str);
+            if(reply->type == REDIS_REPLY_ERROR) {
+                fprintf(stderr, "TYPE returned an error: %s\n", reply->str);
+            } else {
+                fprintf(stderr,
+                    "Invalid reply type (%d) for TYPE on key '%s'!\n",
+                    reply->type, keys->element[i]->str);
+            }
            exit(1);
        }

@@ -2073,7 +2225,7 @@ static void findBigKeys(void) {
    unsigned long long biggest[5] = {0}, counts[5] = {0}, totalsize[5] = {0};
    unsigned long long sampled = 0, total_keys, totlen=0, *sizes=NULL, it=0;
    sds maxkeys[5] = {0};
-    char *typename[] = {"string","list","set","hash","zset"};
+    char *typename[] = {"string","list","set","hash","zset","stream"};
    char *typeunit[] = {"bytes","items","members","fields","members"};
    redisReply *reply, *keys;
    unsigned int arrsize=0, i;
@@ -2200,6 +2352,129 @@ static void findBigKeys(void) {
    exit(0);
 }

+static void getKeyFreqs(redisReply *keys, unsigned long long *freqs) {
+    redisReply *reply;
+    unsigned int i;
+
+    /* Pipeline OBJECT freq commands */
+    for(i=0;i<keys->elements;i++) {
+        redisAppendCommand(context, "OBJECT freq %s", keys->element[i]->str);
+    }
+
+    /* Retrieve freqs */
+    for(i=0;i<keys->elements;i++) {
+        if(redisGetReply(context, (void**)&reply)!=REDIS_OK) {
+            fprintf(stderr, "Error getting freq for key '%s' (%d: %s)\n",
+                keys->element[i]->str, context->err, context->errstr);
+            exit(1);
+        } else if(reply->type != REDIS_REPLY_INTEGER) {
+            if(reply->type == REDIS_REPLY_ERROR) {
+                fprintf(stderr, "Error: %s\n", reply->str);
+                exit(1);
+            } else {
+                fprintf(stderr, "Warning: OBJECT freq on '%s' failed (may have been deleted)\n", keys->element[i]->str);
+                freqs[i] = 0;
+            }
+        } else {
+            freqs[i] = reply->integer;
+        }
+        freeReplyObject(reply);
+    }
+}
+
+#define HOTKEYS_SAMPLE 16
+static void findHotKeys(void) {
+    redisReply *keys, *reply;
+    unsigned long long counters[HOTKEYS_SAMPLE] = {0};
+    sds hotkeys[HOTKEYS_SAMPLE] = {NULL};
+    unsigned long long sampled = 0, total_keys, *freqs = NULL, it = 0;
+    unsigned int arrsize = 0, i, k;
+    double pct;
+
+    /* Total keys pre scanning */
+    total_keys = getDbSize();
+
+    /* Status message */
+    printf("\n# Scanning the entire keyspace to find hot keys as well as\n");
+    printf("# average sizes per key type.  You can use -i 0.1 to sleep 0.1 sec\n");
+    printf("# per 100 SCAN commands (not usually needed).\n\n");
+
+    /* SCAN loop */
+    do {
+        /* Calculate approximate percentage completion */
+        pct = 100 * (double)sampled/total_keys;
+
+        /* Grab some keys and point to the keys array */
+        reply = sendScan(&it);
+        keys  = reply->element[1];
+
+        /* Reallocate our freqs array if we need to */
+        if(keys->elements > arrsize) {
+            freqs = zrealloc(freqs, sizeof(unsigned long long)*keys->elements);
+
+            if(!freqs) {
+                fprintf(stderr, "Failed to allocate storage for keys!\n");
+                exit(1);
+            }
+
+            arrsize = keys->elements;
+        }
+
+        getKeyFreqs(keys, freqs);
+
+        /* Now update our stats */
+        for(i=0;i<keys->elements;i++) {
+            sampled++;
+            /* Update overall progress */
+            if(sampled % 1000000 == 0) {
+                printf("[%05.2f%%] Sampled %llu keys so far\n", pct, sampled);
+            }
+
+            /* Use eviction pool here */
+            k = 0;
+            while (k < HOTKEYS_SAMPLE && freqs[i] > counters[k]) k++;
+            if (k == 0) continue;
+            k--;
+            if (k == 0 || counters[k] == 0) {
+                sdsfree(hotkeys[k]);
+            } else {
+                sdsfree(hotkeys[0]);
+                memmove(counters,counters+1,sizeof(counters[0])*k);
+                memmove(hotkeys,hotkeys+1,sizeof(hotkeys[0])*k);
+            }
+            counters[k] = freqs[i];
+            hotkeys[k] = sdsnew(keys->element[i]->str);
+            printf(
+               "[%05.2f%%] Hot key '%s' found so far with counter %llu\n",
+               pct, keys->element[i]->str, freqs[i]);
+        }
+
+        /* Sleep if we've been directed to do so */
+        if(sampled && (sampled %100) == 0 && config.interval) {
+            usleep(config.interval);
+        }
+
+        freeReplyObject(reply);
+    } while(it != 0);
+
+    if (freqs) zfree(freqs);
+
+    /* We're done */
+    printf("\n-------- summary -------\n\n");
+
+    printf("Sampled %llu keys in the keyspace!\n", sampled);
+
+    for (i=1; i<= HOTKEYS_SAMPLE; i++) {
+        k = HOTKEYS_SAMPLE - i;
+        if(counters[k]>0) {
+            printf("hot key found with counter: %llu\tkeyname: %s\n", counters[k], hotkeys[k]);
+            sdsfree(hotkeys[k]);
+        }
+    }
+
+    exit(0);
+}
+
 /*------------------------------------------------------------------------------
 * Stats mode
 *--------------------------------------------------------------------------- */
@@ -2310,7 +2585,7 @@ static void statMode(void) {
        sprintf(buf,"%ld",aux);
        printf("%-8s",buf);

-        /* Requets */
+        /* Requests */
        aux = getLongInfoField(reply->str,"total_commands_processed");
        sprintf(buf,"%ld (+%ld)",aux,requests == 0 ? 0 : aux-requests);
        printf("%-19s",buf);
@@ -2577,6 +2852,7 @@ int main(int argc, char **argv) {
    config.pipe_mode = 0;
    config.pipe_timeout = REDIS_CLI_DEFAULT_PIPE_TIMEOUT;
    config.bigkeys = 0;
+    config.hotkeys = 0;
    config.stdinarg = 0;
    config.auth = NULL;
    config.eval = NULL;
@@ -2601,11 +2877,6 @@ int main(int argc, char **argv) {
    argc -= firstarg;
    argv += firstarg;

-    /* Initialize the help and, if possible, use the COMMAND command in order
-     * to retrieve missing entries. */
-    cliInitHelp();
-    cliIntegrateHelp();
-
    /* Latency mode */
    if (config.latency_mode) {
        if (cliConnect(0) == REDIS_ERR) exit(1);
@@ -2642,6 +2913,12 @@ int main(int argc, char **argv) {
        findBigKeys();
    }

+    /* Find hot keys */
+    if (config.hotkeys) {
+        if (cliConnect(0) == REDIS_ERR) exit(1);
+        findHotKeys();
+    }
+
    /* Stat mode */
    if (config.stat_mode) {
        if (cliConnect(0) == REDIS_ERR) exit(1);
@@ -701,7 +701,12 @@ class RedisTrib

        masters.each{|m| puts m}

-        # Alloc slots on masters
+        # Rotating the list sometimes helps to get better initial
+        # anti-affinity before the optimizer runs.
+        interleaved.push interleaved.shift
+
+        # Alloc slots on masters. After interleaving to get just the first N
+        # should be optimal. With slaves is more complex, see later...
        slots_per_node = ClusterHashSlots.to_f / masters_count
        first = 0
        cursor = 0.0
@@ -769,6 +774,131 @@ class RedisTrib
                end
            end
        end
+
+        optimize_anti_affinity
+    end
+
+    def optimize_anti_affinity
+        score,aux = get_anti_affinity_score
+        return if score == 0
+
+        xputs ">>> Trying to optimize slaves allocation for anti-affinity"
+
+        maxiter = 500*@nodes.length # Effort is proportional to cluster size...
+        while maxiter > 0
+            score,offenders = get_anti_affinity_score
+            break if score == 0 # Optimal anti affinity reached
+
+            # We'll try to randomly swap a slave's assigned master causing
+            # an affinity problem with another random slave, to see if we
+            # can improve the affinity.
+            first = offenders.shuffle.first
+            nodes = @nodes.select{|n| n != first && n.info[:replicate]}
+            break if nodes.length == 0
+            second = nodes.shuffle.first
+
+            first_master = first.info[:replicate]
+            second_master = second.info[:replicate]
+            first.set_as_replica(second_master)
+            second.set_as_replica(first_master)
+
+            new_score,aux = get_anti_affinity_score
+            # If the change actually makes thing worse, revert. Otherwise
+            # leave as it is becuase the best solution may need a few
+            # combined swaps.
+            if new_score > score
+                first.set_as_replica(first_master)
+                second.set_as_replica(second_master)
+            end
+
+            maxiter -= 1
+        end
+
+        score,aux = get_anti_affinity_score
+        if score == 0
+            xputs "[OK] Perfect anti-affinity obtained!"
+        elsif score >= 10000
+            puts "[WARNING] Some slaves are in the same host as their master"
+        else
+            puts "[WARNING] Some slaves of the same master are in the same host"
+        end
+    end
+
+    # Return the anti-affinity score, which is a measure of the amount of
+    # violations of anti-affinity in the current cluster layout, that is, how
+    # badly the masters and slaves are distributed in the different IP
+    # addresses so that slaves of the same master are not in the master
+    # host and are also in different hosts.
+    #
+    # The score is calculated as follows:
+    #
+    # SAME_AS_MASTER = 10000 * each slave in the same IP of its master.
+    # SAME_AS_SLAVE  = 1 * each slave having the same IP as another slave
+    #                      of the same master.
+    # FINAL_SCORE = SAME_AS_MASTER + SAME_AS_SLAVE
+    #
+    # So a greater score means a worse anti-affinity level, while zero
+    # means perfect anti-affinity.
+    #
+    # The anti affinity optimizator will try to get a score as low as
+    # possible. Since we do not want to sacrifice the fact that slaves should
+    # not be in the same host as the master, we assign 10000 times the score
+    # to this violation, so that we'll optimize for the second factor only
+    # if it does not impact the first one.
+    #
+    # The function returns two things: the above score, and the list of
+    # offending slaves, so that the optimizer can try changing the
+    # configuration of the slaves violating the anti-affinity goals.
+    def get_anti_affinity_score
+        score = 0
+        offending = [] # List of offending slaves to return to the caller
+
+        # First, split nodes by host
+        host_to_node = {}
+        @nodes.each{|n|
+            host = n.info[:host]
+            host_to_node[host] = [] if host_to_node[host] == nil
+            host_to_node[host] << n
+        }
+
+        # Then, for each set of nodes in the same host, split by
+        # related nodes (masters and slaves which are involved in
+        # replication of each other)
+        host_to_node.each{|host,nodes|
+            related = {}
+            nodes.each{|n|
+                if !n.info[:replicate]
+                    name = n.info[:name]
+                    related[name] = [] if related[name] == nil
+                    related[name] << :m
+                else
+                    name = n.info[:replicate]
+                    related[name] = [] if related[name] == nil
+                    related[name] << :s
+                end
+            }
+
+            # Now it's trivial to check, for each related group having the
+            # same host, what is their local score.
+            related.each{|id,types|
+                next if types.length < 2
+                types.sort! # Make sure :m if the first if any
+                if types[0] == :m
+                    score += 10000 * (types.length-1)
+                else
+                    score += 1 * types.length
+                end
+
+                # Populate the list of offending nodes
+                @nodes.each{|n|
+                    if n.info[:replicate] == id &&
+                       n.info[:host] == host
+                       offending << n
+                    end
+                }
+            }
+        }
+        return score,offending
    end

