Fix typos in GetContextFromIO API declaration.

It was noted by @dvirsky that it is not possible to use string functions
when writing the AOF file. This sometimes is critical since the command
rewriting may need to be built in the context of the AOF callback, and
without access to the context, and the limited types that the AOF
production functions will accept, this can be an issue.

Moreover there are other needs that we can't anticipate regarding the
ability to use Redis Modules APIs using the context in order to build
representations to emit AOF / RDB.

Because of this a new API was added that allows the user to get a
temporary context from the IO context. The context is auto released
if obtained when the RDB / AOF callback returns.

Calling multiple time the function to get the context, always returns
the same one, since it is invalid to have more than a single context.

.gitignore

@@ -27,3 +27,4 @@ deps/lua/src/liblua.a
 .make-*
 .prerequisites
 *.dSYM
+Makefile.dep

CONTRIBUTING

@@ -12,7 +12,7 @@ each source file that you contribute.
 
   PLEASE DO NOT POST GENERAL QUESTIONS that are not about bugs or suspected
   bugs in the Github issues system. We'll be very happy to help you and provide
-  all the support Reddit sub:
+  all the support at the Reddit sub:
 
       http://reddit.com/r/redis
 
@@ -24,7 +24,7 @@ each source file that you contribute.
 
 1. If it is a major feature or a semantical change, please post it as a new submission in r/redis on Reddit at http://reddit.com/r/redis. Try to be passionate about why the feature is needed, make users upvote your proposal to gain traction and so forth. Read feedbacks about the community. But in this first step **please don't write code yet**.
 
-2. If in step 1 you get an acknowledge from the project leaders, use the
+2. If in step 1 you get an acknowledgment from the project leaders, use the
    following procedure to submit a patch:
 
     a. Fork Redis on github ( http://help.github.com/fork-a-repo/ )

README.md

@@ -39,7 +39,7 @@ You can run a 32 bit Redis binary using:
 
     % make 32bit
 
-After building Redis is a good idea to test it, using:
+After building Redis, it is a good idea to test it using:
 
     % make test
 
@@ -47,8 +47,8 @@ Fixing build problems with dependencies or cached build options
 ---------
 
 Redis has some dependencies which are included into the `deps` directory.
-`make` does not rebuild dependencies automatically, even if something in the
-source code of dependencies is changed.
+`make` does not automatically rebuild dependencies even if something in
+the source code of dependencies changes.
 
 When you update the source code with `git pull` or when code inside the
 dependencies tree is modified in any other way, make sure to use the following
@@ -109,14 +109,14 @@ To run Redis with the default configuration just type:
 
     % cd src
     % ./redis-server
-    
+
 If you want to provide your redis.conf, you have to run it using an additional
 parameter (the path of the configuration file):
 
     % cd src
     % ./redis-server /path/to/redis.conf
 
-It is possible to alter the Redis configuration passing parameters directly
+It is possible to alter the Redis configuration by passing parameters directly
 as options using the command line. Examples:
 
     % ./redis-server --port 9999 --slaveof 127.0.0.1 6379
@@ -174,7 +174,7 @@ You'll be able to stop and start Redis using the script named
 `/etc/init.d/redis_<portnumber>`, for instance `/etc/init.d/redis_6379`.
 
 Code contributions
----
+-----------------
 
 Note: by contributing code to the Redis project in any form, including sending
 a pull request via Github, a code fragment or patch via private email or
@@ -185,7 +185,262 @@ source distribution.
 Please see the [CONTRIBUTING][2] file in this source distribution for more
 information.
 
-Enjoy!
-
 [1]: https://github.com/antirez/redis/blob/unstable/COPYING
 [2]: https://github.com/antirez/redis/blob/unstable/CONTRIBUTING
+
+Redis internals
+===
+
+If you are reading this README you are likely in front of a Github page
+or you just untarred the Redis distribution tar ball. In both the cases
+you are basically one step away from the source code, so here we explain
+the Redis source code layout, what is in each file as a general idea, the
+most important functions and structures inside the Redis server and so forth.
+We keep all the discussion at a high level without digging into the details
+since this document would be huge otherwise and our code base changes
+continuously, but a general idea should be a good starting point to
+understand more. Moreover most of the code is heavily commented and easy
+to follow.
+
+Source code layout
+---
+
+The Redis root directory just contains this README, the Makefile which
+calls the real Makefile inside the `src` directory and an example
+configuration for Redis and Sentinel. You can find a few shell
+scripts that are used in order to execute the Redis, Redis Cluster and
+Redis Sentinel unit tests, which are implemented inside the `tests`
+directory.
+
+Inside the root are the following important directories:
+
+* `src`: contains the Redis implementation, written in C.
+* `tests`: contains the unit tests, implemented in Tcl.
+* `deps`: contains libraries Redis uses. Everything needed to compile Redis is inside this directory; your system just needs to provide `libc`, a POSIX compatible interface and a C compiler. Notably `deps` contains a copy of `jemalloc`, which is the default allocator of Redis under Linux. Note that under `deps` there are also things which started with the Redis project, but for which the main repository is not `anitrez/redis`. An exception to this rule is `deps/geohash-int` which is the low level geocoding library used by Redis: it originated from a different project, but at this point it diverged so much that it is developed as a separated entity directly inside the Redis repository.
+
+There are a few more directories but they are not very important for our goals
+here. We'll focus mostly on `src`, where the Redis implementation is contained,
+exploring what there is inside each file. The order in which files are
+exposed is the logical one to follow in order to disclose different layers
+of complexity incrementally.
+
+Note: lately Redis was refactored quite a bit. Function names and file
+names have been changed, so you may find that this documentation reflects the
+`unstable` branch more closely. For instance in Redis 3.0 the `server.c`
+and `server.h` files were named to `redis.c` and `redis.h`. However the overall
+structure is the same. Keep in mind that all the new developments and pull
+requests should be performed against the `unstable` branch.
+
+server.h
+---
+
+The simplest way to understand how a program works is to understand the
+data structures it uses. So we'll start from the main header file of
+Redis, which is `server.h`.
+
+All the server configuration and in general all the shared state is
+defined in a global structure called `server`, of type `struct redisServer`.
+A few important fields in this structure are:
+
+* `server.db` is an array of Redis databases, where data is stored.
+* `server.commands` is the command table.
+* `server.clients` is a linked list of clients connected to the server.
+* `server.master` is a special client, the master, if the instance is a slave.
+
+There are tons of other fields. Most fields are commented directly inside
+the structure definition.
+
+Another important Redis data structure is the one defining a client.
+In the past it was called `redisClient`, now just `client`. The structure
+has many fields, here we'll just show the main ones:
+
+    struct client {
+        int fd;
+        sds querybuf;
+        int argc;
+        robj **argv;
+        redisDb *db;
+        int flags;
+        list *reply;
+        char buf[PROTO_REPLY_CHUNK_BYTES];
+        ... many other fields ...
+    }
+
+The client structure defines a *connected client*:
+
+* The `fd` field is the client socket file descriptor.
+* `argc` and `argv` are populated with the command the client is executing, so that functions implementing a given Redis command can read the arguments.
+* `querybuf` accumulates the requests from the client, which are parsed by the Redis server according to the Redis protocol and executed by calling the implementations of the commands the client is executing.
+* `reply` and `buf` are dynamic and static buffers that accumulate the replies the server sends to the client. These buffers are incrementally written to the socket as soon as the file descriptor is writable.
+
+As you can see in the client structure above, arguments in a command
+are described as `robj` structures. The following is the full `robj`
+structure, which defines a *Redis object*:
+
+    typedef struct redisObject {
+        unsigned type:4;
+        unsigned encoding:4;
+        unsigned lru:LRU_BITS; /* lru time (relative to server.lruclock) */
+        int refcount;
+        void *ptr;
+    } robj;
+
+Basically this structure can represent all the basic Redis data types like
+strings, lists, sets, sorted sets and so forth. The interesting thing is that
+it has a `type` field, so that it is possible to know what type a given
+object has, and a `refcount`, so that the same object can be referenced
+in multiple places without allocating it multiple times. Finally the `ptr`
+field points to the actual representation of the object, which might vary
+even for the same type, depending on the `encoding` used.
+
+Redis objects are used extensively in the Redis internals, however in order
+to avoid the overhead of indirect accesses, recently in many places
+we just use plain dynamic strings not wrapped inside a Redis object.
+
+server.c
+---
+
+This is the entry point of the Redis server, where the `main()` function
+is defined. The following are the most important steps in order to startup
+the Redis server.
+
+* `initServerConfig()` setups the default values of the `server` structure.
+* `initServer()` allocates the data structures needed to operate, setup the listening socket, and so forth.
+* `aeMain()` starts the event loop which listens for new connections.
+
+There are two special functions called periodically by the event loop:
+
+1. `serverCron()` is called periodically (according to `server.hz` frequency), and performs tasks that must be performed from time to time, like checking for timedout clients.
+2. `beforeSleep()` is called every time the event loop fired, Redis served a few requests, and is returning back into the event loop.
+
+Inside server.c you can find code that handles other vital things of the Redis server:
+
+* `call()` is used in order to call a given command in the context of a given client.
+* `activeExpireCycle()` handles eviciton of keys with a time to live set via the `EXPIRE` command.
+* `freeMemoryIfNeeded()` is called when a new write command should be performed but Redis is out of memory according to the `maxmemory` directive.
+* The global variable `redisCommandTable` defines all the Redis commands, specifying the name of the command, the function implementing the command, the number of arguments required, and other properties of each command.
+
+networking.c
+---
+
+This file defines all the I/O functions with clients, masters and slaves
+(which in Redis are just special clients):
+
+* `createClient()` allocates and initializes a new client.
+* the `addReply*()` family of functions are used by commands implementations in order to append data to the client structure, that will be transmitted to the client as a reply for a given command executed.
+* `writeToClient()` transmits the data pending in the output buffers to the client and is called by the *writable event handler* `sendReplyToClient()`.
+* `readQueryFromClient()` is the *readable event handler* and accumulates data from read from the client into the query buffer.
+* `processInputBuffer()` is the entry point in order to parse the client query buffer according to the Redis protocol. Once commands are ready to be processed, it calls `processCommand()` which is defined inside `server.c` in order to actually execute the command.
+* `freeClient()` deallocates, disconnects and removes a client.
+
+aof.c and rdb.c
+---
+
+As you can guess from the names these files implement the RDB and AOF
+persistence for Redis. Redis uses a persistence model based on the `fork()`
+system call in order to create a thread with the same (shared) memory
+content of the main Redis thread. This secondary thread dumps the content
+of the memory on disk. This is used by `rdb.c` to create the snapshots
+on disk and by `aof.c` in order to perform the AOF rewrite when the
+append only file gets too big.
+
+The implementation inside `aof.c` has additional functions in order to
+implement an API that allows commands to append new commands into the AOF
+file as clients execute them.
+
+The `call()` function defined inside `server.c` is responsible to call
+the functions that in turn will write the commands into the AOF.
+
+db.c
+---
+
+Certain Redis commands operate on specific data types, others are general.
+Examples of generic commands are `DEL` and `EXPIRE`. They operate on keys
+and not on their values specifically. All those generic commands are
+defined inside `db.c`.
+
+Moreover `db.c` implements an API in order to perform certain operations
+on the Redis dataset without directly accessing the internal data structures.
+
+The most important functions inside `db.c` which are used in many commands
+implementations are the following:
+
+* `lookupKeyRead()` and `lookupKeyWrite()` are used in order to get a pointer to the value associated to a given key, or `NULL` if the key does not exist.
+* `dbAdd()` and its higher level counterpart `setKey()` create a new key in a Redis database.
+* `dbDelete()` removes a key and its associated value.
+* `emptyDb()` removes an entire single database or all the databases defined.
+
+The rest of the file implements the generic commands exposed to the client.
+
+object.c
+---
+
+The `robj` structure defining Redis objects was already described. Inside
+`object.c` there are all the functions that operate with Redis objects at
+a basic level, like functions to allocate new objects, handle the reference
+counting and so forth. Notable functions inside this file:
+
+* `incrRefcount()` and `decrRefCount()` are used in order to increment or decrement an object reference count. When it drops to 0 the object is finally freed.
+* `createObject()` allocates a new object. There are also specialized functions to allocate string objects having a specific content, like `createStringObjectFromLongLong()` and similar functions.
+
+This file also implements the `OBJECT` command.
+
+replication.c
+---
+
+This is one of the most complex files inside Redis, it is recommended to
+approach it only after getting a bit familiar with the rest of the code base.
+In this file there is the implementation of both the master and slave role
+of Redis.
+
+One of the most important functions inside this file is `replicationFeedSlaves()` that writes commands to the clients representing slave instances connected
+to our master, so that the slaves can get the writes performed by the clients:
+this way their data set will remain synchronized with the one in the master.
+
+This file also implements both the `SYNC` and `PSYNC` commands that are
+used in order to perform the first synchronization between masters and
+slaves, or to continue the replication after a disconnection.
+
+Other C files
+---
+
+* `t_hash.c`, `t_list.c`, `t_set.c`, `t_string.c` and `t_zset.c` contains the implementation of the Redis data types. They implement both an API to access a given data type, and the client commands implementations for these data types.
+* `ae.c` implements the Redis event loop, it's a self contained library which is simple to read and understand.
+* `sds.c` is the Redis string library, check http://github.com/antirez/sds for more information.
+* `anet.c` is a library to use POSIX networking in a simpler way compared to the raw interface exposed by the kernel.
+* `dict.c` is an implementation of a non-blocking hash table which rehashes incrementally.
+* `scripting.c` implements Lua scripting. It is completely self contained from the rest of the Redis implementation and is simple enough to understand if you are familar with the Lua API.
+* `cluster.c` implements the Redis Cluster. Probably a good read only after being very familiar with the rest of the Redis code base. If you want to read `cluster.c` make sure to read the [Redis Cluster specification][3].
+
+[3]: http://redis.io/topics/cluster-spec
+
+Anatomy of a Redis command
+---
+
+All the Redis commands are defined in the following way:
+
+    void foobarCommand(client *c) {
+        printf("%s",c->argv[1]->ptr); /* Do something with the argument. */
+        addReply(c,shared.ok); /* Reply something to the client. */
+    }
+
+The command is then referenced inside `server.c` in the command table:
+
+    {"foobar",foobarCommand,2,"rtF",0,NULL,0,0,0,0,0},
+
+In the above example `2` is the number of arguments the command takes,
+while `"rtF"` are the command flags, as documented in the command table
+top comment inside `server.c`.
+
+After the command operates in some way, it returns a reply to the client,
+usually using `addReply()` or a similar function defined inside `networking.c`.
+
+There are tons of commands implementations inside th Redis source code
+that can serve as examples of actual commands implementations. To write
+a few toy commands can be a good exercise to familiarize with the code base.
+
+There are also many other files not described here, but it is useless to
+cover everything. We want to just help you with the first steps.
+Eventually you'll find your way inside the Redis code base :-)
+
+Enjoy!

deps/Makefile

@@ -36,7 +36,6 @@ distclean:
 	-(cd hiredis && $(MAKE) clean) > /dev/null || true
 	-(cd linenoise && $(MAKE) clean) > /dev/null || true
 	-(cd lua && $(MAKE) clean) > /dev/null || true
-	-(cd geohash-int && $(MAKE) clean) > /dev/null || true
 	-(cd jemalloc && [ -f Makefile ] && $(MAKE) distclean) > /dev/null || true
 	-(rm -f .make-*)
 
@@ -82,9 +81,3 @@ jemalloc: .make-prerequisites
 	cd jemalloc && $(MAKE) CFLAGS="$(JEMALLOC_CFLAGS)" LDFLAGS="$(JEMALLOC_LDFLAGS)" lib/libjemalloc.a
 
 .PHONY: jemalloc
-
-geohash-int: .make-prerequisites
-	@printf '%b %b\n' $(MAKECOLOR)MAKE$(ENDCOLOR) $(BINCOLOR)$@$(ENDCOLOR)
-	cd geohash-int && $(MAKE)
-
-.PHONY: geohash-int

deps/geohash-int/Makefile

@@ -1,23 +0,0 @@
-STD=
-WARN= -Wall
-OPT= -O2
-
-R_CFLAGS= $(STD) $(WARN) $(OPT) $(DEBUG) $(CFLAGS)
-R_LDFLAGS= $(LDFLAGS)
-DEBUG= -g
-
-R_CC=$(CC) $(R_CFLAGS)
-R_LD=$(CC) $(R_LDFLAGS)
-
-all: geohash.o geohash_helper.o
-
-.PHONY: all
-
-geohash.o: geohash.h geohash.c
-geohash_helper.o: geohash.h geohash_helper.h geohash_helper.c
-
-.c.o:
-	$(R_CC) -c $<
-
-clean:
-	rm -f *.o

redis.conf

@@ -35,6 +35,14 @@
 # include /path/to/local.conf
 # include /path/to/other.conf
 
+################################## MODULES #####################################
+
+# Load modules at startup. If the server is not able to load modules
+# it will abort. It is possible to use multiple loadmodule directives.
+#
+# loadmodule /path/to/my_module.so
+# loadmodule /path/to/other_module.so
+
 ################################## NETWORK #####################################
 
 # By default, if no "bind" configuration directive is specified, Redis listens
@@ -498,7 +506,7 @@ slave-priority 100
 # Please note that changing the name of commands that are logged into the
 # AOF file or transmitted to slaves may cause problems.
 
-################################### LIMITS ####################################
+################################### CLIENTS ####################################
 
 # Set the max number of connected clients at the same time. By default
 # this limit is set to 10000 clients, however if the Redis server is not
@@ -511,7 +519,9 @@ slave-priority 100
 #
 # maxclients 10000
 
-# Don't use more memory than the specified amount of bytes.
+############################## MEMORY MANAGEMENT ################################
+
+# Set a memory usage limit to the specified amount of bytes.
 # When the memory limit is reached Redis will try to remove keys
 # according to the eviction policy selected (see maxmemory-policy).
 #
@@ -520,8 +530,8 @@ slave-priority 100
 # that would use more memory, like SET, LPUSH, and so on, and will continue
 # to reply to read-only commands like GET.
 #
-# This option is usually useful when using Redis as an LRU cache, or to set
-# a hard memory limit for an instance (using the 'noeviction' policy).
+# This option is usually useful when using Redis as an LRU or LFU cache, or to
+# set a hard memory limit for an instance (using the 'noeviction' policy).
 #
 # WARNING: If you have slaves attached to an instance with maxmemory on,
 # the size of the output buffers needed to feed the slaves are subtracted
@@ -539,12 +549,20 @@ slave-priority 100
 # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
 # is reached. You can select among five behaviors:
 #
-# volatile-lru -> remove the key with an expire set using an LRU algorithm
-# allkeys-lru -> remove any key according to the LRU algorithm
-# volatile-random -> remove a random key with an expire set
-# allkeys-random -> remove a random key, any key
-# volatile-ttl -> remove the key with the nearest expire time (minor TTL)
-# noeviction -> don't expire at all, just return an error on write operations
+# volatile-lru -> Evict using approximated LRU among the keys with an expire set.
+# allkeys-lru -> Evict any key using approximated LRU.
+# volatile-lfu -> Evict using approximated LFU among the keys with an expire set.
+# allkeys-lfu -> Evict any key using approximated LFU.
+# volatile-random -> Remove a random key among the ones with an expire set.
+# allkeys-random -> Remove a random key, any key.
+# volatile-ttl -> Remove the key with the nearest expire time (minor TTL)
+# noeviction -> Don't evict anything, just return an error on write operations.
+#
+# LRU means Least Recently Used
+# LFU means Least Frequently Used
+#
+# Both LRU, LFU and volatile-ttl are implemented using approximated
+# randomized algorithms.
 #
 # Note: with any of the above policies, Redis will return an error on write
 #       operations, when there are no suitable keys for eviction.
@@ -559,17 +577,66 @@ slave-priority 100
 #
 # maxmemory-policy noeviction
 
-# LRU and minimal TTL algorithms are not precise algorithms but approximated
+# LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated
 # algorithms (in order to save memory), so you can tune it for speed or
 # accuracy. For default Redis will check five keys and pick the one that was
 # used less recently, you can change the sample size using the following
 # configuration directive.
 #
 # The default of 5 produces good enough results. 10 Approximates very closely
-# true LRU but costs a bit more CPU. 3 is very fast but not very accurate.
+# true LRU but costs more CPU. 3 is faster but not very accurate.
 #
 # maxmemory-samples 5
 
+############################# LAZY FREEING ####################################
+
+# Redis has two primitives to delete keys. One is called DEL and is a blocking
+# 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
+# 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.
+#
+# For the above reasons Redis also offers non blocking deletion primitives
+# such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and
+# FLUSHDB commands, in order to reclaim memory in background. Those commands
+# are executed in constant time. Another thread will incrementally free the
+# object in the background as fast as possible.
+#
+# DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.
+# 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
+# following scenarios:
+#
+# 1) On eviction, because of the maxmemory and maxmemory policy configurations,
+#    in order to make room for new data, without going over the specified
+#    memory limit.
+# 2) Because of expire: when a key with an associated time to live (see the
+#    EXPIRE command) must be deleted from memory.
+# 3) Because of a side effect of a command that stores data on a key that may
+#    already exist. For example the RENAME command may delete the old key
+#    content when it is replaced with another one. Similarly SUNIONSTORE
+#    or SORT with STORE option may delete existing keys. The SET command
+#    itself removes any old content of the specified key in order to replace
+#    it with the specified string.
+# 4) During replication, when a slave performs a full resynchronization with
+#    its master, the content of the whole database is removed in order to
+#    load the RDB file just transfered.
+#
+# In all the above cases the default is to delete objects in a blocking way,
+# like if DEL was called. However you can configure each case specifically
+# in order to instead release memory in a non-blocking way like if UNLINK
+# was called, using the following configuration directives:
+
+lazyfree-lazy-eviction no
+lazyfree-lazy-expire no
+lazyfree-lazy-server-del no
+slave-lazy-flush no
+
 ############################## APPEND ONLY MODE ###############################
 
 # By default Redis asynchronously dumps the dataset on disk. This mode is
@@ -688,6 +755,20 @@ auto-aof-rewrite-min-size 64mb
 # will be found.
 aof-load-truncated yes
 
+# When rewriting the AOF file, Redis is able to use an RDB preamble in the
+# AOF file for faster rewrites and recoveries. When this option is turned
+# on the rewritten AOF file is composed of two different stanzas:
+#
+#   [RDB file][AOF tail]
+#
+# When loading Redis recognizes that the AOF file starts with the "REDIS"
+# string and loads the prefixed RDB file, and continues loading the AOF
+# tail.
+#
+# This is currently turned off by default in order to avoid the surprise
+# of a format change, but will at some point be used as the default.
+aof-use-rdb-preamble no
+
 ################################ LUA SCRIPTING  ###############################
 
 # Max execution time of a Lua script in milliseconds.
@@ -814,6 +895,39 @@ lua-time-limit 5000
 # In order to setup your cluster make sure to read the documentation
 # available at http://redis.io web site.
 
+########################## CLUSTER DOCKER/NAT support  ########################
+
+# In certain deployments, Redis Cluster nodes address discovery fails, because
+# addresses are NAT-ted or because ports are forwarded (the typical case is
+# 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
+# following two options are used for this scope, and are:
+#
+# * cluster-announce-ip
+# * cluster-announce-port
+# * cluster-announce-bus-port
+#
+# Each instruct the node about its address, client port, and cluster message
+# bus port. The information is then published in the header of the bus packets
+# so that other nodes will be able to correctly map the address of the node
+# publishing the information.
+#
+# If the above options are not used, the normal Redis Cluster auto-detection
+# will be used instead.
+#
+# Note that when remapped, the bus port may not be at the fixed offset of
+# clients port + 10000, so you can specify any port and bus-port depending
+# on how they get remapped. If the bus-port is not set, a fixed offset of
+# 10000 will be used as usually.
+#
+# Example:
+#
+# cluster-announce-ip 10.1.1.5
+# cluster-announce-port 6379
+# cluster-announce-bus-port 6380
+
 ################################## SLOW LOG ###################################
 
 # The Redis Slow Log is a system to log queries that exceeded a specified
@@ -1050,3 +1164,55 @@ hz 10
 # in order to commit the file to the disk more incrementally and avoid
 # big latency spikes.
 aof-rewrite-incremental-fsync yes
+
+# Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good
+# idea to start with the default settings and only change them after investigating
+# how to improve the performances and how the keys LFU change over time, which
+# is possible to inspect via the OBJECT FREQ command.
+#
+# There are two tunable parameters in the Redis LFU implementation: the
+# counter logarithm factor and the counter decay time. It is important to
+# understand what the two parameters mean before changing them.
+#
+# The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis
+# uses a probabilistic increment with logarithmic behavior. Given the value
+# of the old counter, when a key is accessed, the counter is incremented in
+# this way:
+#
+# 1. A random number R between 0 and 1 is extracted.
+# 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1).
+# 3. The counter is incremented only if R < P.
+#
+# The default lfu-log-factor is 10. This is a table of how the frequency
+# counter changes with a different number of accesses with different
+# logarithmic factors:
+#
+# +--------+------------+------------+------------+------------+------------+
+# | factor | 100 hits   | 1000 hits  | 100K hits  | 1M hits    | 10M hits   |
+# +--------+------------+------------+------------+------------+------------+
+# | 0      | 104        | 255        | 255        | 255        | 255        |
+# +--------+------------+------------+------------+------------+------------+
+# | 1      | 18         | 49         | 255        | 255        | 255        |
+# +--------+------------+------------+------------+------------+------------+
+# | 10     | 10         | 18         | 142        | 255        | 255        |
+# +--------+------------+------------+------------+------------+------------+
+# | 100    | 8          | 11         | 49         | 143        | 255        |
+# +--------+------------+------------+------------+------------+------------+
+#
+# NOTE: The above table was obtained by running the following commands:
+#
+#   redis-benchmark -n 1000000 incr foo
+#   redis-cli object freq foo
+#
+# NOTE 2: The counter initial value is 5 in order to give new objects a chance
+# to accumulate hits.
+#
+# The counter decay time is the time, in minutes, that must elapse in order
+# for the key counter to be divided by two (or decremented if it has a value
+# less <= 10).
+#
+# The default value for the lfu-decay-time is 1. A Special value of 0 means to
+# decay the counter every time it happens to be scanned.
+#
+# lfu-log-factor 10
+# lfu-decay-time 1

src/Makefile

@@ -15,11 +15,12 @@
 release_hdr := $(shell sh -c './mkreleasehdr.sh')
 uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')
 OPTIMIZATION?=-O2
-DEPENDENCY_TARGETS=hiredis linenoise lua geohash-int
+DEPENDENCY_TARGETS=hiredis linenoise lua
+NODEPS:=clean distclean
 
 # Default settings
 STD=-std=c99 -pedantic -DREDIS_STATIC=''
-WARN=-Wall -W
+WARN=-Wall -W -Wno-missing-field-initializers
 OPT=$(OPTIMIZATION)
 
 PREFIX?=/usr/local
@@ -53,7 +54,7 @@ endif
 # Override default settings if possible
 -include .make-settings
 
-FINAL_CFLAGS=$(STD) $(WARN) $(OPT) $(DEBUG) $(CFLAGS) $(REDIS_CFLAGS) -I../deps/geohash-int
+FINAL_CFLAGS=$(STD) $(WARN) $(OPT) $(DEBUG) $(CFLAGS) $(REDIS_CFLAGS)
 FINAL_LDFLAGS=$(LDFLAGS) $(REDIS_LDFLAGS) $(DEBUG)
 FINAL_LIBS=-lm
 DEBUG=-g -ggdb
@@ -127,8 +128,7 @@ 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
-REDIS_GEOHASH_OBJ=../deps/geohash-int/geohash.o ../deps/geohash-int/geohash_helper.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 geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o
 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
@@ -142,16 +142,15 @@ all: $(REDIS_SERVER_NAME) $(REDIS_SENTINEL_NAME) $(REDIS_CLI_NAME) $(REDIS_BENCH
 	@echo "Hint: It's a good idea to run 'make test' ;)"
 	@echo ""
 
+Makefile.dep:
+	-$(REDIS_CC) -MM *.c > Makefile.dep 2> /dev/null || true
+
+ifeq (0, $(words $(findstring $(MAKECMDGOALS), $(NODEPS))))
+-include Makefile.dep
+endif
+
 .PHONY: all
 
-# Deps (use make dep to generate this)
-include Makefile.dep
-
-dep:
-	$(REDIS_CC) -MM *.c > Makefile.dep
-
-.PHONY: dep
-
 persist-settings: distclean
 	echo STD=$(STD) >> .make-settings
 	echo WARN=$(WARN) >> .make-settings
@@ -182,7 +181,7 @@ endif
 
 # redis-server
 $(REDIS_SERVER_NAME): $(REDIS_SERVER_OBJ)
-	$(REDIS_LD) -o $@ $^ ../deps/hiredis/libhiredis.a ../deps/lua/src/liblua.a $(REDIS_GEOHASH_OBJ) $(FINAL_LIBS)
+	$(REDIS_LD) -o $@ $^ ../deps/hiredis/libhiredis.a ../deps/lua/src/liblua.a $(FINAL_LIBS)
 
 # redis-sentinel
 $(REDIS_SENTINEL_NAME): $(REDIS_SERVER_NAME)
@@ -204,6 +203,9 @@ $(REDIS_BENCHMARK_NAME): $(REDIS_BENCHMARK_OBJ)
 $(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
+
 # 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
 # depending on a single artifact, build all dependencies first.
@@ -211,7 +213,7 @@ $(REDIS_CHECK_AOF_NAME): $(REDIS_CHECK_AOF_OBJ)
 	$(REDIS_CC) -c $<
 
 clean:
-	rm -rf $(REDIS_SERVER_NAME) $(REDIS_SENTINEL_NAME) $(REDIS_CLI_NAME) $(REDIS_BENCHMARK_NAME) $(REDIS_CHECK_RDB_NAME) $(REDIS_CHECK_AOF_NAME) *.o *.gcda *.gcno *.gcov redis.info lcov-html
+	rm -rf $(REDIS_SERVER_NAME) $(REDIS_SENTINEL_NAME) $(REDIS_CLI_NAME) $(REDIS_BENCHMARK_NAME) $(REDIS_CHECK_RDB_NAME) $(REDIS_CHECK_AOF_NAME) *.o *.gcda *.gcno *.gcov redis.info lcov-html Makefile.dep dict-benchmark
 
 .PHONY: clean
 

src/Makefile.dep

@@ -1,181 +0,0 @@
-adlist.o: adlist.c adlist.h zmalloc.h
-ae.o: ae.c ae.h zmalloc.h config.h ae_kqueue.c ae_epoll.c ae_select.c ae_evport.c
-ae_epoll.o: ae_epoll.c
-ae_evport.o: ae_evport.c
-ae_kqueue.o: ae_kqueue.c
-ae_select.o: ae_select.c
-anet.o: anet.c fmacros.h anet.h
-aof.o: aof.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- bio.h
-bio.o: bio.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- bio.h
-bitops.o: bitops.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-blocked.o: blocked.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-cluster.o: cluster.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- cluster.h
-config.o: config.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- cluster.h
-crc16.o: crc16.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-crc64.o: crc64.c
-db.o: db.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- cluster.h
-debug.o: debug.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- bio.h
-dict.o: dict.c fmacros.h dict.h zmalloc.h redisassert.h
-endianconv.o: endianconv.c
-geo.o: geo.c geo.h server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- ../deps/geohash-int/geohash_helper.h ../deps/geohash-int/geohash.h
-hyperloglog.o: hyperloglog.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-intset.o: intset.c intset.h zmalloc.h endianconv.h config.h
-latency.o: latency.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-lzf_c.o: lzf_c.c lzfP.h
-lzf_d.o: lzf_d.c lzfP.h
-memtest.o: memtest.c config.h
-multi.o: multi.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-networking.o: networking.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-notify.o: notify.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-object.o: object.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-pqsort.o: pqsort.c
-pubsub.o: pubsub.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-quicklist.o: quicklist.c quicklist.h zmalloc.h ziplist.h util.h sds.h \
- lzf.h
-rand.o: rand.c
-rdb.o: rdb.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- lzf.h
-redis-benchmark.o: redis-benchmark.c fmacros.h ../deps/hiredis/sds.h ae.h \
- ../deps/hiredis/hiredis.h adlist.h zmalloc.h
-redis-check-aof.o: redis-check-aof.c fmacros.h config.h
-redis-check-rdb.o: redis-check-rdb.c server.h fmacros.h config.h \
- solarisfixes.h ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h \
- sds.h dict.h adlist.h zmalloc.h anet.h ziplist.h intset.h version.h \
- util.h latency.h sparkline.h quicklist.h zipmap.h sha1.h endianconv.h \
- crc64.h rdb.h rio.h lzf.h
-redis-cli.o: redis-cli.c fmacros.h version.h ../deps/hiredis/hiredis.h \
- ../deps/hiredis/sds.h zmalloc.h ../deps/linenoise/linenoise.h help.h \
- anet.h ae.h
-release.o: release.c release.h version.h crc64.h
-replication.o: replication.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-rio.o: rio.c fmacros.h rio.h sds.h util.h crc64.h config.h server.h \
- solarisfixes.h ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h \
- dict.h adlist.h zmalloc.h anet.h ziplist.h intset.h version.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h rdb.h
-scripting.o: scripting.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- rand.h cluster.h ../deps/lua/src/lauxlib.h ../deps/lua/src/lua.h \
- ../deps/lua/src/lualib.h
-sds.o: sds.c sds.h sdsalloc.h zmalloc.h
-sentinel.o: sentinel.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- ../deps/hiredis/hiredis.h ../deps/hiredis/async.h \
- ../deps/hiredis/hiredis.h
-server.o: server.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- cluster.h slowlog.h bio.h asciilogo.h
-setproctitle.o: setproctitle.c
-sha1.o: sha1.c solarisfixes.h sha1.h config.h
-slowlog.o: slowlog.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- slowlog.h
-sort.o: sort.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h \
- pqsort.h
-sparkline.o: sparkline.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-syncio.o: syncio.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-t_hash.o: t_hash.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-t_list.o: t_list.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-t_set.o: t_set.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-t_string.o: t_string.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-t_zset.o: t_zset.c server.h fmacros.h config.h solarisfixes.h \
- ../deps/lua/src/lua.h ../deps/lua/src/luaconf.h ae.h sds.h dict.h \
- adlist.h zmalloc.h anet.h ziplist.h intset.h version.h util.h latency.h \
- sparkline.h quicklist.h zipmap.h sha1.h endianconv.h crc64.h rdb.h rio.h
-util.o: util.c fmacros.h util.h sds.h sha1.h
-ziplist.o: ziplist.c zmalloc.h util.h sds.h ziplist.h endianconv.h \
- config.h redisassert.h
-zipmap.o: zipmap.c zmalloc.h endianconv.h config.h
-zmalloc.o: zmalloc.c config.h zmalloc.h

src/aof.c

@@ -616,19 +616,23 @@ int loadAppendOnlyFile(char *filename) {
     struct redis_stat sb;
     int old_aof_state = server.aof_state;
     long loops = 0;
-    off_t valid_up_to = 0; /* Offset of the latest well-formed command loaded. */
-
-    if (fp && redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0) {
-        server.aof_current_size = 0;
-        fclose(fp);
-        return C_ERR;
-    }
+    off_t valid_up_to = 0; /* Offset of latest well-formed command loaded. */
 
     if (fp == NULL) {
         serverLog(LL_WARNING,"Fatal error: can't open the append log file for reading: %s",strerror(errno));
         exit(1);
     }
 
+    /* Handle a zero-length AOF file as a special case. An emtpy AOF file
+     * is a valid AOF because an empty server with AOF enabled will create
+     * a zero length file at startup, that will remain like that if no write
+     * operation is received. */
+    if (fp && redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0) {
+        server.aof_current_size = 0;
+        fclose(fp);
+        return C_ERR;
+    }
+
     /* Temporarily disable AOF, to prevent EXEC from feeding a MULTI
      * to the same file we're about to read. */
     server.aof_state = AOF_OFF;
@@ -636,6 +640,28 @@ int loadAppendOnlyFile(char *filename) {
     fakeClient = createFakeClient();
     startLoading(fp);
 
+    /* Check if this AOF file has an RDB preamble. In that case we need to
+     * load the RDB file and later continue loading the AOF tail. */
+    char sig[5]; /* "REDIS" */
+    if (fread(sig,1,5,fp) != 5 || memcmp(sig,"REDIS",5) != 0) {
+        /* No RDB preamble, seek back at 0 offset. */
+        if (fseek(fp,0,SEEK_SET) == -1) goto readerr;
+    } else {
+        /* RDB preamble. Pass loading the RDB functions. */
+        rio rdb;
+
+        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) {
+            serverLog(LL_WARNING,"Error reading the RDB preamble of the AOF file, AOF loading aborted");
+            goto readerr;
+        } else {
+            serverLog(LL_NOTICE,"Reading the remaining AOF tail...");
+        }
+    }
+
+    /* Read the actual AOF file, in REPL format, command by command. */
     while(1) {
         int argc, j;
         unsigned long len;
@@ -696,6 +722,7 @@ int loadAppendOnlyFile(char *filename) {
         }
 
         /* Run the command in the context of a fake client */
+        fakeClient->cmd = cmd;
         cmd->proc(fakeClient);
 
         /* The fake client should not have a reply */
@@ -706,6 +733,7 @@ int loadAppendOnlyFile(char *filename) {
         /* Clean up. Command code may have changed argv/argc so we use the
          * argv/argc of the client instead of the local variables. */
         freeFakeClientArgv(fakeClient);
+        fakeClient->cmd = NULL;
         if (server.aof_load_truncated) valid_up_to = ftello(fp);
     }
 
@@ -843,7 +871,7 @@ int rewriteSetObject(rio *r, robj *key, robj *o) {
         dictEntry *de;
 
         while((de = dictNext(di)) != NULL) {
-            robj *eleobj = dictGetKey(de);
+            sds ele = dictGetKey(de);
             if (count == 0) {
                 int cmd_items = (items > AOF_REWRITE_ITEMS_PER_CMD) ?
                     AOF_REWRITE_ITEMS_PER_CMD : items;
@@ -852,7 +880,7 @@ int rewriteSetObject(rio *r, robj *key, robj *o) {
                 if (rioWriteBulkString(r,"SADD",4) == 0) return 0;
                 if (rioWriteBulkObject(r,key) == 0) return 0;
             }
-            if (rioWriteBulkObject(r,eleobj) == 0) return 0;
+            if (rioWriteBulkString(r,ele,sdslen(ele)) == 0) return 0;
             if (++count == AOF_REWRITE_ITEMS_PER_CMD) count = 0;
             items--;
         }
@@ -909,7 +937,7 @@ int rewriteSortedSetObject(rio *r, robj *key, robj *o) {
         dictEntry *de;
 
         while((de = dictNext(di)) != NULL) {
-            robj *eleobj = dictGetKey(de);
+            sds ele = dictGetKey(de);
             double *score = dictGetVal(de);
 
             if (count == 0) {
@@ -921,7 +949,7 @@ int rewriteSortedSetObject(rio *r, robj *key, robj *o) {
                 if (rioWriteBulkObject(r,key) == 0) return 0;
             }
             if (rioWriteBulkDouble(r,*score) == 0) return 0;
-            if (rioWriteBulkObject(r,eleobj) == 0) return 0;
+            if (rioWriteBulkString(r,ele,sdslen(ele)) == 0) return 0;
             if (++count == AOF_REWRITE_ITEMS_PER_CMD) count = 0;
             items--;
         }
@@ -945,17 +973,13 @@ static int rioWriteHashIteratorCursor(rio *r, hashTypeIterator *hi, int what) {
         long long vll = LLONG_MAX;
 
         hashTypeCurrentFromZiplist(hi, what, &vstr, &vlen, &vll);
-        if (vstr) {
+        if (vstr)
             return rioWriteBulkString(r, (char*)vstr, vlen);
-        } else {
+        else
             return rioWriteBulkLongLong(r, vll);
-        }
-
     } else if (hi->encoding == OBJ_ENCODING_HT) {
-        robj *value;
-
-        hashTypeCurrentFromHashTable(hi, what, &value);
-        return rioWriteBulkObject(r, value);
+        sds value = hashTypeCurrentFromHashTable(hi, what);
+        return rioWriteBulkString(r, value, sdslen(value));
     }
 
     serverPanic("Unknown hash encoding");
@@ -990,6 +1014,22 @@ int rewriteHashObject(rio *r, robj *key, robj *o) {
     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. */
+int rewriteModuleObject(rio *r, robj *key, robj *o) {
+    RedisModuleIO io;
+    moduleValue *mv = o->ptr;
+    moduleType *mt = mv->type;
+    moduleInitIOContext(io,mt,r);
+    mt->aof_rewrite(&io,key,mv->value);
+    if (io.ctx) {
+        moduleFreeContext(io.ctx);
+        zfree(io.ctx);
+    }
+    return io.error ? 0 : 1;
+}
+
 /* This function is called by the child rewriting the AOF file to read
  * the difference accumulated from the parent into a buffer, that is
  * concatenated at the end of the rewrite. */
@@ -1005,51 +1045,23 @@ ssize_t aofReadDiffFromParent(void) {
     return total;
 }
 
-/* Write a sequence of commands able to fully rebuild the dataset into
- * "filename". Used both by REWRITEAOF and BGREWRITEAOF.
- *
- * In order to minimize the number of commands needed in the rewritten
- * log Redis uses variadic commands when possible, such as RPUSH, SADD
- * and ZADD. However at max AOF_REWRITE_ITEMS_PER_CMD items per time
- * are inserted using a single command. */
-int rewriteAppendOnlyFile(char *filename) {
+int rewriteAppendOnlyFileRio(rio *aof) {
     dictIterator *di = NULL;
     dictEntry *de;
-    rio aof;
-    FILE *fp;
-    char tmpfile[256];
-    int j;
-    long long now = mstime();
-    char byte;
     size_t processed = 0;
+    long long now = mstime();
+    int j;
 
-    /* Note that we have to use a different temp name here compared to the
-     * one used by rewriteAppendOnlyFileBackground() function. */
-    snprintf(tmpfile,256,"temp-rewriteaof-%d.aof", (int) getpid());
-    fp = fopen(tmpfile,"w");
-    if (!fp) {
-        serverLog(LL_WARNING, "Opening the temp file for AOF rewrite in rewriteAppendOnlyFile(): %s", strerror(errno));
-        return C_ERR;
-    }
-
-    server.aof_child_diff = sdsempty();
-    rioInitWithFile(&aof,fp);
-    if (server.aof_rewrite_incremental_fsync)
-        rioSetAutoSync(&aof,AOF_AUTOSYNC_BYTES);
     for (j = 0; j < server.dbnum; j++) {
         char selectcmd[] = "*2\r\n$6\r\nSELECT\r\n";
         redisDb *db = server.db+j;
         dict *d = db->dict;
         if (dictSize(d) == 0) continue;
         di = dictGetSafeIterator(d);
-        if (!di) {
-            fclose(fp);
-            return C_ERR;
-        }
 
         /* SELECT the new DB */
-        if (rioWrite(&aof,selectcmd,sizeof(selectcmd)-1) == 0) goto werr;
-        if (rioWriteBulkLongLong(&aof,j) == 0) goto werr;
+        if (rioWrite(aof,selectcmd,sizeof(selectcmd)-1) == 0) goto werr;
+        if (rioWriteBulkLongLong(aof,j) == 0) goto werr;
 
         /* Iterate this DB writing every entry */
         while((de = dictNext(di)) != NULL) {
@@ -1070,37 +1082,83 @@ int rewriteAppendOnlyFile(char *filename) {
             if (o->type == OBJ_STRING) {
                 /* Emit a SET command */
                 char cmd[]="*3\r\n$3\r\nSET\r\n";
-                if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                if (rioWrite(aof,cmd,sizeof(cmd)-1) == 0) goto werr;
                 /* Key and value */
-                if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
-                if (rioWriteBulkObject(&aof,o) == 0) goto werr;
+                if (rioWriteBulkObject(aof,&key) == 0) goto werr;
+                if (rioWriteBulkObject(aof,o) == 0) goto werr;
             } else if (o->type == OBJ_LIST) {
-                if (rewriteListObject(&aof,&key,o) == 0) goto werr;
+                if (rewriteListObject(aof,&key,o) == 0) goto werr;
             } else if (o->type == OBJ_SET) {
-                if (rewriteSetObject(&aof,&key,o) == 0) goto werr;
+                if (rewriteSetObject(aof,&key,o) == 0) goto werr;
             } else if (o->type == OBJ_ZSET) {
-                if (rewriteSortedSetObject(&aof,&key,o) == 0) goto werr;
+                if (rewriteSortedSetObject(aof,&key,o) == 0) goto werr;
             } else if (o->type == OBJ_HASH) {
-                if (rewriteHashObject(&aof,&key,o) == 0) goto werr;
+                if (rewriteHashObject(aof,&key,o) == 0) goto werr;
+            } else if (o->type == OBJ_MODULE) {
+                if (rewriteModuleObject(aof,&key,o) == 0) goto werr;
             } else {
                 serverPanic("Unknown object type");
             }
             /* Save the expire time */
             if (expiretime != -1) {
                 char cmd[]="*3\r\n$9\r\nPEXPIREAT\r\n";
-                if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
-                if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
-                if (rioWriteBulkLongLong(&aof,expiretime) == 0) goto werr;
+                if (rioWrite(aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                if (rioWriteBulkObject(aof,&key) == 0) goto werr;
+                if (rioWriteBulkLongLong(aof,expiretime) == 0) goto werr;
             }
             /* Read some diff from the parent process from time to time. */
-            if (aof.processed_bytes > processed+1024*10) {
-                processed = aof.processed_bytes;
+            if (aof->processed_bytes > processed+AOF_READ_DIFF_INTERVAL_BYTES) {
+                processed = aof->processed_bytes;
                 aofReadDiffFromParent();
             }
         }
         dictReleaseIterator(di);
         di = NULL;
     }
+    return C_OK;
+
+werr:
+    if (di) dictReleaseIterator(di);
+    return C_ERR;
+}
+
+/* Write a sequence of commands able to fully rebuild the dataset into
+ * "filename". Used both by REWRITEAOF and BGREWRITEAOF.
+ *
+ * In order to minimize the number of commands needed in the rewritten
+ * log Redis uses variadic commands when possible, such as RPUSH, SADD
+ * and ZADD. However at max AOF_REWRITE_ITEMS_PER_CMD items per time
+ * are inserted using a single command. */
+int rewriteAppendOnlyFile(char *filename) {
+    rio aof;
+    FILE *fp;
+    char tmpfile[256];
+    char byte;
+
+    /* Note that we have to use a different temp name here compared to the
+     * one used by rewriteAppendOnlyFileBackground() function. */
+    snprintf(tmpfile,256,"temp-rewriteaof-%d.aof", (int) getpid());
+    fp = fopen(tmpfile,"w");
+    if (!fp) {
+        serverLog(LL_WARNING, "Opening the temp file for AOF rewrite in rewriteAppendOnlyFile(): %s", strerror(errno));
+        return C_ERR;
+    }
+
+    server.aof_child_diff = sdsempty();
+    rioInitWithFile(&aof,fp);
+
+    if (server.aof_rewrite_incremental_fsync)
+        rioSetAutoSync(&aof,AOF_AUTOSYNC_BYTES);
+
+    if (server.aof_use_rdb_preamble) {
+        int error;
+        if (rdbSaveRio(&aof,&error,RDB_SAVE_AOF_PREAMBLE) == C_ERR) {
+            errno = error;
+            goto werr;
+        }
+    } else {
+        if (rewriteAppendOnlyFileRio(&aof) == C_ERR) goto werr;
+    }
 
     /* Do an initial slow fsync here while the parent is still sending
      * data, in order to make the next final fsync faster. */
@@ -1166,7 +1224,6 @@ werr:
     serverLog(LL_WARNING,"Write error writing append only file on disk: %s", strerror(errno));
     fclose(fp);
     unlink(tmpfile);
-    if (di) dictReleaseIterator(di);
     return C_ERR;
 }
 
@@ -1266,6 +1323,7 @@ int rewriteAppendOnlyFileBackground(void) {
 
     if (server.aof_child_pid != -1 || server.rdb_child_pid != -1) return C_ERR;
     if (aofCreatePipes() != C_OK) return C_ERR;
+    openChildInfoPipe();
     start = ustime();
     if ((childpid = fork()) == 0) {
         char tmpfile[256];
@@ -1275,13 +1333,16 @@ int rewriteAppendOnlyFileBackground(void) {
         redisSetProcTitle("redis-aof-rewrite");
         snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid());
         if (rewriteAppendOnlyFile(tmpfile) == C_OK) {
-            size_t private_dirty = zmalloc_get_private_dirty();
+            size_t private_dirty = zmalloc_get_private_dirty(-1);
 
             if (private_dirty) {
                 serverLog(LL_NOTICE,
                     "AOF rewrite: %zu MB of memory used by copy-on-write",
                     private_dirty/(1024*1024));
             }
+
+            server.child_info_data.cow_size = private_dirty;
+            sendChildInfo(CHILD_INFO_TYPE_AOF);
             exitFromChild(0);
         } else {
             exitFromChild(1);
@@ -1292,6 +1353,7 @@ int rewriteAppendOnlyFileBackground(void) {
         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) {
+            closeChildInfoPipe();
             serverLog(LL_WARNING,
                 "Can't rewrite append only file in background: fork: %s",
                 strerror(errno));

src/atomicvar.h

@@ -0,0 +1,94 @@
+/* This file implements atomic counters using __atomic or __sync macros if
+ * available, otherwise synchronizing different threads using a mutex.
+ *
+ * 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
+ *
+ * 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:
+ *
+ *  atomicIncr(mycounter,...);
+ *  atomicGet(mycounter,newvalue);
+ *  doSomethingWith(newvalue);
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2015, 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 <pthread.h>
+
+#ifndef __ATOMIC_VAR_H
+#define __ATOMIC_VAR_H
+
+#if defined(__ATOMIC_RELAXED)
+/* 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 { \
+    dstvar = __atomic_load_n(&var,__ATOMIC_RELAXED); \
+} while(0)
+
+#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 { \
+    dstvar = __sync_sub_and_fetch(&var,0); \
+} while(0)
+
+#else
+/* Implementation using pthread mutex. */
+
+#define atomicIncr(var,count,mutex) do { \
+    pthread_mutex_lock(&mutex); \
+    var += (count); \
+    pthread_mutex_unlock(&mutex); \
+} while(0)
+
+#define atomicDecr(var,count,mutex) do { \
+    pthread_mutex_lock(&mutex); \
+    var -= (count); \
+    pthread_mutex_unlock(&mutex); \
+} while(0)
+
+#define atomicGet(var,dstvar,mutex) do { \
+    pthread_mutex_lock(&mutex); \
+    dstvar = var; \
+    pthread_mutex_unlock(&mutex); \
+} while(0)
+#endif
+
+#endif /* __ATOMIC_VAR_H */

src/bio.c

@@ -63,7 +63,8 @@
 
 static pthread_t bio_threads[BIO_NUM_OPS];
 static pthread_mutex_t bio_mutex[BIO_NUM_OPS];
-static pthread_cond_t bio_condvar[BIO_NUM_OPS];
+static pthread_cond_t bio_newjob_cond[BIO_NUM_OPS];
+static pthread_cond_t bio_step_cond[BIO_NUM_OPS];
 static list *bio_jobs[BIO_NUM_OPS];
 /* The following array is used to hold the number of pending jobs for every
  * OP type. This allows us to export the bioPendingJobsOfType() API that is
@@ -83,6 +84,9 @@ struct bio_job {
 };
 
 void *bioProcessBackgroundJobs(void *arg);
+void lazyfreeFreeObjectFromBioThread(robj *o);
+void lazyfreeFreeDatabaseFromBioThread(dict *ht1, dict *ht2);
+void lazyfreeFreeSlotsMapFromBioThread(zskiplist *sl);
 