    def flush_nodes_config
@@ -1445,7 +1575,7 @@ class RedisTrib
        xputs ">>> Importing data from #{source_addr} to cluster #{argv[1]}"
        use_copy = opt['copy']
        use_replace = opt['replace']
-        
+
        # Check the existing cluster.
        load_cluster_info_from_node(argv[0])
        check_cluster
@@ -1669,7 +1799,6 @@ ALLOWED_OPTIONS={
 def show_help
    puts "Usage: redis-trib <command> <options> <arguments ...>\n\n"
    COMMANDS.each{|k,v|
-        o = ""
        puts "  #{k.ljust(15)} #{v[2]}"
        if ALLOWED_OPTIONS[k]
            ALLOWED_OPTIONS[k].each{|optname,has_arg|
@@ -41,7 +41,9 @@
 #include <unistd.h> /* for _exit() */

 #define assert(_e) ((_e)?(void)0 : (_serverAssert(#_e,__FILE__,__LINE__),_exit(1)))
+#define panic(...) _serverPanic(__FILE__,__LINE__,__VA_ARGS__),_exit(1)

 void _serverAssert(char *estr, char *file, int line);
+void _serverPanic(const char *file, int line, const char *msg, ...);

 #endif
@@ -58,6 +58,30 @@
 #define REDISMODULE_HASH_CFIELDS    (1<<2)
 #define REDISMODULE_HASH_EXISTS     (1<<3)

+/* Context Flags: Info about the current context returned by RM_GetContextFlags */
+
+/* The command is running in the context of a Lua script */
+#define REDISMODULE_CTX_FLAGS_LUA 0x0001
+/* The command is running inside a Redis transaction */
+#define REDISMODULE_CTX_FLAGS_MULTI 0x0002
+/* The instance is a master */
+#define REDISMODULE_CTX_FLAGS_MASTER 0x0004
+/* The instance is a slave */
+#define REDISMODULE_CTX_FLAGS_SLAVE 0x0008
+/* The instance is read-only (usually meaning it's a slave as well) */
+#define REDISMODULE_CTX_FLAGS_READONLY 0x0010
+/* The instance is running in cluster mode */
+#define REDISMODULE_CTX_FLAGS_CLUSTER 0x0020
+/* The instance has AOF enabled */
+#define REDISMODULE_CTX_FLAGS_AOF 0x0040 //
+/* The instance has RDB enabled */
+#define REDISMODULE_CTX_FLAGS_RDB 0x0080 //
+/* The instance has Maxmemory set */
+#define REDISMODULE_CTX_FLAGS_MAXMEMORY 0x0100
+/* Maxmemory is set and has an eviction policy that may delete keys */
+#define REDISMODULE_CTX_FLAGS_EVICT 0x0200 
+
+
 /* A special pointer that we can use between the core and the module to signal
 * field deletion, and that is impossible to be a valid pointer. */
 #define REDISMODULE_HASH_DELETE ((RedisModuleString*)(long)1)
@@ -68,6 +92,8 @@
 #define REDISMODULE_POSITIVE_INFINITE (1.0/0.0)
 #define REDISMODULE_NEGATIVE_INFINITE (-1.0/0.0)

+#define REDISMODULE_NOT_USED(V) ((void) V)
+
 /* ------------------------- End of common defines ------------------------ */

 #ifndef REDISMODULE_CORE
@@ -82,15 +108,28 @@ typedef struct RedisModuleCallReply RedisModuleCallReply;
 typedef struct RedisModuleIO RedisModuleIO;
 typedef struct RedisModuleType RedisModuleType;
 typedef struct RedisModuleDigest RedisModuleDigest;
+typedef struct RedisModuleBlockedClient RedisModuleBlockedClient;

 typedef int (*RedisModuleCmdFunc) (RedisModuleCtx *ctx, RedisModuleString **argv, int argc);

 typedef void *(*RedisModuleTypeLoadFunc)(RedisModuleIO *rdb, int encver);
 typedef void (*RedisModuleTypeSaveFunc)(RedisModuleIO *rdb, void *value);
 typedef void (*RedisModuleTypeRewriteFunc)(RedisModuleIO *aof, RedisModuleString *key, void *value);
+typedef size_t (*RedisModuleTypeMemUsageFunc)(const void *value);
 typedef void (*RedisModuleTypeDigestFunc)(RedisModuleDigest *digest, void *value);
 typedef void (*RedisModuleTypeFreeFunc)(void *value);

+#define REDISMODULE_TYPE_METHOD_VERSION 1
+typedef struct RedisModuleTypeMethods {
+    uint64_t version;
+    RedisModuleTypeLoadFunc rdb_load;
+    RedisModuleTypeSaveFunc rdb_save;
+    RedisModuleTypeRewriteFunc aof_rewrite;
+    RedisModuleTypeMemUsageFunc mem_usage;
+    RedisModuleTypeDigestFunc digest;
+    RedisModuleTypeFreeFunc free;
+} RedisModuleTypeMethods;
+
 #define REDISMODULE_GET_API(name) \
    RedisModule_GetApi("RedisModule_" #name, ((void **)&RedisModule_ ## name))

@@ -104,7 +143,8 @@ void *REDISMODULE_API_FUNC(RedisModule_Calloc)(size_t nmemb, size_t size);
 char *REDISMODULE_API_FUNC(RedisModule_Strdup)(const char *str);
 int REDISMODULE_API_FUNC(RedisModule_GetApi)(const char *, void *);
 int REDISMODULE_API_FUNC(RedisModule_CreateCommand)(RedisModuleCtx *ctx, const char *name, RedisModuleCmdFunc cmdfunc, const char *strflags, int firstkey, int lastkey, int keystep);
-int REDISMODULE_API_FUNC(RedisModule_SetModuleAttribs)(RedisModuleCtx *ctx, const char *name, int ver, int apiver);
+void REDISMODULE_API_FUNC(RedisModule_SetModuleAttribs)(RedisModuleCtx *ctx, const char *name, int ver, int apiver);
+int REDISMODULE_API_FUNC(RedisModule_IsModuleNameBusy)(const char *name);
 int REDISMODULE_API_FUNC(RedisModule_WrongArity)(RedisModuleCtx *ctx);
 int REDISMODULE_API_FUNC(RedisModule_ReplyWithLongLong)(RedisModuleCtx *ctx, long long ll);
 int REDISMODULE_API_FUNC(RedisModule_GetSelectedDb)(RedisModuleCtx *ctx);
@@ -168,8 +208,9 @@ int REDISMODULE_API_FUNC(RedisModule_HashGet)(RedisModuleKey *key, int flags, ..
 int REDISMODULE_API_FUNC(RedisModule_IsKeysPositionRequest)(RedisModuleCtx *ctx);
 void REDISMODULE_API_FUNC(RedisModule_KeyAtPos)(RedisModuleCtx *ctx, int pos);
 unsigned long long REDISMODULE_API_FUNC(RedisModule_GetClientId)(RedisModuleCtx *ctx);
+int REDISMODULE_API_FUNC(RedisModule_GetContextFlags)(RedisModuleCtx *ctx);
 void *REDISMODULE_API_FUNC(RedisModule_PoolAlloc)(RedisModuleCtx *ctx, size_t bytes);
-RedisModuleType *REDISMODULE_API_FUNC(RedisModule_CreateDataType)(RedisModuleCtx *ctx, const char *name, int encver, RedisModuleTypeLoadFunc rdb_load, RedisModuleTypeSaveFunc rdb_save, RedisModuleTypeRewriteFunc aof_rewrite, RedisModuleTypeDigestFunc digest, RedisModuleTypeFreeFunc free);
+RedisModuleType *REDISMODULE_API_FUNC(RedisModule_CreateDataType)(RedisModuleCtx *ctx, const char *name, int encver, RedisModuleTypeMethods *typemethods);
 int REDISMODULE_API_FUNC(RedisModule_ModuleTypeSetValue)(RedisModuleKey *key, RedisModuleType *mt, void *value);
 RedisModuleType *REDISMODULE_API_FUNC(RedisModule_ModuleTypeGetType)(RedisModuleKey *key);
 void *REDISMODULE_API_FUNC(RedisModule_ModuleTypeGetValue)(RedisModuleKey *key);
@@ -192,6 +233,24 @@ int REDISMODULE_API_FUNC(RedisModule_StringAppendBuffer)(RedisModuleCtx *ctx, Re
 void REDISMODULE_API_FUNC(RedisModule_RetainString)(RedisModuleCtx *ctx, RedisModuleString *str);
 int REDISMODULE_API_FUNC(RedisModule_StringCompare)(RedisModuleString *a, RedisModuleString *b);
 RedisModuleCtx *REDISMODULE_API_FUNC(RedisModule_GetContextFromIO)(RedisModuleIO *io);
+long long REDISMODULE_API_FUNC(RedisModule_Milliseconds)(void);
+void REDISMODULE_API_FUNC(RedisModule_DigestAddStringBuffer)(RedisModuleDigest *md, unsigned char *ele, size_t len);
+void REDISMODULE_API_FUNC(RedisModule_DigestAddLongLong)(RedisModuleDigest *md, long long ele);
+void REDISMODULE_API_FUNC(RedisModule_DigestEndSequence)(RedisModuleDigest *md);
+
+/* Experimental APIs */
+#ifdef REDISMODULE_EXPERIMENTAL_API
+RedisModuleBlockedClient *REDISMODULE_API_FUNC(RedisModule_BlockClient)(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(void*), long long timeout_ms);
+int REDISMODULE_API_FUNC(RedisModule_UnblockClient)(RedisModuleBlockedClient *bc, void *privdata);
+int REDISMODULE_API_FUNC(RedisModule_IsBlockedReplyRequest)(RedisModuleCtx *ctx);
+int REDISMODULE_API_FUNC(RedisModule_IsBlockedTimeoutRequest)(RedisModuleCtx *ctx);
+void *REDISMODULE_API_FUNC(RedisModule_GetBlockedClientPrivateData)(RedisModuleCtx *ctx);
+int REDISMODULE_API_FUNC(RedisModule_AbortBlock)(RedisModuleBlockedClient *bc);
+RedisModuleCtx *REDISMODULE_API_FUNC(RedisModule_GetThreadSafeContext)(RedisModuleBlockedClient *bc);
+void REDISMODULE_API_FUNC(RedisModule_FreeThreadSafeContext)(RedisModuleCtx *ctx);
+void REDISMODULE_API_FUNC(RedisModule_ThreadSafeContextLock)(RedisModuleCtx *ctx);
+void REDISMODULE_API_FUNC(RedisModule_ThreadSafeContextUnlock)(RedisModuleCtx *ctx);
+#endif

 /* This is included inline inside each Redis module. */
 static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int apiver) __attribute__((unused));
@@ -205,6 +264,7 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
    REDISMODULE_GET_API(Strdup);
    REDISMODULE_GET_API(CreateCommand);
    REDISMODULE_GET_API(SetModuleAttribs);
+    REDISMODULE_GET_API(IsModuleNameBusy);
    REDISMODULE_GET_API(WrongArity);
    REDISMODULE_GET_API(ReplyWithLongLong);
    REDISMODULE_GET_API(ReplyWithError);
@@ -269,6 +329,7 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
    REDISMODULE_GET_API(IsKeysPositionRequest);
    REDISMODULE_GET_API(KeyAtPos);
    REDISMODULE_GET_API(GetClientId);
+    REDISMODULE_GET_API(GetContextFlags);
    REDISMODULE_GET_API(PoolAlloc);
    REDISMODULE_GET_API(CreateDataType);
    REDISMODULE_GET_API(ModuleTypeSetValue);
@@ -293,7 +354,25 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
    REDISMODULE_GET_API(RetainString);
    REDISMODULE_GET_API(StringCompare);
    REDISMODULE_GET_API(GetContextFromIO);
+    REDISMODULE_GET_API(Milliseconds);
+    REDISMODULE_GET_API(DigestAddStringBuffer);
+    REDISMODULE_GET_API(DigestAddLongLong);
+    REDISMODULE_GET_API(DigestEndSequence);

+#ifdef REDISMODULE_EXPERIMENTAL_API
+    REDISMODULE_GET_API(GetThreadSafeContext);
+    REDISMODULE_GET_API(FreeThreadSafeContext);
+    REDISMODULE_GET_API(ThreadSafeContextLock);
+    REDISMODULE_GET_API(ThreadSafeContextUnlock);
+    REDISMODULE_GET_API(BlockClient);
+    REDISMODULE_GET_API(UnblockClient);
+    REDISMODULE_GET_API(IsBlockedReplyRequest);
+    REDISMODULE_GET_API(IsBlockedTimeoutRequest);
+    REDISMODULE_GET_API(GetBlockedClientPrivateData);
+    REDISMODULE_GET_API(AbortBlock);
+#endif
+
+    if (RedisModule_IsModuleNameBusy(name)) return REDISMODULE_ERR;
    RedisModule_SetModuleAttribs(ctx,name,ver,apiver);
    return REDISMODULE_OK;
 }
@@ -79,11 +79,6 @@ void createReplicationBacklog(void) {
    server.repl_backlog = zmalloc(server.repl_backlog_size);
    server.repl_backlog_histlen = 0;
    server.repl_backlog_idx = 0;
-    /* When a new backlog buffer is created, we increment the replication
-     * offset by one to make sure we'll not be able to PSYNC with any
-     * previous slave. This is needed because we avoid incrementing the
-     * master_repl_offset if no backlog exists nor slaves are attached. */
-    server.master_repl_offset++;

    /* We don't have any data inside our buffer, but virtually the first
     * byte we have is the next byte that will be generated for the
@@ -127,7 +122,7 @@ void freeReplicationBacklog(void) {
 /* Add data to the replication backlog.
 * This function also increments the global replication offset stored at
 * server.master_repl_offset, because there is no case where we want to feed
- * the backlog without incrementing the buffer. */
+ * the backlog without incrementing the offset. */
 void feedReplicationBacklog(void *ptr, size_t len) {
    unsigned char *p = ptr;

@@ -170,12 +165,24 @@ void feedReplicationBacklogWithObject(robj *o) {
    feedReplicationBacklog(p,len);
 }

+/* Propagate write commands to slaves, and populate the replication backlog
+ * as well. This function is used if the instance is a master: we use
+ * the commands received by our clients in order to create the replication
+ * stream. Instead if the instance is a slave and has sub-slaves attached,
+ * we use replicationFeedSlavesFromMaster() */
 void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
    listNode *ln;
    listIter li;
    int j, len;
    char llstr[LONG_STR_SIZE];

+    /* If the instance is not a top level master, return ASAP: we'll just proxy
+     * the stream of data we receive from our master instead, in order to
+     * propagate *identical* replication stream. In this way this slave can
+     * advertise the same replication ID as the master (since it shares the
+     * master replication history and has the same backlog and offsets). */
+    if (server.masterhost != NULL) return;
+
    /* If there aren't slaves, and there is no backlog buffer to populate,
     * we can return ASAP. */
    if (server.repl_backlog == NULL && listLength(slaves) == 0) return;
@@ -244,7 +251,7 @@ void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
    }

    /* Write the command to every slave. */
-    listRewind(server.slaves,&li);
+    listRewind(slaves,&li);
    while((ln = listNext(&li))) {
        client *slave = ln->value;

@@ -265,6 +272,34 @@ void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
    }
 }

+/* This function is used in order to proxy what we receive from our master
+ * to our sub-slaves. */
+#include <ctype.h>
+void replicationFeedSlavesFromMasterStream(list *slaves, char *buf, size_t buflen) {
+    listNode *ln;
+    listIter li;
+
+    /* Debugging: this is handy to see the stream sent from master
+     * to slaves. Disabled with if(0). */
+    if (0) {
+        printf("%zu:",buflen);
+        for (size_t j = 0; j < buflen; j++) {
+            printf("%c", isprint(buf[j]) ? buf[j] : '.');
+        }
+        printf("\n");
+    }
+
+    if (server.repl_backlog) feedReplicationBacklog(buf,buflen);
+    listRewind(slaves,&li);
+    while((ln = listNext(&li))) {
+        client *slave = ln->value;
+
+        /* Don't feed slaves that are still waiting for BGSAVE to start */
+        if (slave->replstate == SLAVE_STATE_WAIT_BGSAVE_START) continue;
+        addReplyString(slave,buf,buflen);
+    }
+}
+
 void replicationFeedMonitors(client *c, list *monitors, int dictid, robj **argv, int argc) {
    listNode *ln;
    listIter li;
@@ -329,7 +364,7 @@ long long addReplyReplicationBacklog(client *c, long long offset) {
    skip = offset - server.repl_backlog_off;
    serverLog(LL_DEBUG, "[PSYNC] Skipping: %lld", skip);