 /* Make sure we have enough stack to perform all the things we do in the
  * main thread. */
@@ -98,7 +102,8 @@ void bioInit(void) {
     /* Initialization of state vars and objects */
     for (j = 0; j < BIO_NUM_OPS; j++) {
         pthread_mutex_init(&bio_mutex[j],NULL);
-        pthread_cond_init(&bio_condvar[j],NULL);
+        pthread_cond_init(&bio_newjob_cond[j],NULL);
+        pthread_cond_init(&bio_step_cond[j],NULL);
         bio_jobs[j] = listCreate();
         bio_pending[j] = 0;
     }
@@ -133,7 +138,7 @@ void bioCreateBackgroundJob(int type, void *arg1, void *arg2, void *arg3) {
     pthread_mutex_lock(&bio_mutex[type]);
     listAddNodeTail(bio_jobs[type],job);
     bio_pending[type]++;
-    pthread_cond_signal(&bio_condvar[type]);
+    pthread_cond_signal(&bio_newjob_cond[type]);
     pthread_mutex_unlock(&bio_mutex[type]);
 }
 
@@ -168,7 +173,7 @@ void *bioProcessBackgroundJobs(void *arg) {
 
         /* The loop always starts with the lock hold. */
         if (listLength(bio_jobs[type]) == 0) {
-            pthread_cond_wait(&bio_condvar[type],&bio_mutex[type]);
+            pthread_cond_wait(&bio_newjob_cond[type],&bio_mutex[type]);
             continue;
         }
         /* Pop the job from the queue. */
@@ -183,11 +188,25 @@ void *bioProcessBackgroundJobs(void *arg) {
             close((long)job->arg1);
         } else if (type == BIO_AOF_FSYNC) {
             aof_fsync((long)job->arg1);
+        } else if (type == BIO_LAZY_FREE) {
+            /* What we free changes depending on what arguments are set:
+             * arg1 -> free the object at pointer.
+             * arg2 & arg3 -> free two dictionaries (a Redis DB).
+             * only arg3 -> free the skiplist. */
+            if (job->arg1)
+                lazyfreeFreeObjectFromBioThread(job->arg1);
+            else if (job->arg2 && job->arg3)
+                lazyfreeFreeDatabaseFromBioThread(job->arg2,job->arg3);
+            else if (job->arg3)
+                lazyfreeFreeSlotsMapFromBioThread(job->arg3);
         } else {
             serverPanic("Wrong job type in bioProcessBackgroundJobs().");
         }
         zfree(job);
 
+        /* Unblock threads blocked on bioWaitStepOfType() if any. */
+        pthread_cond_broadcast(&bio_step_cond[type]);
+
         /* Lock again before reiterating the loop, if there are no longer
          * jobs to process we'll block again in pthread_cond_wait(). */
         pthread_mutex_lock(&bio_mutex[type]);
@@ -205,6 +224,28 @@ unsigned long long bioPendingJobsOfType(int type) {
     return val;
 }
 
+/* If there are pending jobs for the specified type, the function blocks
+ * and waits that the next job was processed. Otherwise the function
+ * does not block and returns ASAP.
+ *
+ * The function returns the number of jobs still to process of the
+ * requested type.
+ *
+ * This function is useful when from another thread, we want to wait
+ * a bio.c thread to do more work in a blocking way.
+ */
+unsigned long long bioWaitStepOfType(int type) {
+    unsigned long long val;
+    pthread_mutex_lock(&bio_mutex[type]);
+    val = bio_pending[type];
+    if (val != 0) {
+        pthread_cond_wait(&bio_step_cond[type],&bio_mutex[type]);
+        val = bio_pending[type];
+    }
+    pthread_mutex_unlock(&bio_mutex[type]);
+    return val;
+}
+
 /* Kill the running bio threads in an unclean way. This function should be
  * used only when it's critical to stop the threads for some reason.
  * Currently Redis does this only on crash (for instance on SIGSEGV) in order

src/bio.h

@@ -31,11 +31,12 @@
 void bioInit(void);
 void bioCreateBackgroundJob(int type, void *arg1, void *arg2, void *arg3);
 unsigned long long bioPendingJobsOfType(int type);
-void bioWaitPendingJobsLE(int type, unsigned long long num);
+unsigned long long bioWaitStepOfType(int type);
 time_t bioOlderJobOfType(int type);
 void bioKillThreads(void);
 
 /* Background job opcodes */
 #define BIO_CLOSE_FILE    0 /* Deferred close(2) syscall. */
 #define BIO_AOF_FSYNC     1 /* Deferred AOF fsync. */
-#define BIO_NUM_OPS       2
+#define BIO_LAZY_FREE     2 /* Deferred objects freeing. */
+#define BIO_NUM_OPS       3

src/bitops.c

@@ -907,7 +907,7 @@ void bitfieldCommand(client *c) {
     struct bitfieldOp *ops = NULL; /* Array of ops to execute at end. */
     int owtype = BFOVERFLOW_WRAP; /* Overflow type. */
     int readonly = 1;
-    size_t higest_write_offset = 0;
+    long higest_write_offset = 0;
 
     for (j = 2; j < c->argc; j++) {
         int remargs = c->argc-j-1; /* Remaining args other than current. */
@@ -957,8 +957,7 @@ void bitfieldCommand(client *c) {
 
         if (opcode != BITFIELDOP_GET) {
             readonly = 0;
-            if (higest_write_offset < bitoffset + bits - 1)
-                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);

src/childinfo.c

@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+
+#include "server.h"
+#include <unistd.h>
+
+/* Open a child-parent channel used in order to move information about the
+ * RDB / AOF saving process from the child to the parent (for instance
+ * the amount of copy on write memory used) */
+void openChildInfoPipe(void) {
+    if (pipe(server.child_info_pipe) == -1) {
+        /* On error our two file descriptors should be still set to -1,
+         * but we call anyway cloesChildInfoPipe() since can't hurt. */
+        closeChildInfoPipe();
+    } else if (anetNonBlock(NULL,server.child_info_pipe[0]) != ANET_OK) {
+        closeChildInfoPipe();
+    } else {
+        memset(&server.child_info_data,0,sizeof(server.child_info_data));
+    }
+}
+
+/* Close the pipes opened with openChildInfoPipe(). */
+void closeChildInfoPipe(void) {
+    if (server.child_info_pipe[0] != -1 ||
+        server.child_info_pipe[1] != -1)
+    {
+        close(server.child_info_pipe[0]);
+        close(server.child_info_pipe[1]);
+        server.child_info_pipe[0] = -1;
+        server.child_info_pipe[1] = -1;
+    }
+}
+
+/* Send COW data to parent. The child should call this function after populating
+ * the corresponding fields it want to sent (according to the process type). */
+void sendChildInfo(int ptype) {
+    if (server.child_info_pipe[1] == -1) return;
+    server.child_info_data.magic = CHILD_INFO_MAGIC;
+    server.child_info_data.process_type = ptype;
+    ssize_t wlen = sizeof(server.child_info_data);
+    if (write(server.child_info_pipe[1],&server.child_info_data,wlen) != wlen) {
+        /* Nothing to do on error, this will be detected by the other side. */
+    }
+}
+
+/* Receive COW data from parent. */
+void receiveChildInfo(void) {
+    if (server.child_info_pipe[0] == -1) return;
+    ssize_t wlen = sizeof(server.child_info_data);
+    if (read(server.child_info_pipe[0],&server.child_info_data,wlen) == wlen &&
+        server.child_info_data.magic == CHILD_INFO_MAGIC)
+    {
+        if (server.child_info_data.process_type == CHILD_INFO_TYPE_RDB) {
+            server.stat_rdb_cow_bytes = server.child_info_data.cow_size;
+        } else if (server.child_info_data.process_type == CHILD_INFO_TYPE_AOF) {
+            server.stat_aof_cow_bytes = server.child_info_data.cow_size;
+        }
+    }
+}

src/cluster.c

@@ -129,7 +129,7 @@ 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' || line[0] == '\0') continue;
+        if (line[0] == '\n') continue;
 
         /* Split the line into arguments for processing. */
         argv = sdssplitargs(line,&argc);
@@ -168,7 +168,17 @@ int clusterLoadConfig(char *filename) {
         if ((p = strrchr(argv[1],':')) == NULL) goto fmterr;
         *p = '\0';
         memcpy(n->ip,argv[1],strlen(argv[1])+1);
-        n->port = atoi(p+1);
+        char *port = p+1;
+        char *busp = strchr(port,'@');
+        if (busp) {
+            *busp = '\0';
+            busp++;
+        }
+        n->port = atoi(port);
+        /* In older versions of nodes.conf the "@busport" part is missing.
+         * In this case we set it to the default offset of 10000 from the
+         * base port. */
+        n->cport = busp ? atoi(busp) : n->port + CLUSTER_PORT_INCR;
 
         /* Parse flags */
         p = s = argv[2];
@@ -469,9 +479,14 @@ void clusterInit(void) {
     /* The slots -> keys map is a sorted set. Init it. */
     server.cluster->slots_to_keys = zslCreate();
 
-    /* Set myself->port to my listening port, we'll just need to discover
-     * the IP address via MEET messages. */
+    /* Set myself->port / cport to my listening ports, we'll just need to
+     * discover the IP address via MEET messages. */
     myself->port = server.port;
+    myself->cport = server.port+CLUSTER_PORT_INCR;
+    if (server.cluster_announce_port)
+        myself->port = server.cluster_announce_port;
+    if (server.cluster_announce_bus_port)
+        myself->cport = server.cluster_announce_bus_port;
 
     server.cluster->mf_end = 0;
     resetManualFailover();
@@ -495,7 +510,7 @@ void clusterReset(int hard) {
     if (nodeIsSlave(myself)) {
         clusterSetNodeAsMaster(myself);
         replicationUnsetMaster();
-        emptyDb(NULL);
+        emptyDb(-1,EMPTYDB_NO_FLAGS,NULL);
     }
 
     /* Close slots, reset manual failover state. */
@@ -670,6 +685,7 @@ clusterNode *createClusterNode(char *nodename, int flags) {
     node->link = NULL;
     memset(node->ip,0,sizeof(node->ip));
     node->port = 0;
+    node->cport = 0;
     node->fail_reports = listCreate();
     node->voted_time = 0;
     node->orphaned_time = 0;
@@ -1212,7 +1228,7 @@ void clearNodeFailureIfNeeded(clusterNode *node) {
 /* Return true if we already have a node in HANDSHAKE state matching the
  * specified ip address and port number. This function is used in order to
  * avoid adding a new handshake node for the same address multiple times. */
-int clusterHandshakeInProgress(char *ip, int port) {
+int clusterHandshakeInProgress(char *ip, int port, int cport) {
     dictIterator *di;
     dictEntry *de;
 
@@ -1221,7 +1237,9 @@ int clusterHandshakeInProgress(char *ip, int port) {
         clusterNode *node = dictGetVal(de);
 
         if (!nodeInHandshake(node)) continue;
-        if (!strcasecmp(node->ip,ip) && node->port == port) break;
+        if (!strcasecmp(node->ip,ip) &&
+            node->port == port &&
+            node->cport == cport) break;
     }
     dictReleaseIterator(di);
     return de != NULL;
@@ -1234,7 +1252,7 @@ int clusterHandshakeInProgress(char *ip, int port) {
  *
  * EAGAIN - There is already an handshake in progress for this address.
  * EINVAL - IP or port are not valid. */
-int clusterStartHandshake(char *ip, int port) {
+int clusterStartHandshake(char *ip, int port, int cport) {
     clusterNode *n;
     char norm_ip[NET_IP_STR_LEN];
     struct sockaddr_storage sa;
@@ -1254,7 +1272,7 @@ int clusterStartHandshake(char *ip, int port) {
     }
 
     /* Port sanity check */
-    if (port <= 0 || port > (65535-CLUSTER_PORT_INCR)) {
+    if (port <= 0 || port > 65535 || cport <= 0 || cport > 65535) {
         errno = EINVAL;
         return 0;
     }
@@ -1271,7 +1289,7 @@ int clusterStartHandshake(char *ip, int port) {
             (void*)&(((struct sockaddr_in6 *)&sa)->sin6_addr),
             norm_ip,NET_IP_STR_LEN);
 
-    if (clusterHandshakeInProgress(norm_ip,port)) {
+    if (clusterHandshakeInProgress(norm_ip,port,cport)) {
         errno = EAGAIN;
         return 0;
     }
@@ -1282,6 +1300,7 @@ int clusterStartHandshake(char *ip, int port) {
     n = createClusterNode(NULL,CLUSTER_NODE_HANDSHAKE|CLUSTER_NODE_MEET);
     memcpy(n->ip,norm_ip,sizeof(n->ip));
     n->port = port;
+    n->cport = cport;
     clusterAddNode(n);
     return 1;
 }
@@ -1301,10 +1320,11 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
         sds ci;
 
         ci = representClusterNodeFlags(sdsempty(), flags);
-        serverLog(LL_DEBUG,"GOSSIP %.40s %s:%d %s",
+        serverLog(LL_DEBUG,"GOSSIP %.40s %s:%d@%d %s",
             g->nodename,
             g->ip,
             ntohs(g->port),
+            ntohs(g->cport),
             ci);
         sdsfree(ci);
 
@@ -1338,11 +1358,14 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
             if (node->flags & (CLUSTER_NODE_FAIL|CLUSTER_NODE_PFAIL) &&
                 !(flags & CLUSTER_NODE_NOADDR) &&
                 !(flags & (CLUSTER_NODE_FAIL|CLUSTER_NODE_PFAIL)) &&
-                (strcasecmp(node->ip,g->ip) || node->port != ntohs(g->port)))
+                (strcasecmp(node->ip,g->ip) ||
+                 node->port != ntohs(g->port) ||
+                 node->cport != ntohs(g->cport)))
             {
                 if (node->link) freeClusterLink(node->link);
                 memcpy(node->ip,g->ip,NET_IP_STR_LEN);
                 node->port = ntohs(g->port);
+                node->cport = ntohs(g->cport);
                 node->flags &= ~CLUSTER_NODE_NOADDR;
             }
         } else {
@@ -1356,7 +1379,7 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
                 !(flags & CLUSTER_NODE_NOADDR) &&
                 !clusterBlacklistExists(g->nodename))
             {
-                clusterStartHandshake(g->ip,ntohs(g->port));
+                clusterStartHandshake(g->ip,ntohs(g->port),ntohs(g->cport));
             }
         }
 
@@ -1365,23 +1388,36 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
     }
 }
 
-/* IP -> string conversion. 'buf' is supposed to at least be 46 bytes. */
-void nodeIp2String(char *buf, clusterLink *link) {
-    anetPeerToString(link->fd, buf, NET_IP_STR_LEN, NULL);
+/* IP -> string conversion. 'buf' is supposed to at least be 46 bytes.
+ * If 'announced_ip' length is non-zero, it is used instead of extracting
+ * the IP from the socket peer address. */
+void nodeIp2String(char *buf, clusterLink *link, char *announced_ip) {
+    if (announced_ip[0] != '\0') {
+        memcpy(buf,announced_ip,NET_IP_STR_LEN);
+        buf[NET_IP_STR_LEN-1] = '\0'; /* We are not sure the input is sane. */
+    } else {
+        anetPeerToString(link->fd, buf, NET_IP_STR_LEN, NULL);
+    }
 }
 
 /* Update the node address to the IP address that can be extracted
- * from link->fd, and at the specified port.
- * Also disconnect the node link so that we'll connect again to the new
- * address.
+ * from link->fd, or if hdr->myip is non empty, to the address the node
+ * is announcing us. The port is taken from the packet header as well.
+ *
+ * If the address or port changed, disconnect the node link so that we'll
+ * connect again to the new address.
  *
  * If the ip/port pair are already correct no operation is performed at
  * all.
  *
  * The function returns 0 if the node address is still the same,
  * otherwise 1 is returned. */
-int nodeUpdateAddressIfNeeded(clusterNode *node, clusterLink *link, int port) {
+int nodeUpdateAddressIfNeeded(clusterNode *node, clusterLink *link,
+                              clusterMsg *hdr)
+{
     char ip[NET_IP_STR_LEN] = {0};
+    int port = ntohs(hdr->port);
+    int cport = ntohs(hdr->cport);
 
     /* We don't proceed if the link is the same as the sender link, as this
      * function is designed to see if the node link is consistent with the
@@ -1391,12 +1427,14 @@ int nodeUpdateAddressIfNeeded(clusterNode *node, clusterLink *link, int port) {
      * it is safe to call during packet processing. */
     if (link == node->link) return 0;
 
-    nodeIp2String(ip,link);
-    if (node->port == port && strcmp(ip,node->ip) == 0) return 0;
+    nodeIp2String(ip,link,hdr->myip);
+    if (node->port == port && node->cport == cport &&
+        strcmp(ip,node->ip) == 0) return 0;
 
     /* IP / port is different, update it. */
     memcpy(node->ip,ip,sizeof(ip));
     node->port = port;
+    node->cport = cport;
     if (node->link) freeClusterLink(node->link);
     node->flags &= ~CLUSTER_NODE_NOADDR;
     serverLog(LL_WARNING,"Address updated for node %.40s, now %s:%d",
@@ -1635,7 +1673,7 @@ int clusterProcessPacket(clusterLink *link) {
 
         /* We use incoming MEET messages in order to set the address
          * for 'myself', since only other cluster nodes will send us
-         * MEET messagses on handshakes, when the cluster joins, or
+         * MEET messages on handshakes, when the cluster joins, or
          * later if we changed address, and those nodes will use our
          * official address to connect to us. So by obtaining this address
          * from the socket is a simple way to discover / update our own
@@ -1644,7 +1682,9 @@ int clusterProcessPacket(clusterLink *link) {
          * However if we don't have an address at all, we update the address
          * even with a normal PING packet. If it's wrong it will be fixed
          * by MEET later. */
-        if (type == CLUSTERMSG_TYPE_MEET || myself->ip[0] == '\0') {
+        if ((type == CLUSTERMSG_TYPE_MEET || myself->ip[0] == '\0') &&
+            server.cluster_announce_ip == NULL)
+        {
             char ip[NET_IP_STR_LEN];
 
             if (anetSockName(link->fd,ip,sizeof(ip),NULL) != -1 &&
@@ -1665,8 +1705,9 @@ int clusterProcessPacket(clusterLink *link) {
             clusterNode *node;
 
             node = createClusterNode(NULL,CLUSTER_NODE_HANDSHAKE);
-            nodeIp2String(node->ip,link);
+            nodeIp2String(node->ip,link,hdr->myip);
             node->port = ntohs(hdr->port);
+            node->cport = ntohs(hdr->cport);
             clusterAddNode(node);
             clusterDoBeforeSleep(CLUSTER_TODO_SAVE_CONFIG);
         }
@@ -1696,7 +1737,7 @@ int clusterProcessPacket(clusterLink *link) {
                     serverLog(LL_VERBOSE,
                         "Handshake: we already know node %.40s, "
                         "updating the address if needed.", sender->name);
-                    if (nodeUpdateAddressIfNeeded(sender,link,ntohs(hdr->port)))
+                    if (nodeUpdateAddressIfNeeded(sender,link,hdr))
                     {
                         clusterDoBeforeSleep(CLUSTER_TODO_SAVE_CONFIG|
                                              CLUSTER_TODO_UPDATE_STATE);
@@ -1728,6 +1769,7 @@ int clusterProcessPacket(clusterLink *link) {
                 link->node->flags |= CLUSTER_NODE_NOADDR;
                 link->node->ip[0] = '\0';
                 link->node->port = 0;
+                link->node->cport = 0;
                 freeClusterLink(link);
                 clusterDoBeforeSleep(CLUSTER_TODO_SAVE_CONFIG);
                 return 0;
@@ -1737,7 +1779,7 @@ int clusterProcessPacket(clusterLink *link) {
         /* Update the node address if it changed. */
         if (sender && type == CLUSTERMSG_TYPE_PING &&
             !nodeInHandshake(sender) &&
-            nodeUpdateAddressIfNeeded(sender,link,ntohs(hdr->port)))
+            nodeUpdateAddressIfNeeded(sender,link,hdr))
         {
             clusterDoBeforeSleep(CLUSTER_TODO_SAVE_CONFIG|
                                  CLUSTER_TODO_UPDATE_STATE);
@@ -2134,11 +2176,28 @@ void clusterBuildMessageHdr(clusterMsg *hdr, int type) {
     hdr->type = htons(type);
     memcpy(hdr->sender,myself->name,CLUSTER_NAMELEN);
 
+    /* If cluster-announce-ip option is enabled, force the receivers of our
+     * packets to use the specified address for this node. Otherwise if the
+     * first byte is zero, they'll do auto discovery. */
+    memset(hdr->myip,0,NET_IP_STR_LEN);
+    if (server.cluster_announce_ip) {
+        strncpy(hdr->myip,server.cluster_announce_ip,NET_IP_STR_LEN);
+        hdr->myip[NET_IP_STR_LEN-1] = '\0';
+    }
+
+    /* Handle cluster-announce-port as well. */
+    int announced_port = server.cluster_announce_port ?
+                         server.cluster_announce_port : server.port;
+    int announced_cport = server.cluster_announce_bus_port ?
+                          server.cluster_announce_bus_port :
+                          (server.port + CLUSTER_PORT_INCR);
+
     memcpy(hdr->myslots,master->slots,sizeof(hdr->myslots));
     memset(hdr->slaveof,0,CLUSTER_NAMELEN);
     if (myself->slaveof != NULL)
         memcpy(hdr->slaveof,myself->slaveof->name, CLUSTER_NAMELEN);
-    hdr->port = htons(server.port);
+    hdr->port = htons(announced_port);
+    hdr->cport = htons(announced_cport);
     hdr->flags = htons(myself->flags);
     hdr->state = server.cluster->state;
 
@@ -2274,9 +2333,9 @@ void clusterSendPing(clusterLink *link, int type) {
         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;
-        gossip->notused2 = 0;
         gossipcount++;
     }
 
@@ -3073,6 +3132,31 @@ void clusterCron(void) {
 
     iteration++; /* Number of times this function was called so far. */
 
+    /* We want to take myself->ip in sync with the cluster-announce-ip option.
+     * The option can be set at runtime via CONFIG SET, so we periodically check
+     * if the option changed to reflect this into myself->ip. */
+    {
+        static char *prev_ip = NULL;
+        char *curr_ip = server.cluster_announce_ip;
+        int changed = 0;
+
+        if (prev_ip == NULL && curr_ip != NULL) changed = 1;
+        if (prev_ip != NULL && curr_ip == NULL) changed = 1;
+        if (prev_ip && curr_ip && strcmp(prev_ip,curr_ip)) changed = 1;
+
+        if (changed) {
+            prev_ip = curr_ip;
+            if (prev_ip) prev_ip = zstrdup(prev_ip);
+
+            if (curr_ip) {
+                strncpy(myself->ip,server.cluster_announce_ip,NET_IP_STR_LEN);
+                myself->ip[NET_IP_STR_LEN-1] = '\0';
+            } else {
+                myself->ip[0] = '\0'; /* Force autodetection. */
+            }
+        }
+    }
+
     /* The handshake timeout is the time after which a handshake node that was
      * not turned into a normal node is removed from the nodes. Usually it is
      * just the NODE_TIMEOUT value, but when NODE_TIMEOUT is too small we use
@@ -3100,7 +3184,7 @@ void clusterCron(void) {
             clusterLink *link;
 
             fd = anetTcpNonBlockBindConnect(server.neterr, node->ip,
-                node->port+CLUSTER_PORT_INCR, NET_FIRST_BIND_ADDR);
+                node->cport, NET_FIRST_BIND_ADDR);
             if (fd == -1) {
                 /* We got a synchronous error from connect before
                  * clusterSendPing() had a chance to be called.
@@ -3110,8 +3194,7 @@ void clusterCron(void) {
                 if (node->ping_sent == 0) node->ping_sent = mstime();
                 serverLog(LL_DEBUG, "Unable to connect to "
                     "Cluster Node [%s]:%d -> %s", node->ip,
-                    node->port+CLUSTER_PORT_INCR,
-                    server.neterr);
+                    node->cport, server.neterr);
                 continue;
             }
             link = createClusterLink(node);
@@ -3142,7 +3225,7 @@ void clusterCron(void) {
             node->flags &= ~CLUSTER_NODE_MEET;
 
             serverLog(LL_DEBUG,"Connecting with Node %.40s at %s:%d",
-                    node->name, node->ip, node->port+CLUSTER_PORT_INCR);
+                    node->name, node->ip, node->cport);
         }
     }
     dictReleaseIterator(di);
@@ -3697,10 +3780,11 @@ sds clusterGenNodeDescription(clusterNode *node) {
     sds ci;
 
     /* Node coordinates */
-    ci = sdscatprintf(sdsempty(),"%.40s %s:%d ",
+    ci = sdscatprintf(sdsempty(),"%.40s %s:%d@%d ",
         node->name,
         node->ip,
-        node->port);
+        node->port,
+        node->cport);
 
     /* Flags */
     ci = representClusterNodeFlags(ci, node->flags);
@@ -3883,16 +3967,27 @@ void clusterCommand(client *c) {
         return;
     }
 
-    if (!strcasecmp(c->argv[1]->ptr,"meet") && c->argc == 4) {
-        long long port;
+    if (!strcasecmp(c->argv[1]->ptr,"meet") && (c->argc == 4 || c->argc == 5)) {
+        /* CLUSTER MEET <ip> <port> [cport] */
+        long long port, cport;
 
         if (getLongLongFromObject(c->argv[3], &port) != C_OK) {
-            addReplyErrorFormat(c,"Invalid TCP port specified: %s",
+            addReplyErrorFormat(c,"Invalid TCP base port specified: %s",
                                 (char*)c->argv[3]->ptr);
             return;
         }
 
-        if (clusterStartHandshake(c->argv[2]->ptr,port) == 0 &&
+        if (c->argc == 5) {
+            if (getLongLongFromObject(c->argv[4], &cport) != C_OK) {
+                addReplyErrorFormat(c,"Invalid TCP bus port specified: %s",
+                                    (char*)c->argv[4]->ptr);
+                return;
+            }
+        } else {
+            cport = port + CLUSTER_PORT_INCR;
+        }
+
+        if (clusterStartHandshake(c->argv[2]->ptr,port,cport) == 0 &&
             errno == EINVAL)
         {
             addReplyErrorFormat(c,"Invalid node address specified: %s:%s",
@@ -4172,7 +4267,10 @@ void clusterCommand(client *c) {
         keys = zmalloc(sizeof(robj*)*maxkeys);
         numkeys = getKeysInSlot(slot, keys, maxkeys);
         addReplyMultiBulkLen(c,numkeys);
-        for (j = 0; j < numkeys; j++) addReplyBulk(c,keys[j]);
+        for (j = 0; j < numkeys; j++) {
+            addReplyBulk(c,keys[j]);
+            decrRefCount(keys[j]);
+        }
         zfree(keys);
     } else if (!strcasecmp(c->argv[1]->ptr,"forget") && c->argc == 3) {
         /* CLUSTER FORGET <NODE ID> */
@@ -4652,13 +4750,13 @@ 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. */
@@ -4667,6 +4765,7 @@ void migrateCommand(client *c) {
     /* Initialization */
     copy = 0;
     replace = 0;
+    ttl = 0;
 
     /* Parse additional options */
     for (j = 6; j < c->argc; j++) {
@@ -4742,9 +4841,7 @@ try_again:
 
     /* Create RESTORE payload and generate the protocol to call the command. */
     for (j = 0; j < num_keys; j++) {
-        long long ttl = 0;
-        long long expireat = getExpire(c->db,kv[j]);
-
+        expireat = getExpire(c->db,kv[j]);
         if (expireat != -1) {
             ttl = expireat-mstime();
             if (ttl < 1) ttl = 1;
@@ -4842,20 +4939,12 @@ 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. 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. */
+        /* Translate MIGRATE as DEL for replication/AOF. */
         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);
@@ -4864,8 +4953,8 @@ 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 did not
-     * already queue a different error reported by the destination server. */
+     * 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. */
     if (!error_from_target && socket_error) {
         may_retry = 0;
         goto socket_err;
@@ -4873,11 +4962,7 @@ 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.
-         *
-         * 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. */
+         * avoid SELECT the next time if the target DB is the same. Reply +OK. */
         cs->last_dbid = dbid;
         addReply(c,shared.ok);
     } else {
@@ -4887,6 +4972,7 @@ 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.
@@ -4896,12 +4982,7 @@ 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);
-
-    /* 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]);
+    migrateCloseSocket(c->argv[1],c->argv[2]);
     zfree(newargv);
     newargv = NULL; /* This will get reallocated on retry. */
 

src/cluster.h

@@ -100,7 +100,8 @@ typedef struct clusterNode {
     mstime_t orphaned_time;     /* Starting time of orphaned master condition */
     long long repl_offset;      /* Last known repl offset for this node. */
     char ip[NET_IP_STR_LEN];  /* Latest known IP address of this node */
-    int port;                   /* Latest known port of this node */
+    int port;                   /* Latest known clients port of this node */
+    int cport;                  /* Latest known cluster port of this node. */
     clusterLink *link;          /* TCP/IP link with this node */
     list *fail_reports;         /* List of nodes signaling this as failing */
 } clusterNode;
@@ -171,10 +172,10 @@ typedef struct {
     uint32_t ping_sent;
     uint32_t pong_received;
     char ip[NET_IP_STR_LEN];  /* IP address last time it was seen */
-    uint16_t port;              /* port last time it was seen */
+    uint16_t port;              /* base port last time it was seen */
+    uint16_t cport;             /* cluster port last time it was seen */
     uint16_t flags;             /* node->flags copy */
-    uint16_t notused1;          /* Some room for future improvements. */
-    uint32_t notused2;
+    uint32_t notused1;
 } clusterMsgDataGossip;
 
 typedef struct {
@@ -219,13 +220,13 @@ union clusterMsgData {
     } update;
 };
 
-#define CLUSTER_PROTO_VER 0 /* Cluster bus protocol version. */
+#define CLUSTER_PROTO_VER 1 /* Cluster bus protocol version. */
 
 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 notused0;  /* 2 bytes not used. */
+    uint16_t port;      /* TCP base port number. */
     uint16_t type;      /* Message type */
     uint16_t count;     /* Only used for some kind of messages. */
     uint64_t currentEpoch;  /* The epoch accordingly to the sending node. */
@@ -237,9 +238,10 @@ typedef struct {
     char sender[CLUSTER_NAMELEN]; /* Name of the sender node */
     unsigned char myslots[CLUSTER_SLOTS/8];
     char slaveof[CLUSTER_NAMELEN];
-    char notused1[32];  /* 32 bytes reserved for future usage. */
-    uint16_t port;      /* Sender TCP base port */
-    uint16_t flags;     /* Sender node flags */
+    char myip[NET_IP_STR_LEN];    /* Sender IP, if not all zeroed. */
+    char notused1[34];  /* 34 bytes reserved for future usage. */
+    uint16_t cport;      /* Sender TCP cluster bus port */
+    uint16_t flags;      /* Sender node flags */
     unsigned char state; /* Cluster state from the POV of the sender */
     unsigned char mflags[3]; /* Message flags: CLUSTERMSG_FLAG[012]_... */
     union clusterMsgData data;

src/config.c

@@ -45,9 +45,11 @@ typedef struct configEnum {
 
 configEnum maxmemory_policy_enum[] = {
     {"volatile-lru", MAXMEMORY_VOLATILE_LRU},
+    {"volatile-lfu", MAXMEMORY_VOLATILE_LFU},
     {"volatile-random",MAXMEMORY_VOLATILE_RANDOM},
     {"volatile-ttl",MAXMEMORY_VOLATILE_TTL},
     {"allkeys-lru",MAXMEMORY_ALLKEYS_LRU},
+    {"allkeys-lfu",MAXMEMORY_ALLKEYS_LFU},
     {"allkeys-random",MAXMEMORY_ALLKEYS_RANDOM},
     {"noeviction",MAXMEMORY_NO_EVICTION},
     {NULL, 0}
@@ -153,6 +155,20 @@ void resetServerSaveParams(void) {
     server.saveparamslen = 0;
 }
 
+void queueLoadModule(sds path, sds *argv, int argc) {
+    int i;
+    struct moduleLoadQueueEntry *loadmod;
+
+    loadmod = zmalloc(sizeof(struct moduleLoadQueueEntry));
+    loadmod->argv = zmalloc(sizeof(robj*)*argc);
+    loadmod->path = sdsnew(path);
+    loadmod->argc = argc;
+    for (i = 0; i < argc; i++) {
+        loadmod->argv[i] = createRawStringObject(argv[i],sdslen(argv[i]));
+    }
+    listAddNodeTail(server.loadmodule_queue,loadmod);
+}
+
 void loadServerConfigFromString(char *config) {
     char *err = NULL;
     int linenum = 0, totlines, i;
@@ -308,6 +324,18 @@ void loadServerConfigFromString(char *config) {
                 err = "maxmemory-samples must be 1 or greater";
                 goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"lfu-log-factor") && argc == 2) {
+            server.lfu_log_factor = atoi(argv[1]);
+            if (server.maxmemory_samples < 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) {
+                err = "lfu-decay-time must be 0 or greater";
+                goto loaderr;
+            }
         } else if (!strcasecmp(argv[0],"slaveof") && argc == 3) {
             slaveof_linenum = linenum;
             server.masterhost = sdsnew(argv[1]);
@@ -375,6 +403,22 @@ void loadServerConfigFromString(char *config) {
             if ((server.activerehashing = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"lazyfree-lazy-eviction") && argc == 2) {
+            if ((server.lazyfree_lazy_eviction = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"lazyfree-lazy-expire") && argc == 2) {
+            if ((server.lazyfree_lazy_expire = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"lazyfree-lazy-server-del") && argc == 2){
+            if ((server.lazyfree_lazy_server_del = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"slave-lazy-flush") && argc == 2) {
+            if ((server.repl_slave_lazy_flush = 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;
@@ -431,6 +475,10 @@ void loadServerConfigFromString(char *config) {
             if ((server.aof_load_truncated = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"aof-use-rdb-preamble") && argc == 2) {
+            if ((server.aof_use_rdb_preamble = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
         } else if (!strcasecmp(argv[0],"requirepass") && argc == 2) {
             if (strlen(argv[1]) > CONFIG_AUTHPASS_MAX_LEN) {
                 err = "Password is longer than CONFIG_AUTHPASS_MAX_LEN";
@@ -498,6 +546,25 @@ void loadServerConfigFromString(char *config) {
         } else if (!strcasecmp(argv[0],"cluster-config-file") && argc == 2) {
             zfree(server.cluster_configfile);
             server.cluster_configfile = zstrdup(argv[1]);
+        } else if (!strcasecmp(argv[0],"cluster-announce-ip") && argc == 2) {
+            zfree(server.cluster_announce_ip);
+            server.cluster_announce_ip = zstrdup(argv[1]);
+        } else if (!strcasecmp(argv[0],"cluster-announce-port") && argc == 2) {
+            server.cluster_announce_port = atoi(argv[1]);
+            if (server.cluster_announce_port < 0 ||
+                server.cluster_announce_port > 65535)
+            {
+                err = "Invalid port"; goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"cluster-announce-bus-port") &&
+                   argc == 2)
+        {
+            server.cluster_announce_bus_port = atoi(argv[1]);
+            if (server.cluster_announce_bus_port < 0 ||
+                server.cluster_announce_bus_port > 65535)
+            {
+                err = "Invalid port"; goto loaderr;
+            }
         } else if (!strcasecmp(argv[0],"cluster-require-full-coverage") &&
                     argc == 2)
         {
@@ -608,6 +675,8 @@ void loadServerConfigFromString(char *config) {
                     "Allowed values: 'upstart', 'systemd', 'auto', or 'no'";
                 goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"loadmodule") && argc >= 2) {
+            queueLoadModule(argv[1],&argv[2],argc-2);
         } else if (!strcasecmp(argv[0],"sentinel")) {
             /* argc == 1 is handled by main() as we need to enter the sentinel
              * mode ASAP. */
@@ -740,6 +809,9 @@ void configSetCommand(client *c) {
     } config_set_special_field("masterauth") {
         zfree(server.masterauth);
         server.masterauth = ((char*)o->ptr)[0] ? zstrdup(o->ptr) : NULL;
+    } config_set_special_field("cluster-announce-ip") {
+        zfree(server.cluster_announce_ip);
+        server.cluster_announce_ip = ((char*)o->ptr)[0] ? zstrdup(o->ptr) : NULL;
     } config_set_special_field("maxclients") {
         int orig_value = server.maxclients;
 
@@ -887,6 +959,8 @@ void configSetCommand(client *c) {
       "aof-rewrite-incremental-fsync",server.aof_rewrite_incremental_fsync) {
     } config_set_bool_field(
       "aof-load-truncated",server.aof_load_truncated) {
+    } config_set_bool_field(
+      "aof-use-rdb-preamble",server.aof_use_rdb_preamble) {
     } config_set_bool_field(
       "slave-serve-stale-data",server.repl_serve_stale_data) {
     } config_set_bool_field(
@@ -897,6 +971,14 @@ void configSetCommand(client *c) {
       "protected-mode",server.protected_mode) {
     } config_set_bool_field(
       "stop-writes-on-bgsave-error",server.stop_writes_on_bgsave_err) {
+    } config_set_bool_field(
+      "lazyfree-lazy-eviction",server.lazyfree_lazy_eviction) {
+    } config_set_bool_field(
+      "lazyfree-lazy-expire",server.lazyfree_lazy_expire) {
+    } config_set_bool_field(
+      "lazyfree-lazy-server-del",server.lazyfree_lazy_server_del) {
+    } config_set_bool_field(
+      "slave-lazy-flush",server.repl_slave_lazy_flush) {
     } config_set_bool_field(
       "no-appendfsync-on-rewrite",server.aof_no_fsync_on_rewrite) {
 
@@ -906,6 +988,10 @@ void configSetCommand(client *c) {
       "tcp-keepalive",server.tcpkeepalive,0,LLONG_MAX) {
     } config_set_numerical_field(
       "maxmemory-samples",server.maxmemory_samples,1,LLONG_MAX) {
+    } config_set_numerical_field(
+      "lfu-log-factor",server.lfu_log_factor,0,LLONG_MAX) {
+    } config_set_numerical_field(
+      "lfu-decay-time",server.lfu_decay_time,0,LLONG_MAX) {
     } config_set_numerical_field(
       "timeout",server.maxidletime,0,LONG_MAX) {
     } config_set_numerical_field(
@@ -958,6 +1044,10 @@ void configSetCommand(client *c) {
         refreshGoodSlavesCount();
     } config_set_numerical_field(
       "cluster-node-timeout",server.cluster_node_timeout,0,LLONG_MAX) {
+    } config_set_numerical_field(
+      "cluster-announce-port",server.cluster_announce_port,0,65535) {
+    } config_set_numerical_field(
+      "cluster-announce-bus-port",server.cluster_announce_bus_port,0,65535) {
     } config_set_numerical_field(
       "cluster-migration-barrier",server.cluster_migration_barrier,0,LLONG_MAX){
     } config_set_numerical_field(
@@ -1062,6 +1152,7 @@ void configGetCommand(client *c) {
     config_get_string_field("dbfilename",server.rdb_filename);
     config_get_string_field("requirepass",server.requirepass);
     config_get_string_field("masterauth",server.masterauth);
+    config_get_string_field("cluster-announce-ip",server.cluster_announce_ip);
     config_get_string_field("unixsocket",server.unixsocket);
     config_get_string_field("logfile",server.logfile);
     config_get_string_field("pidfile",server.pidfile);
@@ -1099,6 +1190,8 @@ void configGetCommand(client *c) {
     config_get_numerical_field("slowlog-max-len",
             server.slowlog_max_len);
     config_get_numerical_field("port",server.port);
+    config_get_numerical_field("cluster-announce-port",server.cluster_announce_port);
+    config_get_numerical_field("cluster-announce-bus-port",server.cluster_announce_bus_port);
     config_get_numerical_field("tcp-backlog",server.tcp_backlog);
     config_get_numerical_field("databases",server.dbnum);
     config_get_numerical_field("repl-ping-slave-period",server.repl_ping_slave_period);
@@ -1142,6 +1235,16 @@ void configGetCommand(client *c) {
             server.aof_rewrite_incremental_fsync);
     config_get_bool_field("aof-load-truncated",
             server.aof_load_truncated);
+    config_get_bool_field("aof-use-rdb-preamble",
+            server.aof_use_rdb_preamble);
+    config_get_bool_field("lazyfree-lazy-eviction",
+            server.lazyfree_lazy_eviction);
+    config_get_bool_field("lazyfree-lazy-expire",
+            server.lazyfree_lazy_expire);
+    config_get_bool_field("lazyfree-lazy-server-del",
+            server.lazyfree_lazy_server_del);
+    config_get_bool_field("slave-lazy-flush",
+            server.repl_slave_lazy_flush);
 
     /* Enum values */
     config_get_enum_field("maxmemory-policy",
@@ -1781,6 +1884,8 @@ int rewriteConfig(char *path) {
     rewriteConfigYesNoOption(state,"daemonize",server.daemonize,0);
     rewriteConfigStringOption(state,"pidfile",server.pidfile,CONFIG_DEFAULT_PID_FILE);
     rewriteConfigNumericalOption(state,"port",server.port,CONFIG_DEFAULT_SERVER_PORT);
+    rewriteConfigNumericalOption(state,"cluster-announce-port",server.cluster_announce_port,CONFIG_DEFAULT_CLUSTER_ANNOUNCE_PORT);
+    rewriteConfigNumericalOption(state,"cluster-announce-bus-port",server.cluster_announce_bus_port,CONFIG_DEFAULT_CLUSTER_ANNOUNCE_BUS_PORT);
     rewriteConfigNumericalOption(state,"tcp-backlog",server.tcp_backlog,CONFIG_DEFAULT_TCP_BACKLOG);
     rewriteConfigBindOption(state);
     rewriteConfigStringOption(state,"unixsocket",server.unixsocket,NULL);
@@ -1803,6 +1908,7 @@ int rewriteConfig(char *path) {
     rewriteConfigSlaveofOption(state);
     rewriteConfigStringOption(state,"slave-announce-ip",server.slave_announce_ip,CONFIG_DEFAULT_SLAVE_ANNOUNCE_IP);
     rewriteConfigStringOption(state,"masterauth",server.masterauth,NULL);
+    rewriteConfigStringOption(state,"cluster-announce-ip",server.cluster_announce_ip,NULL);
     rewriteConfigYesNoOption(state,"slave-serve-stale-data",server.repl_serve_stale_data,CONFIG_DEFAULT_SLAVE_SERVE_STALE_DATA);
     rewriteConfigYesNoOption(state,"slave-read-only",server.repl_slave_ro,CONFIG_DEFAULT_SLAVE_READ_ONLY);
     rewriteConfigNumericalOption(state,"repl-ping-slave-period",server.repl_ping_slave_period,CONFIG_DEFAULT_REPL_PING_SLAVE_PERIOD);
@@ -1851,7 +1957,12 @@ int rewriteConfig(char *path) {
     rewriteConfigNumericalOption(state,"hz",server.hz,CONFIG_DEFAULT_HZ);
     rewriteConfigYesNoOption(state,"aof-rewrite-incremental-fsync",server.aof_rewrite_incremental_fsync,CONFIG_DEFAULT_AOF_REWRITE_INCREMENTAL_FSYNC);
     rewriteConfigYesNoOption(state,"aof-load-truncated",server.aof_load_truncated,CONFIG_DEFAULT_AOF_LOAD_TRUNCATED);
+    rewriteConfigYesNoOption(state,"aof-use-rdb-preamble",server.aof_use_rdb_preamble,CONFIG_DEFAULT_AOF_USE_RDB_PREAMBLE);
     rewriteConfigEnumOption(state,"supervised",server.supervised_mode,supervised_mode_enum,SUPERVISED_NONE);
+    rewriteConfigYesNoOption(state,"lazyfree-lazy-eviction",server.lazyfree_lazy_eviction,CONFIG_DEFAULT_LAZYFREE_LAZY_EVICTION);
+    rewriteConfigYesNoOption(state,"lazyfree-lazy-expire",server.lazyfree_lazy_expire,CONFIG_DEFAULT_LAZYFREE_LAZY_EXPIRE);
+    rewriteConfigYesNoOption(state,"lazyfree-lazy-server-del",server.lazyfree_lazy_server_del,CONFIG_DEFAULT_LAZYFREE_LAZY_SERVER_DEL);
+    rewriteConfigYesNoOption(state,"slave-lazy-flush",server.repl_slave_lazy_flush,CONFIG_DEFAULT_SLAVE_LAZY_FLUSH);
 
     /* Rewrite Sentinel config if in Sentinel mode. */
     if (server.sentinel_mode) rewriteConfigSentinelOption(state);

src/db.c

@@ -29,14 +29,11 @@
 
 #include "server.h"
 #include "cluster.h"
+#include "atomicvar.h"
 
 #include <signal.h>
 #include <ctype.h>
 
-void slotToKeyAdd(robj *key);
-void slotToKeyDel(robj *key);
-void slotToKeyFlush(void);
-
 /*-----------------------------------------------------------------------------
  * C-level DB API
  *----------------------------------------------------------------------------*/
@@ -56,7 +53,13 @@ robj *lookupKey(redisDb *db, robj *key, int flags) {
             server.aof_child_pid == -1 &&
             !(flags & LOOKUP_NOTOUCH))
         {
-            val->lru = LRU_CLOCK();
+            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;
+            } else {
+                val->lru = LRU_CLOCK();
+            }
         }
         return val;
     } else {
@@ -172,7 +175,14 @@ void dbOverwrite(redisDb *db, robj *key, robj *val) {
     dictEntry *de = dictFind(db->dict,key->ptr);
 
     serverAssertWithInfo(NULL,key,de != NULL);
-    dictReplace(db->dict, key->ptr, val);
+    if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
+        robj *old = dictGetVal(de);
+        int saved_lru = old->lru;
+        dictReplace(db->dict, key->ptr, val);
+        val->lru = saved_lru;
+    } else {
+        dictReplace(db->dict, key->ptr, val);
+    }
 }
 
 /* High level Set operation. This function can be used in order to set
@@ -223,7 +233,7 @@ robj *dbRandomKey(redisDb *db) {
 }
 
 /* Delete a key, value, and associated expiration entry if any, from the DB */
-int dbDelete(redisDb *db, robj *key) {
+int dbSyncDelete(redisDb *db, robj *key) {
     /* Deleting an entry from the expires dict will not free the sds of
      * the key, because it is shared with the main dictionary. */
     if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);
@@ -235,6 +245,13 @@ int dbDelete(redisDb *db, robj *key) {
     }
 }
 
+/* This is a wrapper whose behavior depends on the Redis lazy free
+ * configuration. Deletes the key synchronously or asynchronously. */
+int dbDelete(redisDb *db, robj *key) {
+    return server.lazyfree_lazy_server_del ? dbAsyncDelete(db,key) :
+                                             dbSyncDelete(db,key);
+}
+
 /* Prepare the string object stored at 'key' to be modified destructively
  * to implement commands like SETBIT or APPEND.
  *
@@ -273,16 +290,46 @@ robj *dbUnshareStringValue(redisDb *db, robj *key, robj *o) {
     return o;
 }
 
-long long emptyDb(void(callback)(void*)) {
-    int j;
+/* Remove all keys from all the databases in a Redis server.
+ * If callback is given the function is called from time to time to
+ * signal that work is in progress.
+ *
+ * The dbnum can be -1 if all teh DBs should be flushed, or the specified
+ * DB number if we want to flush only a single Redis database number.
+ *
+ * Flags are be EMPTYDB_NO_FLAGS if no special flags are specified or
+ * EMPTYDB_ASYNC if we want the memory to be freed in a different thread
+ * and the function to return ASAP.
+ *
+ * On success the fuction returns the number of keys removed from the
+ * database(s). Otherwise -1 is returned in the specific case the
+ * DB number is out of range, and errno is set to EINVAL. */
+long long emptyDb(int dbnum, int flags, void(callback)(void*)) {
+    int j, async = (flags & EMPTYDB_ASYNC);
     long long removed = 0;
 
+    if (dbnum < -1 || dbnum >= server.dbnum) {
+        errno = EINVAL;
+        return -1;
+    }
+
     for (j = 0; j < server.dbnum; j++) {
+        if (dbnum != -1 && dbnum != j) continue;
         removed += dictSize(server.db[j].dict);
-        dictEmpty(server.db[j].dict,callback);
-        dictEmpty(server.db[j].expires,callback);
+        if (async) {
+            emptyDbAsync(&server.db[j]);
+        } else {
+            dictEmpty(server.db[j].dict,callback);
+            dictEmpty(server.db[j].expires,callback);
+        }
+    }
+    if (server.cluster_enabled) {
+        if (async) {
+            slotToKeyFlushAsync();
+        } else {
+            slotToKeyFlush();
+        }
     }
-    if (server.cluster_enabled) slotToKeyFlush();
     return removed;
 }
 
@@ -314,18 +361,49 @@ void signalFlushedDb(int dbid) {
  * Type agnostic commands operating on the key space
  *----------------------------------------------------------------------------*/
 
+/* Return the set of flags to use for the emptyDb() call for FLUSHALL
+ * and FLUSHDB commands.
+ *
+ * Currently the command just attempts to parse the "ASYNC" option. It
+ * also checks if the command arity is wrong.
+ *
+ * On success C_OK is returned and the flags are stored in *flags, otherwise
+ * C_ERR is returned and the function sends an error to the client. */
+int getFlushCommandFlags(client *c, int *flags) {
+    /* Parse the optional ASYNC option. */
+    if (c->argc > 1) {
+        if (c->argc > 2 || strcasecmp(c->argv[1]->ptr,"async")) {
+            addReply(c,shared.syntaxerr);
+            return C_ERR;
+        }
+        *flags = EMPTYDB_ASYNC;
+    } else {
+        *flags = EMPTYDB_NO_FLAGS;
+    }
+    return C_OK;
+}
+
+/* FLUSHDB [ASYNC]
+ *
+ * Flushes the currently SELECTed Redis DB. */
 void flushdbCommand(client *c) {
-    server.dirty += dictSize(c->db->dict);
+    int flags;
+
+    if (getFlushCommandFlags(c,&flags) == C_ERR) return;
     signalFlushedDb(c->db->id);
-    dictEmpty(c->db->dict,NULL);
-    dictEmpty(c->db->expires,NULL);
-    if (server.cluster_enabled) slotToKeyFlush();
+    server.dirty += emptyDb(c->db->id,flags,NULL);
     addReply(c,shared.ok);
 }
 