-    /* Point j to the oldest byte, that is actaully our
+    /* Point j to the oldest byte, that is actually our
     * server.repl_backlog_off byte. */
    j = (server.repl_backlog_idx +
        (server.repl_backlog_size-server.repl_backlog_histlen)) %
@@ -361,18 +396,14 @@ long long addReplyReplicationBacklog(client *c, long long offset) {
 * the BGSAVE process started and before executing any other command
 * from clients. */
 long long getPsyncInitialOffset(void) {
-    long long psync_offset = server.master_repl_offset;
-    /* Add 1 to psync_offset if it the replication backlog does not exists
-     * as when it will be created later we'll increment the offset by one. */
-    if (server.repl_backlog == NULL) psync_offset++;
-    return psync_offset;
+    return server.master_repl_offset;
 }

 /* Send a FULLRESYNC reply in the specific case of a full resynchronization,
 * as a side effect setup the slave for a full sync in different ways:
 *
- * 1) Remember, into the slave client structure, the offset we sent
- *    here, so that if new slaves will later attach to the same
+ * 1) Remember, into the slave client structure, the replication offset
+ *    we sent here, so that if new slaves will later attach to the same
 *    background RDB saving process (by duplicating this client output
 *    buffer), we can get the right offset from this slave.
 * 2) Set the replication state of the slave to WAIT_BGSAVE_END so that
@@ -392,14 +423,14 @@ int replicationSetupSlaveForFullResync(client *slave, long long offset) {
    slave->replstate = SLAVE_STATE_WAIT_BGSAVE_END;
    /* We are going to accumulate the incremental changes for this
     * slave as well. Set slaveseldb to -1 in order to force to re-emit
-     * a SLEECT statement in the replication stream. */
+     * a SELECT statement in the replication stream. */
    server.slaveseldb = -1;

    /* Don't send this reply to slaves that approached us with
     * the old SYNC command. */
    if (!(slave->flags & CLIENT_PRE_PSYNC)) {
        buflen = snprintf(buf,sizeof(buf),"+FULLRESYNC %s %lld\r\n",
-                          server.runid,offset);
+                          server.replid,offset);
        if (write(slave->fd,buf,buflen) != buflen) {
            freeClientAsync(slave);
            return C_ERR;
@@ -415,19 +446,40 @@ int replicationSetupSlaveForFullResync(client *slave, long long offset) {
 * with the usual full resync. */
 int masterTryPartialResynchronization(client *c) {
    long long psync_offset, psync_len;
-    char *master_runid = c->argv[1]->ptr;
+    char *master_replid = c->argv[1]->ptr;
    char buf[128];
    int buflen;

-    /* Is the runid of this master the same advertised by the wannabe slave
-     * via PSYNC? If runid changed this master is a different instance and
-     * there is no way to continue. */
-    if (strcasecmp(master_runid, server.runid)) {
+    /* Parse the replication offset asked by the slave. Go to full sync
+     * on parse error: this should never happen but we try to handle
+     * it in a robust way compared to aborting. */
+    if (getLongLongFromObjectOrReply(c,c->argv[2],&psync_offset,NULL) !=
+       C_OK) goto need_full_resync;
+
+    /* Is the replication ID of this master the same advertised by the wannabe
+     * slave via PSYNC? If the replication ID changed this master has a
+     * different replication history, and there is no way to continue.
+     *
+     * Note that there are two potentially valid replication IDs: the ID1
+     * and the ID2. The ID2 however is only valid up to a specific offset. */
+    if (strcasecmp(master_replid, server.replid) &&
+        (strcasecmp(master_replid, server.replid2) ||
+         psync_offset > server.second_replid_offset))
+    {
        /* Run id "?" is used by slaves that want to force a full resync. */
-        if (master_runid[0] != '?') {
-            serverLog(LL_NOTICE,"Partial resynchronization not accepted: "
-                "Runid mismatch (Client asked for runid '%s', my runid is '%s')",
-                master_runid, server.runid);
+        if (master_replid[0] != '?') {
+            if (strcasecmp(master_replid, server.replid) &&
+                strcasecmp(master_replid, server.replid2))
+            {
+                serverLog(LL_NOTICE,"Partial resynchronization not accepted: "
+                    "Replication ID mismatch (Slave asked for '%s', my "
+                    "replication IDs are '%s' and '%s')",
+                    master_replid, server.replid, server.replid2);
+            } else {
+                serverLog(LL_NOTICE,"Partial resynchronization not accepted: "
+                    "Requested offset for second ID was %lld, but I can reply "
+                    "up to %lld", psync_offset, server.second_replid_offset);
+            }
        } else {
            serverLog(LL_NOTICE,"Full resync requested by slave %s",
                replicationGetSlaveName(c));
@@ -436,8 +488,6 @@ int masterTryPartialResynchronization(client *c) {
    }

    /* We still have the data our slave is asking for? */
-    if (getLongLongFromObjectOrReply(c,c->argv[2],&psync_offset,NULL) !=
-       C_OK) goto need_full_resync;
    if (!server.repl_backlog ||
        psync_offset < server.repl_backlog_off ||
        psync_offset > (server.repl_backlog_off + server.repl_backlog_histlen))
@@ -463,7 +513,11 @@ int masterTryPartialResynchronization(client *c) {
    /* We can't use the connection buffers since they are used to accumulate
     * new commands at this stage. But we are sure the socket send buffer is
     * empty so this write will never fail actually. */
-    buflen = snprintf(buf,sizeof(buf),"+CONTINUE\r\n");
+    if (c->slave_capa & SLAVE_CAPA_PSYNC2) {
+        buflen = snprintf(buf,sizeof(buf),"+CONTINUE %s\r\n", server.replid);
+    } else {
+        buflen = snprintf(buf,sizeof(buf),"+CONTINUE\r\n");
+    }
    if (write(c->fd,buf,buflen) != buflen) {
        freeClientAsync(c);
        return C_OK;
@@ -515,10 +569,19 @@ int startBgsaveForReplication(int mincapa) {
    serverLog(LL_NOTICE,"Starting BGSAVE for SYNC with target: %s",
        socket_target ? "slaves sockets" : "disk");

-    if (socket_target)
-        retval = rdbSaveToSlavesSockets();
-    else
-        retval = rdbSaveBackground(server.rdb_filename);
+    rdbSaveInfo rsi, *rsiptr;
+    rsiptr = rdbPopulateSaveInfo(&rsi);
+    /* Only do rdbSave* when rsiptr is not NULL,
+     * otherwise slave will miss repl-stream-db. */
+    if (rsiptr) {
+        if (socket_target)
+            retval = rdbSaveToSlavesSockets(rsiptr);
+        else
+            retval = rdbSaveBackground(server.rdb_filename,rsiptr);
+    } else {
+        serverLog(LL_WARNING,"BGSAVE for replication: replication information not available, can't generate the RDB file right now. Try later.");
+        retval = C_ERR;
+    }

    /* If we failed to BGSAVE, remove the slaves waiting for a full
     * resynchorinization from the list of salves, inform them with
@@ -568,7 +631,7 @@ void syncCommand(client *c) {
    /* Refuse SYNC requests if we are a slave but the link with our master
     * is not ok... */
    if (server.masterhost && server.repl_state != REPL_STATE_CONNECTED) {
-        addReplyError(c,"Can't SYNC while not connected with my master");
+        addReplySds(c,sdsnew("-NOMASTERLINK Can't SYNC while not connected with my master\r\n"));
        return;
    }

@@ -589,22 +652,22 @@ void syncCommand(client *c) {
     * when this happens masterTryPartialResynchronization() already
     * replied with:
     *
-     * +FULLRESYNC <runid> <offset>
+     * +FULLRESYNC <replid> <offset>
     *
-     * So the slave knows the new runid and offset to try a PSYNC later
+     * So the slave knows the new replid and offset to try a PSYNC later
     * if the connection with the master is lost. */
    if (!strcasecmp(c->argv[0]->ptr,"psync")) {
        if (masterTryPartialResynchronization(c) == C_OK) {
            server.stat_sync_partial_ok++;
            return; /* No full resync needed, return. */
        } else {
-            char *master_runid = c->argv[1]->ptr;
+            char *master_replid = c->argv[1]->ptr;

            /* Increment stats for failed PSYNCs, but only if the
-             * runid is not "?", as this is used by slaves to force a full
+             * replid is not "?", as this is used by slaves to force a full
             * resync on purpose when they are not albe to partially
             * resync. */
-            if (master_runid[0] != '?') server.stat_sync_partial_err++;
+            if (master_replid[0] != '?') server.stat_sync_partial_err++;
        }
    } else {
        /* If a slave uses SYNC, we are dealing with an old implementation
@@ -625,6 +688,16 @@ void syncCommand(client *c) {
    c->flags |= CLIENT_SLAVE;
    listAddNodeTail(server.slaves,c);

+    /* Create the replication backlog if needed. */
+    if (listLength(server.slaves) == 1 && server.repl_backlog == NULL) {
+        /* When we create the backlog from scratch, we always use a new
+         * replication ID and clear the ID2, since there is no valid
+         * past history. */
+        changeReplicationId();
+        clearReplicationId2();
+        createReplicationBacklog();
+    }
+
    /* CASE 1: BGSAVE is in progress, with disk target. */
    if (server.rdb_child_pid != -1 &&
        server.rdb_child_type == RDB_CHILD_TYPE_DISK)
@@ -685,9 +758,6 @@ void syncCommand(client *c) {
            }
        }
    }
-
-    if (listLength(server.slaves) == 1 && server.repl_backlog == NULL)
-        createReplicationBacklog();
    return;
 }

@@ -735,6 +805,8 @@ void replconfCommand(client *c) {
            /* Ignore capabilities not understood by this master. */
            if (!strcasecmp(c->argv[j+1]->ptr,"eof"))
                c->slave_capa |= SLAVE_CAPA_EOF;
+            else if (!strcasecmp(c->argv[j+1]->ptr,"psync2"))
+                c->slave_capa |= SLAVE_CAPA_PSYNC2;
        } else if (!strcasecmp(c->argv[j]->ptr,"ack")) {
            /* REPLCONF ACK is used by slave to inform the master the amount
             * of replication stream that it processed so far. It is an
@@ -758,7 +830,7 @@ void replconfCommand(client *c) {
            /* REPLCONF GETACK is used in order to request an ACK ASAP
             * to the slave. */
            if (server.masterhost && server.master) replicationSendAck();
-            /* Note: this command does not reply anything! */
+            return;
        } else {
            addReplyErrorFormat(c,"Unrecognized REPLCONF option: %s",
                (char*)c->argv[j]->ptr);
@@ -928,6 +1000,43 @@ void updateSlavesWaitingBgsave(int bgsaveerr, int type) {
    if (startbgsave) startBgsaveForReplication(mincapa);
 }

+/* Change the current instance replication ID with a new, random one.
+ * This will prevent successful PSYNCs between this master and other
+ * slaves, so the command should be called when something happens that
+ * alters the current story of the dataset. */
+void changeReplicationId(void) {
+    getRandomHexChars(server.replid,CONFIG_RUN_ID_SIZE);
+    server.replid[CONFIG_RUN_ID_SIZE] = '\0';
+}
+
+/* Clear (invalidate) the secondary replication ID. This happens, for
+ * example, after a full resynchronization, when we start a new replication
+ * history. */
+void clearReplicationId2(void) {
+    memset(server.replid2,'0',sizeof(server.replid));
+    server.replid2[CONFIG_RUN_ID_SIZE] = '\0';
+    server.second_replid_offset = -1;
+}
+
+/* Use the current replication ID / offset as secondary replication
+ * ID, and change the current one in order to start a new history.
+ * This should be used when an instance is switched from slave to master
+ * so that it can serve PSYNC requests performed using the master
+ * replication ID. */
+void shiftReplicationId(void) {
+    memcpy(server.replid2,server.replid,sizeof(server.replid));
+    /* We set the second replid offset to the master offset + 1, since
+     * the slave will ask for the first byte it has not yet received, so
+     * we need to add one to the offset: for example if, as a slave, we are
+     * sure we have the same history as the master for 50 bytes, after we
+     * are turned into a master, we can accept a PSYNC request with offset
+     * 51, since the slave asking has the same history up to the 50th
+     * byte, and is asking for the new bytes starting at offset 51. */
+    server.second_replid_offset = server.master_repl_offset+1;
+    changeReplicationId();
+    serverLog(LL_WARNING,"Setting secondary replication ID to %s, valid up to offset: %lld. New replication ID is %s", server.replid2, server.second_replid_offset, server.replid);
+}
+
 /* ----------------------------------- SLAVE -------------------------------- */

 /* Returns 1 if the given replication state is a handshake state,
@@ -965,18 +1074,31 @@ void replicationEmptyDbCallback(void *privdata) {
 /* Once we have a link with the master and the synchroniziation was
 * performed, this function materializes the master client we store
 * at server.master, starting from the specified file descriptor. */
-void replicationCreateMasterClient(int fd) {
+void replicationCreateMasterClient(int fd, int dbid) {
    server.master = createClient(fd);
    server.master->flags |= CLIENT_MASTER;
    server.master->authenticated = 1;
-    server.repl_state = REPL_STATE_CONNECTED;
-    server.master->reploff = server.repl_master_initial_offset;
-    memcpy(server.master->replrunid, server.repl_master_runid,
-        sizeof(server.repl_master_runid));
+    server.master->reploff = server.master_initial_offset;
+    server.master->read_reploff = server.master->reploff;
+    memcpy(server.master->replid, server.master_replid,
+        sizeof(server.master_replid));
    /* If master offset is set to -1, this master is old and is not
     * PSYNC capable, so we flag it accordingly. */
    if (server.master->reploff == -1)
        server.master->flags |= CLIENT_PRE_PSYNC;
+    if (dbid != -1) selectDb(server.master,dbid);
+}
+
+void restartAOF() {
+    int retry = 10;
+    while (retry-- && startAppendOnly() == C_ERR) {
+        serverLog(LL_WARNING,"Failed enabling the AOF after successful master synchronization! Trying it again in one second.");
+        sleep(1);
+    }
+    if (!retry) {
+        serverLog(LL_WARNING,"FATAL: this slave instance finished the synchronization with its master, but the AOF can't be turned on. Exiting now.");
+        exit(1);
+    }
 }

 /* Asynchronously read the SYNC payload we receive from a master */
@@ -1120,12 +1242,17 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
    }

    if (eof_reached) {
+        int aof_is_enabled = server.aof_state != AOF_OFF;
+
        if (rename(server.repl_transfer_tmpfile,server.rdb_filename) == -1) {
            serverLog(LL_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> SLAVE synchronization: %s", strerror(errno));
            cancelReplicationHandshake();
            return;
        }
        serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Flushing old data");
+        /* We need to stop any AOFRW fork before flusing and parsing
+         * RDB, otherwise we'll create a copy-on-write disaster. */
+        if(aof_is_enabled) stopAppendOnly();
        signalFlushedDb(-1);
        emptyDb(
            -1,
@@ -1137,34 +1264,38 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
         * time for non blocking loading. */
        aeDeleteFileEvent(server.el,server.repl_transfer_s,AE_READABLE);
        serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Loading DB in memory");
-        if (rdbLoad(server.rdb_filename) != C_OK) {
+        rdbSaveInfo rsi = RDB_SAVE_INFO_INIT;
+        if (rdbLoad(server.rdb_filename,&rsi) != C_OK) {
            serverLog(LL_WARNING,"Failed trying to load the MASTER synchronization DB from disk");
            cancelReplicationHandshake();
+            /* Re-enable the AOF if we disabled it earlier, in order to restore
+             * the original configuration. */
+            if (aof_is_enabled) restartAOF();
            return;
        }
        /* Final setup of the connected slave <- master link */
        zfree(server.repl_transfer_tmpfile);
        close(server.repl_transfer_fd);
-        replicationCreateMasterClient(server.repl_transfer_s);
+        replicationCreateMasterClient(server.repl_transfer_s,rsi.repl_stream_db);
+        server.repl_state = REPL_STATE_CONNECTED;
+        /* After a full resynchroniziation we use the replication ID and
+         * offset of the master. The secondary ID / offset are cleared since
+         * we are starting a new history. */
+        memcpy(server.replid,server.master->replid,sizeof(server.replid));
+        server.master_repl_offset = server.master->reploff;
+        clearReplicationId2();
+        /* Let's create the replication backlog if needed. Slaves need to
+         * accumulate the backlog regardless of the fact they have sub-slaves
+         * or not, in order to behave correctly if they are promoted to
+         * masters after a failover. */
+        if (server.repl_backlog == NULL) createReplicationBacklog();
+
        serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Finished with success");
        /* Restart the AOF subsystem now that we finished the sync. This
         * will trigger an AOF rewrite, and when done will start appending
         * to the new file. */
-        if (server.aof_state != AOF_OFF) {
-            int retry = 10;
-
-            stopAppendOnly();
-            while (retry-- && startAppendOnly() == C_ERR) {
-                serverLog(LL_WARNING,"Failed enabling the AOF after successful master synchronization! Trying it again in one second.");
-                sleep(1);
-            }
-            if (!retry) {
-                serverLog(LL_WARNING,"FATAL: this slave instance finished the synchronization with its master, but the AOF can't be turned on. Exiting now.");
-                exit(1);
-            }
-        }
+        if (aof_is_enabled) restartAOF();
    }
-
    return;

 error:
@@ -1263,14 +1394,15 @@ char *sendSynchronousCommand(int flags, int fd, ...) {
 *                   offset is saved.
 * PSYNC_NOT_SUPPORTED: If the server does not understand PSYNC at all and
 *                      the caller should fall back to SYNC.
- * PSYNC_WRITE_ERR: There was an error writing the command to the socket.
+ * PSYNC_WRITE_ERROR: There was an error writing the command to the socket.
 * PSYNC_WAIT_REPLY: Call again the function with read_reply set to 1.
+ * PSYNC_TRY_LATER: Master is currently in a transient error condition.
 *
 * Notable side effects:
 *
 * 1) As a side effect of the function call the function removes the readable
 *    event handler from "fd", unless the return value is PSYNC_WAIT_REPLY.
- * 2) server.repl_master_initial_offset is set to the right value according
+ * 2) server.master_initial_offset is set to the right value according
 *    to the master reply. This will be used to populate the 'server.master'
 *    structure replication offset.
 */
@@ -1280,32 +1412,33 @@ char *sendSynchronousCommand(int flags, int fd, ...) {
 #define PSYNC_CONTINUE 2
 #define PSYNC_FULLRESYNC 3
 #define PSYNC_NOT_SUPPORTED 4
+#define PSYNC_TRY_LATER 5
 int slaveTryPartialResynchronization(int fd, int read_reply) {
-    char *psync_runid;
+    char *psync_replid;
    char psync_offset[32];
    sds reply;

    /* Writing half */
    if (!read_reply) {
-        /* Initially set repl_master_initial_offset to -1 to mark the current
+        /* Initially set master_initial_offset to -1 to mark the current
         * master run_id and offset as not valid. Later if we'll be able to do
         * a FULL resync using the PSYNC command we'll set the offset at the
         * right value, so that this information will be propagated to the
         * client structure representing the master into server.master. */
-        server.repl_master_initial_offset = -1;
+        server.master_initial_offset = -1;

        if (server.cached_master) {
-            psync_runid = server.cached_master->replrunid;
+            psync_replid = server.cached_master->replid;
            snprintf(psync_offset,sizeof(psync_offset),"%lld", server.cached_master->reploff+1);
-            serverLog(LL_NOTICE,"Trying a partial resynchronization (request %s:%s).", psync_runid, psync_offset);
+            serverLog(LL_NOTICE,"Trying a partial resynchronization (request %s:%s).", psync_replid, psync_offset);
        } else {
            serverLog(LL_NOTICE,"Partial resynchronization not possible (no cached master)");
-            psync_runid = "?";
+            psync_replid = "?";
            memcpy(psync_offset,"-1",3);
        }