+/* FLUSHALL [ASYNC]
+ *
+ * Flushes the whole server data set. */
 void flushallCommand(client *c) {
+    int flags;
+
+    if (getFlushCommandFlags(c,&flags) == C_ERR) return;
     signalFlushedDb(-1);
-    server.dirty += emptyDb(NULL);
+    server.dirty += emptyDb(-1,flags,NULL);
     addReply(c,shared.ok);
     if (server.rdb_child_pid != -1) {
         kill(server.rdb_child_pid,SIGUSR1);
@@ -341,20 +419,31 @@ void flushallCommand(client *c) {
     server.dirty++;
 }
 
-void delCommand(client *c) {
-    int deleted = 0, j;
+/* This command implements DEL and LAZYDEL. */
+void delGenericCommand(client *c, int lazy) {
+    int numdel = 0, j;
 
     for (j = 1; j < c->argc; j++) {
         expireIfNeeded(c->db,c->argv[j]);
-        if (dbDelete(c->db,c->argv[j])) {
+        int deleted  = lazy ? dbAsyncDelete(c->db,c->argv[j]) :
+                              dbSyncDelete(c->db,c->argv[j]);
+        if (deleted) {
             signalModifiedKey(c->db,c->argv[j]);
             notifyKeyspaceEvent(NOTIFY_GENERIC,
                 "del",c->argv[j],c->db->id);
             server.dirty++;
-            deleted++;
+            numdel++;
         }
     }
-    addReplyLongLong(c,deleted);
+    addReplyLongLong(c,numdel);
+}
+
+void delCommand(client *c) {
+    delGenericCommand(c,0);
+}
+
+void unlinkCommand(client *c) {
+    delGenericCommand(c,1);
 }
 
 /* EXISTS key1 key2 ... key_N.
@@ -439,16 +528,16 @@ void scanCallback(void *privdata, const dictEntry *de) {
         sds sdskey = dictGetKey(de);
         key = createStringObject(sdskey, sdslen(sdskey));
     } else if (o->type == OBJ_SET) {
-        key = dictGetKey(de);
-        incrRefCount(key);
+        sds keysds = dictGetKey(de);
+        key = createStringObject(keysds,sdslen(keysds));
     } else if (o->type == OBJ_HASH) {
-        key = dictGetKey(de);
-        incrRefCount(key);
-        val = dictGetVal(de);
-        incrRefCount(val);
+        sds sdskey = dictGetKey(de);
+        sds sdsval = dictGetVal(de);
+        key = createStringObject(sdskey,sdslen(sdskey));
+        val = createStringObject(sdsval,sdslen(sdsval));
     } else if (o->type == OBJ_ZSET) {
-        key = dictGetKey(de);
-        incrRefCount(key);
+        sds sdskey = dictGetKey(de);
+        key = createStringObject(sdskey,sdslen(sdskey));
         val = createStringObjectFromLongDouble(*(double*)dictGetVal(de),0);
     } else {
         serverPanic("Type not handled in SCAN callback.");
@@ -694,6 +783,10 @@ void typeCommand(client *c) {
         case OBJ_SET: type = "set"; break;
         case OBJ_ZSET: type = "zset"; break;
         case OBJ_HASH: type = "hash"; break;
+        case OBJ_MODULE: {
+            moduleValue *mv = o->ptr;
+            type = mv->type->name;
+        }; break;
         default: type = "unknown"; break;
         }
     }
@@ -850,7 +943,7 @@ void setExpire(redisDb *db, robj *key, long long when) {
     /* Reuse the sds from the main dict in the expire dict */
     kde = dictFind(db->dict,key->ptr);
     serverAssertWithInfo(NULL,key,kde != NULL);
-    de = dictReplaceRaw(db->expires,dictGetKey(kde));
+    de = dictAddOrFind(db->expires,dictGetKey(kde));
     dictSetSignedIntegerVal(de,when);
 }
 
@@ -877,10 +970,10 @@ long long getExpire(redisDb *db, robj *key) {
  * AOF and the master->slave link guarantee operation ordering, everything
  * will be consistent even if we allow write operations against expiring
  * keys. */
-void propagateExpire(redisDb *db, robj *key) {
+void propagateExpire(redisDb *db, robj *key, int lazy) {
     robj *argv[2];
 
-    argv[0] = shared.del;
+    argv[0] = lazy ? shared.unlink : shared.del;
     argv[1] = key;
     incrRefCount(argv[0]);
     incrRefCount(argv[1]);
@@ -923,137 +1016,11 @@ int expireIfNeeded(redisDb *db, robj *key) {
 
     /* Delete the key */
     server.stat_expiredkeys++;
-    propagateExpire(db,key);
+    propagateExpire(db,key,server.lazyfree_lazy_expire);
     notifyKeyspaceEvent(NOTIFY_EXPIRED,
         "expired",key,db->id);
-    return dbDelete(db,key);
-}
-
-/*-----------------------------------------------------------------------------
- * Expires Commands
- *----------------------------------------------------------------------------*/
-
-/* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT
- * and PEXPIREAT. Because the commad second argument may be relative or absolute
- * the "basetime" argument is used to signal what the base time is (either 0
- * for *AT variants of the command, or the current time for relative expires).
- *
- * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for
- * the argv[2] parameter. The basetime is always specified in milliseconds. */
-void expireGenericCommand(client *c, long long basetime, int unit) {
-    robj *key = c->argv[1], *param = c->argv[2];
-    long long when; /* unix time in milliseconds when the key will expire. */
-
-    if (getLongLongFromObjectOrReply(c, param, &when, NULL) != C_OK)
-        return;
-
-    if (unit == UNIT_SECONDS) when *= 1000;
-    when += basetime;
-
-    /* No key, return zero. */
-    if (lookupKeyWrite(c->db,key) == NULL) {
-        addReply(c,shared.czero);
-        return;
-    }
-
-    /* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past
-     * should never be executed as a DEL when load the AOF or in the context
-     * of a slave instance.
-     *
-     * Instead we take the other branch of the IF statement setting an expire
-     * (possibly in the past) and wait for an explicit DEL from the master. */
-    if (when <= mstime() && !server.loading && !server.masterhost) {
-        robj *aux;
-
-        serverAssertWithInfo(c,key,dbDelete(c->db,key));
-        server.dirty++;
-
-        /* Replicate/AOF this as an explicit DEL. */
-        aux = createStringObject("DEL",3);
-        rewriteClientCommandVector(c,2,aux,key);
-        decrRefCount(aux);
-        signalModifiedKey(c->db,key);
-        notifyKeyspaceEvent(NOTIFY_GENERIC,"del",key,c->db->id);
-        addReply(c, shared.cone);
-        return;
-    } else {
-        setExpire(c->db,key,when);
-        addReply(c,shared.cone);
-        signalModifiedKey(c->db,key);
-        notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",key,c->db->id);
-        server.dirty++;
-        return;
-    }
-}
-
-void expireCommand(client *c) {
-    expireGenericCommand(c,mstime(),UNIT_SECONDS);
-}
-
-void expireatCommand(client *c) {
-    expireGenericCommand(c,0,UNIT_SECONDS);
-}
-
-void pexpireCommand(client *c) {
-    expireGenericCommand(c,mstime(),UNIT_MILLISECONDS);
-}
-
-void pexpireatCommand(client *c) {
-    expireGenericCommand(c,0,UNIT_MILLISECONDS);
-}
-
-void ttlGenericCommand(client *c, int output_ms) {
-    long long expire, ttl = -1;
-
-    /* If the key does not exist at all, return -2 */
-    if (lookupKeyReadWithFlags(c->db,c->argv[1],LOOKUP_NOTOUCH) == NULL) {
-        addReplyLongLong(c,-2);
-        return;
-    }
-    /* The key exists. Return -1 if it has no expire, or the actual
-     * TTL value otherwise. */
-    expire = getExpire(c->db,c->argv[1]);
-    if (expire != -1) {
-        ttl = expire-mstime();
-        if (ttl < 0) ttl = 0;
-    }
-    if (ttl == -1) {
-        addReplyLongLong(c,-1);
-    } else {
-        addReplyLongLong(c,output_ms ? ttl : ((ttl+500)/1000));
-    }
-}
-
-void ttlCommand(client *c) {
-    ttlGenericCommand(c, 0);
-}
-
-void pttlCommand(client *c) {
-    ttlGenericCommand(c, 1);
-}
-
-void persistCommand(client *c) {
-    dictEntry *de;
-
-    de = dictFind(c->db->dict,c->argv[1]->ptr);
-    if (de == NULL) {
-        addReply(c,shared.czero);
-    } else {
-        if (removeExpire(c->db,c->argv[1])) {
-            addReply(c,shared.cone);
-            server.dirty++;
-        } else {
-            addReply(c,shared.czero);
-        }
-    }
-}
-
-/* TOUCH key1 [key2 key3 ... keyN] */
-void touchCommand(client *c) {
-    int touched = 0;
-    for (int j = 1; j < c->argc; j++)
-        if (lookupKeyRead(c->db,c->argv[j]) != NULL) touched++;
-    addReplyLongLong(c,touched);
+    return server.lazyfree_lazy_expire ? dbAsyncDelete(db,key) :
+                                         dbSyncDelete(db,key);
 }
 
 /* -----------------------------------------------------------------------------
@@ -1093,7 +1060,9 @@ int *getKeysUsingCommandTable(struct redisCommand *cmd,robj **argv, int argc, in
  * This function uses the command table if a command-specific helper function
  * is not required, otherwise it calls the command-specific function. */
 int *getKeysFromCommand(struct redisCommand *cmd, robj **argv, int argc, int *numkeys) {
-    if (cmd->getkeys_proc) {
+    if (cmd->flags & CMD_MODULE_GETKEYS) {
+        return moduleGetCommandKeysViaAPI(cmd,argv,argc,numkeys);
+    } else if (!(cmd->flags & CMD_MODULE) && cmd->getkeys_proc) {
         return cmd->getkeys_proc(cmd,argv,argc,numkeys);
     } else {
         return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
@@ -1240,14 +1209,13 @@ int *migrateGetKeys(struct redisCommand *cmd, robj **argv, int argc, int *numkey
 void slotToKeyAdd(robj *key) {
     unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
 
-    zslInsert(server.cluster->slots_to_keys,hashslot,key);
-    incrRefCount(key);
+    sds sdskey = sdsdup(key->ptr);
+    zslInsert(server.cluster->slots_to_keys,hashslot,sdskey);
 }
 
 void slotToKeyDel(robj *key) {
     unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
-
-    zslDelete(server.cluster->slots_to_keys,hashslot,key);
+    zslDelete(server.cluster->slots_to_keys,hashslot,key->ptr,NULL);
 }
 
 void slotToKeyFlush(void) {
@@ -1255,6 +1223,9 @@ void slotToKeyFlush(void) {
     server.cluster->slots_to_keys = zslCreate();
 }
 
+/* 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;
@@ -1265,7 +1236,7 @@ unsigned int getKeysInSlot(unsigned int hashslot, robj **keys, unsigned int coun
 
     n = zslFirstInRange(server.cluster->slots_to_keys, &range);
     while(n && n->score == hashslot && count--) {
-        keys[j++] = n->obj;
+        keys[j++] = createStringObject(n->ele,sdslen(n->ele));
         n = n->level[0].forward;
     }
     return j;
@@ -1283,9 +1254,9 @@ unsigned int delKeysInSlot(unsigned int hashslot) {
 
     n = zslFirstInRange(server.cluster->slots_to_keys, &range);
     while(n && n->score == hashslot) {
-        robj *key = n->obj;
+        sds sdskey = n->ele;
+        robj *key = createStringObject(sdskey,sdslen(sdskey));
         n = n->level[0].forward; /* Go to the next item before freeing it. */
-        incrRefCount(key); /* Protect the object while freeing it. */
         dbDelete(&server.db[0],key);
         decrRefCount(key);
         j++;
@@ -1307,7 +1278,7 @@ unsigned int countKeysInSlot(unsigned int hashslot) {
 
     /* Use rank of first element, if any, to determine preliminary count */
     if (zn != NULL) {
-        rank = zslGetRank(zsl, zn->score, zn->obj);
+        rank = zslGetRank(zsl, zn->score, zn->ele);
         count = (zsl->length - (rank - 1));
 
         /* Find last element in range */
@@ -1315,7 +1286,7 @@ unsigned int countKeysInSlot(unsigned int hashslot) {
 
         /* Use rank of last element, if any, to determine the actual count */
         if (zn != NULL) {
-            rank = zslGetRank(zsl, zn->score, zn->obj);
+            rank = zslGetRank(zsl, zn->score, zn->ele);
             count -= (zsl->length - rank);
         }
     }

src/debug.c

@@ -33,6 +33,7 @@
 
 #include <arpa/inet.h>
 #include <signal.h>
+#include <dlfcn.h>
 
 #ifdef HAVE_BACKTRACE
 #include <execinfo.h>
@@ -40,7 +41,6 @@
 #include <fcntl.h>
 #include "bio.h"
 #include <unistd.h>
-#include <dlfcn.h>
 #endif /* HAVE_BACKTRACE */
 
 #ifdef __CYGWIN__
@@ -126,7 +126,7 @@ void computeDatasetDigest(unsigned char *final) {
         redisDb *db = server.db+j;
 
         if (dictSize(db->dict) == 0) continue;
-        di = dictGetSafeIterator(db->dict);
+        di = dictGetIterator(db->dict);
 
         /* hash the DB id, so the same dataset moved in a different
          * DB will lead to a different digest */
@@ -165,10 +165,10 @@ void computeDatasetDigest(unsigned char *final) {
                 listTypeReleaseIterator(li);
             } else if (o->type == OBJ_SET) {
                 setTypeIterator *si = setTypeInitIterator(o);
-                robj *ele;
-                while((ele = setTypeNextObject(si)) != NULL) {
-                    xorObjectDigest(digest,ele);
-                    decrRefCount(ele);
+                sds sdsele;
+                while((sdsele = setTypeNextObject(si)) != NULL) {
+                    xorDigest(digest,sdsele,sdslen(sdsele));
+                    sdsfree(sdsele);
                 }
                 setTypeReleaseIterator(si);
             } else if (o->type == OBJ_ZSET) {
@@ -210,12 +210,12 @@ void computeDatasetDigest(unsigned char *final) {
                     dictEntry *de;
 
                     while((de = dictNext(di)) != NULL) {
-                        robj *eleobj = dictGetKey(de);
+                        sds sdsele = dictGetKey(de);
                         double *score = dictGetVal(de);
 
                         snprintf(buf,sizeof(buf),"%.17g",*score);
                         memset(eledigest,0,20);
-                        mixObjectDigest(eledigest,eleobj);
+                        mixDigest(eledigest,sdsele,sdslen(sdsele));
                         mixDigest(eledigest,buf,strlen(buf));
                         xorDigest(digest,eledigest,20);
                     }
@@ -224,20 +224,18 @@ void computeDatasetDigest(unsigned char *final) {
                     serverPanic("Unknown sorted set encoding");
                 }
             } else if (o->type == OBJ_HASH) {
-                hashTypeIterator *hi;
-                robj *obj;
-
-                hi = hashTypeInitIterator(o);
+                hashTypeIterator *hi = hashTypeInitIterator(o);
                 while (hashTypeNext(hi) != C_ERR) {
                     unsigned char eledigest[20];
+                    sds sdsele;
 
                     memset(eledigest,0,20);
-                    obj = hashTypeCurrentObject(hi,OBJ_HASH_KEY);
-                    mixObjectDigest(eledigest,obj);
-                    decrRefCount(obj);
-                    obj = hashTypeCurrentObject(hi,OBJ_HASH_VALUE);
-                    mixObjectDigest(eledigest,obj);
-                    decrRefCount(obj);
+                    sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_KEY);
+                    mixDigest(eledigest,sdsele,sdslen(sdsele));
+                    sdsfree(sdsele);
+                    sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_VALUE);
+                    mixDigest(eledigest,sdsele,sdslen(sdsele));
+                    sdsfree(sdsele);
                     xorDigest(digest,eledigest,20);
                 }
                 hashTypeReleaseIterator(hi);
@@ -254,14 +252,6 @@ void computeDatasetDigest(unsigned char *final) {
     }
 }
 
-#if defined(USE_JEMALLOC)
-void inputCatSds(void *result, const char *str) {
-    /* result is actually a (sds *), so re-cast it here */
-    sds *info = (sds *)result;
-    *info = sdscat(*info, str);
-}
-#endif
-
 void debugCommand(client *c) {
     if (c->argc == 1) {
         addReplyError(c,"You must specify a subcommand for DEBUG. Try DEBUG HELP for info.");
@@ -305,10 +295,6 @@ void debugCommand(client *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.");
-        blen++; addReplyStatus(c,
-        "jemalloc info  -- Show internal jemalloc statistics.");
-        blen++; addReplyStatus(c,
-        "jemalloc purge -- Force jemalloc to release unused memory.");
         setDeferredMultiBulkLength(c,blenp,blen);
     } else if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
         *((char*)-1) = 'x';
@@ -338,7 +324,7 @@ void debugCommand(client *c) {
             addReply(c,shared.err);
             return;
         }
-        emptyDb(NULL);
+        emptyDb(-1,EMPTYDB_NO_FLAGS,NULL);
         if (rdbLoad(server.rdb_filename) != C_OK) {
             addReplyError(c,"Error trying to load the RDB dump");
             return;
@@ -347,7 +333,7 @@ void debugCommand(client *c) {
         addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
         if (server.aof_state == AOF_ON) flushAppendOnlyFile(1);
-        emptyDb(NULL);
+        emptyDb(-1,EMPTYDB_NO_FLAGS,NULL);
         if (loadAppendOnlyFile(server.aof_filename) != C_OK) {
             addReply(c,shared.err);
             return;
@@ -423,12 +409,14 @@ void debugCommand(client *c) {
             addReplyError(c,"Not an sds encoded string.");
         } else {
             addReplyStatusFormat(c,
-                "key_sds_len:%lld, key_sds_avail:%lld, "
-                "val_sds_len:%lld, val_sds_avail:%lld",
+                "key_sds_len:%lld, key_sds_avail:%lld, key_zmalloc: %lld, "
+                "val_sds_len:%lld, val_sds_avail:%lld, val_zmalloc: %lld",
                 (long long) sdslen(key),
                 (long long) sdsavail(key),
+                (long long) sdsZmallocSize(key),
                 (long long) sdslen(val->ptr),
-                (long long) sdsavail(val->ptr));
+                (long long) sdsavail(val->ptr),
+                (long long) getStringObjectSdsUsedMemory(val));
         }
     } else if (!strcasecmp(c->argv[1]->ptr,"populate") &&
                (c->argc == 3 || c->argc == 4)) {
@@ -522,30 +510,6 @@ void debugCommand(client *c) {
         stats = sdscat(stats,buf);
 
         addReplyBulkSds(c,stats);
-    } else if (!strcasecmp(c->argv[1]->ptr,"jemalloc") && c->argc == 3) {
-#if defined(USE_JEMALLOC)
-        if (!strcasecmp(c->argv[2]->ptr, "info")) {
-            sds info = sdsempty();
-            je_malloc_stats_print(inputCatSds, &info, NULL);
-            addReplyBulkSds(c, info);
-        } else if (!strcasecmp(c->argv[2]->ptr, "purge")) {
-            char tmp[32];
-            unsigned narenas = 0;
-            size_t sz = sizeof(unsigned);
-            if (!je_mallctl("arenas.narenas", &narenas, &sz, NULL, 0)) {
-                sprintf(tmp, "arena.%d.purge", narenas);
-                if (!je_mallctl(tmp, NULL, 0, NULL, 0)) {
-                    addReply(c, shared.ok);
-                    return;
-                }
-            }
-            addReplyError(c, "Error purging dirty pages");
-        } else {
-            addReplyErrorFormat(c, "Valid jemalloc debug fields: info, purge");
-        }
-#else
-        addReplyErrorFormat(c, "jemalloc support not available");
-#endif
     } else {
         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
             (char*)c->argv[1]->ptr);
@@ -554,7 +518,7 @@ void debugCommand(client *c) {
 
 /* =========================== Crash handling  ============================== */
 
-void _serverAssert(char *estr, char *file, int line) {
+void _serverAssert(const char *estr, const char *file, int line) {
     bugReportStart();
     serverLog(LL_WARNING,"=== ASSERTION FAILED ===");
     serverLog(LL_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
@@ -567,7 +531,7 @@ void _serverAssert(char *estr, char *file, int line) {
     *((char*)-1) = 'x';
 }
 
-void _serverAssertPrintClientInfo(client *c) {
+void _serverAssertPrintClientInfo(const client *c) {
     int j;
 
     bugReportStart();
@@ -591,7 +555,7 @@ void _serverAssertPrintClientInfo(client *c) {
     }
 }
 
-void serverLogObjectDebugInfo(robj *o) {
+void serverLogObjectDebugInfo(const robj *o) {
     serverLog(LL_WARNING,"Object type: %d", o->type);
     serverLog(LL_WARNING,"Object encoding: %d", o->encoding);
     serverLog(LL_WARNING,"Object refcount: %d", o->refcount);
@@ -611,23 +575,23 @@ void serverLogObjectDebugInfo(robj *o) {
     } else if (o->type == OBJ_ZSET) {
         serverLog(LL_WARNING,"Sorted set size: %d", (int) zsetLength(o));
         if (o->encoding == OBJ_ENCODING_SKIPLIST)
-            serverLog(LL_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
+            serverLog(LL_WARNING,"Skiplist level: %d", (int) ((const zset*)o->ptr)->zsl->level);
     }
 }
 
-void _serverAssertPrintObject(robj *o) {
+void _serverAssertPrintObject(const robj *o) {
     bugReportStart();
     serverLog(LL_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
     serverLogObjectDebugInfo(o);
 }
 
-void _serverAssertWithInfo(client *c, robj *o, char *estr, char *file, int line) {
+void _serverAssertWithInfo(const client *c, const robj *o, const char *estr, const char *file, int line) {
     if (c) _serverAssertPrintClientInfo(c);
     if (o) _serverAssertPrintObject(o);
     _serverAssert(estr,file,line);
 }
 
-void _serverPanic(char *msg, char *file, int line) {
+void _serverPanic(const char *msg, const char *file, int line) {
     bugReportStart();
     serverLog(LL_WARNING,"------------------------------------------------");
     serverLog(LL_WARNING,"!!! Software Failure. Press left mouse button to continue");

src/dict.c

@@ -45,7 +45,11 @@
 
 #include "dict.h"
 #include "zmalloc.h"
+#ifndef DICT_BENCHMARK_MAIN
 #include "redisassert.h"
+#else
+#include <assert.h>
+#endif
 
 /* Using dictEnableResize() / dictDisableResize() we make possible to
  * enable/disable resizing of the hash table as needed. This is very important
@@ -62,23 +66,11 @@ 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);
+static int _dictKeyIndex(dict *ht, const void *key, unsigned int hash, dictEntry **existing);
 static int _dictInit(dict *ht, dictType *type, void *privDataPtr);
 
 /* -------------------------- hash functions -------------------------------- */
 
-/* Thomas Wang's 32 bit Mix Function */
-unsigned int dictIntHashFunction(unsigned int key)
-{
-    key += ~(key << 15);
-    key ^=  (key >> 10);
-    key +=  (key << 3);
-    key ^=  (key >> 6);
-    key += ~(key << 11);
-    key ^=  (key >> 16);
-    return key;
-}
-
 static uint32_t dict_hash_function_seed = 5381;
 
 void dictSetHashFunctionSeed(uint32_t seed) {
@@ -321,29 +313,32 @@ static void _dictRehashStep(dict *d) {
 /* Add an element to the target hash table */
 int dictAdd(dict *d, void *key, void *val)
 {
-    dictEntry *entry = dictAddRaw(d,key);
+    dictEntry *entry = dictAddRaw(d,key,NULL);
 
     if (!entry) return DICT_ERR;
     dictSetVal(d, entry, val);
     return DICT_OK;
 }
 
-/* Low level add. This function adds the entry but instead of setting
- * a value returns the dictEntry structure to the user, that will make
- * sure to fill the value field as he wishes.
+/* Low level add or find:
+ * This function adds the entry but instead of setting a value returns the
+ * dictEntry structure to the user, that will make sure to fill the value
+ * field as he wishes.
  *
  * This function is also directly exposed to the user API to be called
  * mainly in order to store non-pointers inside the hash value, example:
  *
- * entry = dictAddRaw(dict,mykey);
+ * entry = dictAddRaw(dict,mykey,NULL);
  * if (entry != NULL) dictSetSignedIntegerVal(entry,1000);
  *
  * Return values:
  *
- * If key already exists NULL is returned.
+ * If key already exists NULL is returned, and "*existing" is populated
+ * with the existing entry if existing is not NULL.
+ *
  * If key was added, the hash entry is returned to be manipulated by the caller.
  */
-dictEntry *dictAddRaw(dict *d, void *key)
+dictEntry *dictAddRaw(dict *d, void *key, dictEntry **existing)
 {
     int index;
     dictEntry *entry;
@@ -353,7 +348,7 @@ dictEntry *dictAddRaw(dict *d, void *key)
 
     /* Get the index of the new element, or -1 if
      * the element already exists. */
-    if ((index = _dictKeyIndex(d, key)) == -1)
+    if ((index = _dictKeyIndex(d, key, dictHashKey(d,key), existing)) == -1)
         return NULL;
 
     /* Allocate the memory and store the new entry.
@@ -371,51 +366,57 @@ dictEntry *dictAddRaw(dict *d, void *key)
     return entry;
 }
 
-/* Add an element, discarding the old if the key already exists.
+/* Add or Overwrite:
+ * Add an element, discarding the old value if the key already exists.
  * Return 1 if the key was added from scratch, 0 if there was already an
  * element with such key and dictReplace() just performed a value update
  * operation. */
 int dictReplace(dict *d, void *key, void *val)
 {
-    dictEntry *entry, auxentry;
+    dictEntry *entry, *existing, auxentry;
 
     /* Try to add the element. If the key
      * does not exists dictAdd will suceed. */
-    if (dictAdd(d, key, val) == DICT_OK)
+    entry = dictAddRaw(d,key,&existing);
+    if (entry) {
+        dictSetVal(d, entry, val);
         return 1;
-    /* It already exists, get the entry */
-    entry = dictFind(d, key);
+    }
+
     /* Set the new value and free the old one. Note that it is important
      * to do that in this order, as the value may just be exactly the same
      * as the previous one. In this context, think to reference counting,
      * you want to increment (set), and then decrement (free), and not the
      * reverse. */
-    auxentry = *entry;
-    dictSetVal(d, entry, val);
+    auxentry = *existing;
+    dictSetVal(d, existing, val);
     dictFreeVal(d, &auxentry);
     return 0;
 }
 
-/* dictReplaceRaw() is simply a version of dictAddRaw() that always
+/* Add or Find:
+ * dictAddOrFind() is simply a version of dictAddRaw() that always
  * returns the hash entry of the specified key, even if the key already
  * exists and can't be added (in that case the entry of the already
  * existing key is returned.)
  *
  * See dictAddRaw() for more information. */
-dictEntry *dictReplaceRaw(dict *d, void *key) {
-    dictEntry *entry = dictFind(d,key);
-
-    return entry ? entry : dictAddRaw(d,key);
+dictEntry *dictAddOrFind(dict *d, void *key) {
+    dictEntry *entry, *existing;
+    entry = dictAddRaw(d,key,&existing);
+    return entry ? entry : existing;
 }
 
-/* Search and remove an element */
-static int dictGenericDelete(dict *d, const void *key, int nofree)
-{
+/* Search and remove an element. This is an helper function for
+ * 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;
     dictEntry *he, *prevHe;
     int table;
 
-    if (d->ht[0].size == 0) return DICT_ERR; /* d->ht[0].table is NULL */
+    if (d->ht[0].used == 0 && d->ht[1].used == 0) return NULL;
+
     if (dictIsRehashing(d)) _dictRehashStep(d);
     h = dictHashKey(d, key);
 
@@ -433,27 +434,59 @@ static int dictGenericDelete(dict *d, const void *key, int nofree)
                 if (!nofree) {
                     dictFreeKey(d, he);
                     dictFreeVal(d, he);
+                    zfree(he);
                 }
-                zfree(he);
                 d->ht[table].used--;
-                return DICT_OK;
+                return he;
             }
             prevHe = he;
             he = he->next;
         }
         if (!dictIsRehashing(d)) break;
     }
-    return DICT_ERR; /* not found */
+    return NULL; /* not found */
 }
 
+/* Remove an element, returning DICT_OK on success or DICT_ERR if the
+ * element was not found. */
 int dictDelete(dict *ht, const void *key) {
-    return dictGenericDelete(ht,key,0);
+    return dictGenericDelete(ht,key,0) ? DICT_OK : DICT_ERR;
 }
 
-int dictDeleteNoFree(dict *ht, const void *key) {
+/* Remove an element from the table, but without actually releasing
+ * the key, value and dictionary entry. The dictionary entry is returned
+ * if the element was found (and unlinked from the table), and the user
+ * should later call `dictFreeUnlinkedEntry()` with it in order to release it.
+ * Otherwise if the key is not found, NULL is returned.
+ *
+ * This function is useful when we want to remove something from the hash
+ * table but want to use its value before actually deleting the entry.
+ * Without this function the pattern would require two lookups:
+ *
+ *  entry = dictFind(...);
+ *  // Do something with entry
+ *  dictDelete(dictionary,entry);
+ *
+ * Thanks to this function it is possible to avoid this, and use
+ * instead:
+ *
+ * entry = dictUnlink(dictionary,entry);
+ * // Do something with entry
+ * dictFreeUnlinkedEntry(entry); // <- This does not need to lookup again.
+ */
+dictEntry *dictUnlink(dict *ht, const void *key) {
     return dictGenericDelete(ht,key,1);
 }
 
+/* You need to call this function to really free the entry after a call
+ * to dictUnlink(). It's safe to call this function with 'he' = NULL. */
+void dictFreeUnlinkedEntry(dict *d, dictEntry *he) {
+    if (he == NULL) return;
+    dictFreeKey(d, he);
+    dictFreeVal(d, he);
+    zfree(he);
+}
+
 /* Destroy an entire dictionary */
 int _dictClear(dict *d, dictht *ht, void(callback)(void *)) {
     unsigned long i;
@@ -855,7 +888,7 @@ unsigned long dictScan(dict *d,
                        void *privdata)
 {
     dictht *t0, *t1;
-    const dictEntry *de;
+    const dictEntry *de, *next;
     unsigned long m0, m1;
 
     if (dictSize(d) == 0) return 0;
@@ -867,8 +900,9 @@ unsigned long dictScan(dict *d,
         /* Emit entries at cursor */
         de = t0->table[v & m0];
         while (de) {
+            next = de->next;
             fn(privdata, de);
-            de = de->next;
+            de = next;
         }
 
     } else {
@@ -887,8 +921,9 @@ unsigned long dictScan(dict *d,
         /* Emit entries at cursor */
         de = t0->table[v & m0];
         while (de) {
+            next = de->next;
             fn(privdata, de);
-            de = de->next;
+            de = next;
         }
 
         /* Iterate over indices in larger table that are the expansion
@@ -897,8 +932,9 @@ unsigned long dictScan(dict *d,
             /* Emit entries at cursor */
             de = t1->table[v & m1];
             while (de) {
+                next = de->next;
                 fn(privdata, de);
-                de = de->next;
+                de = next;
             }
 
             /* Increment bits not covered by the smaller mask */
@@ -959,27 +995,29 @@ static unsigned long _dictNextPower(unsigned long size)
 
 /* Returns the index of a free slot that can be populated with
  * a hash entry for the given 'key'.
- * If the key already exists, -1 is returned.
+ * If the key already exists, -1 is returned
+ * and the optional output parameter may be filled.
  *
  * 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)
+static int _dictKeyIndex(dict *d, const void *key, unsigned int hash, dictEntry **existing)
 {
-    unsigned int h, idx, table;
+    unsigned int idx, table;
     dictEntry *he;
+    if (existing) *existing = NULL;
 
     /* Expand the hash table if needed */
     if (_dictExpandIfNeeded(d) == DICT_ERR)
         return -1;
-    /* Compute the key hash value */
-    h = dictHashKey(d, key);
     for (table = 0; table <= 1; table++) {
-        idx = h & d->ht[table].sizemask;
+        idx = hash & d->ht[table].sizemask;
         /* Search if this slot does not already contain the given key */
         he = d->ht[table].table[idx];
         while(he) {
-            if (key==he->key || dictCompareKeys(d, key, he->key))
+            if (key==he->key || dictCompareKeys(d, key, he->key)) {
+                if (existing) *existing = he;
                 return -1;
+            }
             he = he->next;
         }
         if (!dictIsRehashing(d)) break;
@@ -1080,3 +1118,120 @@ void dictGetStats(char *buf, size_t bufsize, dict *d) {
     /* Make sure there is a NULL term at the end. */
     if (orig_bufsize) orig_buf[orig_bufsize-1] = '\0';
 }
+
+/* ------------------------------- Benchmark ---------------------------------*/
+
+#ifdef DICT_BENCHMARK_MAIN
+
+#include "sds.h"
+
+unsigned int hashCallback(const void *key) {
+    return dictGenHashFunction((unsigned char*)key, sdslen((char*)key));
+}
+
+int compareCallback(void *privdata, const void *key1, const void *key2) {
+    int l1,l2;
+    DICT_NOTUSED(privdata);
+
+    l1 = sdslen((sds)key1);
+    l2 = sdslen((sds)key2);
+    if (l1 != l2) return 0;
+    return memcmp(key1, key2, l1) == 0;
+}
+
+void freeCallback(void *privdata, void *val) {
+    DICT_NOTUSED(privdata);
+
+    sdsfree(val);
+}
+
+dictType BenchmarkDictType = {
+    hashCallback,
+    NULL,
+    NULL,
+    compareCallback,
+    freeCallback,
+    NULL
+};
+
+#define start_benchmark() start = timeInMilliseconds()
+#define end_benchmark(msg) do { \
+    elapsed = timeInMilliseconds()-start; \
+    printf(msg ": %ld items in %lld ms\n", count, elapsed); \
+} while(0);
+
+/* dict-benchmark [count] */
+int main(int argc, char **argv) {
+    long j;
+    long long start, elapsed;
+    dict *dict = dictCreate(&BenchmarkDictType,NULL);
+    long count = 0;
+
+    if (argc == 2) {
+        count = strtol(argv[1],NULL,10);
+    } else {
+        count = 5000000;
+    }
+
+    start_benchmark();
+    for (j = 0; j < count; j++) {
+        int retval = dictAdd(dict,sdsfromlonglong(j),(void*)j);
+        assert(retval == DICT_OK);
+    }
+    end_benchmark("Inserting");
+    assert((long)dictSize(dict) == count);
+
+    /* Wait for rehashing. */
+    while (dictIsRehashing(dict)) {
+        dictRehashMilliseconds(dict,100);
+    }
+
+    start_benchmark();
+    for (j = 0; j < count; j++) {
+        sds key = sdsfromlonglong(j);
+        dictEntry *de = dictFind(dict,key);
+        assert(de != NULL);
+        sdsfree(key);
+    }
+    end_benchmark("Linear access of existing elements");
+
+    start_benchmark();
+    for (j = 0; j < count; j++) {
+        sds key = sdsfromlonglong(j);
+        dictEntry *de = dictFind(dict,key);
+        assert(de != NULL);
+        sdsfree(key);
+    }
+    end_benchmark("Linear access of existing elements (2nd round)");
+
+    start_benchmark();
+    for (j = 0; j < count; j++) {
+        sds key = sdsfromlonglong(rand() % count);
+        dictEntry *de = dictFind(dict,key);
+        assert(de != NULL);
+        sdsfree(key);
+    }
+    end_benchmark("Random access of existing elements");
+
+    start_benchmark();
+    for (j = 0; j < count; j++) {
+        sds key = sdsfromlonglong(rand() % count);
+        key[0] = 'X';
+        dictEntry *de = dictFind(dict,key);
+        assert(de == NULL);
+        sdsfree(key);
+    }
+    end_benchmark("Accessing missing");
+
+    start_benchmark();
+    for (j = 0; j < count; j++) {
+        sds key = sdsfromlonglong(j);
+        int retval = dictDelete(dict,key);
+        assert(retval == DICT_OK);
+        key[0] += 17; /* Change first number to letter. */
+        retval = dictAdd(dict,key,(void*)j);
+        assert(retval == DICT_OK);
+    }
+    end_benchmark("Removing and adding");
+}
+#endif

src/dict.h

@@ -78,7 +78,7 @@ typedef struct dict {
     void *privdata;
     dictht ht[2];
     long rehashidx; /* rehashing not in progress if rehashidx == -1 */
-    int iterators; /* number of iterators currently running */
+    unsigned long iterators; /* number of iterators currently running */
 } dict;
 
 /* If safe is set to 1 this is a safe iterator, that means, you can call
@@ -106,19 +106,19 @@ typedef void (dictScanFunction)(void *privdata, const dictEntry *de);
 
 #define dictSetVal(d, entry, _val_) do { \
     if ((d)->type->valDup) \
-        entry->v.val = (d)->type->valDup((d)->privdata, _val_); \
+        (entry)->v.val = (d)->type->valDup((d)->privdata, _val_); \
     else \
-        entry->v.val = (_val_); \
+        (entry)->v.val = (_val_); \
 } while(0)
 
 #define dictSetSignedIntegerVal(entry, _val_) \
-    do { entry->v.s64 = _val_; } while(0)
+    do { (entry)->v.s64 = _val_; } while(0)
 
 #define dictSetUnsignedIntegerVal(entry, _val_) \
-    do { entry->v.u64 = _val_; } while(0)
+    do { (entry)->v.u64 = _val_; } while(0)
 
 #define dictSetDoubleVal(entry, _val_) \
-    do { entry->v.d = _val_; } while(0)
+    do { (entry)->v.d = _val_; } while(0)
 
 #define dictFreeKey(d, entry) \
     if ((d)->type->keyDestructor) \
@@ -126,9 +126,9 @@ typedef void (dictScanFunction)(void *privdata, const dictEntry *de);
 
 #define dictSetKey(d, entry, _key_) do { \
     if ((d)->type->keyDup) \
-        entry->key = (d)->type->keyDup((d)->privdata, _key_); \
+        (entry)->key = (d)->type->keyDup((d)->privdata, _key_); \
     else \
-        entry->key = (_key_); \
+        (entry)->key = (_key_); \
 } while(0)
 
 #define dictCompareKeys(d, key1, key2) \
@@ -150,11 +150,12 @@ typedef void (dictScanFunction)(void *privdata, const dictEntry *de);
 dict *dictCreate(dictType *type, void *privDataPtr);
 int dictExpand(dict *d, unsigned long size);
 int dictAdd(dict *d, void *key, void *val);
-dictEntry *dictAddRaw(dict *d, void *key);
+dictEntry *dictAddRaw(dict *d, void *key, dictEntry **existing);
+dictEntry *dictAddOrFind(dict *d, void *key);
 int dictReplace(dict *d, void *key, void *val);
-dictEntry *dictReplaceRaw(dict *d, void *key);
 int dictDelete(dict *d, const void *key);
-int dictDeleteNoFree(dict *d, const void *key);
+dictEntry *dictUnlink(dict *ht, const void *key);
+void dictFreeUnlinkedEntry(dict *d, dictEntry *he);
 void dictRelease(dict *d);
 dictEntry * dictFind(dict *d, const void *key);
 void *dictFetchValue(dict *d, const void *key);

src/evict.c

@@ -0,0 +1,524 @@
+/* Maxmemory directive handling (LRU eviction and other policies).
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2009-2016, 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.
+ */
+
+#include "server.h"
+#include "bio.h"
+
+/* ----------------------------------------------------------------------------
+ * Data structures
+ * --------------------------------------------------------------------------*/
+
+/* To improve the quality of the LRU approximation we take a set of keys
+ * that are good candidate for eviction across freeMemoryIfNeeded() calls.
+ *
+ * Entries inside the eviciton pool are taken ordered by idle time, putting
+ * greater idle times to the right (ascending order).
+ *
+ * When an LFU policy is used instead, a reverse frequency indication is used
+ * instead of the idle time, so that we still evict by larger value (larger
+ * inverse frequency means to evict keys with the least frequent accesses).
+ *
+ * Empty entries have the key pointer set to NULL. */
+#define EVPOOL_SIZE 16
+#define EVPOOL_CACHED_SDS_SIZE 255
+struct evictionPoolEntry {
+    unsigned long long idle;    /* Object idle time (inverse frequency for LFU) */
+    sds key;                    /* Key name. */
+    sds cached;                 /* Cached SDS object for key name. */
+    int dbid;                   /* Key DB number. */
+};
+
+static struct evictionPoolEntry *EvictionPoolLRU;
+
+unsigned long LFUDecrAndReturn(robj *o);
+
+/* ----------------------------------------------------------------------------
+ * Implementation of eviction, aging and LRU
+ * --------------------------------------------------------------------------*/
+
+/* Return the LRU clock, based on the clock resolution. This is a time
+ * in a reduced-bits format that can be used to set and check the
+ * object->lru field of redisObject structures. */
+unsigned int getLRUClock(void) {
+    return (mstime()/LRU_CLOCK_RESOLUTION) & LRU_CLOCK_MAX;
+}
+
+/* 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) {
+    unsigned long long lruclock = LRU_CLOCK();
+    if (lruclock >= o->lru) {
+        return (lruclock - o->lru) * LRU_CLOCK_RESOLUTION;
+    } else {
+        return (lruclock + (LRU_CLOCK_MAX - o->lru)) *
+                    LRU_CLOCK_RESOLUTION;
+    }
+}
+
+/* freeMemoryIfNeeded() gets called when 'maxmemory' is set on the config
+ * file to limit the max memory used by the server, before processing a
+ * command.
+ *
+ * The goal of the function is to free enough memory to keep Redis under the
+ * configured memory limit.
+ *
+ * The function starts calculating how many bytes should be freed to keep
+ * Redis under the limit, and enters a loop selecting the best keys to
+ * evict accordingly to the configured policy.
+ *
+ * If all the bytes needed to return back under the limit were freed the
+ * function returns C_OK, otherwise C_ERR is returned, and the caller
+ * should block the execution of commands that will result in more memory
+ * used by the server.
+ *
+ * ------------------------------------------------------------------------
+ *
+ * LRU approximation algorithm
+ *
+ * Redis uses an approximation of the LRU algorithm that runs in constant
+ * memory. Every time there is a key to expire, we sample N keys (with
+ * N very small, usually in around 5) to populate a pool of best keys to
+ * evict of M keys (the pool size is defined by EVPOOL_SIZE).
+ *
+ * The N keys sampled are added in the pool of good keys to expire (the one
+ * with an old access time) if they are better than one of the current keys
+ * in the pool.
+ *
+ * After the pool is populated, the best key we have in the pool is expired.
+ * However note that we don't remove keys from the pool when they are deleted
+ * so the pool may contain keys that no longer exist.
+ *
+ * When we try to evict a key, and all the entries in the pool don't exist
+ * we populate it again. This time we'll be sure that the pool has at least
+ * one key that can be evicted, if there is at least one key that can be
+ * evicted in the whole database. */
+
+/* Create a new eviction pool. */
+void evictionPoolAlloc(void) {
+    struct evictionPoolEntry *ep;
+    int j;
+
+    ep = zmalloc(sizeof(*ep)*EVPOOL_SIZE);
+    for (j = 0; j < EVPOOL_SIZE; j++) {
+        ep[j].idle = 0;
+        ep[j].key = NULL;
+        ep[j].cached = sdsnewlen(NULL,EVPOOL_CACHED_SDS_SIZE);
+        ep[j].dbid = 0;
+    }
+    EvictionPoolLRU = ep;
+}
+
+/* This is an helper function for freeMemoryIfNeeded(), it is used in order
+ * to populate the evictionPool with a few entries every time we want to
+ * expire a key. Keys with idle time smaller than one of the current
+ * keys are added. Keys are always added if there are free entries.
+ *
+ * We insert keys on place in ascending order, so keys with the smaller
+ * idle time are on the left, and keys with the higher idle time on the
+ * right. */
+
+void evictionPoolPopulate(int dbid, dict *sampledict, dict *keydict, struct evictionPoolEntry *pool) {
+    int j, k, count;
+    dictEntry *samples[server.maxmemory_samples];
+
+    count = dictGetSomeKeys(sampledict,samples,server.maxmemory_samples);
+    for (j = 0; j < count; j++) {
+        unsigned long long idle;
+        sds key;
+        robj *o;
+        dictEntry *de;
+
+        de = samples[j];
+        key = dictGetKey(de);
+
+        /* If the dictionary we are sampling from is not the main
+         * dictionary (but the expires one) we need to lookup the key
+         * again in the key dictionary to obtain the value object. */
+        if (server.maxmemory_policy != MAXMEMORY_VOLATILE_TTL) {
+            if (sampledict != keydict) de = dictFind(keydict, key);
+            o = dictGetVal(de);
+        }
+
+        /* Calculate the idle time according to the policy. This is called
+         * idle just because the code initially handled LRU, but is in fact
+         * just a score where an higher score means better candidate. */
+        if (server.maxmemory_policy & MAXMEMORY_FLAG_LRU) {
+            idle = estimateObjectIdleTime(o);
+        } else if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
+            /* When we use an LRU policy, we sort the keys by idle time
+             * so that we expire keys starting from greater idle time.
+             * However when the policy is an LFU one, we have a frequency
+             * estimation, and we want to evict keys with lower frequency
+             * first. So inside the pool we put objects using the inverted
+             * frequency subtracting the actual frequency to the maximum
+             * frequency of 255. */
+            idle = 255-LFUDecrAndReturn(o);
+        } else if (server.maxmemory_policy == MAXMEMORY_VOLATILE_TTL) {
+            /* In this case the sooner the expire the better. */
+            idle = ULLONG_MAX - (long)dictGetVal(de);
+        } else {
+            serverPanic("Unknown eviction policy in evictionPoolPopulate()");
+        }
+
+        /* Insert the element inside the pool.
+         * First, find the first empty bucket or the first populated
+         * bucket that has an idle time smaller than our idle time. */
+        k = 0;
+        while (k < EVPOOL_SIZE &&
+               pool[k].key &&
+               pool[k].idle < idle) k++;
+        if (k == 0 && pool[EVPOOL_SIZE-1].key != NULL) {
+            /* Can't insert if the element is < the worst element we have
+             * and there are no empty buckets. */
+            continue;
+        } else if (k < EVPOOL_SIZE && pool[k].key == NULL) {
+            /* Inserting into empty position. No setup needed before insert. */
+        } else {
+            /* Inserting in the middle. Now k points to the first element
+             * greater than the element to insert.  */
+            if (pool[EVPOOL_SIZE-1].key == NULL) {
+                /* Free space on the right? Insert at k shifting
+                 * all the elements from k to end to the right. */
+
+                /* Save SDS before overwriting. */
+                sds cached = pool[EVPOOL_SIZE-1].cached;
+                memmove(pool+k+1,pool+k,
+                    sizeof(pool[0])*(EVPOOL_SIZE-k-1));
+                pool[k].cached = cached;
+            } else {
+                /* No free space on right? Insert at k-1 */
+                k--;
+                /* Shift all elements on the left of k (included) to the
+                 * left, so we discard the element with smaller idle time. */
+                sds cached = pool[0].cached; /* Save SDS before overwriting. */
+                if (pool[0].key != pool[0].cached) sdsfree(pool[0].key);
+                memmove(pool,pool+1,sizeof(pool[0])*k);
+                pool[k].cached = cached;
+            }
+        }
+
+        /* Try to reuse the cached SDS string allocated in the pool entry,
+         * because allocating and deallocating this object is costly
+         * (according to the profiler, not my fantasy. Remember:
+         * premature optimizbla bla bla bla. */
+        int klen = sdslen(key);
+        if (klen > EVPOOL_CACHED_SDS_SIZE) {
+            pool[k].key = sdsdup(key);
+        } else {
+            memcpy(pool[k].cached,key,klen+1);
+            sdssetlen(pool[k].cached,klen);
+            pool[k].key = pool[k].cached;
+        }
+        pool[k].idle = idle;
+        pool[k].dbid = dbid;
+    }
+}
+
+/* ----------------------------------------------------------------------------
+ * LFU (Least Frequently Used) implementation.
+
+ * We have 24 total bits of space in each object in order to implement
+ * an LFU (Least Frequently Used) eviction policy, since we re-use the
+ * LRU field for this purpose.
+ *
+ * We split the 24 bits into two fields:
+ *
+ *          16 bits      8 bits
+ *     +----------------+--------+
+ *     + Last decr time | LOG_C  |
+ *     +----------------+--------+
+ *
+ * LOG_C is a logarithmic counter that provides an indication of the access
+ * frequency. However this field must also be decremented otherwise what used
+ * to be a frequently accessed key in the past, will remain ranked like that
+ * forever, while we want the algorithm to adapt to access pattern changes.
+ *
+ * So the remaining 16 bits are used in order to store the "decrement time",
+ * a reduced-precision Unix time (we take 16 bits of the time converted
+ * in minutes since we don't care about wrapping around) where the LOG_C
+ * counter is halved if it has an high value, or just decremented if it
+ * has a low value.
+ *
+ * New keys don't start at zero, in order to have the ability to collect
+ * some accesses before being trashed away, so they start at COUNTER_INIT_VAL.
+ * The logarithmic increment performed on LOG_C takes care of COUNTER_INIT_VAL
+ * when incrementing the key, so that keys starting at COUNTER_INIT_VAL
+ * (or having a smaller value) have a very high chance of being incremented
+ * on access.
+ *
+ * During decrement, the value of the logarithmic counter is halved if
+ * its current value is greater than two times the COUNTER_INIT_VAL, otherwise
+ * it is just decremented by one.
+ * --------------------------------------------------------------------------*/
+
+/* Return the current time in minutes, just taking the least significant
+ * 16 bits. The returned time is suitable to be stored as LDT (last decrement
+ * time) for the LFU implementation. */
+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
+ * the current 16 bits minutes time) considering the time as wrapping
+ * exactly once. */
+unsigned long LFUTimeElapsed(unsigned long ldt) {
+    unsigned long now = LFUGetTimeInMinutes();
+    if (now >= ldt) return now-ldt;
+    return 65535-ldt+now;
+}
+
+/* Logarithmically increment a counter. The greater is the current counter value
+ * the less likely is that it gets really implemented. Saturate it at 255. */
+uint8_t LFULogIncr(uint8_t counter) {
+    if (counter == 255) return 255;
+    double r = (double)rand()/RAND_MAX;
+    double baseval = counter - LFU_INIT_VAL;
+    if (baseval < 0) baseval = 0;
+    double p = 1.0/(baseval*server.lfu_log_factor+1);
+    if (r < p) 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.
+ *
+ * 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;
+    }
+    return counter;
+}
+
+/* ----------------------------------------------------------------------------
+ * The external API for eviction: freeMemroyIfNeeded() is called by the
+ * server when there is data to add in order to make space if needed.
+ * --------------------------------------------------------------------------*/
+
+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;
+
+    /* 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. */
+    mem_reported = zmalloc_used_memory();
+    if (mem_reported <= server.maxmemory) return C_OK;
+
+    /* 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();
+    }
+
+    /* Check if we are still over the memory limit. */
+    if (mem_used <= server.maxmemory) return C_OK;
+
+    /* Compute how much memory we need to free. */
+    mem_tofree = mem_used - server.maxmemory;
+    mem_freed = 0;
+
+    if (server.maxmemory_policy == MAXMEMORY_NO_EVICTION)
+        goto cant_free; /* We need to free memory, but policy forbids. */
+
+    latencyStartMonitor(latency);
+    while (mem_freed < mem_tofree) {
+        int j, k, i, keys_freed = 0;
+        static int next_db = 0;
+        sds bestkey = NULL;
+        int bestdbid;
+        redisDb *db;
+        dict *dict;
+        dictEntry *de;
+
+        if (server.maxmemory_policy & (MAXMEMORY_FLAG_LRU|MAXMEMORY_FLAG_LFU) ||
+            server.maxmemory_policy == MAXMEMORY_VOLATILE_TTL)
+        {
+            struct evictionPoolEntry *pool = EvictionPoolLRU;
+
+            while(bestkey == NULL) {
+                unsigned long total_keys = 0, keys;
+
+                /* We don't want to make local-db choices when expiring keys,
+                 * so to start populate the eviction pool sampling keys from
+                 * every DB. */
+                for (i = 0; i < server.dbnum; i++) {
+                    db = server.db+i;
+                    dict = (server.maxmemory_policy & MAXMEMORY_FLAG_ALLKEYS) ?
+                            db->dict : db->expires;
+                    if ((keys = dictSize(dict)) != 0) {
+                        evictionPoolPopulate(i, dict, db->dict, pool);
+                        total_keys += keys;
+                    }
+                }
+                if (!total_keys) break; /* No keys to evict. */
+
+                /* Go backward from best to worst element to evict. */
+                for (k = EVPOOL_SIZE-1; k >= 0; k--) {
+                    if (pool[k].key == NULL) continue;
+                    bestdbid = pool[k].dbid;
+
+                    if (server.maxmemory_policy & MAXMEMORY_FLAG_ALLKEYS) {
+                        de = dictFind(server.db[pool[k].dbid].dict,
+                            pool[k].key);
+                    } else {
+                        de = dictFind(server.db[pool[k].dbid].expires,
+                            pool[k].key);
+                    }
+
+                    /* Remove the entry from the pool. */
+                    if (pool[k].key != pool[k].cached)
+                        sdsfree(pool[k].key);
+                    pool[k].key = NULL;
+                    pool[k].idle = 0;
+
+                    /* If the key exists, is our pick. Otherwise it is
+                     * a ghost and we need to try the next element. */
+                    if (de) {
+                        bestkey = dictGetKey(de);
+                        break;
+                    } else {
+                        /* Ghost... Iterate again. */
+                    }
+                }
+            }
+        }
+
+        /* volatile-random and allkeys-random policy */
+        else if (server.maxmemory_policy == MAXMEMORY_ALLKEYS_RANDOM ||
+                 server.maxmemory_policy == MAXMEMORY_VOLATILE_RANDOM)
+        {
+            /* When evicting a random key, we try to evict a key for
+             * each DB, so we use the static 'next_db' variable to
+             * incrementally visit all DBs. */
+            for (i = 0; i < server.dbnum; i++) {
+                j = (++next_db) % server.dbnum;
+                db = server.db+j;
+                dict = (server.maxmemory_policy == MAXMEMORY_ALLKEYS_RANDOM) ?
+                        db->dict : db->expires;
+                if (dictSize(dict) != 0) {
+                    de = dictGetRandomKey(dict);
+                    bestkey = dictGetKey(de);
+                    bestdbid = j;
+                    break;
+                }
+            }
+        }
+
+        /* Finally remove the selected key. */
+        if (bestkey) {
+            db = server.db+bestdbid;
+            robj *keyobj = createStringObject(bestkey,sdslen(bestkey));
+            propagateExpire(db,keyobj,server.lazyfree_lazy_eviction);
+            /* We compute the amount of memory freed by db*Delete() alone.
+             * It is possible that actually the memory needed to propagate
+             * the DEL in AOF and replication link is greater than the one
+             * we are freeing removing the key, but we can't account for
+             * that otherwise we would never exit the loop.
+             *
+             * AOF and Output buffer memory will be freed eventually so
+             * we only care about memory used by the key space. */
+            delta = (long long) zmalloc_used_memory();
+            latencyStartMonitor(eviction_latency);
+            if (server.lazyfree_lazy_eviction)
+                dbAsyncDelete(db,keyobj);
+            else
+                dbSyncDelete(db,keyobj);
+            latencyEndMonitor(eviction_latency);
+            latencyAddSampleIfNeeded("eviction-del",eviction_latency);
+            latencyRemoveNestedEvent(latency,eviction_latency);
+            delta -= (long long) zmalloc_used_memory();
+            mem_freed += delta;
+            server.stat_evictedkeys++;
+            notifyKeyspaceEvent(NOTIFY_EVICTED, "evicted",
+                keyobj, db->id);
+            decrRefCount(keyobj);
+            keys_freed++;
+
+            /* When the memory to free starts to be big enough, we may
+             * start spending so much time here that is impossible to
+             * deliver data to the slaves fast enough, so we force the
+             * transmission here inside the loop. */
+            if (slaves) flushSlavesOutputBuffers();
+        }
+
+        if (!keys_freed) {
+            latencyEndMonitor(latency);
+            latencyAddSampleIfNeeded("eviction-cycle",latency);
+            goto cant_free; /* nothing to free... */
+        }
+    }
+    latencyEndMonitor(latency);
+    latencyAddSampleIfNeeded("eviction-cycle",latency);
+    return C_OK;
+
+cant_free:
+    /* We are here if we are not able to reclaim memory. There is only one
+     * last thing we can try: check if the lazyfree thread has jobs in queue
+     * and wait... */
+    while(bioPendingJobsOfType(BIO_LAZY_FREE)) {
+        if (((mem_reported - zmalloc_used_memory()) + mem_freed) >= mem_tofree)
+            break;
+        usleep(1000);
+    }
+    return C_ERR;
+}
+

src/expire.c

@@ -0,0 +1,354 @@
+/* Implementation of EXPIRE (keys with fixed time to live).
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2009-2016, 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.
+ */
+
+#include "server.h"
+
+/*-----------------------------------------------------------------------------
+ * Incremental collection of expired keys.
+ *
+ * When keys are accessed they are expired on-access. However we need a
+ * mechanism in order to ensure keys are eventually removed when expired even
+ * if no access is performed on them.
+ *----------------------------------------------------------------------------*/
+
+/* Helper function for the activeExpireCycle() function.
+ * This function will try to expire the key that is stored in the hash table
+ * entry 'de' of the 'expires' hash table of a Redis database.
+ *
+ * If the key is found to be expired, it is removed from the database and
+ * 1 is returned. Otherwise no operation is performed and 0 is returned.
+ *
+ * When a key is expired, server.stat_expiredkeys is incremented.
+ *
+ * The parameter 'now' is the current time in milliseconds as is passed
+ * to the function to avoid too many gettimeofday() syscalls. */
+int activeExpireCycleTryExpire(redisDb *db, dictEntry *de, long long now) {
+    long long t = dictGetSignedIntegerVal(de);
+    if (now > t) {
+        sds key = dictGetKey(de);
+        robj *keyobj = createStringObject(key,sdslen(key));
+
+        propagateExpire(db,keyobj,server.lazyfree_lazy_expire);
+        if (server.lazyfree_lazy_expire)
+            dbAsyncDelete(db,keyobj);
+        else
+            dbSyncDelete(db,keyobj);
+        notifyKeyspaceEvent(NOTIFY_EXPIRED,
+            "expired",keyobj,db->id);
+        decrRefCount(keyobj);
+        server.stat_expiredkeys++;
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+/* Try to expire a few timed out keys. The algorithm used is adaptive and
+ * will use few CPU cycles if there are few expiring keys, otherwise
+ * it will get more aggressive to avoid that too much memory is used by
+ * keys that can be removed from the keyspace.
+ *
+ * No more than CRON_DBS_PER_CALL databases are tested at every
+ * iteration.
+ *
+ * This kind of call is used when Redis detects that timelimit_exit is
+ * true, so there is more work to do, and we do it more incrementally from
+ * the beforeSleep() function of the event loop.
+ *
+ * Expire cycle type:
+ *
+ * If type is ACTIVE_EXPIRE_CYCLE_FAST the function will try to run a
+ * "fast" expire cycle that takes no longer than EXPIRE_FAST_CYCLE_DURATION
+ * microseconds, and is not repeated again before the same amount of time.
+ *
+ * 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. */
+
+void activeExpireCycle(int type) {
+    /* This function has some global state in order to continue the work
+     * incrementally across calls. */
+    static unsigned int current_db = 0; /* Last DB tested. */
+    static int timelimit_exit = 0;      /* Time limit hit in previous call? */
+    static long long last_fast_cycle = 0; /* When last fast cycle ran. */
+
+    int j, iteration = 0;
+    int dbs_per_call = CRON_DBS_PER_CALL;
+    long long start = ustime(), timelimit;
+
+    if (type == ACTIVE_EXPIRE_CYCLE_FAST) {
+        /* Don't start a fast cycle if the previous cycle did not exited
+         * for time limt. Also don't repeat a fast cycle for the same period
+         * as the fast cycle total duration itself. */
+        if (!timelimit_exit) return;
+        if (start < last_fast_cycle + ACTIVE_EXPIRE_CYCLE_FAST_DURATION*2) return;
+        last_fast_cycle = start;
+    }
+
+    /* We usually should test CRON_DBS_PER_CALL per iteration, with
+     * two exceptions:
+     *
+     * 1) Don't test more DBs than we have.
+     * 2) If last time we hit the time limit, we want to scan all DBs
+     * in this iteration, as there is work to do in some DB and we don't want
+     * expired keys to use memory for too much time. */
+    if (dbs_per_call > server.dbnum || timelimit_exit)
+        dbs_per_call = server.dbnum;
+
+    /* We can use at max ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC percentage of CPU time
+     * per iteration. Since this function gets called with a frequency of
+     * server.hz times per second, the following is the max amount of
+     * microseconds we can spend in this function. */
+    timelimit = 1000000*ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC/server.hz/100;
+    timelimit_exit = 0;
+    if (timelimit <= 0) timelimit = 1;
+
+    if (type == ACTIVE_EXPIRE_CYCLE_FAST)
+        timelimit = ACTIVE_EXPIRE_CYCLE_FAST_DURATION; /* in microseconds. */
+
+    for (j = 0; j < dbs_per_call; j++) {
+        int expired;
+        redisDb *db = server.db+(current_db % server.dbnum);
+
+        /* Increment the DB now so we are sure if we run out of time
+         * in the current DB we'll restart from the next. This allows to
+         * distribute the time evenly across DBs. */
+        current_db++;
+
+        /* Continue to expire if at the end of the cycle more than 25%
+         * of the keys were expired. */
+        do {
+            unsigned long num, slots;
+            long long now, ttl_sum;
+            int ttl_samples;
+
+            /* If there is nothing to expire try next DB ASAP. */
+            if ((num = dictSize(db->expires)) == 0) {
+                db->avg_ttl = 0;
+                break;
+            }
+            slots = dictSlots(db->expires);
+            now = mstime();
+
+            /* When there are less than 1% filled slots getting random
+             * keys is expensive, so stop here waiting for better times...
+             * The dictionary will be resized asap. */
+            if (num && slots > DICT_HT_INITIAL_SIZE &&
+                (num*100/slots < 1)) break;
+
+            /* The main collection cycle. Sample random keys among keys
+             * with an expire set, checking for expired ones. */
+            expired = 0;
+            ttl_sum = 0;
+            ttl_samples = 0;
+
+            if (num > ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP)
+                num = ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP;
+
+            while (num--) {
+                dictEntry *de;
+                long long ttl;
+
+                if ((de = dictGetRandomKey(db->expires)) == NULL) break;
+                ttl = dictGetSignedIntegerVal(de)-now;
+                if (activeExpireCycleTryExpire(db,de,now)) expired++;
+                if (ttl > 0) {
+                    /* We want the average TTL of keys yet not expired. */
+                    ttl_sum += ttl;
+                    ttl_samples++;
+                }
+            }
+
+            /* Update the average TTL stats for this database. */
+            if (ttl_samples) {
+                long long avg_ttl = ttl_sum/ttl_samples;
+
+                /* Do a simple running average with a few samples.
+                 * We just use the current estimate with a weight of 2%
+                 * and the previous estimate with a weight of 98%. */
+                if (db->avg_ttl == 0) db->avg_ttl = avg_ttl;
+                db->avg_ttl = (db->avg_ttl/50)*49 + (avg_ttl/50);
+            }
+
+            /* 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;
+            }
+            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);
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * Expires Commands
+ *----------------------------------------------------------------------------*/
+
+/* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT
+ * and PEXPIREAT. Because the commad second argument may be relative or absolute
+ * the "basetime" argument is used to signal what the base time is (either 0
+ * for *AT variants of the command, or the current time for relative expires).
+ *
+ * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for
+ * the argv[2] parameter. The basetime is always specified in milliseconds. */
+void expireGenericCommand(client *c, long long basetime, int unit) {
+    robj *key = c->argv[1], *param = c->argv[2];
+    long long when; /* unix time in milliseconds when the key will expire. */
+
+    if (getLongLongFromObjectOrReply(c, param, &when, NULL) != C_OK)
+        return;
+
+    if (unit == UNIT_SECONDS) when *= 1000;
+    when += basetime;
+
+    /* No key, return zero. */
+    if (lookupKeyWrite(c->db,key) == NULL) {
+        addReply(c,shared.czero);
+        return;
+    }
+
+    /* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past
+     * should never be executed as a DEL when load the AOF or in the context
+     * of a slave instance.
+     *
+     * Instead we take the other branch of the IF statement setting an expire
+     * (possibly in the past) and wait for an explicit DEL from the master. */
+    if (when <= mstime() && !server.loading && !server.masterhost) {
+        robj *aux;
+
+        int deleted = server.lazyfree_lazy_expire ? dbAsyncDelete(c->db,key) :
+                                                    dbSyncDelete(c->db,key);
+        serverAssertWithInfo(c,key,deleted);
+        server.dirty++;
+
+        /* Replicate/AOF this as an explicit DEL or UNLINK. */
+        aux = server.lazyfree_lazy_expire ? shared.unlink : shared.del;
+        rewriteClientCommandVector(c,2,aux,key);
+        signalModifiedKey(c->db,key);
+        notifyKeyspaceEvent(NOTIFY_GENERIC,"del",key,c->db->id);
+        addReply(c, shared.cone);
+        return;
+    } else {
+        setExpire(c->db,key,when);
+        addReply(c,shared.cone);
+        signalModifiedKey(c->db,key);
+        notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",key,c->db->id);
+        server.dirty++;
+        return;
+    }
+}
+
+/* EXPIRE key seconds */
+void expireCommand(client *c) {
+    expireGenericCommand(c,mstime(),UNIT_SECONDS);
+}
+
+/* EXPIREAT key time */
+void expireatCommand(client *c) {
+    expireGenericCommand(c,0,UNIT_SECONDS);
+}
+
+/* PEXPIRE key milliseconds */
+void pexpireCommand(client *c) {
+    expireGenericCommand(c,mstime(),UNIT_MILLISECONDS);
+}
+
+/* PEXPIREAT key ms_time */
+void pexpireatCommand(client *c) {
+    expireGenericCommand(c,0,UNIT_MILLISECONDS);
+}
+
+/* Implements TTL and PTTL */
+void ttlGenericCommand(client *c, int output_ms) {
+    long long expire, ttl = -1;
+
+    /* If the key does not exist at all, return -2 */
+    if (lookupKeyReadWithFlags(c->db,c->argv[1],LOOKUP_NOTOUCH) == NULL) {
+        addReplyLongLong(c,-2);
+        return;
+    }
+    /* The key exists. Return -1 if it has no expire, or the actual
+     * TTL value otherwise. */
+    expire = getExpire(c->db,c->argv[1]);
+    if (expire != -1) {
+        ttl = expire-mstime();
+        if (ttl < 0) ttl = 0;
+    }
+    if (ttl == -1) {
+        addReplyLongLong(c,-1);
+    } else {
+        addReplyLongLong(c,output_ms ? ttl : ((ttl+500)/1000));
+    }
+}
+
+/* TTL key */
+void ttlCommand(client *c) {
+    ttlGenericCommand(c, 0);
+}
+
+/* PTTL key */
+void pttlCommand(client *c) {
+    ttlGenericCommand(c, 1);
+}
+
+/* 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 (removeExpire(c->db,c->argv[1])) {
+            addReply(c,shared.cone);
+            server.dirty++;
+        } else {
+            addReply(c,shared.czero);
+        }
+    }
+}
+
+/* TOUCH key1 [key2 key3 ... keyN] */
+void touchCommand(client *c) {
+    int touched = 0;
+    for (int j = 1; j < c->argc; j++)
+        if (lookupKeyRead(c->db,c->argv[j]) != NULL) touched++;
+    addReplyLongLong(c,touched);
+}
+

src/geo.c

@@ -113,7 +113,7 @@ int extractLongLatOrReply(client *c, robj **argv, double *xy) {
 int longLatFromMember(robj *zobj, robj *member, double *xy) {
     double score = 0;
 
-    if (zsetScore(zobj, member, &score) == C_ERR) return C_ERR;
+    if (zsetScore(zobj, member->ptr, &score) == C_ERR) return C_ERR;
     if (!decodeGeohash(score, xy)) return C_ERR;
     return C_OK;
 }
@@ -269,16 +269,14 @@ int geoGetPointsInRange(robj *zobj, double min, double max, double lon, double l
         }
 
         while (ln) {
-            robj *o = ln->obj;
+            sds ele = ln->ele;
             /* Abort when the node is no longer in range. */
             if (!zslValueLteMax(ln->score, &range))
                 break;
 
-            member = (o->encoding == OBJ_ENCODING_INT) ?
-                        sdsfromlonglong((long)o->ptr) :
-                        sdsdup(o->ptr);
-            if (geoAppendIfWithinRadius(ga,lon,lat,radius,ln->score,member)
-                == C_ERR) sdsfree(member);
+            ele = sdsdup(ele);
+            if (geoAppendIfWithinRadius(ga,lon,lat,radius,ln->score,ele)
+                == C_ERR) sdsfree(ele);
             ln = ln->level[0].forward;
         }
     }
@@ -328,7 +326,6 @@ 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;
@@ -343,26 +340,8 @@ 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 (debugmsg) D("neighbors[%d] is zero",i);
+        if (HASHISZERO(neighbors[i]))
             continue;
-        }
-
-        /* Debugging info. */
-        if (debugmsg) {
-            GeoHashRange long_range, lat_range;
-            geohashGetCoordRange(&long_range,&lat_range);
-            GeoHashArea myarea = {{0,0},{0,0},{0,0}};
-            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
@@ -371,11 +350,7 @@ 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;
     }
@@ -643,13 +618,10 @@ void georadiusGeneric(client *c, int type) {
             gp->dist /= conversion; /* Fix according to unit. */
             double score = storedist ? gp->dist : gp->score;
             size_t elelen = sdslen(gp->member);
-            robj *ele = createObject(OBJ_STRING,gp->member);
 
             if (maxelelen < elelen) maxelelen = elelen;
-            incrRefCount(ele); /* Set refcount to 2 since we reference the
-                                  object both in the skiplist and dict. */
-            znode = zslInsert(zs->zsl,score,ele);
-            serverAssert(dictAdd(zs->dict,ele,&znode->score) == DICT_OK);
+            znode = zslInsert(zs->zsl,score,gp->member);
+            serverAssert(dictAdd(zs->dict,gp->member,&znode->score) == DICT_OK);
             gp->member = NULL;
         }
 
@@ -698,7 +670,7 @@ void geohashCommand(client *c) {
     addReplyMultiBulkLen(c,c->argc-2);
     for (j = 2; j < c->argc; j++) {
         double score;
-        if (zsetScore(zobj, c->argv[j], &score) == C_ERR) {
+        if (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
@@ -752,7 +724,7 @@ void geoposCommand(client *c) {
     addReplyMultiBulkLen(c,c->argc-2);
     for (j = 2; j < c->argc; j++) {
         double score;
-        if (zsetScore(zobj, c->argv[j], &score) == C_ERR) {
+        if (zsetScore(zobj, c->argv[j]->ptr, &score) == C_ERR) {
             addReply(c,shared.nullmultibulk);
         } else {
             /* Decode... */
@@ -792,8 +764,8 @@ void geodistCommand(client *c) {
 
     /* Get the scores. We need both otherwise NULL is returned. */
     double score1, score2, xyxy[4];
-    if (zsetScore(zobj, c->argv[2], &score1) == C_ERR ||
-        zsetScore(zobj, c->argv[3], &score2) == C_ERR)
+    if (zsetScore(zobj, c->argv[2]->ptr, &score1) == C_ERR ||
+        zsetScore(zobj, c->argv[3]->ptr, &score2) == C_ERR)
     {
         addReply(c,shared.nullbulk);
         return;

src/geohash.c

@@ -151,7 +151,7 @@ int geohashEncode(const GeoHashRange *long_range, const GeoHashRange *lat_range,
 }
 
 int geohashEncodeType(double longitude, double latitude, uint8_t step, GeoHashBits *hash) {
-    GeoHashRange r[2] = { { 0 } };
+    GeoHashRange r[2] = {{0}};
     geohashGetCoordRange(&r[0], &r[1]);
     return geohashEncode(&r[0], &r[1], longitude, latitude, step, hash);
 }
@@ -194,7 +194,7 @@ int geohashDecode(const GeoHashRange long_range, const GeoHashRange lat_range,
 }
 
 int geohashDecodeType(const GeoHashBits hash, GeoHashArea *area) {
-    GeoHashRange r[2] = { { 0 } };
+    GeoHashRange r[2] = {{0}};
     geohashGetCoordRange(&r[0], &r[1]);
     return geohashDecode(r[0], r[1], hash, area);
 }
@@ -211,7 +211,7 @@ int geohashDecodeAreaToLongLat(const GeoHashArea *area, double *xy) {
 }
 
 int geohashDecodeToLongLatType(const GeoHashBits hash, double *xy) {
-    GeoHashArea area = { { 0 } };
+    GeoHashArea area = {{0}};
     if (!xy || !geohashDecodeType(hash, &area))
         return 0;
     return geohashDecodeAreaToLongLat(&area, xy);

src/geohash_helper.c

@@ -34,7 +34,9 @@
  * https://github.com/yinqiwen/ardb/blob/d42503/src/geo/geohash_helper.cpp
  */
 
+#include "fmacros.h"
 #include "geohash_helper.h"
+#include "debugmacro.h"
 #include <math.h>
 
 #define D_R (M_PI / 180.0)
@@ -80,18 +82,30 @@ 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. */
 int geohashBoundingBox(double longitude, double latitude, double radius_meters,
                        double *bounds) {
     if (!bounds) return 0;
 
-    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);
+    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);
     return 1;
 }
 
@@ -144,13 +158,35 @@ GeoHashRadius geohashGetAreasByRadius(double longitude, double latitude, double
             < radius_meters) decrease_step = 1;
     }
 
-    if (steps > 1 && decrease_step) {
+    if (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);

src/geohash_helper.h

@@ -32,7 +32,6 @@
 #ifndef GEOHASH_HELPER_HPP_
 #define GEOHASH_HELPER_HPP_
 
-#include <math.h>
 #include "geohash.h"
 
 #define GZERO(s) s.bits = s.step = 0;

src/intset.c

@@ -272,7 +272,7 @@ uint8_t intsetGet(intset *is, uint32_t pos, int64_t *value) {
 }
 
 /* Return intset length */
-uint32_t intsetLen(intset *is) {
+uint32_t intsetLen(const intset *is) {
     return intrev32ifbe(is->length);
 }
 

src/intset.h

@@ -44,7 +44,7 @@ intset *intsetRemove(intset *is, int64_t value, int *success);
 uint8_t intsetFind(intset *is, int64_t value);
 int64_t intsetRandom(intset *is);
 uint8_t intsetGet(intset *is, uint32_t pos, int64_t *value);
-uint32_t intsetLen(intset *is);
+uint32_t intsetLen(const intset *is);
 size_t intsetBlobLen(intset *is);
 
 #ifdef REDIS_TEST

src/latency.c

@@ -79,7 +79,7 @@ int THPIsEnabled(void) {
  * value of the function is non-zero, the process is being targeted by
  * THP support, and is likely to have memory usage / latency issues. */
 int THPGetAnonHugePagesSize(void) {
-    return zmalloc_get_smap_bytes_by_field("AnonHugePages:");
+    return zmalloc_get_smap_bytes_by_field("AnonHugePages:",-1);
 }
 
 /* ---------------------------- Latency API --------------------------------- */

src/lazyfree.c

@@ -0,0 +1,132 @@
+#include "server.h"
+#include "bio.h"
+#include "atomicvar.h"
+#include "cluster.h"
+
+static size_t lazyfree_objects = 0;
+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;
+}
+
+/* Return the amount of work needed in order to free an object.
+ * The return value is not always the actual number of allocations the
+ * object is compoesd of, but a number proportional to it.
+ *
+ * For strings the function always returns 1.
+ *
+ * For aggregated objects represented by hash tables or other data structures
+ * the function just returns the number of elements the object is composed of.
+ *
+ * Objects composed of single allocations are always reported as having a
+ * single item even if they are actaully logical composed of multiple
+ * elements.
+ *
+ * For lists the funciton returns the number of elements in the quicklist
+ * representing the list. */
+size_t lazyfreeGetFreeEffort(robj *obj) {
+    if (obj->type == OBJ_LIST) {
+        quicklist *ql = obj->ptr;
+        return ql->len;
+    } else if (obj->type == OBJ_SET && obj->encoding == OBJ_ENCODING_HT) {
+        dict *ht = obj->ptr;
+        return dictSize(ht);
+    } else if (obj->type == OBJ_ZSET && obj->encoding == OBJ_ENCODING_SKIPLIST){
+        zset *zs = obj->ptr;
+        return zs->zsl->length;
+    } else if (obj->type == OBJ_HASH && obj->encoding == OBJ_ENCODING_HT) {
+        dict *ht = obj->ptr;
+        return dictSize(ht);
+    } else {
+        return 1; /* Everything else is a single allocation. */
+    }
+}
+
+/* Delete a key, value, and associated expiration entry if any, from the DB.
+ * If there are enough allocations to free the value object may be put into
+ * a lazy free list instead of being freed synchronously. The lazy free list
+ * will be reclaimed in a different bio.c thread. */
+#define LAZYFREE_THRESHOLD 64
+int dbAsyncDelete(redisDb *db, robj *key) {
+    /* Deleting an entry from the expires dict will not free the sds of
+     * the key, because it is shared with the main dictionary. */
+    if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);
+
+    /* If the value is composed of a few allocations, to free in a lazy way
+     * is actually just slower... So under a certain limit we just free
+     * the object synchronously. */
+    dictEntry *de = dictUnlink(db->dict,key->ptr);
+    if (de) {
+        robj *val = dictGetVal(de);
+        size_t free_effort = lazyfreeGetFreeEffort(val);
+
+        /* 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);
+            bioCreateBackgroundJob(BIO_LAZY_FREE,val,NULL,NULL);
+            dictSetVal(db->dict,de,NULL);
+        }
+    }
+
+    /* Release the key-val pair, or just the key if we set the val
+     * field to NULL in order to lazy free it later. */
+    if (de) {
+        dictFreeUnlinkedEntry(db->dict,de);
+        if (server.cluster_enabled) slotToKeyDel(key);
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+/* Empty a Redis DB asynchronously. What the function does actually is to
+ * create a new empty set of hash tables and scheduling the old ones for
+ * lazy freeing. */
+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);
+    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);
+}
+
+/* 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);
+}
+
+/* Release a database from the lazyfree thread. The 'db' pointer is the
+ * database which was substitutied with a fresh one in the main thread
+ * when the database was logically deleted. 'sl' is a skiplist used by
+ * Redis Cluster in order to take the hash slots -> keys mapping. This
+ * may be NULL if Redis Cluster is disabled. */
+void lazyfreeFreeDatabaseFromBioThread(dict *ht1, dict *ht2) {
+    size_t numkeys = dictSize(ht1);
+    dictRelease(ht1);
+    dictRelease(ht2);
+    atomicDecr(lazyfree_objects,numkeys,lazyfree_objects_mutex);
+}
+
+/* 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);
+}

src/modules/.gitignore

@@ -0,0 +1,2 @@
+*.so
+*.xo

src/modules/INTRO.md

@@ -0,0 +1,856 @@
+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);

src/modules/Makefile

@@ -0,0 +1,37 @@
+
+# find the OS
+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_LDFLAGS ?= -shared
+else
+	SHOBJ_CFLAGS ?= -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
+
+.c.xo:
+	$(CC) -I. $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@
+
+helloworld.xo: ../redismodule.h
+
+helloworld.so: helloworld.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
+
+hellotype.xo: ../redismodule.h
+
+hellotype.so: hellotype.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
+
+testmodule.xo: ../redismodule.h
+
+testmodule.so: testmodule.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
+
+clean:
+	rm -rf *.xo *.so

src/modules/TYPES.md

@@ -0,0 +1,371 @@
+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()`.

src/modules/gendoc.rb

@@ -0,0 +1,43 @@
+# gendoc.rb -- Converts the top-comments inside module.c to modules API
+#              reference documentaiton in markdown format.
+
+# Convert the C comment to markdown
+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
+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])
+    proto = src[i].sub("{","").strip+";\n"
+    puts "## `#{m[0]}`\n\n"
+    puts "    #{proto}\n"
+    comment = ""
+    while true
+        i = i-1
+        comment = src[i]+comment
+        break if src[i] =~ /\/\*/
+    end
+    comment = markdown(comment)
+    puts comment+"\n\n"
+end
+
+puts "# Modules API reference\n\n"
+src = File.open("../module.c").to_a
+src.each_with_index{|line,i|
+    if line =~ /RM_/ && line[0] != ' ' && line[0] != '#' && line[0] != '/'
+        if src[i-1] =~ /\*\//
+            docufy(src,i)
+        end
+    end
+}

src/modules/hellotype.c

@@ -0,0 +1,259 @@
+/* This file implements a new module native data type called "HELLOTYPE".
+ * The data structure implemented is a very simple ordered linked list of
+ * 64 bit integers, in order to have something that is real world enough, but
+ * at the same time, extremely simple to understand, to show how the API
+ * works, how a new data type is created, and how to write basic methods
+ * for RDB loading, saving and AOF rewriting.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * 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.
+ */
+
+#include "../redismodule.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdint.h>
+
+static RedisModuleType *HelloType;
+
+/* ========================== Internal data structure  =======================
+ * This is just a linked list of 64 bit integers where elements are inserted
+ * in-place, so it's ordered. There is no pop/push operation but just insert
+ * because it is enough to show the implementation of new data types without
+ * making things complex. */
+
+struct HelloTypeNode {
+    int64_t value;
+    struct HelloTypeNode *next;
+};
+
+struct HelloTypeObject {
+    struct HelloTypeNode *head;
+    size_t len; /* Number of elements added. */
+};
+
+struct HelloTypeObject *createHelloTypeObject(void) {
+    struct HelloTypeObject *o;
+    o = RedisModule_Alloc(sizeof(*o));
+    o->head = NULL;
+    o->len = 0;
+    return o;
+}
+
+void HelloTypeInsert(struct HelloTypeObject *o, int64_t ele) {
+    struct HelloTypeNode *next = o->head, *newnode, *prev = NULL;
+
+    while(next && next->value < ele) {
+        prev = next;
+        next = next->next;
+    }
+    newnode = RedisModule_Alloc(sizeof(*newnode));
+    newnode->value = ele;
+    newnode->next = next;
+    if (prev) {
+        prev->next = newnode;
+    } else {
+        o->head = newnode;
+    }
+    o->len++;
+}
+
+void HelloTypeReleaseObject(struct HelloTypeObject *o) {
+    struct HelloTypeNode *cur, *next;
+    cur = o->head;
+    while(cur) {
+        next = cur->next;
+        RedisModule_Free(cur);
+        cur = next;
+    }
+    RedisModule_Free(o);
+}
+
+/* ========================= "hellotype" type commands ======================= */
+
+/* HELLOTYPE.INSERT key value */
+int HelloTypeInsert_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    int type = RedisModule_KeyType(key);
+    if (type != REDISMODULE_KEYTYPE_EMPTY &&
+        RedisModule_ModuleTypeGetType(key) != HelloType)
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    long long value;
+    if ((RedisModule_StringToLongLong(argv[2],&value) != REDISMODULE_OK)) {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid value: must be a signed 64 bit integer");
+    }
+
+    /* Create an empty value object if the key is currently empty. */
+    struct HelloTypeObject *hto;
+    if (type == REDISMODULE_KEYTYPE_EMPTY) {
+        hto = createHelloTypeObject();
+        RedisModule_ModuleTypeSetValue(key,HelloType,hto);
+    } else {
+        hto = RedisModule_ModuleTypeGetValue(key);
+    }
+
+    /* Insert the new element. */
+    HelloTypeInsert(hto,value);
+
+    RedisModule_ReplyWithLongLong(ctx,hto->len);
+    RedisModule_ReplicateVerbatim(ctx);
+    return REDISMODULE_OK;
+}
+
+/* HELLOTYPE.RANGE key first count */
+int HelloTypeRange_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    int type = RedisModule_KeyType(key);
+    if (type != REDISMODULE_KEYTYPE_EMPTY &&
+        RedisModule_ModuleTypeGetType(key) != HelloType)
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    long long first, count;
+    if (RedisModule_StringToLongLong(argv[2],&first) != REDISMODULE_OK ||
+        RedisModule_StringToLongLong(argv[3],&count) != REDISMODULE_OK ||
+        first < 0 || count < 0)
+    {
+        return RedisModule_ReplyWithError(ctx,
+            "ERR invalid first or count parameters");
+    }
+
+    struct HelloTypeObject *hto = RedisModule_ModuleTypeGetValue(key);
+    struct HelloTypeNode *node = hto ? hto->head : NULL;
+    RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
+    long long arraylen = 0;
+    while(node && count--) {
+        RedisModule_ReplyWithLongLong(ctx,node->value);
+        arraylen++;
+        node = node->next;
+    }
+    RedisModule_ReplySetArrayLength(ctx,arraylen);
+    return REDISMODULE_OK;
+}
+
+/* HELLOTYPE.LEN key */
+int HelloTypeLen_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 2) return RedisModule_WrongArity(ctx);
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    int type = RedisModule_KeyType(key);
+    if (type != REDISMODULE_KEYTYPE_EMPTY &&
+        RedisModule_ModuleTypeGetType(key) != HelloType)
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    struct HelloTypeObject *hto = RedisModule_ModuleTypeGetValue(key);
+    RedisModule_ReplyWithLongLong(ctx,hto ? hto->len : 0);
+    return REDISMODULE_OK;
+}
+
+
+/* ========================== "hellotype" type methods ======================= */
+
+void *HelloTypeRdbLoad(RedisModuleIO *rdb, int encver) {
+    if (encver != 0) {
+        /* RedisModule_Log("warning","Can't load data with version %d", encver);*/
+        return NULL;
+    }
+    uint64_t elements = RedisModule_LoadUnsigned(rdb);
+    struct HelloTypeObject *hto = createHelloTypeObject();
+    while(elements--) {
+        int64_t ele = RedisModule_LoadSigned(rdb);
+        HelloTypeInsert(hto,ele);
+    }
+    return hto;
+}
+
+void HelloTypeRdbSave(RedisModuleIO *rdb, void *value) {
+    struct HelloTypeObject *hto = value;
+    struct HelloTypeNode *node = hto->head;
+    RedisModule_SaveUnsigned(rdb,hto->len);
+    while(node) {
+        RedisModule_SaveSigned(rdb,node->value);
+        node = node->next;
+    }
+}
+
+void HelloTypeAofRewrite(RedisModuleIO *aof, RedisModuleString *key, void *value) {
+    struct HelloTypeObject *hto = value;
+    struct HelloTypeNode *node = hto->head;
+    while(node) {
+        RedisModule_EmitAOF(aof,"HELLOTYPE.INSERT","sl",key,node->value);
+        node = node->next;
+    }
+}
+
+void HelloTypeDigest(RedisModuleDigest *digest, void *value) {
+    /* TODO: The DIGEST module interface is yet not implemented. */
+}
+
+void HelloTypeFree(void *value) {
+    HelloTypeReleaseObject(value);
+}
+
+/* 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) {
+    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);
+    if (HelloType == NULL) return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellotype.insert",
+        HelloTypeInsert_RedisCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellotype.range",
+        HelloTypeRange_RedisCommand,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellotype.len",
+        HelloTypeLen_RedisCommand,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    return REDISMODULE_OK;
+}

src/modules/helloworld.c

@@ -0,0 +1,618 @@
+/* Helloworld module -- A few examples of the Redis Modules API in the form
+ * of commands showing how to accomplish common tasks.
+ *
+ * This module does not do anything useful, if not for a few commands. The
+ * examples are designed in order to show the API.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * 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.
+ */
+
+#include "../redismodule.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+
+/* HELLO.SIMPLE is among the simplest commands you can implement.
+ * It just returns the currently selected DB id, a functionality which is
+ * missing in Redis. The command uses two important API calls: one to
+ * 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_ReplyWithLongLong(ctx,RedisModule_GetSelectedDb(ctx));
+    return REDISMODULE_OK;
+}
+
+/* HELLO.PUSH.NATIVE re-implements RPUSH, and shows the low level modules API
+ * where you can "open" keys, make low level operations, create new keys by
+ * pushing elements into non-existing keys, and so forth.
+ *
+ * You'll find this command to be roughly as fast as the actual RPUSH
+ * command. */
+int HelloPushNative_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+
+    RedisModule_ListPush(key,REDISMODULE_LIST_TAIL,argv[2]);
+    size_t newlen = RedisModule_ValueLength(key);
+    RedisModule_CloseKey(key);
+    RedisModule_ReplyWithLongLong(ctx,newlen);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.PUSH.CALL implements RPUSH using an higher level approach, calling
+ * a Redis command instead of working with the key in a low level way. This
+ * approach is useful when you need to call Redis commands that are not
+ * available as low level APIs, or when you don't need the maximum speed
+ * possible but instead prefer implementation simplicity. */
+int HelloPushCall_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+
+    RedisModuleCallReply *reply;
+
+    reply = RedisModule_Call(ctx,"RPUSH","ss",argv[1],argv[2]);
+    long long len = RedisModule_CallReplyInteger(reply);
+    RedisModule_FreeCallReply(reply);
+    RedisModule_ReplyWithLongLong(ctx,len);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.PUSH.CALL2
+ * This is exaxctly as HELLO.PUSH.CALL, but shows how we can reply to the
+ * client using directly a reply object that Call() returned. */
+int HelloPushCall2_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+
+    RedisModuleCallReply *reply;
+
+    reply = RedisModule_Call(ctx,"RPUSH","ss",argv[1],argv[2]);
+    RedisModule_ReplyWithCallReply(ctx,reply);
+    RedisModule_FreeCallReply(reply);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.LIST.SUM.LEN returns the total length of all the items inside
+ * a Redis list, by using the high level Call() API.
+ * This command is an example of the array reply access. */
+int HelloListSumLen_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 2) return RedisModule_WrongArity(ctx);
+
+    RedisModuleCallReply *reply;
+
+    reply = RedisModule_Call(ctx,"LRANGE","sll",argv[1],(long long)0,(long long)-1);
+    size_t strlen = 0;
+    size_t items = RedisModule_CallReplyLength(reply);
+    size_t j;
+    for (j = 0; j < items; j++) {
+        RedisModuleCallReply *ele = RedisModule_CallReplyArrayElement(reply,j);
+        strlen += RedisModule_CallReplyLength(ele);
+    }
+    RedisModule_FreeCallReply(reply);
+    RedisModule_ReplyWithLongLong(ctx,strlen);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.LIST.SPLICE srclist dstlist count
+ * Moves 'count' elements from the tail of 'srclist' to the head of
+ * 'dstlist'. If less than count elements are available, it moves as much
+ * elements as possible. */
+int HelloListSplice_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+
+    RedisModuleKey *srckey = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    RedisModuleKey *dstkey = RedisModule_OpenKey(ctx,argv[2],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+
+    /* Src and dst key must be empty or lists. */
+    if ((RedisModule_KeyType(srckey) != REDISMODULE_KEYTYPE_LIST &&
+         RedisModule_KeyType(srckey) != REDISMODULE_KEYTYPE_EMPTY) ||
+        (RedisModule_KeyType(dstkey) != REDISMODULE_KEYTYPE_LIST &&
+         RedisModule_KeyType(dstkey) != REDISMODULE_KEYTYPE_EMPTY))
+    {
+        RedisModule_CloseKey(srckey);
+        RedisModule_CloseKey(dstkey);
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    long long count;
+    if ((RedisModule_StringToLongLong(argv[3],&count) != REDISMODULE_OK) ||
+        (count < 0)) {
+        RedisModule_CloseKey(srckey);
+        RedisModule_CloseKey(dstkey);
+        return RedisModule_ReplyWithError(ctx,"ERR invalid count");
+    }
+
+    while(count-- > 0) {
+        RedisModuleString *ele;
+
+        ele = RedisModule_ListPop(srckey,REDISMODULE_LIST_TAIL);
+        if (ele == NULL) break;
+        RedisModule_ListPush(dstkey,REDISMODULE_LIST_HEAD,ele);
+        RedisModule_FreeString(ctx,ele);
+    }
+
+    size_t len = RedisModule_ValueLength(srckey);
+    RedisModule_CloseKey(srckey);
+    RedisModule_CloseKey(dstkey);
+    RedisModule_ReplyWithLongLong(ctx,len);
+    return REDISMODULE_OK;
+}
+
+/* Like the HELLO.LIST.SPLICE above, but uses automatic memory management
+ * in order to avoid freeing stuff. */
+int HelloListSpliceAuto_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+
+    RedisModule_AutoMemory(ctx);
+
+    RedisModuleKey *srckey = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    RedisModuleKey *dstkey = RedisModule_OpenKey(ctx,argv[2],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+
+    /* Src and dst key must be empty or lists. */
+    if ((RedisModule_KeyType(srckey) != REDISMODULE_KEYTYPE_LIST &&
+         RedisModule_KeyType(srckey) != REDISMODULE_KEYTYPE_EMPTY) ||
+        (RedisModule_KeyType(dstkey) != REDISMODULE_KEYTYPE_LIST &&
+         RedisModule_KeyType(dstkey) != REDISMODULE_KEYTYPE_EMPTY))
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    long long count;
+    if ((RedisModule_StringToLongLong(argv[3],&count) != REDISMODULE_OK) ||
+        (count < 0))
+    {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid count");
+    }
+
+    while(count-- > 0) {
+        RedisModuleString *ele;
+
+        ele = RedisModule_ListPop(srckey,REDISMODULE_LIST_TAIL);
+        if (ele == NULL) break;
+        RedisModule_ListPush(dstkey,REDISMODULE_LIST_HEAD,ele);
+    }
+
+    size_t len = RedisModule_ValueLength(srckey);
+    RedisModule_ReplyWithLongLong(ctx,len);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.RAND.ARRAY <count>
+ * Shows how to generate arrays as commands replies.
+ * It just outputs <count> random numbers. */
+int HelloRandArray_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 2) return RedisModule_WrongArity(ctx);
+    long long count;
+    if (RedisModule_StringToLongLong(argv[1],&count) != REDISMODULE_OK ||
+        count < 0)
+        return RedisModule_ReplyWithError(ctx,"ERR invalid count");
+
+    /* To reply with an array, we call RedisModule_ReplyWithArray() followed
+     * by other "count" calls to other reply functions in order to generate
+     * the elements of the array. */
+    RedisModule_ReplyWithArray(ctx,count);
+    while(count--) RedisModule_ReplyWithLongLong(ctx,rand());
+    return REDISMODULE_OK;
+}
+
+/* This is a simple command to test replication. Because of the "!" modified
+ * in the RedisModule_Call() call, the two INCRs get replicated.
+ * Also note how the ECHO is replicated in an unexpected position (check
+ * comments the function implementation). */
+int HelloRepl1_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    RedisModuleCallReply *reply;
+    RedisModule_AutoMemory(ctx);
+
+    /* This will be replicated *after* the two INCR statements, since
+     * the Call() replication has precedence, so the actual replication
+     * stream will be:
+     *
+     * MULTI
+     * INCR foo
+     * INCR bar
+     * ECHO c foo
+     * EXEC
+     */
+    RedisModule_Replicate(ctx,"ECHO","c","foo");
+
+    /* 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_ReplyWithLongLong(ctx,0);
+
+    return REDISMODULE_OK;
+}
+
+/* Another command to show replication. In this case, we call
+ * RedisModule_ReplicateVerbatim() to mean we want just the command to be
+ * propagated to slaves / AOF exactly as it was called by the user.
+ *
+ * This command also shows how to work with string objects.
+ * It takes a list, and increments all the elements (that must have
+ * a numerical value) by 1, returning the sum of all the elements
+ * as reply.
+ *
+ * Usage: HELLO.REPL2 <list-key> */
+int HelloRepl2_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 2) return RedisModule_WrongArity(ctx);
+
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+
+    if (RedisModule_KeyType(key) != REDISMODULE_KEYTYPE_LIST)
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+
+    size_t listlen = RedisModule_ValueLength(key);
+    long long sum = 0;
+
+    /* Rotate and increment. */
+    while(listlen--) {
+        RedisModuleString *ele = RedisModule_ListPop(key,REDISMODULE_LIST_TAIL);
+        long long val;
+        if (RedisModule_StringToLongLong(ele,&val) != REDISMODULE_OK) val = 0;
+        val++;
+        sum += val;
+        RedisModuleString *newele = RedisModule_CreateStringFromLongLong(ctx,val);
+        RedisModule_ListPush(key,REDISMODULE_LIST_HEAD,newele);
+    }
+    RedisModule_ReplyWithLongLong(ctx,sum);
+    RedisModule_ReplicateVerbatim(ctx);
+    return REDISMODULE_OK;
+}
+
+/* This is an example of strings DMA access. Given a key containing a string
+ * it toggles the case of each character from lower to upper case or the
+ * other way around.
+ *
+ * No automatic memory management is used in this example (for the sake
+ * of variety).
+ *
+ * HELLO.TOGGLE.CASE key */
+int HelloToggleCase_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 2) return RedisModule_WrongArity(ctx);
+
+    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);
+    }
+
+    if (keytype == REDISMODULE_KEYTYPE_STRING) {
+        size_t len, j;
+        char *s = RedisModule_StringDMA(key,&len,REDISMODULE_WRITE);
+        for (j = 0; j < len; j++) {
+            if (isupper(s[j])) {
+                s[j] = tolower(s[j]);
+            } else {
+                s[j] = toupper(s[j]);
+            }
+        }
+    }
+
+    RedisModule_CloseKey(key);
+    RedisModule_ReplyWithSimpleString(ctx,"OK");
+    RedisModule_ReplicateVerbatim(ctx);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.MORE.EXPIRE key milliseconds.
+ *
+ * If they key has already an associated TTL, extends it by "milliseconds"
+ * milliseconds. Otherwise no operation is performed. */
+int HelloMoreExpire_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+
+    mstime_t addms, expire;
+
+    if (RedisModule_StringToLongLong(argv[2],&addms) != REDISMODULE_OK)
+        return RedisModule_ReplyWithError(ctx,"ERR invalid expire time");
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    expire = RedisModule_GetExpire(key);
+    if (expire != REDISMODULE_NO_EXPIRE) {
+        expire += addms;
+        RedisModule_SetExpire(key,expire);
+    }
+    return RedisModule_ReplyWithSimpleString(ctx,"OK");
+}
+
+/* HELLO.ZSUMRANGE key startscore endscore
+ * Return the sum of all the scores elements between startscore and endscore.
+ *
+ * The computation is performed two times, one time from start to end and
+ * another time backward. The two scores, returned as a two element array,
+ * should match.*/
+int HelloZsumRange_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    double score_start, score_end;
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+
+    if (RedisModule_StringToDouble(argv[2],&score_start) != REDISMODULE_OK ||
+        RedisModule_StringToDouble(argv[3],&score_end) != REDISMODULE_OK)
+    {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid range");
+    }
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    if (RedisModule_KeyType(key) != REDISMODULE_KEYTYPE_ZSET) {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    double scoresum_a = 0;
+    double scoresum_b = 0;
+
+    RedisModule_ZsetFirstInScoreRange(key,score_start,score_end,0,0);
+    while(!RedisModule_ZsetRangeEndReached(key)) {
+        double score;
+        RedisModuleString *ele = RedisModule_ZsetRangeCurrentElement(key,&score);
+        RedisModule_FreeString(ctx,ele);
+        scoresum_a += score;
+        RedisModule_ZsetRangeNext(key);
+    }
+    RedisModule_ZsetRangeStop(key);
+
+    RedisModule_ZsetLastInScoreRange(key,score_start,score_end,0,0);
+    while(!RedisModule_ZsetRangeEndReached(key)) {
+        double score;
+        RedisModuleString *ele = RedisModule_ZsetRangeCurrentElement(key,&score);
+        RedisModule_FreeString(ctx,ele);
+        scoresum_b += score;
+        RedisModule_ZsetRangePrev(key);
+    }
+
+    RedisModule_ZsetRangeStop(key);
+
+    RedisModule_CloseKey(key);
+
+    RedisModule_ReplyWithArray(ctx,2);
+    RedisModule_ReplyWithDouble(ctx,scoresum_a);
+    RedisModule_ReplyWithDouble(ctx,scoresum_b);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.LEXRANGE key min_lex max_lex min_age max_age
+ * This command expects a sorted set stored at key in the following form:
+ * - All the elements have score 0.
+ * - Elements are pairs of "<name>:<age>", for example "Anna:52".
+ * The command will return all the sorted set items that are lexicographically
+ * between the specified range (using the same format as ZRANGEBYLEX)
+ * and having an age between min_age and max_age. */
+int HelloLexRange_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 6) return RedisModule_WrongArity(ctx);
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    if (RedisModule_KeyType(key) != REDISMODULE_KEYTYPE_ZSET) {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    if (RedisModule_ZsetFirstInLexRange(key,argv[2],argv[3]) != REDISMODULE_OK) {
+        return RedisModule_ReplyWithError(ctx,"invalid range");
+    }
+
+    int arraylen = 0;
+    RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
+    while(!RedisModule_ZsetRangeEndReached(key)) {
+        double score;
+        RedisModuleString *ele = RedisModule_ZsetRangeCurrentElement(key,&score);
+        RedisModule_ReplyWithString(ctx,ele);
+        RedisModule_FreeString(ctx,ele);
+        RedisModule_ZsetRangeNext(key);
+        arraylen++;
+    }
+    RedisModule_ZsetRangeStop(key);
+    RedisModule_ReplySetArrayLength(ctx,arraylen);
+    RedisModule_CloseKey(key);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.HCOPY key srcfield dstfield
+ * This is just an example command that sets the hash field dstfield to the
+ * same value of srcfield. If srcfield does not exist no operation is
+ * performed.
+ *
+ * The command returns 1 if the copy is performed (srcfield exists) otherwise
+ * 0 is returned. */
+int HelloHCopy_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    int type = RedisModule_KeyType(key);
+    if (type != REDISMODULE_KEYTYPE_HASH &&
+        type != REDISMODULE_KEYTYPE_EMPTY)
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    /* Get the old field value. */
+    RedisModuleString *oldval;
+    RedisModule_HashGet(key,REDISMODULE_HASH_NONE,argv[2],&oldval,NULL);
+    if (oldval) {
+        RedisModule_HashSet(key,REDISMODULE_HASH_NONE,argv[3],oldval,NULL);
+    }
+    RedisModule_ReplyWithLongLong(ctx,oldval != NULL);
+    return REDISMODULE_OK;
+}
+
+/* HELLO.LEFTPAD str len ch
+ * This is an implementation of the infamous LEFTPAD function, that
+ * was at the center of an issue with the npm modules system in March 2016.
+ *
+ * LEFTPAD is a good example of using a Redis Modules API called
+ * "pool allocator", that was a famous way to allocate memory in yet another
+ * open source project, the Apache web server.
+ *
+ * The concept is very simple: there is memory that is useful to allocate
+ * only in the context of serving a request, and must be freed anyway when
+ * the callback implementing the command returns. So in that case the module
+ * does not need to retain a reference to these allocations, it is just
+ * required to free the memory before returning. When this is the case the
+ * module can call RedisModule_PoolAlloc() instead, that works like malloc()
+ * but will automatically free the memory when the module callback returns.
+ *
+ * Note that PoolAlloc() does not necessarily require AutoMemory to be
+ * active. */
+int HelloLeftPad_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+    long long padlen;
+
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+
+    if ((RedisModule_StringToLongLong(argv[2],&padlen) != REDISMODULE_OK) ||
+        (padlen< 0)) {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid padding length");
+    }
+    size_t strlen, chlen;
+    const char *str = RedisModule_StringPtrLen(argv[1], &strlen);
+    const char *ch = RedisModule_StringPtrLen(argv[3], &chlen);
+
+    /* If the string is already larger than the target len, just return
+     * the string itself. */
+    if (strlen >= padlen)
+        return RedisModule_ReplyWithString(ctx,argv[1]);
+
+    /* Padding must be a single character in this simple implementation. */
+    if (chlen != 1)
+        return RedisModule_ReplyWithError(ctx,
+            "ERR padding must be a single char");
+
+    /* 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;
+    memcpy(buf+padlen,str,strlen);
+
+    RedisModule_ReplyWithStringBuffer(ctx,buf,padlen+strlen);
+    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) {
+    if (RedisModule_Init(ctx,"helloworld",1,REDISMODULE_APIVER_1)
+        == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    /* Log the list of parameters passing loading the module. */
+    for (int j = 0; j < argc; j++) {
+        const char *s = RedisModule_StringPtrLen(argv[j],NULL);
+        printf("Module loaded with ARGV[%d] = %s\n", j, s);
+    }
+
+    if (RedisModule_CreateCommand(ctx,"hello.simple",
+        HelloSimple_RedisCommand,"readonly",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.push.native",
+        HelloPushNative_RedisCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.push.call",
+        HelloPushCall_RedisCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.push.call2",
+        HelloPushCall2_RedisCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.list.sum.len",
+        HelloListSumLen_RedisCommand,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.list.splice",
+        HelloListSplice_RedisCommand,"write deny-oom",1,2,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.list.splice.auto",
+        HelloListSpliceAuto_RedisCommand,
+        "write deny-oom",1,2,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.rand.array",
+        HelloRandArray_RedisCommand,"readonly",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.repl1",
+        HelloRepl1_RedisCommand,"write",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.repl2",
+        HelloRepl2_RedisCommand,"write",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.toggle.case",
+        HelloToggleCase_RedisCommand,"write",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.more.expire",
+        HelloMoreExpire_RedisCommand,"write",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.zsumrange",
+        HelloZsumRange_RedisCommand,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.lexrange",
+        HelloLexRange_RedisCommand,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.hcopy",
+        HelloHCopy_RedisCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hello.leftpad",
+        HelloLeftPad_RedisCommand,"",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    return REDISMODULE_OK;
+}