        /* Issue the PSYNC command */
-        reply = sendSynchronousCommand(SYNC_CMD_WRITE,fd,"PSYNC",psync_runid,psync_offset,NULL);
+        reply = sendSynchronousCommand(SYNC_CMD_WRITE,fd,"PSYNC",psync_replid,psync_offset,NULL);
        if (reply != NULL) {
            serverLog(LL_WARNING,"Unable to send PSYNC to master: %s",reply);
            sdsfree(reply);
@@ -1327,31 +1460,31 @@ int slaveTryPartialResynchronization(int fd, int read_reply) {
    aeDeleteFileEvent(server.el,fd,AE_READABLE);

    if (!strncmp(reply,"+FULLRESYNC",11)) {
-        char *runid = NULL, *offset = NULL;
+        char *replid = NULL, *offset = NULL;

        /* FULL RESYNC, parse the reply in order to extract the run id
         * and the replication offset. */
-        runid = strchr(reply,' ');
-        if (runid) {
-            runid++;
-            offset = strchr(runid,' ');
+        replid = strchr(reply,' ');
+        if (replid) {
+            replid++;
+            offset = strchr(replid,' ');
            if (offset) offset++;
        }
-        if (!runid || !offset || (offset-runid-1) != CONFIG_RUN_ID_SIZE) {
+        if (!replid || !offset || (offset-replid-1) != CONFIG_RUN_ID_SIZE) {
            serverLog(LL_WARNING,
                "Master replied with wrong +FULLRESYNC syntax.");
            /* This is an unexpected condition, actually the +FULLRESYNC
             * reply means that the master supports PSYNC, but the reply
             * format seems wrong. To stay safe we blank the master
-             * runid to make sure next PSYNCs will fail. */
-            memset(server.repl_master_runid,0,CONFIG_RUN_ID_SIZE+1);
+             * replid to make sure next PSYNCs will fail. */
+            memset(server.master_replid,0,CONFIG_RUN_ID_SIZE+1);
        } else {
-            memcpy(server.repl_master_runid, runid, offset-runid-1);
-            server.repl_master_runid[CONFIG_RUN_ID_SIZE] = '\0';
-            server.repl_master_initial_offset = strtoll(offset,NULL,10);
+            memcpy(server.master_replid, replid, offset-replid-1);
+            server.master_replid[CONFIG_RUN_ID_SIZE] = '\0';
+            server.master_initial_offset = strtoll(offset,NULL,10);
            serverLog(LL_NOTICE,"Full resync from master: %s:%lld",
-                server.repl_master_runid,
-                server.repl_master_initial_offset);
+                server.master_replid,
+                server.master_initial_offset);
        }
        /* We are going to full resync, discard the cached master structure. */
        replicationDiscardCachedMaster();
@@ -1360,17 +1493,69 @@ int slaveTryPartialResynchronization(int fd, int read_reply) {
    }

    if (!strncmp(reply,"+CONTINUE",9)) {
-        /* Partial resync was accepted, set the replication state accordingly */
+        /* Partial resync was accepted. */
        serverLog(LL_NOTICE,
            "Successful partial resynchronization with master.");
+
+        /* Check the new replication ID advertised by the master. If it
+         * changed, we need to set the new ID as primary ID, and set or
+         * secondary ID as the old master ID up to the current offset, so
+         * that our sub-slaves will be able to PSYNC with us after a
+         * disconnection. */
+        char *start = reply+10;
+        char *end = reply+9;
+        while(end[0] != '\r' && end[0] != '\n' && end[0] != '\0') end++;
+        if (end-start == CONFIG_RUN_ID_SIZE) {
+            char new[CONFIG_RUN_ID_SIZE+1];
+            memcpy(new,start,CONFIG_RUN_ID_SIZE);
+            new[CONFIG_RUN_ID_SIZE] = '\0';
+
+            if (strcmp(new,server.cached_master->replid)) {
+                /* Master ID changed. */
+                serverLog(LL_WARNING,"Master replication ID changed to %s",new);
+
+                /* Set the old ID as our ID2, up to the current offset+1. */
+                memcpy(server.replid2,server.cached_master->replid,
+                    sizeof(server.replid2));
+                server.second_replid_offset = server.master_repl_offset+1;
+
+                /* Update the cached master ID and our own primary ID to the
+                 * new one. */
+                memcpy(server.replid,new,sizeof(server.replid));
+                memcpy(server.cached_master->replid,new,sizeof(server.replid));
+
+                /* Disconnect all the sub-slaves: they need to be notified. */
+                disconnectSlaves();
+            }
+        }
+
+        /* Setup the replication to continue. */
        sdsfree(reply);
        replicationResurrectCachedMaster(fd);
+
+        /* If this instance was restarted and we read the metadata to
+         * PSYNC from the persistence file, our replication backlog could
+         * be still not initialized. Create it. */
+        if (server.repl_backlog == NULL) createReplicationBacklog();
        return PSYNC_CONTINUE;
    }

-    /* If we reach this point we received either an error since the master does
-     * not understand PSYNC, or an unexpected reply from the master.
-     * Return PSYNC_NOT_SUPPORTED to the caller in both cases. */
+    /* If we reach this point we received either an error (since the master does
+     * not understand PSYNC or because it is in a special state and cannot
+     * serve our request), or an unexpected reply from the master.
+     *
+     * Return PSYNC_NOT_SUPPORTED on errors we don't understand, otherwise
+     * return PSYNC_TRY_LATER if we believe this is a transient error. */
+
+    if (!strncmp(reply,"-NOMASTERLINK",13) ||
+        !strncmp(reply,"-LOADING",8))
+    {
+        serverLog(LL_NOTICE,
+            "Master is currently unable to PSYNC "
+            "but should be in the future: %s", reply);
+        sdsfree(reply);
+        return PSYNC_TRY_LATER;
+    }

    if (strncmp(reply,"-ERR",4)) {
        /* If it's not an error, log the unexpected event. */
@@ -1386,9 +1571,11 @@ int slaveTryPartialResynchronization(int fd, int read_reply) {
    return PSYNC_NOT_SUPPORTED;
 }

+/* This handler fires when the non blocking connect was able to
+ * establish a connection with the master. */
 void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {
    char tmpfile[256], *err = NULL;
-    int dfd, maxtries = 5;
+    int dfd = -1, maxtries = 5;
    int sockerr = 0, psync_result;
    socklen_t errlen = sizeof(sockerr);
    UNUSED(el);
@@ -1402,7 +1589,8 @@ void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {
        return;
    }

-    /* Check for errors in the socket. */
+    /* Check for errors in the socket: after a non blocking connect() we
+     * may find that the socket is in error state. */
    if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &sockerr, &errlen) == -1)
        sockerr = errno;
    if (sockerr) {
@@ -1531,13 +1719,15 @@ void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {
        server.repl_state = REPL_STATE_SEND_CAPA;
    }

-    /* Inform the master of our capabilities. While we currently send
-     * just one capability, it is possible to chain new capabilities here
-     * in the form of REPLCONF capa X capa Y capa Z ...
+    /* Inform the master of our (slave) capabilities.
+     *
+     * EOF: supports EOF-style RDB transfer for diskless replication.
+     * PSYNC2: supports PSYNC v2, so understands +CONTINUE <new repl ID>.
+     *
     * The master will ignore capabilities it does not understand. */
    if (server.repl_state == REPL_STATE_SEND_CAPA) {
        err = sendSynchronousCommand(SYNC_CMD_WRITE,fd,"REPLCONF",
-                "capa","eof",NULL);
+                "capa","eof","capa","psync2",NULL);
        if (err) goto write_error;
        sdsfree(err);
        server.repl_state = REPL_STATE_RECEIVE_CAPA;
@@ -1582,6 +1772,12 @@ void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {
    psync_result = slaveTryPartialResynchronization(fd,1);
    if (psync_result == PSYNC_WAIT_REPLY) return; /* Try again later... */

+    /* If the master is in an transient error, we should try to PSYNC
+     * from scratch later, so go to the error path. This happens when
+     * the server is loading the dataset or is not connected with its
+     * master and so forth. */
+    if (psync_result == PSYNC_TRY_LATER) goto error;
+
    /* Note: if PSYNC does not return WAIT_REPLY, it will take care of
     * uninstalling the read handler from the file descriptor. */

@@ -1591,14 +1787,14 @@ void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {
    }

    /* PSYNC failed or is not supported: we want our slaves to resync with us
-     * as well, if we have any (chained replication case). The mater may
-     * transfer us an entirely different data set and we have no way to
-     * incrementally feed our slaves after that. */
+     * as well, if we have any sub-slaves. The master may transfer us an
+     * entirely different data set and we have no way to incrementally feed
+     * our slaves after that. */
    disconnectSlaves(); /* Force our slaves to resync with us as well. */
    freeReplicationBacklog(); /* Don't allow our chained slaves to PSYNC. */