src/modules/testmodule.c

@@ -0,0 +1,222 @@
+/* Module designed to test the Redis modules subsystem.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * 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.
+ */
+
+#include "../redismodule.h"
+#include <string.h>
+
+/* --------------------------------- Helpers -------------------------------- */
+
+/* Return true if the reply and the C null term string matches. */
+int TestMatchReply(RedisModuleCallReply *reply, char *str) {
+    RedisModuleString *mystr;
+    mystr = RedisModule_CreateStringFromCallReply(reply);
+    if (!mystr) return 0;
+    const char *ptr = RedisModule_StringPtrLen(mystr,NULL);
+    return strcmp(ptr,str) == 0;
+}
+
+/* ------------------------------- Test units ------------------------------- */
+
+/* TEST.CALL -- Test Call() API. */
+int TestCall(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx);
+    RedisModuleCallReply *reply;
+
+    RedisModule_Call(ctx,"DEL","c","mylist");
+    RedisModuleString *mystr = RedisModule_CreateString(ctx,"foo",3);
+    RedisModule_Call(ctx,"RPUSH","csl","mylist",mystr,(long long)1234);
+    reply = RedisModule_Call(ctx,"LRANGE","ccc","mylist","0","-1");
+    long long items = RedisModule_CallReplyLength(reply);
+    if (items != 2) goto fail;
+
+    RedisModuleCallReply *item0, *item1;
+
+    item0 = RedisModule_CallReplyArrayElement(reply,0);
+    item1 = RedisModule_CallReplyArrayElement(reply,1);
+    if (!TestMatchReply(item0,"foo")) goto fail;
+    if (!TestMatchReply(item1,"1234")) goto fail;
+
+    RedisModule_ReplyWithSimpleString(ctx,"OK");
+    return REDISMODULE_OK;
+
+fail:
+    RedisModule_ReplyWithSimpleString(ctx,"ERR");
+    return REDISMODULE_OK;
+}
+
+/* TEST.STRING.APPEND -- Test appending to an existing string object. */
+int TestStringAppend(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModuleString *s = RedisModule_CreateString(ctx,"foo",3);
+    RedisModule_StringAppendBuffer(ctx,s,"bar",3);
+    RedisModule_ReplyWithString(ctx,s);
+    RedisModule_FreeString(ctx,s);
+    return REDISMODULE_OK;
+}
+
+/* TEST.STRING.APPEND.AM -- Test append with retain when auto memory is on. */
+int TestStringAppendAM(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx);
+    RedisModuleString *s = RedisModule_CreateString(ctx,"foo",3);
+    RedisModule_RetainString(ctx,s);
+    RedisModule_StringAppendBuffer(ctx,s,"bar",3);
+    RedisModule_ReplyWithString(ctx,s);
+    RedisModule_FreeString(ctx,s);
+    return REDISMODULE_OK;
+}
+
+/* TEST.STRING.PRINTF -- Test string formatting. */
+int TestStringPrintf(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx);
+    if (argc < 3) {
+        return RedisModule_WrongArity(ctx);
+    }
+    RedisModuleString *s = RedisModule_CreateStringPrintf(ctx, 
+        "Got %d args. argv[1]: %s, argv[2]: %s", 
+        argc, 
+        RedisModule_StringPtrLen(argv[1], NULL),
+        RedisModule_StringPtrLen(argv[2], NULL)
+    );
+
+    RedisModule_ReplyWithString(ctx,s);
+
+    return REDISMODULE_OK;
+}
+
+
+/* ----------------------------- Test framework ----------------------------- */
+
+/* Return 1 if the reply matches the specified string, otherwise log errors
+ * in the server log and return 0. */
+int TestAssertStringReply(RedisModuleCtx *ctx, RedisModuleCallReply *reply, char *str, size_t len) {
+    RedisModuleString *mystr, *expected;
+
+    if (RedisModule_CallReplyType(reply) != REDISMODULE_REPLY_STRING) {
+        RedisModule_Log(ctx,"warning","Unexpected reply type %d",
+            RedisModule_CallReplyType(reply));
+        return 0;
+    }
+    mystr = RedisModule_CreateStringFromCallReply(reply);
+    expected = RedisModule_CreateString(ctx,str,len);
+    if (RedisModule_StringCompare(mystr,expected) != 0) {
+        const char *mystr_ptr = RedisModule_StringPtrLen(mystr,NULL);
+        const char *expected_ptr = RedisModule_StringPtrLen(expected,NULL);
+        RedisModule_Log(ctx,"warning",
+            "Unexpected string reply '%s' (instead of '%s')",
+            mystr_ptr, expected_ptr);
+        return 0;
+    }
+    return 1;
+}
+
+/* Return 1 if the reply matches the specified integer, otherwise log errors
+ * in the server log and return 0. */
+int TestAssertIntegerReply(RedisModuleCtx *ctx, RedisModuleCallReply *reply, long long expected) {
+    if (RedisModule_CallReplyType(reply) != REDISMODULE_REPLY_INTEGER) {
+        RedisModule_Log(ctx,"warning","Unexpected reply type %d",
+            RedisModule_CallReplyType(reply));
+        return 0;
+    }
+    long long val = RedisModule_CallReplyInteger(reply);
+    if (val != expected) {
+        RedisModule_Log(ctx,"warning",
+            "Unexpected integer reply '%lld' (instead of '%lld')",
+            val, expected);
+        return 0;
+    }
+    return 1;
+}
+
+#define T(name,...) \
+    do { \
+        RedisModule_Log(ctx,"warning","Testing %s", name); \
+        reply = RedisModule_Call(ctx,name,__VA_ARGS__); \
+    } while (0);
+
+/* TEST.IT -- Run all the tests. */
+int TestIt(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx);
+    RedisModuleCallReply *reply;
+
+    /* Make sure the DB is empty before to proceed. */
+    T("dbsize","");
+    if (!TestAssertIntegerReply(ctx,reply,0)) goto fail;
+
+    T("ping","");
+    if (!TestAssertStringReply(ctx,reply,"PONG",4)) goto fail;
+
+    T("test.call","");
+    if (!TestAssertStringReply(ctx,reply,"OK",2)) goto fail;
+
+    T("test.string.append","");
+    if (!TestAssertStringReply(ctx,reply,"foobar",6)) goto fail;
+
+    T("test.string.append.am","");
+    if (!TestAssertStringReply(ctx,reply,"foobar",6)) goto fail;
+
+    T("test.string.printf", "cc", "foo", "bar");
+    if (!TestAssertStringReply(ctx,reply,"Got 3 args. argv[1]: foo, argv[2]: bar",38)) goto fail;
+
+    RedisModule_ReplyWithSimpleString(ctx,"ALL TESTS PASSED");
+    return REDISMODULE_OK;
+
+fail:
+    RedisModule_ReplyWithSimpleString(ctx,
+        "SOME TEST NOT PASSED! Check server logs");
+    return REDISMODULE_OK;
+}
+
+int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (RedisModule_Init(ctx,"test",1,REDISMODULE_APIVER_1)
+        == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"test.call",
+        TestCall,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"test.string.append",
+        TestStringAppend,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"test.string.append.am",
+        TestStringAppendAM,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"test.string.printf",
+        TestStringPrintf,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"test.it",
+        TestIt,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    return REDISMODULE_OK;
+}

src/networking.c

@@ -52,9 +52,13 @@ size_t getStringObjectSdsUsedMemory(robj *o) {
     }
 }
 
+/* Client.reply list dup and free methods. */
 void *dupClientReplyValue(void *o) {
-    incrRefCount((robj*)o);
-    return o;
+    return sdsdup(o);
+}
+
+void freeClientReplyValue(void *o) {
+    sdsfree(o);
 }
 
 int listMatchObjects(void *a, void *b) {
@@ -110,17 +114,17 @@ client *createClient(int fd) {
     c->reply = listCreate();
     c->reply_bytes = 0;
     c->obuf_soft_limit_reached_time = 0;
-    listSetFreeMethod(c->reply,decrRefCountVoid);
+    listSetFreeMethod(c->reply,freeClientReplyValue);
     listSetDupMethod(c->reply,dupClientReplyValue);
     c->btype = BLOCKED_NONE;
     c->bpop.timeout = 0;
-    c->bpop.keys = dictCreate(&setDictType,NULL);
+    c->bpop.keys = dictCreate(&objectKeyPointerValueDictType,NULL);
     c->bpop.target = NULL;
     c->bpop.numreplicas = 0;
     c->bpop.reploffset = 0;
     c->woff = 0;
     c->watched_keys = listCreate();
-    c->pubsub_channels = dictCreate(&setDictType,NULL);
+    c->pubsub_channels = dictCreate(&objectKeyPointerValueDictType,NULL);
     c->pubsub_patterns = listCreate();
     c->peerid = NULL;
     listSetFreeMethod(c->pubsub_patterns,decrRefCountVoid);
@@ -145,7 +149,7 @@ client *createClient(int fd) {
  * event handler in the following cases:
  *
  * 1) The event handler should already be installed since the output buffer
- *    already contained something.
+ *    already contains something.
  * 2) The client is a slave but not yet online, so we want to just accumulate
  *    writes in the buffer but not actually sending them yet.
  *
@@ -155,7 +159,7 @@ client *createClient(int fd) {
 int prepareClientToWrite(client *c) {
     /* If it's the Lua client we always return ok without installing any
      * handler since there is no socket at all. */
-    if (c->flags & CLIENT_LUA) return C_OK;
+    if (c->flags & (CLIENT_LUA|CLIENT_MODULE)) return C_OK;
 
     /* CLIENT REPLY OFF / SKIP handling: don't send replies. */
     if (c->flags & (CLIENT_REPLY_OFF|CLIENT_REPLY_SKIP)) return C_ERR;
@@ -190,22 +194,6 @@ int prepareClientToWrite(client *c) {
     return C_OK;
 }
 
-/* Create a duplicate of the last object in the reply list when
- * it is not exclusively owned by the reply list. */
-robj *dupLastObjectIfNeeded(list *reply) {
-    robj *new, *cur;
-    listNode *ln;
-    serverAssert(listLength(reply) > 0);
-    ln = listLast(reply);
-    cur = listNodeValue(ln);
-    if (cur->refcount > 1) {
-        new = dupStringObject(cur);
-        decrRefCount(cur);
-        listNodeValue(ln) = new;
-    }
-    return listNodeValue(ln);
-}
-
 /* -----------------------------------------------------------------------------
  * Low level functions to add more data to output buffers.
  * -------------------------------------------------------------------------- */
@@ -228,30 +216,26 @@ int _addReplyToBuffer(client *c, const char *s, size_t len) {
 }
 
 void _addReplyObjectToList(client *c, robj *o) {
-    robj *tail;
-
     if (c->flags & CLIENT_CLOSE_AFTER_REPLY) return;
 
     if (listLength(c->reply) == 0) {
-        incrRefCount(o);
-        listAddNodeTail(c->reply,o);
-        c->reply_bytes += getStringObjectSdsUsedMemory(o);
+        sds s = sdsdup(o->ptr);
+        listAddNodeTail(c->reply,s);
+        c->reply_bytes += sdslen(s);
     } else {
-        tail = listNodeValue(listLast(c->reply));
+        listNode *ln = listLast(c->reply);
+        sds tail = listNodeValue(ln);
 
-        /* Append to this object when possible. */
-        if (tail->ptr != NULL &&
-            tail->encoding == OBJ_ENCODING_RAW &&
-            sdslen(tail->ptr)+sdslen(o->ptr) <= PROTO_REPLY_CHUNK_BYTES)
-        {
-            c->reply_bytes -= sdsZmallocSize(tail->ptr);
-            tail = dupLastObjectIfNeeded(c->reply);
-            tail->ptr = sdscatlen(tail->ptr,o->ptr,sdslen(o->ptr));
-            c->reply_bytes += sdsZmallocSize(tail->ptr);
+        /* Append to this object when possible. If tail == NULL it was
+         * set via addDeferredMultiBulkLength(). */
+        if (tail && sdslen(tail)+sdslen(o->ptr) <= PROTO_REPLY_CHUNK_BYTES) {
+            tail = sdscatsds(tail,o->ptr);
+            listNodeValue(ln) = tail;
+            c->reply_bytes += sdslen(o->ptr);
         } else {
-            incrRefCount(o);
-            listAddNodeTail(c->reply,o);
-            c->reply_bytes += getStringObjectSdsUsedMemory(o);
+            sds s = sdsdup(o->ptr);
+            listAddNodeTail(c->reply,s);
+            c->reply_bytes += sdslen(s);
         }
     }
     asyncCloseClientOnOutputBufferLimitReached(c);
@@ -260,62 +244,54 @@ void _addReplyObjectToList(client *c, robj *o) {
 /* This method takes responsibility over the sds. When it is no longer
  * needed it will be free'd, otherwise it ends up in a robj. */
 void _addReplySdsToList(client *c, sds s) {
-    robj *tail;
-
     if (c->flags & CLIENT_CLOSE_AFTER_REPLY) {
         sdsfree(s);
         return;
     }
 
     if (listLength(c->reply) == 0) {
-        listAddNodeTail(c->reply,createObject(OBJ_STRING,s));
-        c->reply_bytes += sdsZmallocSize(s);
+        listAddNodeTail(c->reply,s);
+        c->reply_bytes += sdslen(s);
     } else {
-        tail = listNodeValue(listLast(c->reply));
+        listNode *ln = listLast(c->reply);
+        sds tail = listNodeValue(ln);
 
-        /* Append to this object when possible. */
-        if (tail->ptr != NULL && tail->encoding == OBJ_ENCODING_RAW &&
-            sdslen(tail->ptr)+sdslen(s) <= PROTO_REPLY_CHUNK_BYTES)
-        {
-            c->reply_bytes -= sdsZmallocSize(tail->ptr);
-            tail = dupLastObjectIfNeeded(c->reply);
-            tail->ptr = sdscatlen(tail->ptr,s,sdslen(s));
-            c->reply_bytes += sdsZmallocSize(tail->ptr);
+        /* Append to this object when possible. If tail == NULL it was
+         * set via addDeferredMultiBulkLength(). */
+        if (tail && sdslen(tail)+sdslen(s) <= PROTO_REPLY_CHUNK_BYTES) {
+            tail = sdscatsds(tail,s);
+            listNodeValue(ln) = tail;
+            c->reply_bytes += sdslen(s);
             sdsfree(s);
         } else {
-            listAddNodeTail(c->reply,createObject(OBJ_STRING,s));
-            c->reply_bytes += sdsZmallocSize(s);
+            listAddNodeTail(c->reply,s);
+            c->reply_bytes += sdslen(s);
         }
     }
     asyncCloseClientOnOutputBufferLimitReached(c);
 }
 
 void _addReplyStringToList(client *c, const char *s, size_t len) {
-    robj *tail;
-
     if (c->flags & CLIENT_CLOSE_AFTER_REPLY) return;
 
     if (listLength(c->reply) == 0) {
-        robj *o = createStringObject(s,len);
-
-        listAddNodeTail(c->reply,o);
-        c->reply_bytes += getStringObjectSdsUsedMemory(o);
+        sds node = sdsnewlen(s,len);
+        listAddNodeTail(c->reply,node);
+        c->reply_bytes += len;
     } else {
-        tail = listNodeValue(listLast(c->reply));
+        listNode *ln = listLast(c->reply);
+        sds tail = listNodeValue(ln);
 
-        /* Append to this object when possible. */
-        if (tail->ptr != NULL && tail->encoding == OBJ_ENCODING_RAW &&
-            sdslen(tail->ptr)+len <= PROTO_REPLY_CHUNK_BYTES)
-        {
-            c->reply_bytes -= sdsZmallocSize(tail->ptr);
-            tail = dupLastObjectIfNeeded(c->reply);
-            tail->ptr = sdscatlen(tail->ptr,s,len);
-            c->reply_bytes += sdsZmallocSize(tail->ptr);
+        /* Append to this object when possible. If tail == NULL it was
+         * set via addDeferredMultiBulkLength(). */
+        if (tail && sdslen(tail)+len <= PROTO_REPLY_CHUNK_BYTES) {
+            tail = sdscatlen(tail,s,len);
+            listNodeValue(ln) = tail;
+            c->reply_bytes += len;
         } else {
-            robj *o = createStringObject(s,len);
-
-            listAddNodeTail(c->reply,o);
-            c->reply_bytes += getStringObjectSdsUsedMemory(o);
+            sds node = sdsnewlen(s,len);
+            listAddNodeTail(c->reply,node);
+            c->reply_bytes += len;
         }
     }
     asyncCloseClientOnOutputBufferLimitReached(c);
@@ -434,32 +410,32 @@ void *addDeferredMultiBulkLength(client *c) {
      * ready to be sent, since we are sure that before returning to the
      * event loop setDeferredMultiBulkLength() will be called. */
     if (prepareClientToWrite(c) != C_OK) return NULL;
-    listAddNodeTail(c->reply,createObject(OBJ_STRING,NULL));
+    listAddNodeTail(c->reply,NULL); /* NULL is our placeholder. */
     return listLast(c->reply);
 }
 
 /* Populate the length object and try gluing it to the next chunk. */
 void setDeferredMultiBulkLength(client *c, void *node, long length) {
     listNode *ln = (listNode*)node;
-    robj *len, *next;
+    sds len, next;
 
-    /* Abort when *node is NULL (see addDeferredMultiBulkLength). */
+    /* Abort when *node is NULL: when the client should not accept writes
+     * we return NULL in addDeferredMultiBulkLength() */
     if (node == NULL) return;
 
-    len = listNodeValue(ln);
-    len->ptr = sdscatprintf(sdsempty(),"*%ld\r\n",length);
-    len->encoding = OBJ_ENCODING_RAW; /* in case it was an EMBSTR. */
-    c->reply_bytes += sdsZmallocSize(len->ptr);
+    len = sdscatprintf(sdsnewlen("*",1),"%ld\r\n",length);
+    listNodeValue(ln) = len;
+    c->reply_bytes += sdslen(len);
     if (ln->next != NULL) {
         next = listNodeValue(ln->next);
 
         /* Only glue when the next node is non-NULL (an sds in this case) */
-        if (next->ptr != NULL) {
-            c->reply_bytes -= sdsZmallocSize(len->ptr);
-            c->reply_bytes -= getStringObjectSdsUsedMemory(next);
-            len->ptr = sdscatlen(len->ptr,next->ptr,sdslen(next->ptr));
-            c->reply_bytes += sdsZmallocSize(len->ptr);
+        if (next != NULL) {
+            len = sdscatsds(len,next);
             listDelNode(c->reply,ln->next);
+            listNodeValue(ln) = len;
+            /* No need to update c->reply_bytes: we are just moving the same
+             * amount of bytes from one node to another. */
         }
     }
     asyncCloseClientOnOutputBufferLimitReached(c);
@@ -902,8 +878,7 @@ void freeClientsInAsyncFreeQueue(void) {
 int writeToClient(int fd, client *c, int handler_installed) {
     ssize_t nwritten = 0, totwritten = 0;
     size_t objlen;
-    size_t objmem;
-    robj *o;
+    sds o;
 
     while(clientHasPendingReplies(c)) {
         if (c->bufpos > 0) {
@@ -920,16 +895,14 @@ int writeToClient(int fd, client *c, int handler_installed) {
             }
         } else {
             o = listNodeValue(listFirst(c->reply));
-            objlen = sdslen(o->ptr);
-            objmem = getStringObjectSdsUsedMemory(o);
+            objlen = sdslen(o);
 
             if (objlen == 0) {
                 listDelNode(c->reply,listFirst(c->reply));
-                c->reply_bytes -= objmem;
                 continue;
             }
 
-            nwritten = write(fd, ((char*)o->ptr)+c->sentlen,objlen-c->sentlen);
+            nwritten = write(fd, o + c->sentlen, objlen - c->sentlen);
             if (nwritten <= 0) break;
             c->sentlen += nwritten;
             totwritten += nwritten;
@@ -938,7 +911,7 @@ int writeToClient(int fd, client *c, int handler_installed) {
             if (c->sentlen == objlen) {
                 listDelNode(c->reply,listFirst(c->reply));
                 c->sentlen = 0;
-                c->reply_bytes -= objmem;
+                c->reply_bytes -= objlen;
             }
         }
         /* Note that we avoid to send more than NET_MAX_WRITES_PER_EVENT
@@ -1744,7 +1717,9 @@ void rewriteClientCommandArgument(client *c, int i, robj *newval) {
  * the caller wishes. The main usage of this function currently is
  * enforcing the client output length limits. */
 unsigned long getClientOutputBufferMemoryUsage(client *c) {
-    unsigned long list_item_size = sizeof(listNode)+sizeof(robj);
+    unsigned long list_item_size = sizeof(listNode)+5;
+    /* The +5 above means we assume an sds16 hdr, may not be true
+     * but is not going to be a problem. */
 
     return c->reply_bytes + (list_item_size*listLength(c->reply));
 }

src/object.c

@@ -36,6 +36,8 @@
 #define strtold(a,b) ((long double)strtod((a),(b)))
 #endif
 
+/* ===================== Creation and parsing of objects ==================== */
+
 robj *createObject(int type, void *ptr) {
     robj *o = zmalloc(sizeof(*o));
     o->type = type;
@@ -43,15 +45,37 @@ robj *createObject(int type, void *ptr) {
     o->ptr = ptr;
     o->refcount = 1;
 
-    /* Set the LRU to the current lruclock (minutes resolution). */
-    o->lru = LRU_CLOCK();
+    /* Set the LRU to the current lruclock (minutes resolution), or
+     * alternatively the LFU counter. */
+    if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
+        o->lru = (LFUGetTimeInMinutes()<<8) | LFU_INIT_VAL;
+    } else {
+        o->lru = LRU_CLOCK();
+    }
+    return o;
+}
+
+/* Set a special refcount in the object to make it "shared":
+ * incrRefCount and decrRefCount() will test for this special refcount
+ * and will not touch the object. This way it is free to access shared
+ * objects such as small integers from different threads without any
+ * mutex.
+ *
+ * A common patter to create shared objects:
+ *
+ * robj *myobject = makeObjectShared(createObject(...));
+ *
+ */
+robj *makeObjectShared(robj *o) {
+    serverAssert(o->refcount == 1);
+    o->refcount = OBJ_SHARED_REFCOUNT;
     return o;
 }
 
 /* Create a string object with encoding OBJ_ENCODING_RAW, that is a plain
  * string object where o->ptr points to a proper sds string. */
 robj *createRawStringObject(const char *ptr, size_t len) {
-    return createObject(OBJ_STRING,sdsnewlen(ptr,len));
+    return createObject(OBJ_STRING, sdsnewlen(ptr,len));
 }
 
 /* Create a string object with encoding OBJ_ENCODING_EMBSTR, that is
@@ -65,7 +89,11 @@ robj *createEmbeddedStringObject(const char *ptr, size_t len) {
     o->encoding = OBJ_ENCODING_EMBSTR;
     o->ptr = sh+1;
     o->refcount = 1;
-    o->lru = LRU_CLOCK();
+    if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
+        o->lru = (LFUGetTimeInMinutes()<<8) | LFU_INIT_VAL;
+    } else {
+        o->lru = LRU_CLOCK();
+    }
 
     sh->len = len;
     sh->alloc = len;
@@ -80,7 +108,7 @@ robj *createEmbeddedStringObject(const char *ptr, size_t len) {
 }
 
 /* Create a string object with EMBSTR encoding if it is smaller than
- * REIDS_ENCODING_EMBSTR_SIZE_LIMIT, otherwise the RAW encoding is
+ * OBJ_ENCODING_EMBSTR_SIZE_LIMIT, otherwise the RAW encoding is
  * used.
  *
  * The current limit of 39 is chosen so that the biggest string object
@@ -118,37 +146,7 @@ robj *createStringObjectFromLongLong(long long value) {
  * The 'humanfriendly' option is used for INCRBYFLOAT and HINCRBYFLOAT. */
 robj *createStringObjectFromLongDouble(long double value, int humanfriendly) {
     char buf[256];
-    int len;
-
-    if (isinf(value)) {
-        /* Libc in odd systems (Hi Solaris!) will format infinite in a
-         * different way, so better to handle it in an explicit way. */
-        if (value > 0) {
-            memcpy(buf,"inf",3);
-            len = 3;
-        } else {
-            memcpy(buf,"-inf",4);
-            len = 4;
-        }
-    } else if (humanfriendly) {
-        /* We use 17 digits precision since with 128 bit floats that precision
-         * after rounding is able to represent most small decimal numbers in a
-         * way that is "non surprising" for the user (that is, most small
-         * decimal numbers will be represented in a way that when converted
-         * back into a string are exactly the same as what the user typed.) */
-        len = snprintf(buf,sizeof(buf),"%.17Lf", value);
-        /* Now remove trailing zeroes after the '.' */
-        if (strchr(buf,'.') != NULL) {
-            char *p = buf+len-1;
-            while(*p == '0') {
-                p--;
-                len--;
-            }
-            if (*p == '.') len--;
-        }
-    } else {
-        len = snprintf(buf,sizeof(buf),"%.17Lg", value);
-    }
+    int len = ld2string(buf,sizeof(buf),value,humanfriendly);
     return createStringObject(buf,len);
 }
 
@@ -160,7 +158,7 @@ robj *createStringObjectFromLongDouble(long double value, int humanfriendly) {
  * will always result in a fresh object that is unshared (refcount == 1).
  *
  * The resulting object always has refcount set to 1. */
-robj *dupStringObject(robj *o) {
+robj *dupStringObject(const robj *o) {
     robj *d;
 
     serverAssert(o->type == OBJ_STRING);
@@ -234,6 +232,13 @@ robj *createZsetZiplistObject(void) {
     return o;
 }
 
+robj *createModuleObject(moduleType *mt, void *value) {
+    moduleValue *mv = zmalloc(sizeof(*mv));
+    mv->type = mt;
+    mv->value = value;
+    return createObject(OBJ_MODULE,mv);
+}
+
 void freeStringObject(robj *o) {
     if (o->encoding == OBJ_ENCODING_RAW) {
         sdsfree(o->ptr);
@@ -241,9 +246,11 @@ void freeStringObject(robj *o) {
 }
 
 void freeListObject(robj *o) {
-    if (o->encoding == OBJ_ENCODING_QUICKLIST) {
+    switch (o->encoding) {
+    case OBJ_ENCODING_QUICKLIST:
         quicklistRelease(o->ptr);
-    } else {
+        break;
+    default:
         serverPanic("Unknown list encoding type");
     }
 }
@@ -292,12 +299,17 @@ void freeHashObject(robj *o) {
     }
 }
 
+void freeModuleObject(robj *o) {
+    moduleValue *mv = o->ptr;
+    mv->type->free(mv->value);
+    zfree(mv);
+}
+
 void incrRefCount(robj *o) {
-    o->refcount++;
+    if (o->refcount != OBJ_SHARED_REFCOUNT) o->refcount++;
 }
 
 void decrRefCount(robj *o) {
-    if (o->refcount <= 0) serverPanic("decrRefCount against refcount <= 0");
     if (o->refcount == 1) {
         switch(o->type) {
         case OBJ_STRING: freeStringObject(o); break;
@@ -305,11 +317,13 @@ void decrRefCount(robj *o) {
         case OBJ_SET: freeSetObject(o); break;
         case OBJ_ZSET: freeZsetObject(o); break;
         case OBJ_HASH: freeHashObject(o); break;
+        case OBJ_MODULE: freeModuleObject(o); break;
         default: serverPanic("Unknown object type"); break;
         }
         zfree(o);
     } else {
-        o->refcount--;
+        if (o->refcount <= 0) serverPanic("decrRefCount against refcount <= 0");
+        if (o->refcount != OBJ_SHARED_REFCOUNT) o->refcount--;
     }
 }
 
@@ -345,13 +359,17 @@ int checkType(client *c, robj *o, int type) {
     return 0;
 }
 
+int isSdsRepresentableAsLongLong(sds s, long long *llval) {
+    return string2ll(s,sdslen(s),llval) ? C_OK : C_ERR;
+}
+
 int isObjectRepresentableAsLongLong(robj *o, long long *llval) {
     serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
     if (o->encoding == OBJ_ENCODING_INT) {
         if (llval) *llval = (long) o->ptr;
         return C_OK;
     } else {
-        return string2ll(o->ptr,sdslen(o->ptr),llval) ? C_OK : C_ERR;
+        return isSdsRepresentableAsLongLong(o->ptr,llval);
     }
 }
 
@@ -387,8 +405,7 @@ robj *tryObjectEncoding(robj *o) {
          * because every object needs to have a private LRU field for the LRU
          * algorithm to work well. */
         if ((server.maxmemory == 0 ||
-             (server.maxmemory_policy != MAXMEMORY_VOLATILE_LRU &&
-              server.maxmemory_policy != MAXMEMORY_ALLKEYS_LRU)) &&
+            !(server.maxmemory_policy & MAXMEMORY_FLAG_NO_SHARED_INTEGERS)) &&
             value >= 0 &&
             value < OBJ_SHARED_INTEGERS)
         {
@@ -532,7 +549,7 @@ size_t stringObjectLen(robj *o) {
     }
 }
 
-int getDoubleFromObject(robj *o, double *target) {
+int getDoubleFromObject(const robj *o, double *target) {
     double value;
     char *eptr;
 
@@ -543,7 +560,7 @@ int getDoubleFromObject(robj *o, double *target) {
         if (sdsEncodedObject(o)) {
             errno = 0;
             value = strtod(o->ptr, &eptr);
-            if (isspace(((char*)o->ptr)[0]) ||
+            if (isspace(((const char*)o->ptr)[0]) ||
                 eptr[0] != '\0' ||
                 (errno == ERANGE &&
                     (value == HUGE_VAL || value == -HUGE_VAL || value == 0)) ||
@@ -675,18 +692,299 @@ char *strEncoding(int encoding) {
     }
 }
 
-/* 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) {
-    unsigned long long lruclock = LRU_CLOCK();
-    if (lruclock >= o->lru) {
-        return (lruclock - o->lru) * LRU_CLOCK_RESOLUTION;
+/* =========================== Memory introspection ========================== */
+
+/* Returns the size in bytes consumed by the key's value in RAM.
+ * Note that the returned value is just an approximation, especially in the
+ * case of aggregated data types where only "sample_size" elements
+ * are checked and averaged to estimate the total size. */
+#define OBJ_COMPUTE_SIZE_DEF_SAMPLES 5 /* Default sample size. */
+size_t objectComputeSize(robj *o, size_t sample_size) {
+    sds ele, ele2;
+    dict *d;
+    dictIterator *di;
+    struct dictEntry *de;
+    size_t asize = 0, elesize = 0, samples = 0;
+
+    if (o->type == OBJ_STRING) {
+        if(o->encoding == OBJ_ENCODING_INT) {
+            asize = sizeof(*o);
+        } else if(o->encoding == OBJ_ENCODING_RAW) {
+            asize = sdsAllocSize(o->ptr)+sizeof(*o);
+        } else if(o->encoding == OBJ_ENCODING_EMBSTR) {
+            asize = sdslen(o->ptr)+2+sizeof(*o);
+        } else {
+            serverPanic("Unknown string encoding");
+        }
+    } else if (o->type == OBJ_LIST) {
+        if (o->encoding == OBJ_ENCODING_QUICKLIST) {
+            quicklist *ql = o->ptr;
+            quicklistNode *node = ql->head;
+            asize = sizeof(*o)+sizeof(quicklist);
+            do {
+                elesize += sizeof(quicklistNode)+ziplistBlobLen(node->zl);
+                samples++;
+            } while ((node = node->next) && samples < sample_size);
+            asize += (double)elesize/samples*listTypeLength(o);
+        } else if (o->encoding == OBJ_ENCODING_ZIPLIST) {
+            asize = sizeof(*o)+ziplistBlobLen(o->ptr);
+        } else {
+            serverPanic("Unknown list encoding");
+        }
+    } else if (o->type == OBJ_SET) {
+        if (o->encoding == OBJ_ENCODING_HT) {
+            d = o->ptr;
+            di = dictGetIterator(d);
+            asize = sizeof(*o)+sizeof(dict)+(sizeof(struct dictEntry*)*dictSlots(d));
+            while((de = dictNext(di)) != NULL && samples < sample_size) {
+                ele = dictGetKey(de);
+                elesize += sizeof(struct dictEntry) + sdsAllocSize(ele);
+                samples++;
+            }
+            dictReleaseIterator(di);
+            if (samples) asize += (double)elesize/samples*dictSize(d);
+        } else if (o->encoding == OBJ_ENCODING_INTSET) {
+            intset *is = o->ptr;
+            asize = sizeof(*o)+sizeof(*is)+is->encoding*is->length;
+        } else {
+            serverPanic("Unknown set encoding");
+        }
+    } else if (o->type == OBJ_ZSET) {
+        if (o->encoding == OBJ_ENCODING_ZIPLIST) {
+            asize = sizeof(*o)+(ziplistBlobLen(o->ptr));
+        } else if (o->encoding == OBJ_ENCODING_SKIPLIST) {
+            d = ((zset*)o->ptr)->dict;
+            zskiplist *zsl = ((zset*)o->ptr)->zsl;
+            zskiplistNode *znode = zsl->header->level[0].forward;
+            asize = sizeof(*o)+sizeof(zset)+(sizeof(struct dictEntry*)*dictSlots(d));
+            while(znode != NULL && samples < sample_size) {
+                elesize += sdsAllocSize(znode->ele);
+                elesize += sizeof(struct dictEntry) + zmalloc_size(znode);
+                samples++;
+                znode = znode->level[0].forward;
+            }
+            if (samples) asize += (double)elesize/samples*dictSize(d);
+        } else {
+            serverPanic("Unknown sorted set encoding");
+        }
+    } else if (o->type == OBJ_HASH) {
+        if (o->encoding == OBJ_ENCODING_ZIPLIST) {
+            asize = sizeof(*o)+(ziplistBlobLen(o->ptr));
+        } else if (o->encoding == OBJ_ENCODING_HT) {
+            d = o->ptr;
+            di = dictGetIterator(d);
+            asize = sizeof(*o)+sizeof(dict)+(sizeof(struct dictEntry*)*dictSlots(d));
+            while((de = dictNext(di)) != NULL && samples < sample_size) {
+                ele = dictGetKey(de);
+                ele2 = dictGetVal(de);
+                elesize += sdsAllocSize(ele) + sdsAllocSize(ele2);
+                elesize += sizeof(struct dictEntry);
+                samples++;
+            }
+            dictReleaseIterator(di);
+            if (samples) asize += (double)elesize/samples*dictSize(d);
+        } else {
+            serverPanic("Unknown hash encoding");
+        }
     } else {
-        return (lruclock + (LRU_CLOCK_MAX - o->lru)) *
-                    LRU_CLOCK_RESOLUTION;
+        serverPanic("Unknown object type");
     }
+    return asize;
 }
 
+/* Release data obtained with getMemoryOverheadData(). */
+void freeMemoryOverheadData(struct redisMemOverhead *mh) {
+    zfree(mh->db);
+    zfree(mh);
+}
+
+/* Return a struct redisMemOverhead filled with memory overhead
+ * information used for the MEMORY OVERHEAD and INFO command. The returned
+ * structure pointer should be freed calling freeMemoryOverheadData(). */
+struct redisMemOverhead *getMemoryOverheadData(void) {
+    int j;
+    size_t mem_total = 0;
+    size_t mem = 0;
+    size_t zmalloc_used = zmalloc_used_memory();
+    struct redisMemOverhead *mh = zcalloc(sizeof(*mh));
+
+    mh->total_allocated = zmalloc_used;
+    mh->startup_allocated = server.initial_memory_usage;
+    mh->peak_allocated = server.stat_peak_memory;
+    mh->fragmentation =
+        zmalloc_get_fragmentation_ratio(server.resident_set_size);
+    mem_total += server.initial_memory_usage;
+
+    mem = 0;
+    if (server.repl_backlog)
+        mem += zmalloc_size(server.repl_backlog);
+    mh->repl_backlog = mem;
+    mem_total += mem;
+
+    mem = 0;
+    if (listLength(server.slaves)) {
+        listIter li;
+        listNode *ln;
+
+        listRewind(server.slaves,&li);
+        while((ln = listNext(&li))) {
+            client *client = listNodeValue(ln);
+            mem += getClientOutputBufferMemoryUsage(client);
+            mem += sdsAllocSize(client->querybuf);
+            mem += sizeof(client);
+        }
+    }
+    mh->clients_slaves = mem;
+    mem_total+=mem;
+
+    mem = 0;
+    if (listLength(server.clients)) {
+        listIter li;
+        listNode *ln;
+
+        listRewind(server.clients,&li);
+        while((ln = listNext(&li))) {
+            client *client = listNodeValue(ln);
+            if (client->flags & CLIENT_SLAVE)
+                continue;
+            mem += getClientOutputBufferMemoryUsage(client);
+            mem += sdsAllocSize(client->querybuf);
+            mem += sizeof(client);
+        }
+    }
+    mh->clients_normal = mem;
+    mem_total+=mem;
+
+    mem = 0;
+    if (server.aof_state != AOF_OFF) {
+        mem += sdslen(server.aof_buf);
+        mem += aofRewriteBufferSize();
+    }
+    mh->aof_buffer = mem;
+    mem_total+=mem;
+
+    for (j = 0; j < server.dbnum; j++) {
+        redisDb *db = server.db+j;
+        long long keyscount = dictSize(db->dict);
+        if (keyscount==0) continue;
+
+        mh->total_keys += keyscount;
+        mh->db = zrealloc(mh->db,sizeof(mh->db[0])*(mh->num_dbs+1));
+        mh->db[mh->num_dbs].dbid = j;
+
+        mem = dictSize(db->dict) * sizeof(dictEntry) +
+              dictSlots(db->dict) * sizeof(dictEntry*) +
+              dictSize(db->dict) * sizeof(robj);
+        mh->db[mh->num_dbs].overhead_ht_main = mem;
+        mem_total+=mem;
+
+        mem = dictSize(db->expires) * sizeof(dictEntry) +
+              dictSlots(db->expires) * sizeof(dictEntry*);
+        mh->db[mh->num_dbs].overhead_ht_expires = mem;
+        mem_total+=mem;
+
+        mh->num_dbs++;
+    }
+
+    mh->overhead_total = mem_total;
+    mh->dataset = zmalloc_used - mem_total;
+    mh->peak_perc = (float)zmalloc_used*100/mh->peak_allocated;
+
+    /* Metrics computed after subtracting the startup memory from
+     * the total memory. */
+    size_t net_usage = 1;
+    if (zmalloc_used > mh->startup_allocated)
+        net_usage = zmalloc_used - mh->startup_allocated;
+    mh->dataset_perc = (float)mh->dataset*100/net_usage;
+    mh->bytes_per_key = mh->total_keys ? (net_usage / mh->total_keys) : 0;
+
+    return mh;
+}
+
+/* Helper for "MEMORY allocator-stats", used as a callback for the jemalloc
+ * stats output. */
+void inputCatSds(void *result, const char *str) {
+    /* result is actually a (sds *), so re-cast it here */
+    sds *info = (sds *)result;
+    *info = sdscat(*info, str);
+}
+
+/* This implements MEMORY DOCTOR. An human readable analysis of the Redis
+ * memory condition. */
+sds getMemoryDoctorReport(void) {
+    int empty = 0;          /* Instance is empty or almost empty. */
+    int big_peak = 0;       /* Memory peak is much larger than used mem. */
+    int high_frag = 0;      /* High fragmentation. */
+    int big_slave_buf = 0;  /* Slave buffers are too big. */
+    int big_client_buf = 0; /* Client buffers are too big. */
+    int num_reports = 0;
+    struct redisMemOverhead *mh = getMemoryOverheadData();
+
+    if (mh->total_allocated < (1024*1024*5)) {
+        empty = 1;
+        num_reports++;
+    } else {
+        /* Peak is > 150% of current used memory? */
+        if (((float)mh->peak_allocated / mh->total_allocated) > 1.5) {
+            big_peak = 1;
+            num_reports++;
+        }
+
+        /* Fragmentation is higher than 1.4? */
+        if (mh->fragmentation > 1.4) {
+            high_frag = 1;
+            num_reports++;
+        }
+
+        /* Clients using more than 200k each average? */
+        long numslaves = listLength(server.slaves);
+        long numclients = listLength(server.clients)-numslaves;
+        if (mh->clients_normal / numclients > (1024*200)) {
+            big_client_buf = 1;
+            num_reports++;
+        }
+
+        /* Slaves using more than 10 MB each? */
+        if (mh->clients_slaves / numslaves > (1024*1024*10)) {
+            big_slave_buf = 1;
+            num_reports++;
+        }
+    }
+
+    sds s;
+    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.");
+    } 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.");
+    } else {
+        s = sdsnew("Sam, I detected a few issues in this Redis instance memory implants:\n\n");
+        if (big_peak) {
+            s = sdscat(s," * Peak memory: In the past this instance used more than 150% the memory that is currently using. The allocator is normally not able to release memory after a peak, so you can expect to see a big fragmentation ratio, however this is actually harmless and is only due to the memory peak, and if the Redis instance Resident Set Size (RSS) is currently bigger than expected, the memory will be used as soon as you fill the Redis instance with more data. If the memory peak was only occasional and you want to try to reclaim memory, please try the MEMORY PURGE command, otherwise the only other option is to shutdown and restart the instance.\n\n");
+        }
+        if (high_frag) {
+            s = sdscatprintf(s," * High fragmentation: This instance has a memory fragmentation greater than 1.4 (this means that the Resident Set Size of the Redis process is much larger than the sum of the logical allocations Redis performed). This problem is usually due either to a large peak memory (check if there is a peak memory entry above in the report) or may result from a workload that causes the allocator to fragment memory a lot. If the problem is a large peak memory, then there is no issue. Otherwise, make sure you are using the Jemalloc allocator and not the default libc malloc. Note: The currently used allocator is \"%s\".\n\n", ZMALLOC_LIB);
+        }
+        if (big_slave_buf) {
+            s = sdscat(s," * Big slave buffers: The slave output buffers in this instance are greater than 10MB for each slave (on average). This likely means that there is some slave instance that is struggling receiving data, either because it is too slow or because of networking issues. As a result, data piles on the master output buffers. Please try to identify what slave is not receiving data correctly and why. You can use the INFO output in order to check the slaves delays and the CLIENT LIST command to check the output buffers of each slave.\n\n");
+        }
+        if (big_client_buf) {
+            s = sdscat(s," * Big client buffers: The clients output buffers in this instance are greater than 200K per client (on average). This may result from different causes, like Pub/Sub clients subscribed to channels bot not receiving data fast enough, so that data piles on the Redis instance output buffer, or clients sending commands with large replies or very large sequences of commands in the same pipeline. Please use the CLIENT LIST command in order to investigate the issue if it causes problems in your instance, or to understand better why certain clients are using a big amount of memory.\n\n");
+        }
+        s = sdscat(s,"I'm here to keep you safe, Sam. I want to help you.\n");
+    }
+    freeMemoryOverheadData(mh);
+    return s;
+}
+
+/* ======================= The OBJECT and MEMORY commands =================== */
+
 /* This is a helper function for the OBJECT command. We need to lookup keys
  * without any modification of LRU or other parameters. */
 robj *objectCommandLookup(client *c, robj *key) {
@@ -719,9 +1017,156 @@ void objectCommand(client *c) {
     } else if (!strcasecmp(c->argv[1]->ptr,"idletime") && c->argc == 3) {
         if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
                 == NULL) return;
+        if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
+            addReplyError(c,"An LFU maxmemory policy is selected, idle time not tracked. Please note that when switching between policies at runtime LRU and LFU data will take some time to adjust.");
+            return;
+        }
         addReplyLongLong(c,estimateObjectIdleTime(o)/1000);
+    } 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.");
+            return;
+        }
+        addReplyLongLong(c,o->lru&255);
     } else {
-        addReplyError(c,"Syntax error. Try OBJECT (refcount|encoding|idletime)");
+        addReplyError(c,"Syntax error. Try OBJECT (refcount|encoding|idletime|freq)");
     }
 }
 
+/* The memory command will eventually be a complete interface for the
+ * memory introspection capabilities of Redis.
+ *
+ * Usage: MEMORY usage <key> */
+void memoryCommand(client *c) {
+    robj *o;
+
+    if (!strcasecmp(c->argv[1]->ptr,"usage") && c->argc >= 3) {
+        long long samples = OBJ_COMPUTE_SIZE_DEF_SAMPLES;
+        for (int j = 3; j < c->argc; j++) {
+            if (!strcasecmp(c->argv[j]->ptr,"samples") &&
+                j+1 < c->argc)
+            {
+                if (getLongLongFromObjectOrReply(c,c->argv[j+1],&samples,NULL)
+                     == C_ERR) return;
+                if (samples < 0) {
+                    addReply(c,shared.syntaxerr);
+                    return;
+                }
+                if (samples == 0) samples = LLONG_MAX;;
+                j++; /* skip option argument. */
+            } else {
+                addReply(c,shared.syntaxerr);
+                return;
+            }
+        }
+        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
+                == NULL) return;
+        size_t usage = objectComputeSize(o,samples);
+        usage += sdsAllocSize(c->argv[1]->ptr);
+        usage += sizeof(dictEntry);
+        addReplyLongLong(c,usage);
+    } else if (!strcasecmp(c->argv[1]->ptr,"stats") && c->argc == 2) {
+        struct redisMemOverhead *mh = getMemoryOverheadData();
+
+        addReplyMultiBulkLen(c,(14+mh->num_dbs)*2);
+
+        addReplyBulkCString(c,"peak.allocated");
+        addReplyLongLong(c,mh->peak_allocated);
+
+        addReplyBulkCString(c,"total.allocated");
+        addReplyLongLong(c,mh->total_allocated);
+
+        addReplyBulkCString(c,"startup.allocated");
+        addReplyLongLong(c,mh->startup_allocated);
+
+        addReplyBulkCString(c,"replication.backlog");
+        addReplyLongLong(c,mh->repl_backlog);
+
+        addReplyBulkCString(c,"clients.slaves");
+        addReplyLongLong(c,mh->clients_slaves);
+
+        addReplyBulkCString(c,"clients.normal");
+        addReplyLongLong(c,mh->clients_normal);
+
+        addReplyBulkCString(c,"aof.buffer");
+        addReplyLongLong(c,mh->aof_buffer);
+
+        for (size_t j = 0; j < mh->num_dbs; j++) {
+            char dbname[32];
+            snprintf(dbname,sizeof(dbname),"db.%zd",mh->db[j].dbid);
+            addReplyBulkCString(c,dbname);
+            addReplyMultiBulkLen(c,4);
+
+            addReplyBulkCString(c,"overhead.hashtable.main");
+            addReplyLongLong(c,mh->db[j].overhead_ht_main);
+
+            addReplyBulkCString(c,"overhead.hashtable.expires");
+            addReplyLongLong(c,mh->db[j].overhead_ht_expires);
+        }
+
+        addReplyBulkCString(c,"overhead.total");
+        addReplyLongLong(c,mh->overhead_total);
+
+        addReplyBulkCString(c,"keys.count");
+        addReplyLongLong(c,mh->total_keys);
+
+        addReplyBulkCString(c,"keys.bytes-per-key");
+        addReplyLongLong(c,mh->bytes_per_key);
+
+        addReplyBulkCString(c,"dataset.bytes");
+        addReplyLongLong(c,mh->dataset);
+
+        addReplyBulkCString(c,"dataset.percentage");
+        addReplyDouble(c,mh->dataset_perc);
+
+        addReplyBulkCString(c,"peak.percentage");
+        addReplyDouble(c,mh->peak_perc);
+
+        addReplyBulkCString(c,"fragmentation");
+        addReplyDouble(c,mh->fragmentation);
+
+        freeMemoryOverheadData(mh);
+    } else if (!strcasecmp(c->argv[1]->ptr,"malloc-stats") && c->argc == 2) {
+#if defined(USE_JEMALLOC)
+        sds info = sdsempty();
+        je_malloc_stats_print(inputCatSds, &info, NULL);
+        addReplyBulkSds(c, info);
+#else
+        addReplyBulkCString(c,"Stats not supported for the current allocator");
+#endif
+    } else if (!strcasecmp(c->argv[1]->ptr,"doctor") && c->argc == 2) {
+        sds report = getMemoryDoctorReport();
+        addReplyBulkSds(c,report);
+    } else if (!strcasecmp(c->argv[1]->ptr,"purge") && c->argc == 2) {
+#if defined(USE_JEMALLOC)
+        char tmp[32];
+        unsigned narenas = 0;
+        size_t sz = sizeof(unsigned);
+        if (!je_mallctl("arenas.narenas", &narenas, &sz, NULL, 0)) {
+            sprintf(tmp, "arena.%d.purge", narenas);
+            if (!je_mallctl(tmp, NULL, 0, NULL, 0)) {
+                addReply(c, shared.ok);
+                return;
+            }
+        }
+        addReplyError(c, "Error purging dirty pages");
+#else
+        addReply(c, shared.ok);
+        /* Nothing to do for other allocators. */
+#endif
+    } else if (!strcasecmp(c->argv[1]->ptr,"help") && c->argc == 2) {
+        addReplyMultiBulkLen(c,4);
+        addReplyBulkCString(c,
+"MEMORY USAGE <key> [SAMPLES <count>] - Estimate memory usage of key");
+        addReplyBulkCString(c,
+"MEMORY STATS                         - Show memory usage details");
+        addReplyBulkCString(c,
+"MEMORY PURGE                         - Ask the allocator to release memory");
+        addReplyBulkCString(c,
+"MEMORY MALLOC-STATS                  - Show allocator internal stats");
+    } else {
+        addReplyError(c,"Syntax error. Try MEMORY HELP");
+    }
+}

src/quicklist.c

@@ -149,7 +149,7 @@ REDIS_STATIC quicklistNode *quicklistCreateNode(void) {
 }
 
 /* Return cached quicklist count */
-unsigned int quicklistCount(quicklist *ql) { return ql->count; }
+unsigned int quicklistCount(const quicklist *ql) { return ql->count; }
 
 /* Free entire quicklist. */
 void quicklistRelease(quicklist *quicklist) {

src/quicklist.h

@@ -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(quicklist *ql);
+unsigned int quicklistCount(const quicklist *ql);
 int quicklistCompare(unsigned char *p1, unsigned char *p2, int p2_len);
 size_t quicklistGetLzf(const quicklistNode *node, void **data);
 

src/rdb.c

@@ -41,10 +41,6 @@
 #include <sys/stat.h>
 #include <sys/param.h>
 
-#define RDB_LOAD_NONE   0
-#define RDB_LOAD_ENC    (1<<0)
-#define RDB_LOAD_PLAIN  (1<<1)
-
 #define rdbExitReportCorruptRDB(...) rdbCheckThenExit(__LINE__,__VA_ARGS__)
 
 extern int rdbCheckMode;
@@ -111,7 +107,7 @@ long long rdbLoadMillisecondTime(rio *rdb) {
 /* Saves an encoded length. The first two bits in the first byte are used to
  * hold the encoding type. See the RDB_* definitions for more information
  * on the types of encoding. */
-int rdbSaveLen(rio *rdb, uint32_t len) {
+int rdbSaveLen(rio *rdb, uint64_t len) {
     unsigned char buf[2];
     size_t nwritten;
 
@@ -126,48 +122,79 @@ int rdbSaveLen(rio *rdb, uint32_t len) {
         buf[1] = len&0xFF;
         if (rdbWriteRaw(rdb,buf,2) == -1) return -1;
         nwritten = 2;
-    } else {
+    } else if (len <= UINT32_MAX) {
         /* Save a 32 bit len */
-        buf[0] = (RDB_32BITLEN<<6);
+        buf[0] = RDB_32BITLEN;
         if (rdbWriteRaw(rdb,buf,1) == -1) return -1;
-        len = htonl(len);
-        if (rdbWriteRaw(rdb,&len,4) == -1) return -1;
+        uint32_t len32 = htonl(len);
+        if (rdbWriteRaw(rdb,&len32,4) == -1) return -1;
         nwritten = 1+4;
+    } else {
+        /* Save a 64 bit len */
+        buf[0] = RDB_64BITLEN;
+        if (rdbWriteRaw(rdb,buf,1) == -1) return -1;
+        len = htonu64(len);
+        if (rdbWriteRaw(rdb,&len,8) == -1) return -1;
+        nwritten = 1+8;
     }
     return nwritten;
 }
 
-/* Load an encoded length. The "isencoded" argument is set to 1 if the length
- * is not actually a length but an "encoding type". See the RDB_ENC_*
- * definitions in rdb.h for more information. */
-uint32_t rdbLoadLen(rio *rdb, int *isencoded) {
+
+/* Load an encoded length. If the loaded length is a normal length as stored
+ * with rdbSaveLen(), the read length is set to '*lenptr'. If instead the
+ * loaded length describes a special encoding that follows, then '*isencoded'
+ * is set to 1 and the encoding format is stored at '*lenptr'.
+ *
+ * See the RDB_ENC_* definitions in rdb.h for more information on special
+ * encodings.
+ *
+ * The function returns -1 on error, 0 on success. */
+int rdbLoadLenByRef(rio *rdb, int *isencoded, uint64_t *lenptr) {
     unsigned char buf[2];
-    uint32_t len;
     int type;
 
     if (isencoded) *isencoded = 0;
-    if (rioRead(rdb,buf,1) == 0) return RDB_LENERR;
+    if (rioRead(rdb,buf,1) == 0) return -1;
     type = (buf[0]&0xC0)>>6;
     if (type == RDB_ENCVAL) {
         /* Read a 6 bit encoding type. */
         if (isencoded) *isencoded = 1;
-        return buf[0]&0x3F;
+        *lenptr = buf[0]&0x3F;
     } else if (type == RDB_6BITLEN) {
         /* Read a 6 bit len. */
-        return buf[0]&0x3F;
+        *lenptr = buf[0]&0x3F;
     } else if (type == RDB_14BITLEN) {
         /* Read a 14 bit len. */
-        if (rioRead(rdb,buf+1,1) == 0) return RDB_LENERR;
-        return ((buf[0]&0x3F)<<8)|buf[1];
-    } else if (type == RDB_32BITLEN) {
+        if (rioRead(rdb,buf+1,1) == 0) return -1;
+        *lenptr = ((buf[0]&0x3F)<<8)|buf[1];
+    } else if (buf[0] == RDB_32BITLEN) {
         /* Read a 32 bit len. */
-        if (rioRead(rdb,&len,4) == 0) return RDB_LENERR;
-        return ntohl(len);
+        uint32_t len;
+        if (rioRead(rdb,&len,4) == 0) return -1;
+        *lenptr = ntohl(len);
+    } else if (buf[0] == RDB_64BITLEN) {
+        /* Read a 64 bit len. */
+        uint64_t len;
+        if (rioRead(rdb,&len,8) == 0) return -1;
+        *lenptr = ntohu64(len);
     } else {
         rdbExitReportCorruptRDB(
             "Unknown length encoding %d in rdbLoadLen()",type);
         return -1; /* Never reached. */
     }
+    return 0;
+}
+
+/* This is like rdbLoadLenByRef() but directly returns the value read
+ * from the RDB stream, signaling an error by returning RDB_LENERR
+ * (since it is a too large count to be applicable in any Redis data
+ * structure). */
+uint64_t rdbLoadLen(rio *rdb, int *isencoded) {
+    uint64_t len;
+
+    if (rdbLoadLenByRef(rdb,isencoded,&len) == -1) return RDB_LENERR;
+    return len;
 }
 
 /* Encodes the "value" argument as integer when it fits in the supported ranges
@@ -199,8 +226,9 @@ int rdbEncodeInteger(long long value, unsigned char *enc) {
 /* Loads an integer-encoded object with the specified encoding type "enctype".
  * The returned value changes according to the flags, see
  * rdbGenerincLoadStringObject() for more info. */
-void *rdbLoadIntegerObject(rio *rdb, int enctype, int flags) {
+void *rdbLoadIntegerObject(rio *rdb, int enctype, int flags, size_t *lenptr) {
     int plain = flags & RDB_LOAD_PLAIN;
+    int sds = flags & RDB_LOAD_SDS;
     int encode = flags & RDB_LOAD_ENC;
     unsigned char enc[4];
     long long val;
@@ -222,10 +250,11 @@ void *rdbLoadIntegerObject(rio *rdb, int enctype, int flags) {
         val = 0; /* anti-warning */
         rdbExitReportCorruptRDB("Unknown RDB integer encoding type %d",enctype);
     }
-    if (plain) {
+    if (plain || sds) {
         char buf[LONG_STR_SIZE], *p;
         int len = ll2string(buf,sizeof(buf),val);
-        p = zmalloc(len);
+        if (lenptr) *lenptr = len;
+        p = plain ? zmalloc(len) : sdsnewlen(NULL,len);
         memcpy(p,buf,len);
         return p;
     } else if (encode) {
@@ -300,11 +329,12 @@ ssize_t rdbSaveLzfStringObject(rio *rdb, unsigned char *s, size_t len) {
 /* Load an LZF compressed string in RDB format. The returned value
  * changes according to 'flags'. For more info check the
  * rdbGenericLoadStringObject() function. */
-void *rdbLoadLzfStringObject(rio *rdb, int flags) {
+void *rdbLoadLzfStringObject(rio *rdb, int flags, size_t *lenptr) {
     int plain = flags & RDB_LOAD_PLAIN;
-    unsigned int len, clen;
+    int sds = flags & RDB_LOAD_SDS;
+    uint64_t len, clen;
     unsigned char *c = NULL;
-    sds val = NULL;
+    char *val = NULL;
 
     if ((clen = rdbLoadLen(rdb,NULL)) == RDB_LENERR) return NULL;
     if ((len = rdbLoadLen(rdb,NULL)) == RDB_LENERR) return NULL;
@@ -313,8 +343,9 @@ void *rdbLoadLzfStringObject(rio *rdb, int flags) {
     /* Allocate our target according to the uncompressed size. */
     if (plain) {
         val = zmalloc(len);
+        if (lenptr) *lenptr = len;
     } else {
-        if ((val = sdsnewlen(NULL,len)) == NULL) goto err;
+        val = sdsnewlen(NULL,len);
     }
 
     /* Load the compressed representation and uncompress it to target. */
@@ -325,10 +356,11 @@ void *rdbLoadLzfStringObject(rio *rdb, int flags) {
     }
     zfree(c);
 
-    if (plain)
+    if (plain || sds) {
         return val;
-    else
+    } else {
         return createObject(OBJ_STRING,val);
+    }
 err:
     zfree(c);
     if (plain)
@@ -391,7 +423,7 @@ ssize_t rdbSaveLongLongAsStringObject(rio *rdb, long long value) {
     return nwritten;
 }
 
-/* Like rdbSaveStringObjectRaw() but handle encoded objects */
+/* Like rdbSaveRawString() gets a Redis object instead. */
 int rdbSaveStringObject(rio *rdb, robj *obj) {
     /* Avoid to decode the object, then encode it again, if the
      * object is already integer encoded. */
@@ -413,12 +445,15 @@ int rdbSaveStringObject(rio *rdb, robj *obj) {
  * RDB_LOAD_PLAIN: Return a plain string allocated with zmalloc()
  *                 instead of a Redis object with an sds in it.
  * RDB_LOAD_SDS: Return an SDS string instead of a Redis object.
+ *
+ * On I/O error NULL is returned.
  */
-void *rdbGenericLoadStringObject(rio *rdb, int flags) {
+void *rdbGenericLoadStringObject(rio *rdb, int flags, size_t *lenptr) {
     int encode = flags & RDB_LOAD_ENC;
     int plain = flags & RDB_LOAD_PLAIN;
+    int sds = flags & RDB_LOAD_SDS;
     int isencoded;
-    uint32_t len;
+    uint64_t len;
 
     len = rdbLoadLen(rdb,&isencoded);
     if (isencoded) {
@@ -426,16 +461,27 @@ void *rdbGenericLoadStringObject(rio *rdb, int flags) {
         case RDB_ENC_INT8:
         case RDB_ENC_INT16:
         case RDB_ENC_INT32:
-            return rdbLoadIntegerObject(rdb,len,flags);
+            return rdbLoadIntegerObject(rdb,len,flags,lenptr);
         case RDB_ENC_LZF:
-            return rdbLoadLzfStringObject(rdb,flags);
+            return rdbLoadLzfStringObject(rdb,flags,lenptr);
         default:
             rdbExitReportCorruptRDB("Unknown RDB string encoding type %d",len);
         }
     }
 
     if (len == RDB_LENERR) return NULL;
-    if (!plain) {
+    if (plain || sds) {
+        void *buf = plain ? zmalloc(len) : sdsnewlen(NULL,len);
+        if (lenptr) *lenptr = len;
+        if (len && rioRead(rdb,buf,len) == 0) {
+            if (plain)
+                zfree(buf);
+            else
+                sdsfree(buf);
+            return NULL;
+        }
+        return buf;
+    } else {
         robj *o = encode ? createStringObject(NULL,len) :
                            createRawStringObject(NULL,len);
         if (len && rioRead(rdb,o->ptr,len) == 0) {
@@ -443,22 +489,15 @@ void *rdbGenericLoadStringObject(rio *rdb, int flags) {
             return NULL;
         }
         return o;
-    } else {
-        void *buf = zmalloc(len);
-        if (len && rioRead(rdb,buf,len) == 0) {
-            zfree(buf);
-            return NULL;
-        }
-        return buf;
     }
 }
 
 robj *rdbLoadStringObject(rio *rdb) {
-    return rdbGenericLoadStringObject(rdb,RDB_LOAD_NONE);
+    return rdbGenericLoadStringObject(rdb,RDB_LOAD_NONE,NULL);
 }
 
 robj *rdbLoadEncodedStringObject(rio *rdb) {
-    return rdbGenericLoadStringObject(rdb,RDB_LOAD_ENC);
+    return rdbGenericLoadStringObject(rdb,RDB_LOAD_ENC,NULL);
 }
 
 /* Save a double value. Doubles are saved as strings prefixed by an unsigned
@@ -521,6 +560,37 @@ int rdbLoadDoubleValue(rio *rdb, double *val) {
     }
 }
 
+/* Saves a double for RDB 8 or greater, where IE754 binary64 format is assumed.
+ * We just make sure the integer is always stored in little endian, otherwise
+ * the value is copied verbatim from memory to disk.
+ *
+ * Return -1 on error, the size of the serialized value on success. */
+int rdbSaveBinaryDoubleValue(rio *rdb, double val) {
+    memrev64ifbe(&val);
+    return rdbWriteRaw(rdb,&val,sizeof(val));
+}
+
+/* Loads a double from RDB 8 or greater. See rdbSaveBinaryDoubleValue() for
+ * more info. On error -1 is returned, otherwise 0. */
+int rdbLoadBinaryDoubleValue(rio *rdb, double *val) {
+    if (rioRead(rdb,val,sizeof(*val)) == 0) return -1;
+    memrev64ifbe(val);
+    return 0;
+}
+
+/* Like rdbSaveBinaryDoubleValue() but single precision. */
+int rdbSaveBinaryFloatValue(rio *rdb, float val) {
+    memrev32ifbe(&val);
+    return rdbWriteRaw(rdb,&val,sizeof(val));
+}
+
+/* Like rdbLoadBinaryDoubleValue() but single precision. */
+int rdbLoadBinaryFloatValue(rio *rdb, float *val) {
+    if (rioRead(rdb,val,sizeof(*val)) == 0) return -1;
+    memrev32ifbe(val);
+    return 0;
+}
+
 /* Save the object type of object "o". */
 int rdbSaveObjectType(rio *rdb, robj *o) {
     switch (o->type) {
@@ -542,7 +612,7 @@ int rdbSaveObjectType(rio *rdb, robj *o) {
         if (o->encoding == OBJ_ENCODING_ZIPLIST)
             return rdbSaveType(rdb,RDB_TYPE_ZSET_ZIPLIST);
         else if (o->encoding == OBJ_ENCODING_SKIPLIST)
-            return rdbSaveType(rdb,RDB_TYPE_ZSET);
+            return rdbSaveType(rdb,RDB_TYPE_ZSET_2);
         else
             serverPanic("Unknown sorted set encoding");
     case OBJ_HASH:
@@ -552,6 +622,8 @@ int rdbSaveObjectType(rio *rdb, robj *o) {
             return rdbSaveType(rdb,RDB_TYPE_HASH);
         else
             serverPanic("Unknown hash encoding");
+    case OBJ_MODULE:
+        return rdbSaveType(rdb,RDB_TYPE_MODULE);
     default:
         serverPanic("Unknown object type");
     }
@@ -609,8 +681,9 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
             nwritten += n;
 
             while((de = dictNext(di)) != NULL) {
-                robj *eleobj = dictGetKey(de);
-                if ((n = rdbSaveStringObject(rdb,eleobj)) == -1) return -1;
+                sds ele = dictGetKey(de);
+                if ((n = rdbSaveRawString(rdb,(unsigned char*)ele,sdslen(ele)))
+                    == -1) return -1;
                 nwritten += n;
             }
             dictReleaseIterator(di);
@@ -638,12 +711,13 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
             nwritten += n;
 
             while((de = dictNext(di)) != NULL) {
-                robj *eleobj = dictGetKey(de);
+                sds ele = dictGetKey(de);
                 double *score = dictGetVal(de);
 
-                if ((n = rdbSaveStringObject(rdb,eleobj)) == -1) return -1;
+                if ((n = rdbSaveRawString(rdb,(unsigned char*)ele,sdslen(ele)))
+                    == -1) return -1;
                 nwritten += n;
-                if ((n = rdbSaveDoubleValue(rdb,*score)) == -1) return -1;
+                if ((n = rdbSaveBinaryDoubleValue(rdb,*score)) == -1) return -1;
                 nwritten += n;
             }
             dictReleaseIterator(di);
@@ -666,20 +740,41 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
             nwritten += n;
 
             while((de = dictNext(di)) != NULL) {
-                robj *key = dictGetKey(de);
-                robj *val = dictGetVal(de);
+                sds field = dictGetKey(de);
+                sds value = dictGetVal(de);
 
-                if ((n = rdbSaveStringObject(rdb,key)) == -1) return -1;
+                if ((n = rdbSaveRawString(rdb,(unsigned char*)field,
+                        sdslen(field))) == -1) return -1;
                 nwritten += n;
-                if ((n = rdbSaveStringObject(rdb,val)) == -1) return -1;
+                if ((n = rdbSaveRawString(rdb,(unsigned char*)value,
+                        sdslen(value))) == -1) return -1;
                 nwritten += n;
             }
             dictReleaseIterator(di);
-
         } else {
             serverPanic("Unknown hash encoding");
         }
 
+    } else if (o->type == OBJ_MODULE) {
+        /* Save a module-specific value. */
+        RedisModuleIO io;
+        moduleValue *mv = o->ptr;
+        moduleType *mt = mv->type;
+        moduleInitIOContext(io,mt,rdb);
+
+        /* Write the "module" identifier as prefix, so that we'll be able
+         * to call the right module during loading. */
+        int retval = rdbSaveLen(rdb,mt->id);
+        if (retval == -1) return -1;
+        io.bytes += retval;
+
+        /* Then write the module-specific representation. */
+        mt->rdb_save(&io,mv->value);
+        if (io.ctx) {
+            moduleFreeContext(io.ctx);
+            zfree(io.ctx);
+        }
+        return io.error ? -1 : (ssize_t)io.bytes;
     } else {
         serverPanic("Unknown object type");
     }
@@ -740,14 +835,16 @@ 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 rdbSaveInfoAuxFields(rio *rdb, int flags) {
     int redis_bits = (sizeof(void*) == 8) ? 64 : 32;
+    int aof_preamble = (flags & RDB_SAVE_AOF_PREAMBLE) != 0;
 
     /* Add a few fields about the state when the RDB was created. */
     if (rdbSaveAuxFieldStrStr(rdb,"redis-ver",REDIS_VERSION) == -1) return -1;
     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;
+    if (rdbSaveAuxFieldStrInt(rdb,"aof-preamble",aof_preamble) == -1) return -1;
     return 1;
 }
 
@@ -759,19 +856,20 @@ int rdbSaveInfoAuxFields(rio *rdb) {
  * 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 rdbSaveRio(rio *rdb, int *error, int flags) {
     dictIterator *di = NULL;
     dictEntry *de;
     char magic[10];
     int j;
     long long now = mstime();
     uint64_t cksum;
+    size_t processed = 0;
 
     if (server.rdb_checksum)
         rdb->update_cksum = rioGenericUpdateChecksum;
     snprintf(magic,sizeof(magic),"REDIS%04d",RDB_VERSION);
     if (rdbWriteRaw(rdb,magic,9) == -1) goto werr;
-    if (rdbSaveInfoAuxFields(rdb) == -1) goto werr;
+    if (rdbSaveInfoAuxFields(rdb,flags) == -1) goto werr;
 
     for (j = 0; j < server.dbnum; j++) {
         redisDb *db = server.db+j;
@@ -808,6 +906,16 @@ int rdbSaveRio(rio *rdb, int *error) {
             initStaticStringObject(key,keystr);
             expire = getExpire(db,&key);
             if (rdbSaveKeyValuePair(rdb,&key,o,expire,now) == -1) goto werr;
+
+            /* When this RDB is produced as part of an AOF rewrite, move
+             * accumulated diff from parent to child while rewriting in
+             * order to have a smaller final write. */
+            if (flags & RDB_SAVE_AOF_PREAMBLE &&
+                rdb->processed_bytes > processed+AOF_READ_DIFF_INTERVAL_BYTES)
+            {
+                processed = rdb->processed_bytes;
+                aofReadDiffFromParent();
+            }
         }
         dictReleaseIterator(di);
     }
@@ -845,7 +953,7 @@ 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) == C_ERR) goto werr;
+    if (rdbSaveRio(rdb,error,RDB_SAVE_NONE) == C_ERR) goto werr;
     if (rioWrite(rdb,eofmark,RDB_EOF_MARK_SIZE) == 0) goto werr;
     return C_OK;
 
@@ -877,7 +985,7 @@ int rdbSave(char *filename) {
     }
 
     rioInitWithFile(&rdb,fp);
-    if (rdbSaveRio(&rdb,&error) == C_ERR) {
+    if (rdbSaveRio(&rdb,&error,RDB_SAVE_NONE) == C_ERR) {
         errno = error;
         goto werr;
     }
@@ -923,6 +1031,7 @@ int rdbSaveBackground(char *filename) {
 
     server.dirty_before_bgsave = server.dirty;
     server.lastbgsave_try = time(NULL);
+    openChildInfoPipe();
 
     start = ustime();
     if ((childpid = fork()) == 0) {
@@ -933,13 +1042,16 @@ int rdbSaveBackground(char *filename) {
         redisSetProcTitle("redis-rdb-bgsave");
         retval = rdbSave(filename);
         if (retval == C_OK) {
-            size_t private_dirty = zmalloc_get_private_dirty();
+            size_t private_dirty = zmalloc_get_private_dirty(-1);
 
             if (private_dirty) {
                 serverLog(LL_NOTICE,
                     "RDB: %zu MB of memory used by copy-on-write",
                     private_dirty/(1024*1024));
             }
+
+            server.child_info_data.cow_size = private_dirty;
+            sendChildInfo(CHILD_INFO_TYPE_RDB);
         }
         exitFromChild((retval == C_OK) ? 0 : 1);
     } else {
@@ -948,6 +1060,7 @@ int rdbSaveBackground(char *filename) {
         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) {
+            closeChildInfoPipe();
             server.lastbgsave_status = C_ERR;
             serverLog(LL_WARNING,"Can't save in background: fork: %s",
                 strerror(errno));
@@ -974,7 +1087,7 @@ void rdbRemoveTempFile(pid_t childpid) {
  * On success a newly allocated object is returned, otherwise NULL. */
 robj *rdbLoadObject(int rdbtype, rio *rdb) {
     robj *o = NULL, *ele, *dec;
-    size_t len;
+    uint64_t len;
     unsigned int i;
 
     if (rdbtype == RDB_TYPE_STRING) {
@@ -999,7 +1112,7 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
             decrRefCount(ele);
         }
     } else if (rdbtype == RDB_TYPE_SET) {
-        /* Read list/set value */
+        /* Read Set value */
         if ((len = rdbLoadLen(rdb,NULL)) == RDB_LENERR) return NULL;
 
         /* Use a regular set when there are too many entries. */
@@ -1013,15 +1126,17 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
             o = createIntsetObject();
         }
 
-        /* Load every single element of the list/set */
+        /* Load every single element of the set */
         for (i = 0; i < len; i++) {
             long long llval;
-            if ((ele = rdbLoadEncodedStringObject(rdb)) == NULL) return NULL;
-            ele = tryObjectEncoding(ele);
+            sds sdsele;
+
+            if ((sdsele = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL))
+                == NULL) return NULL;
 
             if (o->encoding == OBJ_ENCODING_INTSET) {
-                /* Fetch integer value from element */
-                if (isObjectRepresentableAsLongLong(ele,&llval) == C_OK) {
+                /* Fetch integer value from element. */
+                if (isSdsRepresentableAsLongLong(sdsele,&llval) == C_OK) {
                     o->ptr = intsetAdd(o->ptr,llval,NULL);
                 } else {
                     setTypeConvert(o,OBJ_ENCODING_HT);
@@ -1030,16 +1145,16 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
             }
 
             /* This will also be called when the set was just converted
-             * to a regular hash table encoded set */
+             * to a regular hash table encoded set. */
             if (o->encoding == OBJ_ENCODING_HT) {
-                dictAdd((dict*)o->ptr,ele,NULL);
+                dictAdd((dict*)o->ptr,sdsele,NULL);
             } else {
-                decrRefCount(ele);
+                sdsfree(sdsele);
             }
         }
-    } else if (rdbtype == RDB_TYPE_ZSET) {
-        /* Read list/set value */
-        size_t zsetlen;
+    } else if (rdbtype == RDB_TYPE_ZSET_2 || rdbtype == RDB_TYPE_ZSET) {
+        /* Read list/set value. */
+        uint64_t zsetlen;
         size_t maxelelen = 0;
         zset *zs;
 
@@ -1047,23 +1162,26 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
         o = createZsetObject();
         zs = o->ptr;
 
-        /* Load every single element of the list/set */
+        /* Load every single element of the sorted set. */
         while(zsetlen--) {
-            robj *ele;
+            sds sdsele;
             double score;
             zskiplistNode *znode;
 
-            if ((ele = rdbLoadEncodedStringObject(rdb)) == NULL) return NULL;
-            ele = tryObjectEncoding(ele);
-            if (rdbLoadDoubleValue(rdb,&score) == -1) return NULL;
+            if ((sdsele = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL))
+                == NULL) return NULL;
+
+            if (rdbtype == RDB_TYPE_ZSET_2) {
+                if (rdbLoadBinaryDoubleValue(rdb,&score) == -1) return NULL;
+            } else {
+                if (rdbLoadDoubleValue(rdb,&score) == -1) return NULL;
+            }
 
             /* Don't care about integer-encoded strings. */
-            if (sdsEncodedObject(ele) && sdslen(ele->ptr) > maxelelen)
-                maxelelen = sdslen(ele->ptr);
+            if (sdslen(sdsele) > maxelelen) maxelelen = sdslen(sdsele);
 
-            znode = zslInsert(zs->zsl,score,ele);
-            dictAdd(zs->dict,ele,&znode->score);
-            incrRefCount(ele); /* added to skiplist */
+            znode = zslInsert(zs->zsl,score,sdsele);
+            dictAdd(zs->dict,sdsele,&znode->score);
         }
 
         /* Convert *after* loading, since sorted sets are not stored ordered. */
@@ -1071,8 +1189,9 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
             maxelelen <= server.zset_max_ziplist_value)
                 zsetConvert(o,OBJ_ENCODING_ZIPLIST);
     } else if (rdbtype == RDB_TYPE_HASH) {
-        size_t len;
+        uint64_t len;
         int ret;
+        sds field, value;
 
         len = rdbLoadLen(rdb, NULL);
         if (len == RDB_LENERR) return NULL;
@@ -1085,46 +1204,40 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
 
         /* Load every field and value into the ziplist */
         while (o->encoding == OBJ_ENCODING_ZIPLIST && len > 0) {
-            robj *field, *value;
-
             len--;
             /* Load raw strings */
-            field = rdbLoadStringObject(rdb);
-            if (field == NULL) return NULL;
-            serverAssert(sdsEncodedObject(field));
-            value = rdbLoadStringObject(rdb);
-            if (value == NULL) return NULL;
-            serverAssert(sdsEncodedObject(value));
+            if ((field = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL))
+                == NULL) return NULL;
+            if ((value = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL))
+                == NULL) return NULL;
 
             /* Add pair to ziplist */
-            o->ptr = ziplistPush(o->ptr, field->ptr, sdslen(field->ptr), ZIPLIST_TAIL);
-            o->ptr = ziplistPush(o->ptr, value->ptr, sdslen(value->ptr), ZIPLIST_TAIL);
+            o->ptr = ziplistPush(o->ptr, (unsigned char*)field,
+                    sdslen(field), ZIPLIST_TAIL);
+            o->ptr = ziplistPush(o->ptr, (unsigned char*)value,
+                    sdslen(value), ZIPLIST_TAIL);
+
             /* Convert to hash table if size threshold is exceeded */
-            if (sdslen(field->ptr) > server.hash_max_ziplist_value ||
-                sdslen(value->ptr) > server.hash_max_ziplist_value)
+            if (sdslen(field) > server.hash_max_ziplist_value ||
+                sdslen(value) > server.hash_max_ziplist_value)
             {
-                decrRefCount(field);
-                decrRefCount(value);
+                sdsfree(field);
+                sdsfree(value);
                 hashTypeConvert(o, OBJ_ENCODING_HT);
                 break;
             }
-            decrRefCount(field);
-            decrRefCount(value);
+            sdsfree(field);
+            sdsfree(value);
         }
 
         /* Load remaining fields and values into the hash table */
         while (o->encoding == OBJ_ENCODING_HT && len > 0) {
-            robj *field, *value;
-
             len--;
             /* Load encoded strings */
-            field = rdbLoadEncodedStringObject(rdb);
-            if (field == NULL) return NULL;
-            value = rdbLoadEncodedStringObject(rdb);
-            if (value == NULL) return NULL;
-
-            field = tryObjectEncoding(field);
-            value = tryObjectEncoding(value);
+            if ((field = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL))
+                == NULL) return NULL;
+            if ((value = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL))
+                == NULL) return NULL;
 
             /* Add pair to hash table */
             ret = dictAdd((dict*)o->ptr, field, value);
@@ -1142,7 +1255,8 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
                             server.list_compress_depth);
 
         while (len--) {
-            unsigned char *zl = rdbGenericLoadStringObject(rdb,RDB_LOAD_PLAIN);
+            unsigned char *zl =
+                rdbGenericLoadStringObject(rdb,RDB_LOAD_PLAIN,NULL);
             if (zl == NULL) return NULL;
             quicklistAppendZiplist(o->ptr, zl);
         }
@@ -1152,7 +1266,8 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
                rdbtype == RDB_TYPE_ZSET_ZIPLIST ||
                rdbtype == RDB_TYPE_HASH_ZIPLIST)
     {
-        unsigned char *encoded = rdbGenericLoadStringObject(rdb,RDB_LOAD_PLAIN);
+        unsigned char *encoded =
+            rdbGenericLoadStringObject(rdb,RDB_LOAD_PLAIN,NULL);
         if (encoded == NULL) return NULL;
         o = createObject(OBJ_STRING,encoded); /* Obj type fixed below. */
 
@@ -1219,6 +1334,27 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
                 rdbExitReportCorruptRDB("Unknown RDB encoding type %d",rdbtype);
                 break;
         }
+    } else if (rdbtype == RDB_TYPE_MODULE) {
+        uint64_t moduleid = rdbLoadLen(rdb,NULL);
+        moduleType *mt = moduleTypeLookupModuleByID(moduleid);
+        char name[10];
+
+        if (mt == NULL) {
+            moduleTypeNameByID(name,moduleid);
+            serverLog(LL_WARNING,"The RDB file contains module data I can't load: no matching module '%s'", name);
+            exit(1);
+        }
+        RedisModuleIO io;
+        moduleInitIOContext(io,mt,rdb);
+        /* 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 (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);
+            exit(1);
+        }
+        o = createModuleObject(mt,ptr);
     } else {
         rdbExitReportCorruptRDB("Unknown RDB encoding type %d",rdbtype);
     }
@@ -1272,67 +1408,61 @@ void rdbLoadProgressCallback(rio *r, const void *buf, size_t len) {
     }
 }
 
-int rdbLoad(char *filename) {
-    uint32_t dbid;
+/* 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) {
+    uint64_t dbid;
     int type, rdbver;
     redisDb *db = server.db+0;
     char buf[1024];
     long long expiretime, now = mstime();
-    FILE *fp;
-    rio rdb;
 
-    if ((fp = fopen(filename,"r")) == NULL) return C_ERR;
-
-    rioInitWithFile(&rdb,fp);
-    rdb.update_cksum = rdbLoadProgressCallback;
-    rdb.max_processing_chunk = server.loading_process_events_interval_bytes;
-    if (rioRead(&rdb,buf,9) == 0) goto eoferr;
+    rdb->update_cksum = rdbLoadProgressCallback;
+    rdb->max_processing_chunk = server.loading_process_events_interval_bytes;
+    if (rioRead(rdb,buf,9) == 0) goto eoferr;
     buf[9] = '\0';
     if (memcmp(buf,"REDIS",5) != 0) {
-        fclose(fp);
         serverLog(LL_WARNING,"Wrong signature trying to load DB from file");
         errno = EINVAL;
         return C_ERR;
     }
     rdbver = atoi(buf+5);
     if (rdbver < 1 || rdbver > RDB_VERSION) {
-        fclose(fp);
         serverLog(LL_WARNING,"Can't handle RDB format version %d",rdbver);
         errno = EINVAL;
         return C_ERR;
     }
 
-    startLoading(fp);
     while(1) {
         robj *key, *val;
         expiretime = -1;
 
         /* Read type. */
-        if ((type = rdbLoadType(&rdb)) == -1) goto eoferr;
+        if ((type = rdbLoadType(rdb)) == -1) goto eoferr;
 
         /* Handle special types. */
         if (type == RDB_OPCODE_EXPIRETIME) {
             /* EXPIRETIME: load an expire associated with the next key
              * to load. Note that after loading an expire we need to
              * load the actual type, and continue. */
-            if ((expiretime = rdbLoadTime(&rdb)) == -1) goto eoferr;
+            if ((expiretime = rdbLoadTime(rdb)) == -1) goto eoferr;
             /* We read the time so we need to read the object type again. */
-            if ((type = rdbLoadType(&rdb)) == -1) goto eoferr;
+            if ((type = rdbLoadType(rdb)) == -1) goto eoferr;
             /* the EXPIRETIME opcode specifies time in seconds, so convert
              * into milliseconds. */
             expiretime *= 1000;
         } else if (type == RDB_OPCODE_EXPIRETIME_MS) {
             /* EXPIRETIME_MS: milliseconds precision expire times introduced
              * with RDB v3. Like EXPIRETIME but no with more precision. */
-            if ((expiretime = rdbLoadMillisecondTime(&rdb)) == -1) goto eoferr;
+            if ((expiretime = rdbLoadMillisecondTime(rdb)) == -1) goto eoferr;
             /* We read the time so we need to read the object type again. */
-            if ((type = rdbLoadType(&rdb)) == -1) goto eoferr;
+            if ((type = rdbLoadType(rdb)) == -1) goto eoferr;
         } else if (type == RDB_OPCODE_EOF) {
             /* EOF: End of file, exit the main loop. */
             break;
         } else if (type == RDB_OPCODE_SELECTDB) {
             /* SELECTDB: Select the specified database. */
-            if ((dbid = rdbLoadLen(&rdb,NULL)) == RDB_LENERR)
+            if ((dbid = rdbLoadLen(rdb,NULL)) == RDB_LENERR)
                 goto eoferr;
             if (dbid >= (unsigned)server.dbnum) {
                 serverLog(LL_WARNING,
@@ -1346,10 +1476,10 @@ int rdbLoad(char *filename) {
         } else if (type == RDB_OPCODE_RESIZEDB) {
             /* RESIZEDB: Hint about the size of the keys in the currently
              * selected data base, in order to avoid useless rehashing. */
-            uint32_t db_size, expires_size;
-            if ((db_size = rdbLoadLen(&rdb,NULL)) == RDB_LENERR)
+            uint64_t db_size, expires_size;
+            if ((db_size = rdbLoadLen(rdb,NULL)) == RDB_LENERR)
                 goto eoferr;
-            if ((expires_size = rdbLoadLen(&rdb,NULL)) == RDB_LENERR)
+            if ((expires_size = rdbLoadLen(rdb,NULL)) == RDB_LENERR)
                 goto eoferr;
             dictExpand(db->dict,db_size);
             dictExpand(db->expires,expires_size);
@@ -1361,8 +1491,8 @@ int rdbLoad(char *filename) {
              *
              * An AUX field is composed of two strings: key and value. */
             robj *auxkey, *auxval;
-            if ((auxkey = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
-            if ((auxval = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
+            if ((auxkey = rdbLoadStringObject(rdb)) == NULL) goto eoferr;
+            if ((auxval = rdbLoadStringObject(rdb)) == NULL) goto eoferr;
 
             if (((char*)auxkey->ptr)[0] == '%') {
                 /* All the fields with a name staring with '%' are considered
@@ -1384,9 +1514,9 @@ int rdbLoad(char *filename) {
         }
 
         /* Read key */
-        if ((key = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
+        if ((key = rdbLoadStringObject(rdb)) == NULL) goto eoferr;
         /* Read value */
-        if ((val = rdbLoadObject(type,&rdb)) == NULL) goto eoferr;
+        if ((val = rdbLoadObject(type,rdb)) == NULL) goto eoferr;
         /* Check if the key already expired. This function is used when loading
          * an RDB file from disk, either at startup, or when an RDB was
          * received from the master. In the latter case, the master is
@@ -1407,9 +1537,9 @@ int rdbLoad(char *filename) {
     }
     /* Verify the checksum if RDB version is >= 5 */
     if (rdbver >= 5 && server.rdb_checksum) {
-        uint64_t cksum, expected = rdb.cksum;
+        uint64_t cksum, expected = rdb->cksum;
 
-        if (rioRead(&rdb,&cksum,8) == 0) goto eoferr;
+        if (rioRead(rdb,&cksum,8) == 0) goto eoferr;
         memrev64ifbe(&cksum);
         if (cksum == 0) {
             serverLog(LL_WARNING,"RDB file was saved with checksum disabled: no check performed.");
@@ -1418,9 +1548,6 @@ int rdbLoad(char *filename) {
             rdbExitReportCorruptRDB("RDB CRC error");
         }
     }
-
-    fclose(fp);
-    stopLoading();
     return C_OK;
 
 eoferr: /* unexpected end of file is handled here with a fatal exit */
@@ -1429,6 +1556,24 @@ eoferr: /* unexpected end of file is handled here with a fatal exit */
     return C_ERR; /* Just to avoid warning */
 }
 
+/* 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) {
+    FILE *fp;
+    rio rdb;
+    int retval;
+
+    if ((fp = fopen(filename,"r")) == NULL) return C_ERR;
+    startLoading(fp);
+    rioInitWithFile(&rdb,fp);
+    retval = rdbLoadRio(&rdb);
+    fclose(fp);
+    stopLoading();
+    return retval;
+}
+
 /* A background saving child (BGSAVE) terminated its work. Handle this.
  * This function covers the case of actual BGSAVEs. */
 void backgroundSaveDoneHandlerDisk(int exitcode, int bysignal) {
@@ -1621,6 +1766,7 @@ int rdbSaveToSlavesSockets(void) {
     }
 
     /* Create the child process. */
+    openChildInfoPipe();
     start = ustime();
     if ((childpid = fork()) == 0) {
         /* Child */
@@ -1638,7 +1784,7 @@ int rdbSaveToSlavesSockets(void) {
             retval = C_ERR;
 
         if (retval == C_OK) {
-            size_t private_dirty = zmalloc_get_private_dirty();
+            size_t private_dirty = zmalloc_get_private_dirty(-1);
 
             if (private_dirty) {
                 serverLog(LL_NOTICE,
@@ -1646,6 +1792,9 @@ int rdbSaveToSlavesSockets(void) {
                     private_dirty/(1024*1024));
             }
 
+            server.child_info_data.cow_size = private_dirty;
+            sendChildInfo(CHILD_INFO_TYPE_RDB);
+
             /* If we are returning OK, at least one slave was served
              * with the RDB file as expected, so we need to send a report
              * to the parent via the pipe. The format of the message is:
@@ -1714,6 +1863,7 @@ int rdbSaveToSlavesSockets(void) {
             }
             close(pipefds[0]);
             close(pipefds[1]);
+            closeChildInfoPipe();
         } else {
             serverLog(LL_NOTICE,"Background RDB transfer started by pid %d",
                 childpid);

src/rdb.h

@@ -38,16 +38,17 @@
 
 /* The current RDB version. When the format changes in a way that is no longer
  * backward compatible this number gets incremented. */
-#define RDB_VERSION 7
+#define RDB_VERSION 8
 
 /* Defines related to the dump file format. To store 32 bits lengths for short
  * keys requires a lot of space, so we check the most significant 2 bits of
  * the first byte to interpreter the length:
  *
- * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
- * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
- * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
- * 11|000000 this means: specially encoded object will follow. The six bits
+ * 00|XXXXXX => if the two MSB are 00 the len is the 6 bits of this byte
+ * 01|XXXXXX XXXXXXXX =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
+ * 10|000000 [32 bit integer] => A full 32 bit len in net byte order will follow
+ * 10|000001 [64 bit integer] => A full 64 bit len in net byte order will follow
+ * 11|OBKIND this means: specially encoded object will follow. The six bits
  *           number specify the kind of object that follows.
  *           See the RDB_ENC_* defines.
  *
@@ -55,12 +56,13 @@
  * values, will fit inside. */
 #define RDB_6BITLEN 0
 #define RDB_14BITLEN 1
-#define RDB_32BITLEN 2
+#define RDB_32BITLEN 0x80
+#define RDB_64BITLEN 0x81
 #define RDB_ENCVAL 3
-#define RDB_LENERR UINT_MAX
+#define RDB_LENERR UINT64_MAX
 
 /* When a length of a string object stored on disk has the first two bits
- * set, the remaining two bits specify a special encoding for the object
+ * set, the remaining six bits specify a special encoding for the object
  * accordingly to the following defines: */
 #define RDB_ENC_INT8 0        /* 8 bit signed integer */
 #define RDB_ENC_INT16 1       /* 16 bit signed integer */
@@ -74,6 +76,8 @@
 #define RDB_TYPE_SET    2
 #define RDB_TYPE_ZSET   3
 #define RDB_TYPE_HASH   4
+#define RDB_TYPE_ZSET_2 5 /* ZSET version 2 with doubles stored in binary. */
+#define RDB_TYPE_MODULE 6
 /* NOTE: WHEN ADDING NEW RDB TYPE, UPDATE rdbIsObjectType() BELOW */
 
 /* Object types for encoded objects. */
@@ -86,7 +90,7 @@
 /* NOTE: WHEN ADDING NEW RDB TYPE, UPDATE rdbIsObjectType() BELOW */
 
 /* Test if a type is an object type. */
-#define rdbIsObjectType(t) ((t >= 0 && t <= 4) || (t >= 9 && t <= 14))
+#define rdbIsObjectType(t) ((t >= 0 && t <= 6) || (t >= 9 && t <= 14))
 
 /* Special RDB opcodes (saved/loaded with rdbSaveType/rdbLoadType). */
 #define RDB_OPCODE_AUX        250
@@ -96,12 +100,22 @@
 #define RDB_OPCODE_SELECTDB   254
 #define RDB_OPCODE_EOF        255
 
+/* rdbLoad...() functions flags. */
+#define RDB_LOAD_NONE   0
+#define RDB_LOAD_ENC    (1<<0)
+#define RDB_LOAD_PLAIN  (1<<1)
+#define RDB_LOAD_SDS    (1<<2)
+
+#define RDB_SAVE_NONE 0
+#define RDB_SAVE_AOF_PREAMBLE (1<<0)
+
 int rdbSaveType(rio *rdb, unsigned char type);
 int rdbLoadType(rio *rdb);
 int rdbSaveTime(rio *rdb, time_t t);
 time_t rdbLoadTime(rio *rdb);
-int rdbSaveLen(rio *rdb, uint32_t len);
-uint32_t rdbLoadLen(rio *rdb, int *isencoded);
+int rdbSaveLen(rio *rdb, uint64_t len);
+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);
@@ -115,5 +129,13 @@ robj *rdbLoadObject(int type, rio *rdb);
 void backgroundSaveDoneHandler(int exitcode, int bysignal);
 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime, long long now);
 robj *rdbLoadStringObject(rio *rdb);
+int rdbSaveStringObject(rio *rdb, robj *obj);
+ssize_t rdbSaveRawString(rio *rdb, unsigned char *s, size_t len);
+void *rdbGenericLoadStringObject(rio *rdb, int flags, size_t *lenptr);
+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);
 
 #endif

src/redis-check-rdb.c

@@ -172,16 +172,17 @@ void rdbCheckSetupSignals(void) {
     sigaction(SIGILL, &act, NULL);
 }
 
-/* Check the specified RDB file. */
+/* Check the specified RDB file. Return 0 if the RDB looks sane, otherwise
+ * 1 is returned. */
 int redis_check_rdb(char *rdbfilename) {
     uint64_t dbid;
     int type, rdbver;
     char buf[1024];
     long long expiretime, now = mstime();
     FILE *fp;
-    rio rdb;
+    static rio rdb; /* Pointed by global struct riostate. */
 
-    if ((fp = fopen(rdbfilename,"r")) == NULL) return C_ERR;
+    if ((fp = fopen(rdbfilename,"r")) == NULL) return 1;
 
     rioInitWithFile(&rdb,fp);
     rdbstate.rio = &rdb;
@@ -331,7 +332,11 @@ int redis_check_rdb_main(int argc, char **argv) {
         fprintf(stderr, "Usage: %s <rdb-file-name>\n", argv[0]);
         exit(1);
     }
-    createSharedObjects(); /* Needed for loading. */
+    /* In order to call the loading functions we need to create the shared
+     * integer objects, however since this function may be called from
+     * an already initialized Redis instance, check if we really need to. */
+    if (shared.integers[0] == NULL)
+        createSharedObjects();
     server.loading_process_events_interval_bytes = 0;
     rdbCheckMode = 1;
     rdbCheckInfo("Checking RDB file %s", argv[1]);

src/redis-cli.c

@@ -275,10 +275,6 @@ 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;
 
@@ -847,8 +843,10 @@ static int cliSendCommand(int argc, char **argv, int repeat) {
     output_raw = 0;
     if (!strcasecmp(command,"info") ||
         (argc >= 2 && !strcasecmp(command,"debug") &&
-                      ((!strcasecmp(argv[1],"jemalloc") && !strcasecmp(argv[2],"info")) ||
-                       !strcasecmp(argv[1],"htstats"))) ||
+                       !strcasecmp(argv[1],"htstats")) ||
+        (argc >= 2 && !strcasecmp(command,"memory") &&
+                      (!strcasecmp(argv[1],"malloc-stats") ||
+                       !strcasecmp(argv[1],"doctor"))) ||
         (argc == 2 && !strcasecmp(command,"cluster") &&
                       (!strcasecmp(argv[1],"nodes") ||
                        !strcasecmp(argv[1],"info"))) ||
@@ -1259,7 +1257,6 @@ void cliLoadPreferences(void) {
             if (argc > 0) cliSetPreferences(argv,argc,0);
             sdsfreesplitres(argv,argc);
         }
-        fclose(fp);
     }
     sdsfree(rcfile);
 }
@@ -1271,11 +1268,6 @@ 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);
@@ -2412,7 +2404,7 @@ long long powerLawRand(long long min, long long max, double alpha) {
 /* Generates a key name among a set of lru_test_sample_size keys, using
  * an 80-20 distribution. */
 void LRUTestGenKey(char *buf, size_t buflen) {
-    snprintf(buf, buflen, "lru:%lld\n",
+    snprintf(buf, buflen, "lru:%lld",
         powerLawRand(1, config.lru_test_sample_size, 6.2));
 }
 