    /* Fall back to SYNC if needed. Otherwise psync_result == PSYNC_FULLRESYNC
-     * and the server.repl_master_runid and repl_master_initial_offset are
+     * and the server.master_replid and master_initial_offset are
     * already populated. */
    if (psync_result == PSYNC_NOT_SUPPORTED) {
        serverLog(LL_NOTICE,"Retrying with SYNC...");
@@ -1643,6 +1839,7 @@ void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {

 error:
    aeDeleteFileEvent(server.el,fd,AE_READABLE|AE_WRITABLE);
+    if (dfd != -1) close(dfd);
    close(fd);
    server.repl_transfer_s = -1;
    server.repl_state = REPL_STATE_CONNECT;
@@ -1727,17 +1924,24 @@ int cancelReplicationHandshake(void) {

 /* Set replication to the specified master address and port. */
 void replicationSetMaster(char *ip, int port) {
+    int was_master = server.masterhost == NULL;
+
    sdsfree(server.masterhost);
    server.masterhost = sdsnew(ip);
    server.masterport = port;
-    if (server.master) freeClient(server.master);
+    if (server.master) {
+        freeClient(server.master);
+    }
    disconnectAllBlockedClients(); /* Clients blocked in master, now slave. */
-    disconnectSlaves(); /* Force our slaves to resync with us as well. */
-    replicationDiscardCachedMaster(); /* Don't try a PSYNC. */
-    freeReplicationBacklog(); /* Don't allow our chained slaves to PSYNC. */
+
+    /* Force our slaves to resync with us as well. They may hopefully be able
+     * to partially resync with us, but we can notify the replid change. */
+    disconnectSlaves();
    cancelReplicationHandshake();
+    /* Before destroying our master state, create a cached master using
+     * our own parameters, to later PSYNC with the new master. */
+    if (was_master) replicationCacheMasterUsingMyself();
    server.repl_state = REPL_STATE_CONNECT;
-    server.master_repl_offset = 0;
    server.repl_down_since = 0;
 }

@@ -1746,20 +1950,26 @@ void replicationUnsetMaster(void) {
    if (server.masterhost == NULL) return; /* Nothing to do. */
    sdsfree(server.masterhost);
    server.masterhost = NULL;
-    if (server.master) {
-        if (listLength(server.slaves) == 0) {
-            /* If this instance is turned into a master and there are no
-             * slaves, it inherits the replication offset from the master.
-             * Under certain conditions this makes replicas comparable by
-             * replication offset to understand what is the most updated. */
-            server.master_repl_offset = server.master->reploff;
-            freeReplicationBacklog();
-        }
-        freeClient(server.master);
-    }
+    /* When a slave is turned into a master, the current replication ID
+     * (that was inherited from the master at synchronization time) is
+     * used as secondary ID up to the current offset, and a new replication
+     * ID is created to continue with a new replication history. */
+    shiftReplicationId();
+    if (server.master) freeClient(server.master);
    replicationDiscardCachedMaster();
    cancelReplicationHandshake();
+    /* Disconnecting all the slaves is required: we need to inform slaves
+     * of the replication ID change (see shiftReplicationId() call). However
+     * the slaves will be able to partially resync with us, so it will be
+     * a very fast reconnection. */
+    disconnectSlaves();
    server.repl_state = REPL_STATE_NONE;
+
+    /* We need to make sure the new master will start the replication stream
+     * with a SELECT statement. This is forced after a full resync, but
+     * with PSYNC version 2, there is no need for full resync after a
+     * master switch. */
+    server.slaveseldb = -1;
 }

 /* This function is called when the slave lose the connection with the
@@ -1915,6 +2125,18 @@ void replicationCacheMaster(client *c) {
    /* Unlink the client from the server structures. */
    unlinkClient(c);

+    /* Reset the master client so that's ready to accept new commands:
+     * we want to discard te non processed query buffers and non processed
+     * offsets, including pending transactions, already populated arguments,
+     * pending outputs to the master. */
+    sdsclear(server.master->querybuf);
+    sdsclear(server.master->pending_querybuf);
+    server.master->read_reploff = server.master->reploff;
+    if (c->flags & CLIENT_MULTI) discardTransaction(c);
+    listEmpty(c->reply);
+    c->bufpos = 0;
+    resetClient(c);
+
    /* Save the master. Server.master will be set to null later by
     * replicationHandleMasterDisconnection(). */
    server.cached_master = server.master;
@@ -1931,6 +2153,31 @@ void replicationCacheMaster(client *c) {
    replicationHandleMasterDisconnection();
 }

+/* This function is called when a master is turend into a slave, in order to
+ * create from scratch a cached master for the new client, that will allow
+ * to PSYNC with the slave that was promoted as the new master after a
+ * failover.
+ *
+ * Assuming this instance was previously the master instance of the new master,
+ * the new master will accept its replication ID, and potentiall also the
+ * current offset if no data was lost during the failover. So we use our
+ * current replication ID and offset in order to synthesize a cached master. */
+void replicationCacheMasterUsingMyself(void) {
+    /* The master client we create can be set to any DBID, because
+     * the new master will start its replication stream with SELECT. */
+    server.master_initial_offset = server.master_repl_offset;
+    replicationCreateMasterClient(-1,-1);
+
+    /* Use our own ID / offset. */
+    memcpy(server.master->replid, server.replid, sizeof(server.replid));
+
+    /* Set as cached master. */
+    unlinkClient(server.master);
+    server.cached_master = server.master;
+    server.master = NULL;
+    serverLog(LL_NOTICE,"Before turning into a slave, using my master parameters to synthesize a cached master: I may be able to synchronize with the new master with just a partial transfer.");
+}
+
 /* Free a cached master, called when there are no longer the conditions for
 * a partial resync on reconnection. */
 void replicationDiscardCachedMaster(void) {
@@ -1958,7 +2205,7 @@ void replicationResurrectCachedMaster(int newfd) {
    server.repl_state = REPL_STATE_CONNECTED;

    /* Re-add to the list of clients. */
-    listAddNodeTail(server.clients,server.master);
+    linkClient(server.master);
    if (aeCreateFileEvent(server.el, newfd, AE_READABLE,
                          readQueryFromClient, server.master)) {
        serverLog(LL_WARNING,"Error resurrecting the cached master, impossible to add the readable handler: %s", strerror(errno));
@@ -2142,6 +2389,11 @@ void waitCommand(client *c) {
    long numreplicas, ackreplicas;
    long long offset = c->woff;

+    if (server.masterhost) {
+        addReplyError(c,"WAIT cannot be used with slave instances. Please also note that since Redis 4.0 if a slave is configured to be writable (which is not the default) writes to slaves are just local and are not propagated.");
+        return;
+    }
+
    /* Argument parsing. */
    if (getLongFromObjectOrReply(c,c->argv[1],&numreplicas,NULL) != C_OK)
        return;
@@ -2290,7 +2542,9 @@ void replicationCron(void) {
    robj *ping_argv[1];

    /* First, send PING according to ping_slave_period. */
-    if ((replication_cron_loops % server.repl_ping_slave_period) == 0) {
+    if ((replication_cron_loops % server.repl_ping_slave_period) == 0 &&
+        listLength(server.slaves))
+    {
        ping_argv[0] = createStringObject("PING",4);
        replicationFeedSlaves(server.slaves, server.slaveseldb,
            ping_argv, 1);
@@ -2299,20 +2553,30 @@ void replicationCron(void) {

    /* Second, send a newline to all the slaves in pre-synchronization
     * stage, that is, slaves waiting for the master to create the RDB file.
+     *
+     * Also send the a newline to all the chained slaves we have, if we lost
+     * connection from our master, to keep the slaves aware that their
+     * master is online. This is needed since sub-slaves only receive proxied
+     * data from top-level masters, so there is no explicit pinging in order
+     * to avoid altering the replication offsets. This special out of band
+     * pings (newlines) can be sent, they will have no effect in the offset.
+     *
     * The newline will be ignored by the slave but will refresh the
-     * last-io timer preventing a timeout. In this case we ignore the
+     * last interaction timer preventing a timeout. In this case we ignore the
     * ping period and refresh the connection once per second since certain
     * timeouts are set at a few seconds (example: PSYNC response). */
    listRewind(server.slaves,&li);
    while((ln = listNext(&li))) {
        client *slave = ln->value;

-        if (slave->replstate == SLAVE_STATE_WAIT_BGSAVE_START ||
+        int is_presync =
+            (slave->replstate == SLAVE_STATE_WAIT_BGSAVE_START ||
            (slave->replstate == SLAVE_STATE_WAIT_BGSAVE_END &&
-             server.rdb_child_type != RDB_CHILD_TYPE_SOCKET))
-        {
+             server.rdb_child_type != RDB_CHILD_TYPE_SOCKET));
+
+        if (is_presync) {
            if (write(slave->fd, "\n", 1) == -1) {
-                /* Don't worry, it's just a ping. */
+                /* Don't worry about socket errors, it's just a ping. */
            }
        }
    }
@@ -2337,14 +2601,35 @@ void replicationCron(void) {
        }
    }

-    /* If we have no attached slaves and there is a replication backlog
-     * using memory, free it after some (configured) time. */
+    /* If this is a master without attached slaves and there is a replication
+     * backlog active, in order to reclaim memory we can free it after some
+     * (configured) time. Note that this cannot be done for slaves: slaves
+     * without sub-slaves attached should still accumulate data into the
+     * backlog, in order to reply to PSYNC queries if they are turned into
+     * masters after a failover. */
    if (listLength(server.slaves) == 0 && server.repl_backlog_time_limit &&
-        server.repl_backlog)
+        server.repl_backlog && server.masterhost == NULL)
    {
        time_t idle = server.unixtime - server.repl_no_slaves_since;

        if (idle > server.repl_backlog_time_limit) {
+            /* When we free the backlog, we always use a new
+             * replication ID and clear the ID2. This is needed
+             * because when there is no backlog, the master_repl_offset
+             * is not updated, but we would still retain our replication
+             * ID, leading to the following problem:
+             *
+             * 1. We are a master instance.
+             * 2. Our slave is promoted to master. It's repl-id-2 will
+             *    be the same as our repl-id.
+             * 3. We, yet as master, receive some updates, that will not
+             *    increment the master_repl_offset.
+             * 4. Later we are turned into a slave, connecto to the new
+             *    master that will accept our PSYNC request by second
+             *    replication ID, but there will be data inconsistency
+             *    because we received writes. */
+            changeReplicationId();
+            clearReplicationId2();
            freeReplicationBacklog();
            serverLog(LL_NOTICE,
                "Replication backlog freed after %d seconds "
@@ -358,6 +358,13 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
    static size_t cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
    static int inuse = 0;   /* Recursive calls detection. */