@@ -2434,8 +2426,11 @@ static void LRUTestMode(void) {
         while(mstime() - start_cycle < 1000) {
             /* Write cycle. */
             for (j = 0; j < LRU_CYCLE_PIPELINE_SIZE; j++) {
+                char val[6];
+                val[5] = '\0';
+                for (int i = 0; i < 5; i++) val[i] = 'A'+rand()%('z'-'A');
                 LRUTestGenKey(key,sizeof(key));
-                redisAppendCommand(context, "SET %s val",key);
+                redisAppendCommand(context, "SET %s %s",key,val);
             }
             for (j = 0; j < LRU_CYCLE_PIPELINE_SIZE; j++)
                 redisGetReply(context, (void**)&reply);
@@ -2606,6 +2601,11 @@ 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);

src/redis-trib.rb

@@ -56,7 +56,7 @@ end
 
 class ClusterNode
     def initialize(addr)
-        s = addr.split(":")
+        s = addr.split("@")[0].split(":")
         if s.length < 2
            puts "Invalid IP or Port (given as #{addr}) - use IP:Port format"
            exit 1

src/redismodule.h

@@ -0,0 +1,308 @@
+#ifndef REDISMODULE_H
+#define REDISMODULE_H
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdio.h>
+
+/* ---------------- Defines common between core and modules --------------- */
+
+/* Error status return values. */
+#define REDISMODULE_OK 0
+#define REDISMODULE_ERR 1
+
+/* API versions. */
+#define REDISMODULE_APIVER_1 1
+
+/* API flags and constants */
+#define REDISMODULE_READ (1<<0)
+#define REDISMODULE_WRITE (1<<1)
+
+#define REDISMODULE_LIST_HEAD 0
+#define REDISMODULE_LIST_TAIL 1
+
+/* Key types. */
+#define REDISMODULE_KEYTYPE_EMPTY 0
+#define REDISMODULE_KEYTYPE_STRING 1
+#define REDISMODULE_KEYTYPE_LIST 2
+#define REDISMODULE_KEYTYPE_HASH 3
+#define REDISMODULE_KEYTYPE_SET 4
+#define REDISMODULE_KEYTYPE_ZSET 5
+#define REDISMODULE_KEYTYPE_MODULE 6
+
+/* Reply types. */
+#define REDISMODULE_REPLY_UNKNOWN -1
+#define REDISMODULE_REPLY_STRING 0
+#define REDISMODULE_REPLY_ERROR 1
+#define REDISMODULE_REPLY_INTEGER 2
+#define REDISMODULE_REPLY_ARRAY 3
+#define REDISMODULE_REPLY_NULL 4
+
+/* Postponed array length. */
+#define REDISMODULE_POSTPONED_ARRAY_LEN -1
+
+/* Expire */
+#define REDISMODULE_NO_EXPIRE -1
+
+/* Sorted set API flags. */
+#define REDISMODULE_ZADD_XX      (1<<0)
+#define REDISMODULE_ZADD_NX      (1<<1)
+#define REDISMODULE_ZADD_ADDED   (1<<2)
+#define REDISMODULE_ZADD_UPDATED (1<<3)
+#define REDISMODULE_ZADD_NOP     (1<<4)
+
+/* Hash API flags. */
+#define REDISMODULE_HASH_NONE       0
+#define REDISMODULE_HASH_NX         (1<<0)
+#define REDISMODULE_HASH_XX         (1<<1)
+#define REDISMODULE_HASH_CFIELDS    (1<<2)
+#define REDISMODULE_HASH_EXISTS     (1<<3)
+
+/* 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)
+
+/* Error messages. */
+#define REDISMODULE_ERRORMSG_WRONGTYPE "WRONGTYPE Operation against a key holding the wrong kind of value"
+
+#define REDISMODULE_POSITIVE_INFINITE (1.0/0.0)
+#define REDISMODULE_NEGATIVE_INFINITE (-1.0/0.0)
+
+/* ------------------------- End of common defines ------------------------ */
+
+#ifndef REDISMODULE_CORE
+
+typedef long long mstime_t;
+
+/* Incomplete structures for compiler checks but opaque access. */
+typedef struct RedisModuleCtx RedisModuleCtx;
+typedef struct RedisModuleKey RedisModuleKey;
+typedef struct RedisModuleString RedisModuleString;
+typedef struct RedisModuleCallReply RedisModuleCallReply;
+typedef struct RedisModuleIO RedisModuleIO;
+typedef struct RedisModuleType RedisModuleType;
+typedef struct RedisModuleDigest RedisModuleDigest;
+
+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 void (*RedisModuleTypeDigestFunc)(RedisModuleDigest *digest, void *value);
+typedef void (*RedisModuleTypeFreeFunc)(void *value);
+
+#define REDISMODULE_GET_API(name) \
+    RedisModule_GetApi("RedisModule_" #name, ((void **)&RedisModule_ ## name))
+
+#define REDISMODULE_API_FUNC(x) (*x)
+
+
+void *REDISMODULE_API_FUNC(RedisModule_Alloc)(size_t bytes);
+void *REDISMODULE_API_FUNC(RedisModule_Realloc)(void *ptr, size_t bytes);
+void REDISMODULE_API_FUNC(RedisModule_Free)(void *ptr);
+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);
+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);
+int REDISMODULE_API_FUNC(RedisModule_SelectDb)(RedisModuleCtx *ctx, int newid);
+void *REDISMODULE_API_FUNC(RedisModule_OpenKey)(RedisModuleCtx *ctx, RedisModuleString *keyname, int mode);
+void REDISMODULE_API_FUNC(RedisModule_CloseKey)(RedisModuleKey *kp);
+int REDISMODULE_API_FUNC(RedisModule_KeyType)(RedisModuleKey *kp);
+size_t REDISMODULE_API_FUNC(RedisModule_ValueLength)(RedisModuleKey *kp);
+int REDISMODULE_API_FUNC(RedisModule_ListPush)(RedisModuleKey *kp, int where, RedisModuleString *ele);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_ListPop)(RedisModuleKey *key, int where);
+RedisModuleCallReply *REDISMODULE_API_FUNC(RedisModule_Call)(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...);
+const char *REDISMODULE_API_FUNC(RedisModule_CallReplyProto)(RedisModuleCallReply *reply, size_t *len);
+void REDISMODULE_API_FUNC(RedisModule_FreeCallReply)(RedisModuleCallReply *reply);
+int REDISMODULE_API_FUNC(RedisModule_CallReplyType)(RedisModuleCallReply *reply);
+long long REDISMODULE_API_FUNC(RedisModule_CallReplyInteger)(RedisModuleCallReply *reply);
+size_t REDISMODULE_API_FUNC(RedisModule_CallReplyLength)(RedisModuleCallReply *reply);
+RedisModuleCallReply *REDISMODULE_API_FUNC(RedisModule_CallReplyArrayElement)(RedisModuleCallReply *reply, size_t idx);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_CreateString)(RedisModuleCtx *ctx, const char *ptr, size_t len);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_CreateStringFromLongLong)(RedisModuleCtx *ctx, long long ll);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_CreateStringFromString)(RedisModuleCtx *ctx, const RedisModuleString *str);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_CreateStringPrintf)(RedisModuleCtx *ctx, const char *fmt, ...);
+void REDISMODULE_API_FUNC(RedisModule_FreeString)(RedisModuleCtx *ctx, RedisModuleString *str);
+const char *REDISMODULE_API_FUNC(RedisModule_StringPtrLen)(const RedisModuleString *str, size_t *len);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithError)(RedisModuleCtx *ctx, const char *err);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithSimpleString)(RedisModuleCtx *ctx, const char *msg);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithArray)(RedisModuleCtx *ctx, long len);
+void REDISMODULE_API_FUNC(RedisModule_ReplySetArrayLength)(RedisModuleCtx *ctx, long len);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithStringBuffer)(RedisModuleCtx *ctx, const char *buf, size_t len);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithString)(RedisModuleCtx *ctx, RedisModuleString *str);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithNull)(RedisModuleCtx *ctx);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithDouble)(RedisModuleCtx *ctx, double d);
+int REDISMODULE_API_FUNC(RedisModule_ReplyWithCallReply)(RedisModuleCtx *ctx, RedisModuleCallReply *reply);
+int REDISMODULE_API_FUNC(RedisModule_StringToLongLong)(const RedisModuleString *str, long long *ll);
+int REDISMODULE_API_FUNC(RedisModule_StringToDouble)(const RedisModuleString *str, double *d);
+void REDISMODULE_API_FUNC(RedisModule_AutoMemory)(RedisModuleCtx *ctx);
+int REDISMODULE_API_FUNC(RedisModule_Replicate)(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...);
+int REDISMODULE_API_FUNC(RedisModule_ReplicateVerbatim)(RedisModuleCtx *ctx);
+const char *REDISMODULE_API_FUNC(RedisModule_CallReplyStringPtr)(RedisModuleCallReply *reply, size_t *len);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_CreateStringFromCallReply)(RedisModuleCallReply *reply);
+int REDISMODULE_API_FUNC(RedisModule_DeleteKey)(RedisModuleKey *key);
+int REDISMODULE_API_FUNC(RedisModule_StringSet)(RedisModuleKey *key, RedisModuleString *str);
+char *REDISMODULE_API_FUNC(RedisModule_StringDMA)(RedisModuleKey *key, size_t *len, int mode);
+int REDISMODULE_API_FUNC(RedisModule_StringTruncate)(RedisModuleKey *key, size_t newlen);
+mstime_t REDISMODULE_API_FUNC(RedisModule_GetExpire)(RedisModuleKey *key);
+int REDISMODULE_API_FUNC(RedisModule_SetExpire)(RedisModuleKey *key, mstime_t expire);
+int REDISMODULE_API_FUNC(RedisModule_ZsetAdd)(RedisModuleKey *key, double score, RedisModuleString *ele, int *flagsptr);
+int REDISMODULE_API_FUNC(RedisModule_ZsetIncrby)(RedisModuleKey *key, double score, RedisModuleString *ele, int *flagsptr, double *newscore);
+int REDISMODULE_API_FUNC(RedisModule_ZsetScore)(RedisModuleKey *key, RedisModuleString *ele, double *score);
+int REDISMODULE_API_FUNC(RedisModule_ZsetRem)(RedisModuleKey *key, RedisModuleString *ele, int *deleted);
+void REDISMODULE_API_FUNC(RedisModule_ZsetRangeStop)(RedisModuleKey *key);
+int REDISMODULE_API_FUNC(RedisModule_ZsetFirstInScoreRange)(RedisModuleKey *key, double min, double max, int minex, int maxex);
+int REDISMODULE_API_FUNC(RedisModule_ZsetLastInScoreRange)(RedisModuleKey *key, double min, double max, int minex, int maxex);
+int REDISMODULE_API_FUNC(RedisModule_ZsetFirstInLexRange)(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max);
+int REDISMODULE_API_FUNC(RedisModule_ZsetLastInLexRange)(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_ZsetRangeCurrentElement)(RedisModuleKey *key, double *score);
+int REDISMODULE_API_FUNC(RedisModule_ZsetRangeNext)(RedisModuleKey *key);
+int REDISMODULE_API_FUNC(RedisModule_ZsetRangePrev)(RedisModuleKey *key);
+int REDISMODULE_API_FUNC(RedisModule_ZsetRangeEndReached)(RedisModuleKey *key);
+int REDISMODULE_API_FUNC(RedisModule_HashSet)(RedisModuleKey *key, int flags, ...);
+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);
+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);
+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);
+void REDISMODULE_API_FUNC(RedisModule_SaveUnsigned)(RedisModuleIO *io, uint64_t value);
+uint64_t REDISMODULE_API_FUNC(RedisModule_LoadUnsigned)(RedisModuleIO *io);
+void REDISMODULE_API_FUNC(RedisModule_SaveSigned)(RedisModuleIO *io, int64_t value);
+int64_t REDISMODULE_API_FUNC(RedisModule_LoadSigned)(RedisModuleIO *io);
+void REDISMODULE_API_FUNC(RedisModule_EmitAOF)(RedisModuleIO *io, const char *cmdname, const char *fmt, ...);
+void REDISMODULE_API_FUNC(RedisModule_SaveString)(RedisModuleIO *io, RedisModuleString *s);
+void REDISMODULE_API_FUNC(RedisModule_SaveStringBuffer)(RedisModuleIO *io, const char *str, size_t len);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_LoadString)(RedisModuleIO *io);
+char *REDISMODULE_API_FUNC(RedisModule_LoadStringBuffer)(RedisModuleIO *io, size_t *lenptr);
+void REDISMODULE_API_FUNC(RedisModule_SaveDouble)(RedisModuleIO *io, double value);
+double REDISMODULE_API_FUNC(RedisModule_LoadDouble)(RedisModuleIO *io);
+void REDISMODULE_API_FUNC(RedisModule_SaveFloat)(RedisModuleIO *io, float value);
+float REDISMODULE_API_FUNC(RedisModule_LoadFloat)(RedisModuleIO *io);
+void REDISMODULE_API_FUNC(RedisModule_Log)(RedisModuleCtx *ctx, const char *level, const char *fmt, ...);
+void REDISMODULE_API_FUNC(RedisModule_LogIOError)(RedisModuleIO *io, const char *levelstr, const char *fmt, ...);
+int REDISMODULE_API_FUNC(RedisModule_StringAppendBuffer)(RedisModuleCtx *ctx, RedisModuleString *str, const char *buf, size_t len);
+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);
+
+/* This is included inline inside each Redis module. */
+static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int apiver) __attribute__((unused));
+static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int apiver) {
+    void *getapifuncptr = ((void**)ctx)[0];
+    RedisModule_GetApi = (int (*)(const char *, void *)) (unsigned long)getapifuncptr;
+    REDISMODULE_GET_API(Alloc);
+    REDISMODULE_GET_API(Calloc);
+    REDISMODULE_GET_API(Free);
+    REDISMODULE_GET_API(Realloc);
+    REDISMODULE_GET_API(Strdup);
+    REDISMODULE_GET_API(CreateCommand);
+    REDISMODULE_GET_API(SetModuleAttribs);
+    REDISMODULE_GET_API(WrongArity);
+    REDISMODULE_GET_API(ReplyWithLongLong);
+    REDISMODULE_GET_API(ReplyWithError);
+    REDISMODULE_GET_API(ReplyWithSimpleString);
+    REDISMODULE_GET_API(ReplyWithArray);
+    REDISMODULE_GET_API(ReplySetArrayLength);
+    REDISMODULE_GET_API(ReplyWithStringBuffer);
+    REDISMODULE_GET_API(ReplyWithString);
+    REDISMODULE_GET_API(ReplyWithNull);
+    REDISMODULE_GET_API(ReplyWithCallReply);
+    REDISMODULE_GET_API(ReplyWithDouble);
+    REDISMODULE_GET_API(ReplySetArrayLength);
+    REDISMODULE_GET_API(GetSelectedDb);
+    REDISMODULE_GET_API(SelectDb);
+    REDISMODULE_GET_API(OpenKey);
+    REDISMODULE_GET_API(CloseKey);
+    REDISMODULE_GET_API(KeyType);
+    REDISMODULE_GET_API(ValueLength);
+    REDISMODULE_GET_API(ListPush);
+    REDISMODULE_GET_API(ListPop);
+    REDISMODULE_GET_API(StringToLongLong);
+    REDISMODULE_GET_API(StringToDouble);
+    REDISMODULE_GET_API(Call);
+    REDISMODULE_GET_API(CallReplyProto);
+    REDISMODULE_GET_API(FreeCallReply);
+    REDISMODULE_GET_API(CallReplyInteger);
+    REDISMODULE_GET_API(CallReplyType);
+    REDISMODULE_GET_API(CallReplyLength);
+    REDISMODULE_GET_API(CallReplyArrayElement);
+    REDISMODULE_GET_API(CallReplyStringPtr);
+    REDISMODULE_GET_API(CreateStringFromCallReply);
+    REDISMODULE_GET_API(CreateString);
+    REDISMODULE_GET_API(CreateStringFromLongLong);
+    REDISMODULE_GET_API(CreateStringFromString);
+    REDISMODULE_GET_API(CreateStringPrintf);
+    REDISMODULE_GET_API(FreeString);
+    REDISMODULE_GET_API(StringPtrLen);
+    REDISMODULE_GET_API(AutoMemory);
+    REDISMODULE_GET_API(Replicate);
+    REDISMODULE_GET_API(ReplicateVerbatim);
+    REDISMODULE_GET_API(DeleteKey);
+    REDISMODULE_GET_API(StringSet);
+    REDISMODULE_GET_API(StringDMA);
+    REDISMODULE_GET_API(StringTruncate);
+    REDISMODULE_GET_API(GetExpire);
+    REDISMODULE_GET_API(SetExpire);
+    REDISMODULE_GET_API(ZsetAdd);
+    REDISMODULE_GET_API(ZsetIncrby);
+    REDISMODULE_GET_API(ZsetScore);
+    REDISMODULE_GET_API(ZsetRem);
+    REDISMODULE_GET_API(ZsetRangeStop);
+    REDISMODULE_GET_API(ZsetFirstInScoreRange);
+    REDISMODULE_GET_API(ZsetLastInScoreRange);
+    REDISMODULE_GET_API(ZsetFirstInLexRange);
+    REDISMODULE_GET_API(ZsetLastInLexRange);
+    REDISMODULE_GET_API(ZsetRangeCurrentElement);
+    REDISMODULE_GET_API(ZsetRangeNext);
+    REDISMODULE_GET_API(ZsetRangePrev);
+    REDISMODULE_GET_API(ZsetRangeEndReached);
+    REDISMODULE_GET_API(HashSet);
+    REDISMODULE_GET_API(HashGet);
+    REDISMODULE_GET_API(IsKeysPositionRequest);
+    REDISMODULE_GET_API(KeyAtPos);
+    REDISMODULE_GET_API(GetClientId);
+    REDISMODULE_GET_API(PoolAlloc);
+    REDISMODULE_GET_API(CreateDataType);
+    REDISMODULE_GET_API(ModuleTypeSetValue);
+    REDISMODULE_GET_API(ModuleTypeGetType);
+    REDISMODULE_GET_API(ModuleTypeGetValue);
+    REDISMODULE_GET_API(SaveUnsigned);
+    REDISMODULE_GET_API(LoadUnsigned);
+    REDISMODULE_GET_API(SaveSigned);
+    REDISMODULE_GET_API(LoadSigned);
+    REDISMODULE_GET_API(SaveString);
+    REDISMODULE_GET_API(SaveStringBuffer);
+    REDISMODULE_GET_API(LoadString);
+    REDISMODULE_GET_API(LoadStringBuffer);
+    REDISMODULE_GET_API(SaveDouble);
+    REDISMODULE_GET_API(LoadDouble);
+    REDISMODULE_GET_API(SaveFloat);
+    REDISMODULE_GET_API(LoadFloat);
+    REDISMODULE_GET_API(EmitAOF);
+    REDISMODULE_GET_API(Log);
+    REDISMODULE_GET_API(LogIOError);
+    REDISMODULE_GET_API(StringAppendBuffer);
+    REDISMODULE_GET_API(RetainString);
+    REDISMODULE_GET_API(StringCompare);
+    REDISMODULE_GET_API(GetContextFromIO);
+
+    RedisModule_SetModuleAttribs(ctx,name,ver,apiver);
+    return REDISMODULE_OK;
+}
+
+#else
+
+/* Things only defined for the modules core, not exported to modules
+ * including this file. */
+#define RedisModuleString robj
+
+#endif /* REDISMODULE_CORE */
+#endif /* REDISMOUDLE_H */

src/replication.c

@@ -1127,7 +1127,10 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
         }
         serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Flushing old data");
         signalFlushedDb(-1);
-        emptyDb(replicationEmptyDbCallback);
+        emptyDb(
+            -1,
+            server.repl_slave_lazy_flush ? EMPTYDB_ASYNC : EMPTYDB_NO_FLAGS,
+            replicationEmptyDbCallback);
         /* Before loading the DB into memory we need to delete the readable
          * handler, otherwise it will get called recursively since
          * rdbLoad() will call the event loop to process events from time to

src/rio.h

@@ -135,6 +135,9 @@ size_t rioWriteBulkString(rio *r, const char *buf, size_t len);
 size_t rioWriteBulkLongLong(rio *r, long long l);
 size_t rioWriteBulkDouble(rio *r, double d);
 
+struct redisObject;
+int rioWriteBulkObject(rio *r, struct redisObject *obj);
+
 void rioGenericUpdateChecksum(rio *r, const void *buf, size_t len);
 void rioSetAutoSync(rio *r, off_t bytes);
 

src/scripting.c

@@ -566,9 +566,9 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
         reply = sdsnewlen(c->buf,c->bufpos);
         c->bufpos = 0;
         while(listLength(c->reply)) {
-            robj *o = listNodeValue(listFirst(c->reply));
+            sds o = listNodeValue(listFirst(c->reply));
 
-            reply = sdscatlen(reply,o->ptr,sdslen(o->ptr));
+            reply = sdscatsds(reply,o);
             listDelNode(c->reply,listFirst(c->reply));
         }
     }
@@ -869,7 +869,7 @@ void scriptingEnableGlobalsProtection(lua_State *lua) {
     s[j++]="end\n";
     s[j++]="mt.__index = function (t, n)\n";
     s[j++]="  if dbg.getinfo(2) and dbg.getinfo(2, \"S\").what ~= \"C\" then\n";
-    s[j++]="    error(\"Script attempted to access unexisting global variable '\"..tostring(n)..\"'\", 2)\n";
+    s[j++]="    error(\"Script attempted to access nonexistent global variable '\"..tostring(n)..\"'\", 2)\n";
     s[j++]="  end\n";
     s[j++]="  return rawget(t, n)\n";
     s[j++]="end\n";

src/sds.c

@@ -35,6 +35,7 @@
 #include <string.h>
 #include <ctype.h>
 #include <assert.h>
+#include <limits.h>
 #include "sds.h"
 #include "sdsalloc.h"
 
@@ -61,8 +62,10 @@ static inline char sdsReqType(size_t string_size) {
         return SDS_TYPE_8;
     if (string_size < 1<<16)
         return SDS_TYPE_16;
+#if (LONG_MAX == LLONG_MAX)
     if (string_size < 1ll<<32)
         return SDS_TYPE_32;
+#endif
     return SDS_TYPE_64;
 }
 

src/sentinel.c

@@ -3640,15 +3640,15 @@ struct sentinelLeader {
 /* Helper function for sentinelGetLeader, increment the counter
  * relative to the specified runid. */
 int sentinelLeaderIncr(dict *counters, char *runid) {
-    dictEntry *de = dictFind(counters,runid);
+    dictEntry *existing, *de;
     uint64_t oldval;
 
-    if (de) {
-        oldval = dictGetUnsignedIntegerVal(de);
-        dictSetUnsignedIntegerVal(de,oldval+1);
+    de = dictAddRaw(counters,runid,&existing);
+    if (existing) {
+        oldval = dictGetUnsignedIntegerVal(existing);
+        dictSetUnsignedIntegerVal(existing,oldval+1);
         return oldval+1;
     } else {
-        de = dictAddRaw(counters,runid);
         serverAssert(de != NULL);
         dictSetUnsignedIntegerVal(de,1);
         return 1;
@@ -3674,7 +3674,7 @@ char *sentinelGetLeader(sentinelRedisInstance *master, uint64_t epoch) {
     serverAssert(master->flags & (SRI_O_DOWN|SRI_FAILOVER_IN_PROGRESS));
     counters = dictCreate(&leaderVotesDictType,NULL);
 
-    voters = dictSize(master->sentinels)+1; /* All the other sentinels and me. */
+    voters = dictSize(master->sentinels)+1; /* All the other sentinels and me.*/
 
     /* Count other sentinels votes */
     di = dictGetIterator(master->sentinels);

src/server.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2009-2016, Salvatore Sanfilippo <antirez at gmail dot com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -123,6 +123,7 @@ struct redisServer server; /* server global state */
  *    are not fast commands.
  */
 struct redisCommand redisCommandTable[] = {
+    {"module",moduleCommand,-2,"as",0,NULL,1,1,1,0,0},
     {"get",getCommand,2,"rF",0,NULL,1,1,1,0,0},
     {"set",setCommand,-3,"wm",0,NULL,1,1,1,0,0},
     {"setnx",setnxCommand,3,"wmF",0,NULL,1,1,1,0,0},
@@ -131,6 +132,7 @@ struct redisCommand redisCommandTable[] = {
     {"append",appendCommand,3,"wm",0,NULL,1,1,1,0,0},
     {"strlen",strlenCommand,2,"rF",0,NULL,1,1,1,0,0},
     {"del",delCommand,-2,"w",0,NULL,1,-1,1,0,0},
+    {"unlink",unlinkCommand,-2,"wF",0,NULL,1,-1,1,0,0},
     {"exists",existsCommand,-2,"rF",0,NULL,1,-1,1,0,0},
     {"setbit",setbitCommand,4,"wm",0,NULL,1,1,1,0,0},
     {"getbit",getbitCommand,3,"rF",0,NULL,1,1,1,0,0},
@@ -143,8 +145,8 @@ struct redisCommand redisCommandTable[] = {
     {"mget",mgetCommand,-2,"r",0,NULL,1,-1,1,0,0},
     {"rpush",rpushCommand,-3,"wmF",0,NULL,1,1,1,0,0},
     {"lpush",lpushCommand,-3,"wmF",0,NULL,1,1,1,0,0},
-    {"rpushx",rpushxCommand,3,"wmF",0,NULL,1,1,1,0,0},
-    {"lpushx",lpushxCommand,3,"wmF",0,NULL,1,1,1,0,0},
+    {"rpushx",rpushxCommand,-3,"wmF",0,NULL,1,1,1,0,0},
+    {"lpushx",lpushxCommand,-3,"wmF",0,NULL,1,1,1,0,0},
     {"linsert",linsertCommand,5,"wm",0,NULL,1,1,1,0,0},
     {"rpop",rpopCommand,2,"wF",0,NULL,1,1,1,0,0},
     {"lpop",lpopCommand,2,"wF",0,NULL,1,1,1,0,0},
@@ -242,8 +244,8 @@ struct redisCommand redisCommandTable[] = {
     {"sync",syncCommand,1,"ars",0,NULL,0,0,0,0,0},
     {"psync",syncCommand,3,"ars",0,NULL,0,0,0,0,0},
     {"replconf",replconfCommand,-1,"aslt",0,NULL,0,0,0,0,0},
-    {"flushdb",flushdbCommand,1,"w",0,NULL,0,0,0,0,0},
-    {"flushall",flushallCommand,1,"w",0,NULL,0,0,0,0,0},
+    {"flushdb",flushdbCommand,-1,"w",0,NULL,0,0,0,0,0},
+    {"flushall",flushallCommand,-1,"w",0,NULL,0,0,0,0,0},
     {"sort",sortCommand,-2,"wm",0,sortGetKeys,1,1,1,0,0},
     {"info",infoCommand,-1,"lt",0,NULL,0,0,0,0,0},
     {"monitor",monitorCommand,1,"as",0,NULL,0,0,0,0,0},
@@ -272,6 +274,7 @@ struct redisCommand redisCommandTable[] = {
     {"readwrite",readwriteCommand,1,"F",0,NULL,0,0,0,0,0},
     {"dump",dumpCommand,2,"r",0,NULL,1,1,1,0,0},
     {"object",objectCommand,3,"r",0,NULL,2,2,2,0,0},
+    {"memory",memoryCommand,-2,"r",0,NULL,0,0,0,0,0},
     {"client",clientCommand,-2,"as",0,NULL,0,0,0,0,0},
     {"eval",evalCommand,-3,"s",0,evalGetKeys,0,0,0,0,0},
     {"evalsha",evalShaCommand,-3,"s",0,evalGetKeys,0,0,0,0,0},
@@ -299,8 +302,6 @@ struct redisCommand redisCommandTable[] = {
     {"latency",latencyCommand,-2,"aslt",0,NULL,0,0,0,0,0}
 };
 
-struct evictionPoolEntry *evictionPoolAlloc(void);
-
 /*============================ Utility functions ============================ */
 
 /* Low level logging. To use only for very big messages, otherwise
@@ -462,7 +463,7 @@ void dictObjectDestructor(void *privdata, void *val)
 {
     DICT_NOTUSED(privdata);
 
-    if (val == NULL) return; /* Values of swapped out keys as set to NULL */
+    if (val == NULL) return; /* Lazy freeing will set value to NULL. */
     decrRefCount(val);
 }
 
@@ -534,8 +535,9 @@ unsigned int dictEncObjHash(const void *key) {
     }
 }
 
-/* Sets type hash table */
-dictType setDictType = {
+/* Generic hash table type where keys are Redis Objects, Values
+ * dummy pointers. */
+dictType objectKeyPointerValueDictType = {
     dictEncObjHash,            /* hash function */
     NULL,                      /* key dup */
     NULL,                      /* val dup */
@@ -544,13 +546,23 @@ dictType setDictType = {
     NULL                       /* val destructor */
 };
 
-/* Sorted sets hash (note: a skiplist is used in addition to the hash table) */
-dictType zsetDictType = {
-    dictEncObjHash,            /* hash function */
+/* Set dictionary type. Keys are SDS strings, values are ot used. */
+dictType setDictType = {
+    dictSdsHash,               /* hash function */
     NULL,                      /* key dup */
     NULL,                      /* val dup */
-    dictEncObjKeyCompare,      /* key compare */
-    dictObjectDestructor, /* key destructor */
+    dictSdsKeyCompare,         /* key compare */
+    dictSdsDestructor,         /* key destructor */
+    NULL                       /* val destructor */
+};
+
+/* Sorted sets hash (note: a skiplist is used in addition to the hash table) */
+dictType zsetDictType = {
+    dictSdsHash,               /* hash function */
+    NULL,                      /* key dup */
+    NULL,                      /* val dup */
+    dictSdsKeyCompare,         /* key compare */
+    NULL,                      /* Note: SDS string shared & freed by skiplist */
     NULL                       /* val destructor */
 };
 
@@ -571,37 +583,37 @@ dictType shaScriptObjectDictType = {
     NULL,                       /* val dup */
     dictSdsKeyCaseCompare,      /* key compare */
     dictSdsDestructor,          /* key destructor */
-    dictObjectDestructor   /* val destructor */
+    dictObjectDestructor        /* val destructor */
 };
 
 /* Db->expires */
 dictType keyptrDictType = {
-    dictSdsHash,               /* hash function */
-    NULL,                      /* key dup */
-    NULL,                      /* val dup */
-    dictSdsKeyCompare,         /* key compare */
-    NULL,                      /* key destructor */
-    NULL                       /* val destructor */
+    dictSdsHash,                /* hash function */
+    NULL,                       /* key dup */
+    NULL,                       /* val dup */
+    dictSdsKeyCompare,          /* key compare */
+    NULL,                       /* key destructor */
+    NULL                        /* val destructor */
 };
 
 /* Command table. sds string -> command struct pointer. */
 dictType commandTableDictType = {
-    dictSdsCaseHash,           /* hash function */
-    NULL,                      /* key dup */
-    NULL,                      /* val dup */
-    dictSdsKeyCaseCompare,     /* key compare */
-    dictSdsDestructor,         /* key destructor */
-    NULL                       /* val destructor */
+    dictSdsCaseHash,            /* hash function */
+    NULL,                       /* key dup */
+    NULL,                       /* val dup */
+    dictSdsKeyCaseCompare,      /* key compare */
+    dictSdsDestructor,          /* key destructor */
+    NULL                        /* val destructor */
 };
 
 /* Hash type hash table (note that small hashes are represented with ziplists) */
 dictType hashDictType = {
-    dictEncObjHash,             /* hash function */
+    dictSdsHash,                /* hash function */
     NULL,                       /* key dup */
     NULL,                       /* val dup */
-    dictEncObjKeyCompare,       /* key compare */
-    dictObjectDestructor,  /* key destructor */
-    dictObjectDestructor   /* val destructor */
+    dictSdsKeyCompare,          /* key compare */
+    dictSdsDestructor,          /* key destructor */
+    dictSdsDestructor           /* val destructor */
 };
 
 /* Keylist hash table type has unencoded redis objects as keys and
@@ -612,7 +624,7 @@ dictType keylistDictType = {
     NULL,                       /* key dup */
     NULL,                       /* val dup */
     dictObjKeyCompare,          /* key compare */
-    dictObjectDestructor,  /* key destructor */
+    dictObjectDestructor,       /* key destructor */
     dictListDestructor          /* val destructor */
 };
 
@@ -639,6 +651,18 @@ dictType clusterNodesBlackListDictType = {
     NULL                        /* val destructor */
 };
 
+/* Cluster re-addition blacklist. This maps node IDs to the time
+ * we can re-add this node. The goal is to avoid readding a removed
+ * node for some time. */
+dictType modulesDictType = {
+    dictSdsCaseHash,            /* hash function */
+    NULL,                       /* key dup */
+    NULL,                       /* val dup */
+    dictSdsKeyCaseCompare,      /* key compare */
+    dictSdsDestructor,          /* key destructor */
+    NULL                        /* val destructor */
+};
+
 /* Migrate cache dict type. */
 dictType migrateCacheDictType = {
     dictSdsHash,                /* hash function */
@@ -715,183 +739,6 @@ void updateDictResizePolicy(void) {
 
 /* ======================= Cron: called every 100 ms ======================== */
 
-/* Helper function for the activeExpireCycle() function.
- * This function will try to expire the key that is stored in the hash table
- * entry 'de' of the 'expires' hash table of a Redis database.
- *
- * If the key is found to be expired, it is removed from the database and
- * 1 is returned. Otherwise no operation is performed and 0 is returned.
- *
- * When a key is expired, server.stat_expiredkeys is incremented.
- *
- * The parameter 'now' is the current time in milliseconds as is passed
- * to the function to avoid too many gettimeofday() syscalls. */
-int activeExpireCycleTryExpire(redisDb *db, dictEntry *de, long long now) {
-    long long t = dictGetSignedIntegerVal(de);
-    if (now > t) {
-        sds key = dictGetKey(de);
-        robj *keyobj = createStringObject(key,sdslen(key));
-
-        propagateExpire(db,keyobj);
-        dbDelete(db,keyobj);
-        notifyKeyspaceEvent(NOTIFY_EXPIRED,
-            "expired",keyobj,db->id);
-        decrRefCount(keyobj);
-        server.stat_expiredkeys++;
-        return 1;
-    } else {
-        return 0;
-    }
-}
-
-/* Try to expire a few timed out keys. The algorithm used is adaptive and
- * will use few CPU cycles if there are few expiring keys, otherwise
- * it will get more aggressive to avoid that too much memory is used by
- * keys that can be removed from the keyspace.
- *
- * No more than CRON_DBS_PER_CALL databases are tested at every
- * iteration.
- *
- * This kind of call is used when Redis detects that timelimit_exit is
- * true, so there is more work to do, and we do it more incrementally from
- * the beforeSleep() function of the event loop.
- *
- * Expire cycle type:
- *
- * If type is ACTIVE_EXPIRE_CYCLE_FAST the function will try to run a
- * "fast" expire cycle that takes no longer than EXPIRE_FAST_CYCLE_DURATION
- * microseconds, and is not repeated again before the same amount of time.
- *
- * 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. */
-
-void activeExpireCycle(int type) {
-    /* This function has some global state in order to continue the work
-     * incrementally across calls. */
-    static unsigned int current_db = 0; /* Last DB tested. */
-    static int timelimit_exit = 0;      /* Time limit hit in previous call? */
-    static long long last_fast_cycle = 0; /* When last fast cycle ran. */
-
-    int j, iteration = 0;
-    int dbs_per_call = CRON_DBS_PER_CALL;
-    long long start = ustime(), timelimit;
-
-    if (type == ACTIVE_EXPIRE_CYCLE_FAST) {
-        /* Don't start a fast cycle if the previous cycle did not exited
-         * for time limt. Also don't repeat a fast cycle for the same period
-         * as the fast cycle total duration itself. */
-        if (!timelimit_exit) return;
-        if (start < last_fast_cycle + ACTIVE_EXPIRE_CYCLE_FAST_DURATION*2) return;
-        last_fast_cycle = start;
-    }
-
-    /* We usually should test CRON_DBS_PER_CALL per iteration, with
-     * two exceptions:
-     *
-     * 1) Don't test more DBs than we have.
-     * 2) If last time we hit the time limit, we want to scan all DBs
-     * in this iteration, as there is work to do in some DB and we don't want
-     * expired keys to use memory for too much time. */
-    if (dbs_per_call > server.dbnum || timelimit_exit)
-        dbs_per_call = server.dbnum;
-
-    /* We can use at max ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC percentage of CPU time
-     * per iteration. Since this function gets called with a frequency of
-     * server.hz times per second, the following is the max amount of
-     * microseconds we can spend in this function. */
-    timelimit = 1000000*ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC/server.hz/100;
-    timelimit_exit = 0;
-    if (timelimit <= 0) timelimit = 1;
-
-    if (type == ACTIVE_EXPIRE_CYCLE_FAST)
-        timelimit = ACTIVE_EXPIRE_CYCLE_FAST_DURATION; /* in microseconds. */
-
-    for (j = 0; j < dbs_per_call; j++) {
-        int expired;
-        redisDb *db = server.db+(current_db % server.dbnum);
-
-        /* Increment the DB now so we are sure if we run out of time
-         * in the current DB we'll restart from the next. This allows to
-         * distribute the time evenly across DBs. */
-        current_db++;
-
-        /* Continue to expire if at the end of the cycle more than 25%
-         * of the keys were expired. */
-        do {
-            unsigned long num, slots;
-            long long now, ttl_sum;
-            int ttl_samples;
-
-            /* If there is nothing to expire try next DB ASAP. */
-            if ((num = dictSize(db->expires)) == 0) {
-                db->avg_ttl = 0;
-                break;
-            }
-            slots = dictSlots(db->expires);
-            now = mstime();
-
-            /* When there are less than 1% filled slots getting random
-             * keys is expensive, so stop here waiting for better times...
-             * The dictionary will be resized asap. */
-            if (num && slots > DICT_HT_INITIAL_SIZE &&
-                (num*100/slots < 1)) break;
-
-            /* The main collection cycle. Sample random keys among keys
-             * with an expire set, checking for expired ones. */
-            expired = 0;
-            ttl_sum = 0;
-            ttl_samples = 0;
-
-            if (num > ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP)
-                num = ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP;
-
-            while (num--) {
-                dictEntry *de;
-                long long ttl;
-
-                if ((de = dictGetRandomKey(db->expires)) == NULL) break;
-                ttl = dictGetSignedIntegerVal(de)-now;
-                if (activeExpireCycleTryExpire(db,de,now)) expired++;
-                if (ttl > 0) {
-                    /* We want the average TTL of keys yet not expired. */
-                    ttl_sum += ttl;
-                    ttl_samples++;
-                }
-            }
-
-            /* Update the average TTL stats for this database. */
-            if (ttl_samples) {
-                long long avg_ttl = ttl_sum/ttl_samples;
-
-                /* Do a simple running average with a few samples.
-                 * We just use the current estimate with a weight of 2%
-                 * and the previous estimate with a weight of 98%. */
-                if (db->avg_ttl == 0) db->avg_ttl = avg_ttl;
-                db->avg_ttl = (db->avg_ttl/50)*49 + (avg_ttl/50);
-            }
-
-            /* 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;
-            }
-            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);
-    }
-}
-
-unsigned int getLRUClock(void) {
-    return (mstime()/LRU_CLOCK_RESOLUTION) & LRU_CLOCK_MAX;
-}
-
 /* Add a sample to the operations per second array of samples. */
 void trackInstantaneousMetric(int metric, long long current_reading) {
     long long t = mstime() - server.inst_metric[metric].last_sample_time;
@@ -1199,8 +1046,10 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
                     (int) server.aof_child_pid);
             } else if (pid == server.rdb_child_pid) {
                 backgroundSaveDoneHandler(exitcode,bysignal);
+                if (!bysignal && exitcode == 0) receiveChildInfo();
             } else if (pid == server.aof_child_pid) {
                 backgroundRewriteDoneHandler(exitcode,bysignal);
+                if (!bysignal && exitcode == 0) receiveChildInfo();
             } else {
                 if (!ldbRemoveChild(pid)) {
                     serverLog(LL_WARNING,
@@ -1209,6 +1058,7 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
                 }
             }
             updateDictResizePolicy();
+            closeChildInfoPipe();
         }
     } else {
         /* If there is not a background saving/rewrite in progress check if
@@ -1267,7 +1117,7 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
     freeClientsInAsyncFreeQueue();
 
     /* Clear the paused clients flag if needed. */
-    clientsArePaused(); /* Don't check return value, just use the side effect. */
+    clientsArePaused(); /* Don't check return value, just use the side effect.*/
 
     /* Replication cron function -- used to reconnect to master,
      * detect transfer failures, start background RDB transfers and so forth. */
@@ -1427,11 +1277,13 @@ void createSharedObjects(void) {
     shared.psubscribebulk = createStringObject("$10\r\npsubscribe\r\n",17);
     shared.punsubscribebulk = createStringObject("$12\r\npunsubscribe\r\n",19);
     shared.del = createStringObject("DEL",3);
+    shared.unlink = createStringObject("UNLINK",6);
     shared.rpop = createStringObject("RPOP",4);
     shared.lpop = createStringObject("LPOP",4);
     shared.lpush = createStringObject("LPUSH",5);
     for (j = 0; j < OBJ_SHARED_INTEGERS; j++) {
-        shared.integers[j] = createObject(OBJ_STRING,(void*)(long)j);
+        shared.integers[j] =
+            makeObjectShared(createObject(OBJ_STRING,(void*)(long)j));
         shared.integers[j]->encoding = OBJ_ENCODING_INT;
     }
     for (j = 0; j < OBJ_SHARED_BULKHDR_LEN; j++) {
@@ -1444,8 +1296,8 @@ void createSharedObjects(void) {
      * actually used for their value but as a special object meaning
      * respectively the minimum possible string and the maximum possible
      * string in string comparisons for the ZRANGEBYLEX command. */
-    shared.minstring = createStringObject("minstring",9);
-    shared.maxstring = createStringObject("maxstring",9);
+    shared.minstring = sdsnew("minstring");
+    shared.maxstring = sdsnew("maxstring");
 }
 
 void initServerConfig(void) {
@@ -1497,6 +1349,7 @@ void initServerConfig(void) {
     server.aof_flush_postponed_start = 0;
     server.aof_rewrite_incremental_fsync = CONFIG_DEFAULT_AOF_REWRITE_INCREMENTAL_FSYNC;
     server.aof_load_truncated = CONFIG_DEFAULT_AOF_LOAD_TRUNCATED;
+    server.aof_use_rdb_preamble = CONFIG_DEFAULT_AOF_USE_RDB_PREAMBLE;
     server.pidfile = NULL;
     server.rdb_filename = zstrdup(CONFIG_DEFAULT_RDB_FILENAME);
     server.aof_filename = zstrdup(CONFIG_DEFAULT_AOF_FILENAME);
@@ -1511,6 +1364,8 @@ void initServerConfig(void) {
     server.maxmemory = CONFIG_DEFAULT_MAXMEMORY;
     server.maxmemory_policy = CONFIG_DEFAULT_MAXMEMORY_POLICY;
     server.maxmemory_samples = CONFIG_DEFAULT_MAXMEMORY_SAMPLES;
+    server.lfu_log_factor = CONFIG_DEFAULT_LFU_LOG_FACTOR;
+    server.lfu_decay_time = CONFIG_DEFAULT_LFU_DECAY_TIME;
     server.hash_max_ziplist_entries = OBJ_HASH_MAX_ZIPLIST_ENTRIES;
     server.hash_max_ziplist_value = OBJ_HASH_MAX_ZIPLIST_VALUE;
     server.list_max_ziplist_size = OBJ_LIST_MAX_ZIPLIST_SIZE;
@@ -1520,19 +1375,21 @@ void initServerConfig(void) {
     server.zset_max_ziplist_value = OBJ_ZSET_MAX_ZIPLIST_VALUE;
     server.hll_sparse_max_bytes = CONFIG_DEFAULT_HLL_SPARSE_MAX_BYTES;
     server.shutdown_asap = 0;
-    server.repl_ping_slave_period = CONFIG_DEFAULT_REPL_PING_SLAVE_PERIOD;
-    server.repl_timeout = CONFIG_DEFAULT_REPL_TIMEOUT;
-    server.repl_min_slaves_to_write = CONFIG_DEFAULT_MIN_SLAVES_TO_WRITE;
-    server.repl_min_slaves_max_lag = CONFIG_DEFAULT_MIN_SLAVES_MAX_LAG;
     server.cluster_enabled = 0;
     server.cluster_node_timeout = CLUSTER_DEFAULT_NODE_TIMEOUT;
     server.cluster_migration_barrier = CLUSTER_DEFAULT_MIGRATION_BARRIER;
     server.cluster_slave_validity_factor = CLUSTER_DEFAULT_SLAVE_VALIDITY;
     server.cluster_require_full_coverage = CLUSTER_DEFAULT_REQUIRE_FULL_COVERAGE;
     server.cluster_configfile = zstrdup(CONFIG_DEFAULT_CLUSTER_CONFIG_FILE);
+    server.cluster_announce_ip = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_IP;
+    server.cluster_announce_port = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_PORT;
+    server.cluster_announce_bus_port = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_BUS_PORT;
     server.migrate_cached_sockets = dictCreate(&migrateCacheDictType,NULL);
     server.next_client_id = 1; /* Client IDs, start from 1 .*/
     server.loading_process_events_interval_bytes = (1024*1024*2);
+    server.lazyfree_lazy_eviction = CONFIG_DEFAULT_LAZYFREE_LAZY_EVICTION;
+    server.lazyfree_lazy_expire = CONFIG_DEFAULT_LAZYFREE_LAZY_EXPIRE;
+    server.lazyfree_lazy_server_del = CONFIG_DEFAULT_LAZYFREE_LAZY_SERVER_DEL;
 
     server.lruclock = getLRUClock();
     resetServerSaveParams();
@@ -1540,6 +1397,7 @@ void initServerConfig(void) {
     appendServerSaveParams(60*60,1);  /* save after 1 hour and 1 change */
     appendServerSaveParams(300,100);  /* save after 5 minutes and 100 changes */
     appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
+
     /* Replication related */
     server.masterauth = NULL;
     server.masterhost = NULL;
@@ -1551,10 +1409,15 @@ void initServerConfig(void) {
     server.repl_syncio_timeout = CONFIG_REPL_SYNCIO_TIMEOUT;
     server.repl_serve_stale_data = CONFIG_DEFAULT_SLAVE_SERVE_STALE_DATA;
     server.repl_slave_ro = CONFIG_DEFAULT_SLAVE_READ_ONLY;
+    server.repl_slave_lazy_flush = CONFIG_DEFAULT_SLAVE_LAZY_FLUSH;
     server.repl_down_since = 0; /* Never connected, repl is down since EVER. */
     server.repl_disable_tcp_nodelay = CONFIG_DEFAULT_REPL_DISABLE_TCP_NODELAY;
     server.repl_diskless_sync = CONFIG_DEFAULT_REPL_DISKLESS_SYNC;
     server.repl_diskless_sync_delay = CONFIG_DEFAULT_REPL_DISKLESS_SYNC_DELAY;
+    server.repl_ping_slave_period = CONFIG_DEFAULT_REPL_PING_SLAVE_PERIOD;
+    server.repl_timeout = CONFIG_DEFAULT_REPL_TIMEOUT;
+    server.repl_min_slaves_to_write = CONFIG_DEFAULT_MIN_SLAVES_TO_WRITE;
+    server.repl_min_slaves_max_lag = CONFIG_DEFAULT_MIN_SLAVES_MAX_LAG;
     server.slave_priority = CONFIG_DEFAULT_SLAVE_PRIORITY;
     server.slave_announce_ip = CONFIG_DEFAULT_SLAVE_ANNOUNCE_IP;
     server.slave_announce_port = CONFIG_DEFAULT_SLAVE_ANNOUNCE_PORT;
@@ -1919,12 +1782,12 @@ void initServer(void) {
         server.db[j].dict = dictCreate(&dbDictType,NULL);
         server.db[j].expires = dictCreate(&keyptrDictType,NULL);
         server.db[j].blocking_keys = dictCreate(&keylistDictType,NULL);
-        server.db[j].ready_keys = dictCreate(&setDictType,NULL);
+        server.db[j].ready_keys = dictCreate(&objectKeyPointerValueDictType,NULL);
         server.db[j].watched_keys = dictCreate(&keylistDictType,NULL);
-        server.db[j].eviction_pool = evictionPoolAlloc();
         server.db[j].id = j;
         server.db[j].avg_ttl = 0;
     }
+    evictionPoolAlloc(); /* Initialize the LRU keys pool. */
     server.pubsub_channels = dictCreate(&keylistDictType,NULL);
     server.pubsub_patterns = listCreate();
     listSetFreeMethod(server.pubsub_patterns,freePubsubPattern);
@@ -1934,6 +1797,9 @@ void initServer(void) {
     server.aof_child_pid = -1;
     server.rdb_child_type = RDB_CHILD_TYPE_NONE;
     server.rdb_bgsave_scheduled = 0;
+    server.child_info_pipe[0] = -1;
+    server.child_info_pipe[1] = -1;
+    server.child_info_data.magic = 0;
     aofRewriteBufferReset();
     server.aof_buf = sdsempty();
     server.lastsave = time(NULL); /* At startup we consider the DB saved. */
@@ -1945,6 +1811,8 @@ void initServer(void) {
     /* A few stats we don't want to reset: server startup time, and peak mem. */
     server.stat_starttime = time(NULL);
     server.stat_peak_memory = 0;
+    server.stat_rdb_cow_bytes = 0;
+    server.stat_aof_cow_bytes = 0;
     server.resident_set_size = 0;
     server.lastbgsave_status = C_OK;
     server.aof_last_write_status = C_OK;
@@ -1952,10 +1820,11 @@ void initServer(void) {
     server.repl_good_slaves_count = 0;
     updateCachedTime();
 
-    /* Create the serverCron() time event, that's our main way to process
-     * background operations. */
-    if(aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL) == AE_ERR) {
-        serverPanic("Can't create the serverCron time event.");
+    /* Create the timer callback, this is our way to process many background
+     * operations incrementally, like clients timeout, eviction of unaccessed
+     * expired keys and so forth. */
+    if (aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL) == AE_ERR) {
+        serverPanic("Can't create event loop timers.");
         exit(1);
     }
 
@@ -1999,6 +1868,7 @@ void initServer(void) {
     slowlogInit();
     latencyMonitorInit();
     bioInit();
+    server.initial_memory_usage = zmalloc_used_memory();
 }
 
 /* Populates the Redis Command Table starting from the hard coded list
@@ -2244,6 +2114,7 @@ void call(client *c, int flags) {
     /* Initialization: clear the flags that must be set by the command on
      * demand, and initialize the array for additional commands propagation. */
     c->flags &= ~(CLIENT_FORCE_AOF|CLIENT_FORCE_REPL|CLIENT_PREVENT_PROP);
+    redisOpArray prev_also_propagate = server.also_propagate;
     redisOpArrayInit(&server.also_propagate);
 
     /* Call the command. */
@@ -2339,6 +2210,7 @@ void call(client *c, int flags) {
         }
         redisOpArrayFree(&server.also_propagate);
     }
+    server.also_propagate = prev_also_propagate;
     server.stat_numcommands++;
 }
 