+    /* Reflect MULTI state */
+    if (server.lua_multi_emitted || (server.lua_caller->flags & CLIENT_MULTI)) {
+        c->flags |= CLIENT_MULTI;
+    } else {
+        c->flags &= ~CLIENT_MULTI;
+    }
+
    /* By using Lua debug hooks it is possible to trigger a recursive call
     * to luaRedisGenericCommand(), which normally should never happen.
     * To make this function reentrant is futile and makes it slower, but
@@ -443,6 +450,7 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
            if (j == 10) {
                cmdlog = sdscatprintf(cmdlog," ... (%d more)",
                    c->argc-j-1);
+                break;
            } else {
                cmdlog = sdscatlen(cmdlog," ",1);
                cmdlog = sdscatsds(cmdlog,c->argv[j]->ptr);
@@ -534,6 +542,7 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
     * a Lua script in the context of AOF and slaves. */
    if (server.lua_replicate_commands &&
        !server.lua_multi_emitted &&
+        !(server.lua_caller->flags & CLIENT_MULTI) &&
        server.lua_write_dirty &&
        server.lua_repl != PROPAGATE_NONE)
    {
@@ -900,7 +909,6 @@ void scriptingInit(int setup) {
        server.lua_caller = NULL;
        server.lua_timedout = 0;
        server.lua_always_replicate_commands = 0; /* Only DEBUG can change it.*/
-        server.lua_time_limit = LUA_SCRIPT_TIME_LIMIT;
        ldbInit();
    }

@@ -1133,18 +1141,38 @@ int redis_math_randomseed (lua_State *L) {
 * EVAL and SCRIPT commands implementation
 * ------------------------------------------------------------------------- */

-/* Define a lua function with the specified function name and body.
- * The function name musts be a 42 characters long string, since all the
- * functions we defined in the Lua context are in the form:
+/* Define a Lua function with the specified body.
+ * The function name will be generated in the following form:
 *
 *   f_<hex sha1 sum>
 *
- * On success C_OK is returned, and nothing is left on the Lua stack.
- * On error C_ERR is returned and an appropriate error is set in the
- * client context. */
-int luaCreateFunction(client *c, lua_State *lua, char *funcname, robj *body) {
-    sds funcdef = sdsempty();
+ * The function increments the reference count of the 'body' object as a
+ * side effect of a successful call.
+ *
+ * On success a pointer to an SDS string representing the function SHA1 of the
+ * just added function is returned (and will be valid until the next call
+ * to scriptingReset() function), otherwise NULL is returned.
+ *
+ * The function handles the fact of being called with a script that already
+ * exists, and in such a case, it behaves like in the success case.
+ *
+ * If 'c' is not NULL, on error the client is informed with an appropriate
+ * error describing the nature of the problem and the Lua interpreter error. */
+sds luaCreateFunction(client *c, lua_State *lua, robj *body) {
+    char funcname[43];
+    dictEntry *de;

+    funcname[0] = 'f';
+    funcname[1] = '_';
+    sha1hex(funcname+2,body->ptr,sdslen(body->ptr));
+
+    sds sha = sdsnewlen(funcname+2,40);
+    if ((de = dictFind(server.lua_scripts,sha)) != NULL) {
+        sdsfree(sha);
+        return dictGetKey(de);
+    }
+
+    sds funcdef = sdsempty();
    funcdef = sdscat(funcdef,"function ");
    funcdef = sdscatlen(funcdef,funcname,42);
    funcdef = sdscatlen(funcdef,"() ",3);
@@ -1152,30 +1180,35 @@ int luaCreateFunction(client *c, lua_State *lua, char *funcname, robj *body) {
    funcdef = sdscatlen(funcdef,"\nend",4);

    if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"@user_script")) {
-        addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
-            lua_tostring(lua,-1));
+        if (c != NULL) {
+            addReplyErrorFormat(c,
+                "Error compiling script (new function): %s\n",
+                lua_tostring(lua,-1));
+        }
        lua_pop(lua,1);
+        sdsfree(sha);
        sdsfree(funcdef);
-        return C_ERR;
+        return NULL;
    }
    sdsfree(funcdef);
+
    if (lua_pcall(lua,0,0,0)) {
-        addReplyErrorFormat(c,"Error running script (new function): %s\n",
-            lua_tostring(lua,-1));
+        if (c != NULL) {
+            addReplyErrorFormat(c,"Error running script (new function): %s\n",
+                lua_tostring(lua,-1));
+        }
        lua_pop(lua,1);
-        return C_ERR;
+        sdsfree(sha);
+        return NULL;
    }

    /* We also save a SHA1 -> Original script map in a dictionary
     * so that we can replicate / write in the AOF all the
     * EVALSHA commands as EVAL using the original script. */
-    {
-        int retval = dictAdd(server.lua_scripts,
-                             sdsnewlen(funcname+2,40),body);
-        serverAssertWithInfo(c,NULL,retval == DICT_OK);
-        incrRefCount(body);
-    }
-    return C_OK;
+    int retval = dictAdd(server.lua_scripts,sha,body);
+    serverAssertWithInfo(c ? c : server.lua_client,NULL,retval == DICT_OK);
+    incrRefCount(body);
+    return sha;
 }

 /* This is the Lua script "count" hook that we use to detect scripts timeout. */
@@ -1274,10 +1307,10 @@ void evalGenericCommand(client *c, int evalsha) {
            addReply(c, shared.noscripterr);
            return;
        }
-        if (luaCreateFunction(c,lua,funcname,c->argv[1]) == C_ERR) {
+        if (luaCreateFunction(c,lua,c->argv[1]) == NULL) {
            lua_pop(lua,1); /* remove the error handler from the stack. */
            /* The error is sent to the client by luaCreateFunction()
-             * itself when it returns C_ERR. */
+             * itself when it returns NULL. */
            return;
        }
        /* Now the following is guaranteed to return non nil */
@@ -1422,7 +1455,17 @@ void evalShaCommand(client *c) {
 }

 void scriptCommand(client *c) {
-    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"flush")) {
+    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
+        const char *help[] = {
+"debug (yes|sync|no) -- Set the debug mode for subsequent scripts executed.",
+"exists <sha1> [<sha1> ...] -- Return information about the existence of the scripts in the script cache.",
+"flush -- Flush the Lua scripts cache. Very dangerous on slaves.",
+"kill -- Kill the currently executing Lua script.",
+"load <script> -- Load a script into the scripts cache, without executing it.",
+NULL
+        };
+        addReplyHelp(c, help);
+    } else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"flush")) {
        scriptingReset();
        addReply(c,shared.ok);
        replicationScriptCacheFlush();
@@ -1438,22 +1481,9 @@ void scriptCommand(client *c) {
                addReply(c,shared.czero);
        }
    } else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"load")) {
-        char funcname[43];
-        sds sha;
-
-        funcname[0] = 'f';
-        funcname[1] = '_';
-        sha1hex(funcname+2,c->argv[2]->ptr,sdslen(c->argv[2]->ptr));
-        sha = sdsnewlen(funcname+2,40);
-        if (dictFind(server.lua_scripts,sha) == NULL) {
-            if (luaCreateFunction(c,server.lua,funcname,c->argv[2])
-                    == C_ERR) {
-                sdsfree(sha);
-                return;
-            }
-        }
-        addReplyBulkCBuffer(c,funcname+2,40);
-        sdsfree(sha);
+        sds sha = luaCreateFunction(c,server.lua,c->argv[2]);
+        if (sha == NULL) return; /* The error was sent by luaCreateFunction(). */
+        addReplyBulkCBuffer(c,sha,40);
        forceCommandPropagation(c,PROPAGATE_REPL|PROPAGATE_AOF);
    } else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"kill")) {
        if (server.lua_caller == NULL) {
@@ -1481,9 +1511,10 @@ void scriptCommand(client *c) {
            c->flags |= CLIENT_LUA_DEBUG_SYNC;
        } else {
            addReplyError(c,"Use SCRIPT DEBUG yes/sync/no");
+            return;
        }
    } else {
-        addReplyError(c, "Unknown SCRIPT subcommand or wrong # of args.");
+        addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try SCRIPT HELP", (char*)c->argv[1]->ptr);
    }
 }

@@ -2272,7 +2303,7 @@ ldbLog(sdsnew("[e]eval <code>       Execute some Lua code (in a different callfr
 ldbLog(sdsnew("[r]edis <cmd>        Execute a Redis command."));
 ldbLog(sdsnew("[m]axlen [len]       Trim logged Redis replies and Lua var dumps to len."));
 ldbLog(sdsnew("                     Specifying zero as <len> means unlimited."));
-ldbLog(sdsnew("[a]abort             Stop the execution of the script. In sync"));
+ldbLog(sdsnew("[a]bort              Stop the execution of the script. In sync"));
 ldbLog(sdsnew("                     mode dataset changes will be retained."));
 ldbLog(sdsnew(""));
 ldbLog(sdsnew("Debugger functions you can call from Lua scripts:"));
--- a/Show More
+++ b/Show More