@@ -2752,7 +2624,9 @@ void addReplyCommand(client *c, struct redisCommand *cmd) {
         flagcount += addReplyCommandFlag(c,cmd,CMD_SKIP_MONITOR, "skip_monitor");
         flagcount += addReplyCommandFlag(c,cmd,CMD_ASKING, "asking");
         flagcount += addReplyCommandFlag(c,cmd,CMD_FAST, "fast");
-        if (cmd->getkeys_proc) {
+        if ((cmd->getkeys_proc && !(cmd->flags & CMD_MODULE)) ||
+            cmd->flags & CMD_MODULE_GETKEYS)
+        {
             addReplyStatus(c, "movablekeys");
             flagcount += 1;
         }
@@ -2946,6 +2820,7 @@ sds genRedisInfoString(char *section) {
         size_t total_system_mem = server.system_memory_size;
         const char *evict_policy = evictPolicyToString();
         long long memory_lua = (long long)lua_gc(server.lua,LUA_GCCOUNT,0)*1024;
+        struct redisMemOverhead *mh = getMemoryOverheadData();
 
         /* Peak memory is updated from time to time by serverCron() so it
          * may happen that the instantaneous value is slightly bigger than
@@ -2970,6 +2845,11 @@ sds genRedisInfoString(char *section) {
             "used_memory_rss_human:%s\r\n"
             "used_memory_peak:%zu\r\n"
             "used_memory_peak_human:%s\r\n"
+            "used_memory_peak_perc:%.2f%%\r\n"
+            "used_memory_overhead:%zu\r\n"
+            "used_memory_startup:%zu\r\n"
+            "used_memory_dataset:%zu\r\n"
+            "used_memory_dataset_perc:%.2f%%\r\n"
             "total_system_memory:%lu\r\n"
             "total_system_memory_human:%s\r\n"
             "used_memory_lua:%lld\r\n"
@@ -2978,13 +2858,19 @@ sds genRedisInfoString(char *section) {
             "maxmemory_human:%s\r\n"
             "maxmemory_policy:%s\r\n"
             "mem_fragmentation_ratio:%.2f\r\n"
-            "mem_allocator:%s\r\n",
+            "mem_allocator:%s\r\n"
+            "lazyfree_pending_objects:%zu\r\n",
             zmalloc_used,
             hmem,
             server.resident_set_size,
             used_memory_rss_hmem,
             server.stat_peak_memory,
             peak_hmem,
+            mh->peak_perc,
+            mh->overhead_total,
+            mh->startup_allocated,
+            mh->dataset,
+            mh->dataset_perc,
             (unsigned long)total_system_mem,
             total_system_hmem,
             memory_lua,
@@ -2992,9 +2878,11 @@ sds genRedisInfoString(char *section) {
             server.maxmemory,
             maxmemory_hmem,
             evict_policy,
-            zmalloc_get_fragmentation_ratio(server.resident_set_size),
-            ZMALLOC_LIB
-            );
+            mh->fragmentation,
+            ZMALLOC_LIB,
+            lazyfreeGetPendingObjectsCount()
+        );
+        freeMemoryOverheadData(mh);
     }
 
     /* Persistence */
@@ -3009,13 +2897,15 @@ sds genRedisInfoString(char *section) {
             "rdb_last_bgsave_status:%s\r\n"
             "rdb_last_bgsave_time_sec:%jd\r\n"
             "rdb_current_bgsave_time_sec:%jd\r\n"
+            "rdb_last_cow_size:%zu\r\n"
             "aof_enabled:%d\r\n"
             "aof_rewrite_in_progress:%d\r\n"
             "aof_rewrite_scheduled:%d\r\n"
             "aof_last_rewrite_time_sec:%jd\r\n"
             "aof_current_rewrite_time_sec:%jd\r\n"
             "aof_last_bgrewrite_status:%s\r\n"
-            "aof_last_write_status:%s\r\n",
+            "aof_last_write_status:%s\r\n"
+            "aof_last_cow_size:%zu\r\n",
             server.loading,
             server.dirty,
             server.rdb_child_pid != -1,
@@ -3024,6 +2914,7 @@ sds genRedisInfoString(char *section) {
             (intmax_t)server.rdb_save_time_last,
             (intmax_t)((server.rdb_child_pid == -1) ?
                 -1 : time(NULL)-server.rdb_save_time_start),
+            server.stat_rdb_cow_bytes,
             server.aof_state != AOF_OFF,
             server.aof_child_pid != -1,
             server.aof_rewrite_scheduled,
@@ -3031,7 +2922,8 @@ sds genRedisInfoString(char *section) {
             (intmax_t)((server.aof_child_pid == -1) ?
                 -1 : time(NULL)-server.aof_rewrite_time_start),
             (server.aof_lastbgrewrite_status == C_OK) ? "ok" : "err",
-            (server.aof_last_write_status == C_OK) ? "ok" : "err");
+            (server.aof_last_write_status == C_OK) ? "ok" : "err",
+            server.stat_aof_cow_bytes);
 
         if (server.aof_state != AOF_OFF) {
             info = sdscatprintf(info,
@@ -3328,299 +3220,6 @@ void monitorCommand(client *c) {
     addReply(c,shared.ok);
 }
 
-/* ============================ Maxmemory directive  ======================== */
-
-/* freeMemoryIfNeeded() gets called when 'maxmemory' is set on the config
- * file to limit the max memory used by the server, before processing a
- * command.
- *
- * The goal of the function is to free enough memory to keep Redis under the
- * configured memory limit.
- *
- * The function starts calculating how many bytes should be freed to keep
- * Redis under the limit, and enters a loop selecting the best keys to
- * evict accordingly to the configured policy.
- *
- * If all the bytes needed to return back under the limit were freed the
- * function returns C_OK, otherwise C_ERR is returned, and the caller
- * should block the execution of commands that will result in more memory
- * used by the server.
- *
- * ------------------------------------------------------------------------
- *
- * LRU approximation algorithm
- *
- * Redis uses an approximation of the LRU algorithm that runs in constant
- * memory. Every time there is a key to expire, we sample N keys (with
- * N very small, usually in around 5) to populate a pool of best keys to
- * evict of M keys (the pool size is defined by MAXMEMORY_EVICTION_POOL_SIZE).
- *
- * The N keys sampled are added in the pool of good keys to expire (the one
- * with an old access time) if they are better than one of the current keys
- * in the pool.
- *
- * After the pool is populated, the best key we have in the pool is expired.
- * However note that we don't remove keys from the pool when they are deleted
- * so the pool may contain keys that no longer exist.
- *
- * When we try to evict a key, and all the entries in the pool don't exist
- * we populate it again. This time we'll be sure that the pool has at least
- * one key that can be evicted, if there is at least one key that can be
- * evicted in the whole database. */
-
-/* Create a new eviction pool. */
-struct evictionPoolEntry *evictionPoolAlloc(void) {
-    struct evictionPoolEntry *ep;
-    int j;
-
-    ep = zmalloc(sizeof(*ep)*MAXMEMORY_EVICTION_POOL_SIZE);
-    for (j = 0; j < MAXMEMORY_EVICTION_POOL_SIZE; j++) {
-        ep[j].idle = 0;
-        ep[j].key = NULL;
-    }
-    return ep;
-}
-
-/* This is an helper function for freeMemoryIfNeeded(), it is used in order
- * to populate the evictionPool with a few entries every time we want to
- * expire a key. Keys with idle time smaller than one of the current
- * keys are added. Keys are always added if there are free entries.
- *
- * We insert keys on place in ascending order, so keys with the smaller
- * idle time are on the left, and keys with the higher idle time on the
- * right. */
-
-#define EVICTION_SAMPLES_ARRAY_SIZE 16
-void evictionPoolPopulate(dict *sampledict, dict *keydict, struct evictionPoolEntry *pool) {
-    int j, k, count;
-    dictEntry *_samples[EVICTION_SAMPLES_ARRAY_SIZE];
-    dictEntry **samples;
-
-    /* Try to use a static buffer: this function is a big hit...
-     * Note: it was actually measured that this helps. */
-    if (server.maxmemory_samples <= EVICTION_SAMPLES_ARRAY_SIZE) {
-        samples = _samples;
-    } else {
-        samples = zmalloc(sizeof(samples[0])*server.maxmemory_samples);
-    }
-
-    count = dictGetSomeKeys(sampledict,samples,server.maxmemory_samples);
-    for (j = 0; j < count; j++) {
-        unsigned long long idle;
-        sds key;
-        robj *o;
-        dictEntry *de;
-
-        de = samples[j];
-        key = dictGetKey(de);
-        /* If the dictionary we are sampling from is not the main
-         * dictionary (but the expires one) we need to lookup the key
-         * again in the key dictionary to obtain the value object. */
-        if (sampledict != keydict) de = dictFind(keydict, key);
-        o = dictGetVal(de);
-        idle = estimateObjectIdleTime(o);
-
-        /* Insert the element inside the pool.
-         * First, find the first empty bucket or the first populated
-         * bucket that has an idle time smaller than our idle time. */
-        k = 0;
-        while (k < MAXMEMORY_EVICTION_POOL_SIZE &&
-               pool[k].key &&
-               pool[k].idle < idle) k++;
-        if (k == 0 && pool[MAXMEMORY_EVICTION_POOL_SIZE-1].key != NULL) {
-            /* Can't insert if the element is < the worst element we have
-             * and there are no empty buckets. */
-            continue;
-        } else if (k < MAXMEMORY_EVICTION_POOL_SIZE && pool[k].key == NULL) {
-            /* Inserting into empty position. No setup needed before insert. */
-        } else {
-            /* Inserting in the middle. Now k points to the first element
-             * greater than the element to insert.  */
-            if (pool[MAXMEMORY_EVICTION_POOL_SIZE-1].key == NULL) {
-                /* Free space on the right? Insert at k shifting
-                 * all the elements from k to end to the right. */
-                memmove(pool+k+1,pool+k,
-                    sizeof(pool[0])*(MAXMEMORY_EVICTION_POOL_SIZE-k-1));
-            } else {
-                /* No free space on right? Insert at k-1 */
-                k--;
-                /* Shift all elements on the left of k (included) to the
-                 * left, so we discard the element with smaller idle time. */
-                sdsfree(pool[0].key);
-                memmove(pool,pool+1,sizeof(pool[0])*k);
-            }
-        }
-        pool[k].key = sdsdup(key);
-        pool[k].idle = idle;
-    }
-    if (samples != _samples) zfree(samples);
-}
-
-int freeMemoryIfNeeded(void) {
-    size_t mem_used, mem_tofree, mem_freed;
-    int slaves = listLength(server.slaves);
-    mstime_t latency, eviction_latency;
-
-    /* Remove the size of slaves output buffers and AOF buffer from the
-     * count of used memory. */
-    mem_used = zmalloc_used_memory();
-    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();
-    }
-
-    /* Check if we are over the memory limit. */
-    if (mem_used <= server.maxmemory) return C_OK;
-
-    if (server.maxmemory_policy == MAXMEMORY_NO_EVICTION)
-        return C_ERR; /* We need to free memory, but policy forbids. */
-
-    /* Compute how much memory we need to free. */
-    mem_tofree = mem_used - server.maxmemory;
-    mem_freed = 0;
-    latencyStartMonitor(latency);
-    while (mem_freed < mem_tofree) {
-        int j, k, keys_freed = 0;
-
-        for (j = 0; j < server.dbnum; j++) {
-            long bestval = 0; /* just to prevent warning */
-            sds bestkey = NULL;
-            dictEntry *de;
-            redisDb *db = server.db+j;
-            dict *dict;
-
-            if (server.maxmemory_policy == MAXMEMORY_ALLKEYS_LRU ||
-                server.maxmemory_policy == MAXMEMORY_ALLKEYS_RANDOM)
-            {
-                dict = server.db[j].dict;
-            } else {
-                dict = server.db[j].expires;
-            }
-            if (dictSize(dict) == 0) continue;
-
-            /* volatile-random and allkeys-random policy */
-            if (server.maxmemory_policy == MAXMEMORY_ALLKEYS_RANDOM ||
-                server.maxmemory_policy == MAXMEMORY_VOLATILE_RANDOM)
-            {
-                de = dictGetRandomKey(dict);
-                bestkey = dictGetKey(de);
-            }
-
-            /* volatile-lru and allkeys-lru policy */
-            else if (server.maxmemory_policy == MAXMEMORY_ALLKEYS_LRU ||
-                server.maxmemory_policy == MAXMEMORY_VOLATILE_LRU)
-            {
-                struct evictionPoolEntry *pool = db->eviction_pool;
-
-                while(bestkey == NULL) {
-                    evictionPoolPopulate(dict, db->dict, db->eviction_pool);
-                    /* Go backward from best to worst element to evict. */
-                    for (k = MAXMEMORY_EVICTION_POOL_SIZE-1; k >= 0; k--) {
-                        if (pool[k].key == NULL) continue;
-                        de = dictFind(dict,pool[k].key);
-
-                        /* Remove the entry from the pool. */
-                        sdsfree(pool[k].key);
-                        /* Shift all elements on its right to left. */
-                        memmove(pool+k,pool+k+1,
-                            sizeof(pool[0])*(MAXMEMORY_EVICTION_POOL_SIZE-k-1));
-                        /* Clear the element on the right which is empty
-                         * since we shifted one position to the left.  */
-                        pool[MAXMEMORY_EVICTION_POOL_SIZE-1].key = NULL;
-                        pool[MAXMEMORY_EVICTION_POOL_SIZE-1].idle = 0;
-
-                        /* If the key exists, is our pick. Otherwise it is
-                         * a ghost and we need to try the next element. */
-                        if (de) {
-                            bestkey = dictGetKey(de);
-                            break;
-                        } else {
-                            /* Ghost... */
-                            continue;
-                        }
-                    }
-                }
-            }
-
-            /* volatile-ttl */
-            else if (server.maxmemory_policy == MAXMEMORY_VOLATILE_TTL) {
-                for (k = 0; k < server.maxmemory_samples; k++) {
-                    sds thiskey;
-                    long thisval;
-
-                    de = dictGetRandomKey(dict);
-                    thiskey = dictGetKey(de);
-                    thisval = (long) dictGetVal(de);
-
-                    /* Expire sooner (minor expire unix timestamp) is better
-                     * candidate for deletion */
-                    if (bestkey == NULL || thisval < bestval) {
-                        bestkey = thiskey;
-                        bestval = thisval;
-                    }
-                }
-            }
-
-            /* Finally remove the selected key. */
-            if (bestkey) {
-                long long delta;
-
-                robj *keyobj = createStringObject(bestkey,sdslen(bestkey));
-                propagateExpire(db,keyobj);
-                /* We compute the amount of memory freed by dbDelete() alone.
-                 * It is possible that actually the memory needed to propagate
-                 * the DEL in AOF and replication link is greater than the one
-                 * we are freeing removing the key, but we can't account for
-                 * that otherwise we would never exit the loop.
-                 *
-                 * AOF and Output buffer memory will be freed eventually so
-                 * we only care about memory used by the key space. */
-                delta = (long long) zmalloc_used_memory();
-                latencyStartMonitor(eviction_latency);
-                dbDelete(db,keyobj);
-                latencyEndMonitor(eviction_latency);
-                latencyAddSampleIfNeeded("eviction-del",eviction_latency);
-                latencyRemoveNestedEvent(latency,eviction_latency);
-                delta -= (long long) zmalloc_used_memory();
-                mem_freed += delta;
-                server.stat_evictedkeys++;
-                notifyKeyspaceEvent(NOTIFY_EVICTED, "evicted",
-                    keyobj, db->id);
-                decrRefCount(keyobj);
-                keys_freed++;
-
-                /* When the memory to free starts to be big enough, we may
-                 * start spending so much time here that is impossible to
-                 * deliver data to the slaves fast enough, so we force the
-                 * transmission here inside the loop. */
-                if (slaves) flushSlavesOutputBuffers();
-            }
-        }
-        if (!keys_freed) {
-            latencyEndMonitor(latency);
-            latencyAddSampleIfNeeded("eviction-cycle",latency);
-            return C_ERR; /* nothing to free... */
-        }
-    }
-    latencyEndMonitor(latency);
-    latencyAddSampleIfNeeded("eviction-cycle",latency);
-    return C_OK;
-}
-
 /* =================================== Main! ================================ */
 
 #ifdef __linux__
@@ -3795,7 +3394,7 @@ void setupSignalHandlers(void) {
 void memtest(size_t megabytes, int passes);
 
 /* Returns 1 if there is --sentinel among the arguments or if
- * argv[0] is exactly "redis-sentinel". */
+ * argv[0] contains "redis-sentinel". */
 int checkForSentinelMode(int argc, char **argv) {
     int j;
 
@@ -3982,6 +3581,7 @@ int main(int argc, char **argv) {
     dictSetHashFunctionSeed(tv.tv_sec^tv.tv_usec^getpid());
     server.sentinel_mode = checkForSentinelMode(argc,argv);
     initServerConfig();
+    moduleInitModulesSystem();
 
     /* Store the executable path and arguments in a safe place in order
      * to be able to restart the server later. */
@@ -4088,6 +3688,7 @@ int main(int argc, char **argv) {
     #ifdef __linux__
         linuxMemoryWarnings();
     #endif
+        moduleLoadFromQueue();
         loadDataFromDisk();
         if (server.cluster_enabled) {
             if (verifyClusterConfigWithData() == C_ERR) {

src/server.h

@@ -33,6 +33,7 @@
 #include "fmacros.h"
 #include "config.h"
 #include "solarisfixes.h"
+#include "rio.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -92,6 +93,7 @@ typedef long long mstime_t; /* millisecond time type. */
 #define AOF_REWRITE_PERC  100
 #define AOF_REWRITE_MIN_SIZE (64*1024*1024)
 #define AOF_REWRITE_ITEMS_PER_CMD 64
+#define AOF_READ_DIFF_INTERVAL_BYTES (1024*10)
 #define CONFIG_DEFAULT_SLOWLOG_LOG_SLOWER_THAN 10000
 #define CONFIG_DEFAULT_SLOWLOG_MAX_LEN 128
 #define CONFIG_DEFAULT_MAX_CLIENTS 10000
@@ -108,6 +110,9 @@ typedef long long mstime_t; /* millisecond time type. */
 #define CONFIG_DEFAULT_PID_FILE "/var/run/redis.pid"
 #define CONFIG_DEFAULT_SYSLOG_IDENT "redis"
 #define CONFIG_DEFAULT_CLUSTER_CONFIG_FILE "nodes.conf"
+#define CONFIG_DEFAULT_CLUSTER_ANNOUNCE_IP NULL         /* Auto detect. */
+#define CONFIG_DEFAULT_CLUSTER_ANNOUNCE_PORT 0          /* Use server.port */
+#define CONFIG_DEFAULT_CLUSTER_ANNOUNCE_BUS_PORT 0      /* Use +10000 offset. */
 #define CONFIG_DEFAULT_DAEMONIZE 0
 #define CONFIG_DEFAULT_UNIX_SOCKET_PERM 0
 #define CONFIG_DEFAULT_TCP_KEEPALIVE 300
@@ -127,9 +132,12 @@ typedef long long mstime_t; /* millisecond time type. */
 #define CONFIG_DEFAULT_REPL_DISABLE_TCP_NODELAY 0
 #define CONFIG_DEFAULT_MAXMEMORY 0
 #define CONFIG_DEFAULT_MAXMEMORY_SAMPLES 5
+#define CONFIG_DEFAULT_LFU_LOG_FACTOR 10
+#define CONFIG_DEFAULT_LFU_DECAY_TIME 1
 #define CONFIG_DEFAULT_AOF_FILENAME "appendonly.aof"
 #define CONFIG_DEFAULT_AOF_NO_FSYNC_ON_REWRITE 0
 #define CONFIG_DEFAULT_AOF_LOAD_TRUNCATED 1
+#define CONFIG_DEFAULT_AOF_USE_RDB_PREAMBLE 0
 #define CONFIG_DEFAULT_ACTIVE_REHASHING 1
 #define CONFIG_DEFAULT_AOF_REWRITE_INCREMENTAL_FSYNC 1
 #define CONFIG_DEFAULT_MIN_SLAVES_TO_WRITE 0
@@ -139,6 +147,10 @@ typedef long long mstime_t; /* millisecond time type. */
 #define CONFIG_BINDADDR_MAX 16
 #define CONFIG_MIN_RESERVED_FDS 32
 #define CONFIG_DEFAULT_LATENCY_MONITOR_THRESHOLD 0
+#define CONFIG_DEFAULT_SLAVE_LAZY_FLUSH 0
+#define CONFIG_DEFAULT_LAZYFREE_LAZY_EVICTION 0
+#define CONFIG_DEFAULT_LAZYFREE_LAZY_EXPIRE 0
+#define CONFIG_DEFAULT_LAZYFREE_LAZY_SERVER_DEL 0
 
 #define ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP 20 /* Loopkups per loop. */
 #define ACTIVE_EXPIRE_CYCLE_FAST_DURATION 1000 /* Microseconds */
@@ -173,68 +185,22 @@ typedef long long mstime_t; /* millisecond time type. */
 
 /* Command flags. Please check the command table defined in the redis.c file
  * for more information about the meaning of every flag. */
-#define CMD_WRITE 1                   /* "w" flag */
-#define CMD_READONLY 2                /* "r" flag */
-#define CMD_DENYOOM 4                 /* "m" flag */
-#define CMD_NOT_USED_1 8              /* no longer used flag */
-#define CMD_ADMIN 16                  /* "a" flag */
-#define CMD_PUBSUB 32                 /* "p" flag */
-#define CMD_NOSCRIPT  64              /* "s" flag */
-#define CMD_RANDOM 128                /* "R" flag */
-#define CMD_SORT_FOR_SCRIPT 256       /* "S" flag */
-#define CMD_LOADING 512               /* "l" flag */
-#define CMD_STALE 1024                /* "t" flag */
-#define CMD_SKIP_MONITOR 2048         /* "M" flag */
-#define CMD_ASKING 4096               /* "k" flag */
-#define CMD_FAST 8192                 /* "F" flag */
-
-/* Object types */
-#define OBJ_STRING 0
-#define OBJ_LIST 1
-#define OBJ_SET 2
-#define OBJ_ZSET 3
-#define OBJ_HASH 4
-
-/* Objects encoding. Some kind of objects like Strings and Hashes can be
- * internally represented in multiple ways. The 'encoding' field of the object
- * is set to one of this fields for this object. */
-#define OBJ_ENCODING_RAW 0     /* Raw representation */
-#define OBJ_ENCODING_INT 1     /* Encoded as integer */
-#define OBJ_ENCODING_HT 2      /* Encoded as hash table */
-#define OBJ_ENCODING_ZIPMAP 3  /* Encoded as zipmap */
-#define OBJ_ENCODING_LINKEDLIST 4 /* Encoded as regular linked list */
-#define OBJ_ENCODING_ZIPLIST 5 /* Encoded as ziplist */
-#define OBJ_ENCODING_INTSET 6  /* Encoded as intset */
-#define OBJ_ENCODING_SKIPLIST 7  /* Encoded as skiplist */
-#define OBJ_ENCODING_EMBSTR 8  /* Embedded sds string encoding */
-#define OBJ_ENCODING_QUICKLIST 9 /* Encoded as linked list of ziplists */
-
-/* Defines related to the dump file format. To store 32 bits lengths for short
- * keys requires a lot of space, so we check the most significant 2 bits of
- * the first byte to interpreter the length:
- *
- * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
- * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
- * 10|000000 [32 bit integer] => if it's 10, a full 32 bit len will follow
- * 11|000000 this means: specially encoded object will follow. The six bits
- *           number specify the kind of object that follows.
- *           See the RDB_ENC_* defines.
- *
- * Lengths up to 63 are stored using a single byte, most DB keys, and may
- * values, will fit inside. */
-#define RDB_6BITLEN 0
-#define RDB_14BITLEN 1
-#define RDB_32BITLEN 2
-#define RDB_ENCVAL 3
-#define RDB_LENERR UINT_MAX
-
-/* When a length of a string object stored on disk has the first two bits
- * set, the remaining two bits specify a special encoding for the object
- * accordingly to the following defines: */
-#define RDB_ENC_INT8 0        /* 8 bit signed integer */
-#define RDB_ENC_INT16 1       /* 16 bit signed integer */
-#define RDB_ENC_INT32 2       /* 32 bit signed integer */
-#define RDB_ENC_LZF 3         /* string compressed with FASTLZ */
+#define CMD_WRITE (1<<0)            /* "w" flag */
+#define CMD_READONLY (1<<1)         /* "r" flag */
+#define CMD_DENYOOM (1<<2)          /* "m" flag */
+#define CMD_MODULE (1<<3)           /* Command exported by module. */
+#define CMD_ADMIN (1<<4)            /* "a" flag */
+#define CMD_PUBSUB (1<<5)           /* "p" flag */
+#define CMD_NOSCRIPT (1<<6)         /* "s" flag */
+#define CMD_RANDOM (1<<7)           /* "R" flag */
+#define CMD_SORT_FOR_SCRIPT (1<<8)  /* "S" flag */
+#define CMD_LOADING (1<<9)          /* "l" flag */
+#define CMD_STALE (1<<10)           /* "t" flag */
+#define CMD_SKIP_MONITOR (1<<11)    /* "M" flag */
+#define CMD_ASKING (1<<12)          /* "k" flag */
+#define CMD_FAST (1<<13)            /* "F" flag */
+#define CMD_MODULE_GETKEYS (1<<14)  /* Use the modules getkeys interface. */
+#define CMD_MODULE_NO_CLUSTER (1<<15) /* Deny on Redis Cluster. */
 
 /* AOF states */
 #define AOF_OFF 0             /* AOF is off */
@@ -272,6 +238,7 @@ typedef long long mstime_t; /* millisecond time type. */
 #define CLIENT_REPLY_SKIP (1<<24)  /* Don't send just this reply. */
 #define CLIENT_LUA_DEBUG (1<<25)  /* Run EVAL in debug mode. */
 #define CLIENT_LUA_DEBUG_SYNC (1<<26)  /* EVAL debugging without fork() */
+#define CLIENT_MODULE (1<<27) /* Non connected client used by some module. */
 
 /* Client block type (btype field in client structure)
  * if CLIENT_BLOCKED flag is set. */
@@ -382,13 +349,24 @@ typedef long long mstime_t; /* millisecond time type. */
 #define SET_OP_DIFF 1
 #define SET_OP_INTER 2
 
-/* Redis maxmemory strategies */
-#define MAXMEMORY_VOLATILE_LRU 0
-#define MAXMEMORY_VOLATILE_TTL 1
-#define MAXMEMORY_VOLATILE_RANDOM 2
-#define MAXMEMORY_ALLKEYS_LRU 3
-#define MAXMEMORY_ALLKEYS_RANDOM 4
-#define MAXMEMORY_NO_EVICTION 5
+/* Redis maxmemory strategies. Instead of using just incremental number
+ * for this defines, we use a set of flags so that testing for certain
+ * properties common to multiple policies is faster. */
+#define MAXMEMORY_FLAG_LRU (1<<0)
+#define MAXMEMORY_FLAG_LFU (1<<1)
+#define MAXMEMORY_FLAG_ALLKEYS (1<<2)
+#define MAXMEMORY_FLAG_NO_SHARED_INTEGERS \
+    (MAXMEMORY_FLAG_LRU|MAXMEMORY_FLAG_LFU)
+
+#define MAXMEMORY_VOLATILE_LRU ((0<<8)|MAXMEMORY_FLAG_LRU)
+#define MAXMEMORY_VOLATILE_LFU ((1<<8)|MAXMEMORY_FLAG_LFU)
+#define MAXMEMORY_VOLATILE_TTL (2<<8)
+#define MAXMEMORY_VOLATILE_RANDOM (3<<8)
+#define MAXMEMORY_ALLKEYS_LRU ((4<<8)|MAXMEMORY_FLAG_LRU|MAXMEMORY_FLAG_ALLKEYS)
+#define MAXMEMORY_ALLKEYS_LFU ((5<<8)|MAXMEMORY_FLAG_LFU|MAXMEMORY_FLAG_ALLKEYS)
+#define MAXMEMORY_ALLKEYS_RANDOM ((6<<8)|MAXMEMORY_FLAG_ALLKEYS)
+#define MAXMEMORY_NO_EVICTION (7<<8)
+
 #define CONFIG_DEFAULT_MAXMEMORY_POLICY MAXMEMORY_NO_EVICTION
 
 /* Scripting */
@@ -457,13 +435,124 @@ typedef long long mstime_t; /* millisecond time type. */
 /* A redis object, that is a type able to hold a string / list / set */
 
 /* The actual Redis Object */
+#define OBJ_STRING 0
+#define OBJ_LIST 1
+#define OBJ_SET 2
+#define OBJ_ZSET 3
+#define OBJ_HASH 4
+
+/* The "module" object type is a special one that signals that the object
+ * is one directly managed by a Redis module. In this case the value points
+ * to a moduleValue struct, which contains the object value (which is only
+ * handled by the module itself) and the RedisModuleType struct which lists
+ * function pointers in order to serialize, deserialize, AOF-rewrite and
+ * free the object.
+ *
+ * Inside the RDB file, module types are encoded as OBJ_MODULE followed
+ * by a 64 bit module type ID, which has a 54 bits module-specific signature
+ * in order to dispatch the loading to the right module, plus a 10 bits
+ * encoding version. */
+#define OBJ_MODULE 5
+
+/* Extract encver / signature from a module type ID. */
+#define REDISMODULE_TYPE_ENCVER_BITS 10
+#define REDISMODULE_TYPE_ENCVER_MASK ((1<<REDISMODULE_TYPE_ENCVER_BITS)-1)
+#define REDISMODULE_TYPE_ENCVER(id) (id & REDISMODULE_TYPE_ENCVER_MASK)
+#define REDISMODULE_TYPE_SIGN(id) ((id & ~((uint64_t)REDISMODULE_TYPE_ENCVER_MASK)) >>REDISMODULE_TYPE_ENCVER_BITS)
+
+struct RedisModule;
+struct RedisModuleIO;
+struct RedisModuleDigest;
+struct RedisModuleCtx;
+struct redisObject;
+
+/* Each module type implementation should export a set of methods in order
+ * to serialize and deserialize the value in the RDB file, rewrite the AOF
+ * log, create the digest for "DEBUG DIGEST", and free the value when a key
+ * is deleted. */
+typedef void *(*moduleTypeLoadFunc)(struct RedisModuleIO *io, int encver);
+typedef void (*moduleTypeSaveFunc)(struct RedisModuleIO *io, void *value);
+typedef void (*moduleTypeRewriteFunc)(struct RedisModuleIO *io, struct redisObject *key, void *value);
+typedef void (*moduleTypeDigestFunc)(struct RedisModuleDigest *digest, void *value);
+typedef void (*moduleTypeFreeFunc)(void *value);
+
+/* The module type, which is referenced in each value of a given type, defines
+ * the methods and links to the module exporting the type. */
+typedef struct RedisModuleType {
+    uint64_t id; /* Higher 54 bits of type ID + 10 lower bits of encoding ver. */
+    struct RedisModule *module;
+    moduleTypeLoadFunc rdb_load;
+    moduleTypeSaveFunc rdb_save;
+    moduleTypeRewriteFunc aof_rewrite;
+    moduleTypeDigestFunc digest;
+    moduleTypeFreeFunc free;
+    char name[10]; /* 9 bytes name + null term. Charset: A-Z a-z 0-9 _- */
+} moduleType;
+
+/* In Redis objects 'robj' structures of type OBJ_MODULE, the value pointer
+ * is set to the following structure, referencing the moduleType structure
+ * in order to work with the value, and at the same time providing a raw
+ * pointer to the value, as created by the module commands operating with
+ * the module type.
+ *
+ * So for example in order to free such a value, it is possible to use
+ * the following code:
+ *
+ *  if (robj->type == OBJ_MODULE) {
+ *      moduleValue *mt = robj->ptr;
+ *      mt->type->free(mt->value);
+ *      zfree(mt); // We need to release this in-the-middle struct as well.
+ *  }
+ */
+typedef struct moduleValue {
+    moduleType *type;
+    void *value;
+} moduleValue;
+
+/* This is a wrapper for the 'rio' streams used inside rdb.c in Redis, so that
+ * the user does not have to take the total count of the written bytes nor
+ * to care about error conditions. */
+typedef struct RedisModuleIO {
+    size_t bytes;       /* Bytes read / written so far. */
+    rio *rio;           /* Rio stream. */
+    moduleType *type;   /* Module type doing the operation. */
+    int error;          /* True if error condition happened. */
+    struct RedisModuleCtx *ctx; /* Optional context, see RM_GetContextFromIO()*/
+} RedisModuleIO;
+
+#define moduleInitIOContext(iovar,mtype,rioptr) do { \
+    iovar.rio = rioptr; \
+    iovar.type = mtype; \
+    iovar.bytes = 0; \
+    iovar.error = 0; \
+    iovar.ctx = NULL; \
+} while(0);
+
+/* Objects encoding. Some kind of objects like Strings and Hashes can be
+ * internally represented in multiple ways. The 'encoding' field of the object
+ * is set to one of this fields for this object. */
+#define OBJ_ENCODING_RAW 0     /* Raw representation */
+#define OBJ_ENCODING_INT 1     /* Encoded as integer */
+#define OBJ_ENCODING_HT 2      /* Encoded as hash table */
+#define OBJ_ENCODING_ZIPMAP 3  /* Encoded as zipmap */
+#define OBJ_ENCODING_LINKEDLIST 4 /* No longer used: old list encoding. */
+#define OBJ_ENCODING_ZIPLIST 5 /* Encoded as ziplist */
+#define OBJ_ENCODING_INTSET 6  /* Encoded as intset */
+#define OBJ_ENCODING_SKIPLIST 7  /* Encoded as skiplist */
+#define OBJ_ENCODING_EMBSTR 8  /* Embedded sds string encoding */
+#define OBJ_ENCODING_QUICKLIST 9 /* Encoded as linked list of ziplists */
+
 #define LRU_BITS 24
 #define LRU_CLOCK_MAX ((1<<LRU_BITS)-1) /* Max value of obj->lru */
 #define LRU_CLOCK_RESOLUTION 1000 /* LRU clock resolution in ms */
+
+#define OBJ_SHARED_REFCOUNT INT_MAX
 typedef struct redisObject {
     unsigned type:4;
     unsigned encoding:4;
-    unsigned lru:LRU_BITS; /* lru time (relative to server.lruclock) */
+    unsigned lru:LRU_BITS; /* LRU time (relative to server.lruclock) or
+                            * LFU data (least significant 8 bits frequency
+                            * and most significant 16 bits decreas time). */
     int refcount;
     void *ptr;
 } robj;
@@ -485,18 +574,7 @@ typedef struct redisObject {
     _var.ptr = _ptr; \
 } while(0)
 
-/* To improve the quality of the LRU approximation we take a set of keys
- * that are good candidate for eviction across freeMemoryIfNeeded() calls.
- *
- * Entries inside the eviciton pool are taken ordered by idle time, putting
- * greater idle times to the right (ascending order).
- *
- * Empty entries have the key pointer set to NULL. */
-#define MAXMEMORY_EVICTION_POOL_SIZE 16
-struct evictionPoolEntry {
-    unsigned long long idle;    /* Object idle time. */
-    sds key;                    /* Key name. */
-};
+struct evictionPoolEntry; /* Defined in evict.c */
 
 /* Redis database representation. There are multiple databases identified
  * by integers from 0 (the default database) up to the max configured
@@ -504,10 +582,9 @@ struct evictionPoolEntry {
 typedef struct redisDb {
     dict *dict;                 /* The keyspace for this DB */
     dict *expires;              /* Timeout of keys with a timeout set */
-    dict *blocking_keys;        /* Keys with clients waiting for data (BLPOP) */
+    dict *blocking_keys;        /* Keys with clients waiting for data (BLPOP)*/
     dict *ready_keys;           /* Blocked keys that received a PUSH */
     dict *watched_keys;         /* WATCHED keys for MULTI/EXEC CAS */
-    struct evictionPoolEntry *eviction_pool;    /* Eviction pool of keys */
     int id;                     /* Database ID */
     long long avg_ttl;          /* Average TTL, just for stats */
 } redisDb;
@@ -566,7 +643,6 @@ typedef struct client {
     uint64_t id;            /* Client incremental unique ID. */
     int fd;                 /* Client socket. */
     redisDb *db;            /* Pointer to currently SELECTed DB. */
-    int dictid;             /* ID of the currently SELECTed DB. */
     robj *name;             /* As set by CLIENT SETNAME. */
     sds querybuf;           /* Buffer we use to accumulate client queries. */
     size_t querybuf_peak;   /* Recent (100ms or more) peak of querybuf size. */
@@ -620,6 +696,12 @@ struct saveparam {
     int changes;
 };
 
+struct moduleLoadQueueEntry {
+    sds path;
+    int argc;
+    robj **argv;
+};
+
 struct sharedObjectsStruct {
     robj *crlf, *ok, *err, *emptybulk, *czero, *cone, *cnegone, *pong, *space,
     *colon, *nullbulk, *nullmultibulk, *queued,
@@ -627,17 +709,18 @@ struct sharedObjectsStruct {
     *outofrangeerr, *noscripterr, *loadingerr, *slowscripterr, *bgsaveerr,
     *masterdownerr, *roslaveerr, *execaborterr, *noautherr, *noreplicaserr,
     *busykeyerr, *oomerr, *plus, *messagebulk, *pmessagebulk, *subscribebulk,
-    *unsubscribebulk, *psubscribebulk, *punsubscribebulk, *del, *rpop, *lpop,
-    *lpush, *emptyscan, *minstring, *maxstring,
+    *unsubscribebulk, *psubscribebulk, *punsubscribebulk, *del, *unlink,
+    *rpop, *lpop, *lpush, *emptyscan,
     *select[PROTO_SHARED_SELECT_CMDS],
     *integers[OBJ_SHARED_INTEGERS],
     *mbulkhdr[OBJ_SHARED_BULKHDR_LEN], /* "*<value>\r\n" */
     *bulkhdr[OBJ_SHARED_BULKHDR_LEN];  /* "$<value>\r\n" */
+    sds minstring, maxstring;
 };
 
 /* ZSETs use a specialized version of Skiplists */
 typedef struct zskiplistNode {
-    robj *obj;
+    sds ele;
     double score;
     struct zskiplistNode *backward;
     struct zskiplistLevel {
@@ -689,6 +772,31 @@ typedef struct redisOpArray {
     int numops;
 } redisOpArray;
 
+/* This structure is returned by the getMemoryOverheadData() function in
+ * order to return memory overhead information. */
+struct redisMemOverhead {
+    size_t peak_allocated;
+    size_t total_allocated;
+    size_t startup_allocated;
+    size_t repl_backlog;
+    size_t clients_slaves;
+    size_t clients_normal;
+    size_t aof_buffer;
+    size_t overhead_total;
+    size_t dataset;
+    size_t total_keys;
+    size_t bytes_per_key;
+    float dataset_perc;
+    float peak_perc;
+    float fragmentation;
+    size_t num_dbs;
+    struct {
+        size_t dbid;
+        size_t overhead_ht_main;
+        size_t overhead_ht_expires;
+    } *db;
+};
+
 /*-----------------------------------------------------------------------------
  * Global server state
  *----------------------------------------------------------------------------*/
@@ -701,6 +809,10 @@ struct clusterState;
 #undef hz
 #endif
 
+#define CHILD_INFO_MAGIC 0xC17DDA7A12345678LL
+#define CHILD_INFO_TYPE_RDB 0
+#define CHILD_INFO_TYPE_AOF 1
+
 struct redisServer {
     /* General */
     pid_t pid;                  /* Main process pid. */
@@ -721,6 +833,10 @@ struct redisServer {
     int cronloops;              /* Number of times the cron function run */
     char runid[CONFIG_RUN_ID_SIZE+1];  /* ID always different at every exec. */
     int sentinel_mode;          /* True if this instance is a Sentinel. */
+    size_t initial_memory_usage; /* Bytes used after initialization. */
+    /* Modules */
+    dict *moduleapi;            /* Exported APIs dictionary for modules. */
+    list *loadmodule_queue;     /* List of modules to load at startup. */
     /* Networking */
     int port;                   /* TCP listening port */
     int tcp_backlog;            /* TCP listen() backlog */
@@ -775,6 +891,8 @@ struct redisServer {
     size_t resident_set_size;       /* RSS sampled in serverCron(). */
     long long stat_net_input_bytes; /* Bytes read from network. */
     long long stat_net_output_bytes; /* Bytes written to network. */
+    size_t stat_rdb_cow_bytes;      /* Copy on write bytes during RDB saving. */
+    size_t stat_aof_cow_bytes;      /* Copy on write bytes during AOF rewrite. */
     /* The following two are used to track instantaneous metrics, like
      * number of operations per second, network traffic. */
     struct {
@@ -819,6 +937,7 @@ struct redisServer {
     int aof_last_write_status;      /* C_OK or C_ERR */
     int aof_last_write_errno;       /* Valid if aof_last_write_status is ERR */
     int aof_load_truncated;         /* Don't stop on unexpected AOF EOF. */
+    int aof_use_rdb_preamble;       /* Use RDB preamble on AOF rewrites. */
     /* AOF pipes used to communicate between parent and child during rewrite. */
     int aof_pipe_write_data_to_child;
     int aof_pipe_read_data_from_parent;
@@ -848,6 +967,13 @@ struct redisServer {
     int stop_writes_on_bgsave_err;  /* Don't allow writes if can't BGSAVE */
     int rdb_pipe_write_result_to_parent; /* RDB pipes used to return the state */
     int rdb_pipe_read_result_from_child; /* of each slave in diskless SYNC. */
+    /* Pipe and data structures for child -> parent info sharing. */
+    int child_info_pipe[2];         /* Pipe used to write the child_info_data. */
+    struct {
+        int process_type;           /* AOF or RDB child? */
+        size_t cow_size;            /* Copy on write size. */
+        unsigned long long magic;   /* Magic value to make sure data is valid. */
+    } child_info_data;
     /* Propagation of commands in AOF / replication */
     redisOpArray also_propagate;    /* Additional command to propagate. */
     /* Logging */
@@ -899,6 +1025,7 @@ struct redisServer {
     char *slave_announce_ip;        /* Give the master this ip address. */
     char repl_master_runid[CONFIG_RUN_ID_SIZE+1];  /* Master run id for PSYNC.*/
     long long repl_master_initial_offset;         /* Master PSYNC offset. */
+    int repl_slave_lazy_flush;          /* Lazy FLUSHALL before loading DB? */
     /* Replication script cache. */
     dict *repl_scriptcache_dict;        /* SHA1 all slaves are aware of. */
     list *repl_scriptcache_fifo;        /* First in, first out LRU eviction. */
@@ -911,6 +1038,8 @@ struct redisServer {
     unsigned long long maxmemory;   /* Max number of memory bytes to use */
     int maxmemory_policy;           /* Policy for key eviction */
     int maxmemory_samples;          /* Pricision of random sampling */
+    unsigned int lfu_log_factor;    /* LFU logarithmic counter factor. */
+    unsigned int lfu_decay_time;    /* LFU counter decay factor. */
     /* Blocked clients */
     unsigned int bpop_blocked_clients; /* Number of clients blocked by lists */
     list *unblocked_clients; /* list of clients to unblock before next loop */
@@ -932,8 +1061,8 @@ struct redisServer {
     int list_max_ziplist_size;
     int list_compress_depth;
     /* time cache */
-    time_t unixtime;        /* Unix time sampled every cron cycle. */
-    long long mstime;       /* Like 'unixtime' but with milliseconds resolution. */
+    time_t unixtime;    /* Unix time sampled every cron cycle. */
+    long long mstime;   /* Like 'unixtime' but with milliseconds resolution. */
     /* Pubsub */
     dict *pubsub_channels;  /* Map channels to list of subscribed clients */
     list *pubsub_patterns;  /* A list of pubsub_patterns */
@@ -948,6 +1077,9 @@ struct redisServer {
     int cluster_slave_validity_factor; /* Slave max data age for failover. */
     int cluster_require_full_coverage; /* If true, put the cluster down if
                                           there is at least an uncovered slot.*/
+    char *cluster_announce_ip;  /* IP address to announce on cluster bus. */
+    int cluster_announce_port;     /* base port to announce on cluster bus. */
+    int cluster_announce_bus_port; /* bus port to announce on cluster bus. */
     /* Scripting */
     lua_State *lua; /* The Lua interpreter. We use just one for all clients */
     client *lua_client;   /* The "fake client" to query Redis from Lua */
@@ -966,12 +1098,16 @@ struct redisServer {
                              execution. */
     int lua_kill;         /* Kill the script if true. */
     int lua_always_replicate_commands; /* Default replication type. */
+    /* Lazy free */
+    int lazyfree_lazy_eviction;
+    int lazyfree_lazy_expire;
+    int lazyfree_lazy_server_del;
     /* Latency monitor */
     long long latency_monitor_threshold;
     dict *latency_events;
     /* Assert & bug reporting */
-    char *assert_failed;
-    char *assert_file;
+    const char *assert_failed;
+    const char *assert_file;
     int assert_line;
     int bug_report_start; /* True if bug report header was already logged. */
     int watchdog_period;  /* Software watchdog period in ms. 0 = off */
@@ -1065,6 +1201,7 @@ typedef struct {
 
 extern struct redisServer server;
 extern struct sharedObjectsStruct shared;
+extern dictType objectKeyPointerValueDictType;
 extern dictType setDictType;
 extern dictType zsetDictType;
 extern dictType clusterNodesDictType;
@@ -1074,11 +1211,22 @@ extern dictType shaScriptObjectDictType;
 extern double R_Zero, R_PosInf, R_NegInf, R_Nan;
 extern dictType hashDictType;
 extern dictType replScriptCacheDictType;
+extern dictType keyptrDictType;
+extern dictType modulesDictType;
 
 /*-----------------------------------------------------------------------------
  * Functions prototypes
  *----------------------------------------------------------------------------*/
 
+/* Modules */
+void moduleInitModulesSystem(void);
+int moduleLoad(const char *path, void **argv, int argc);
+void moduleLoadFromQueue(void);
+int *moduleGetCommandKeysViaAPI(struct redisCommand *cmd, robj **argv, int argc, int *numkeys);
+moduleType *moduleTypeLookupModuleByID(uint64_t id);
+void moduleTypeNameByID(char *name, uint64_t moduleid);
+void moduleFreeContext(struct RedisModuleCtx *ctx);
+
 /* Utils */
 long long ustime(void);
 long long mstime(void);
@@ -1116,6 +1264,8 @@ void addReplyHumanLongDouble(client *c, long double d);
 void addReplyLongLong(client *c, long long ll);
 void addReplyMultiBulkLen(client *c, long length);
 void copyClientOutputBuffer(client *dst, client *src);
+size_t sdsZmallocSize(sds s);
+size_t getStringObjectSdsUsedMemory(robj *o);
 void *dupClientReplyValue(void *o);
 void getClientsMaxBuffers(unsigned long *longest_output_list,
                           unsigned long *biggest_input_buffer);
@@ -1156,7 +1306,7 @@ void addReplyStatusFormat(client *c, const char *fmt, ...);
 void listTypeTryConversion(robj *subject, robj *value);
 void listTypePush(robj *subject, robj *value, int where);
 robj *listTypePop(robj *subject, int where);
-unsigned long listTypeLength(robj *subject);
+unsigned long listTypeLength(const robj *subject);
 listTypeIterator *listTypeInitIterator(robj *subject, long index, unsigned char direction);
 void listTypeReleaseIterator(listTypeIterator *li);
 int listTypeNext(listTypeIterator *li, listTypeEntry *entry);
@@ -1185,6 +1335,7 @@ void execCommandPropagateMulti(client *c);
 void decrRefCount(robj *o);
 void decrRefCountVoid(void *o);
 void incrRefCount(robj *o);
+robj *makeObjectShared(robj *o);
 robj *resetRefCount(robj *obj);
 void freeStringObject(robj *o);
 void freeListObject(robj *o);
@@ -1195,7 +1346,8 @@ robj *createObject(int type, void *ptr);
 robj *createStringObject(const char *ptr, size_t len);
 robj *createRawStringObject(const char *ptr, size_t len);
 robj *createEmbeddedStringObject(const char *ptr, size_t len);
-robj *dupStringObject(robj *o);
+robj *dupStringObject(const robj *o);
+int isSdsRepresentableAsLongLong(sds s, long long *llval);
 int isObjectRepresentableAsLongLong(robj *o, long long *llongval);
 robj *tryObjectEncoding(robj *o);
 robj *getDecodedObject(robj *o);
@@ -1209,10 +1361,12 @@ robj *createIntsetObject(void);
 robj *createHashObject(void);
 robj *createZsetObject(void);
 robj *createZsetZiplistObject(void);
+robj *createModuleObject(moduleType *mt, void *value);
 int getLongFromObjectOrReply(client *c, robj *o, long *target, const char *msg);
 int checkType(client *c, robj *o, int type);
 int getLongLongFromObjectOrReply(client *c, robj *o, long long *target, const char *msg);
 int getDoubleFromObjectOrReply(client *c, robj *o, double *target, const char *msg);
+int getDoubleFromObject(const robj *o, double *target);
 int getLongLongFromObject(robj *o, long long *target);
 int getLongDoubleFromObject(robj *o, long double *target);
 int getLongDoubleFromObjectOrReply(client *c, robj *o, long double *target, const char *msg);
@@ -1259,6 +1413,7 @@ void stopLoading(void);
 
 /* RDB persistence */
 #include "rdb.h"
+int rdbSaveRio(rio *rdb, int *error, int flags);
 
 /* AOF persistence */
 void flushAppendOnlyFile(int force);
@@ -1271,9 +1426,31 @@ int startAppendOnly(void);
 void backgroundRewriteDoneHandler(int exitcode, int bysignal);
 void aofRewriteBufferReset(void);
 unsigned long aofRewriteBufferSize(void);
+ssize_t aofReadDiffFromParent(void);
+
+/* Child info */
+void openChildInfoPipe(void);
+void closeChildInfoPipe(void);
+void sendChildInfo(int process_type);
+void receiveChildInfo(void);
 
 /* Sorted sets data type */
 
+/* Input flags. */
+#define ZADD_NONE 0
+#define ZADD_INCR (1<<0)    /* Increment the score instead of setting it. */
+#define ZADD_NX (1<<1)      /* Don't touch elements not already existing. */
+#define ZADD_XX (1<<2)      /* Only touch elements already exisitng. */
+
+/* Output flags. */
+#define ZADD_NOP (1<<3)     /* Operation not performed because of conditionals.*/
+#define ZADD_NAN (1<<4)     /* Only touch elements already exisitng. */
+#define ZADD_ADDED (1<<5)   /* The element was new and was added. */
+#define ZADD_UPDATED (1<<6) /* The element already existed, score updated. */
+
+/* Flags only used by the ZADD command but not by zsetAdd() API: */
+#define ZADD_CH (1<<16)      /* Return num of elements added or updated. */
+
 /* Struct to hold a inclusive/exclusive range spec by score comparison. */
 typedef struct {
     double min, max;
@@ -1282,25 +1459,43 @@ typedef struct {
 
 /* Struct to hold an inclusive/exclusive range spec by lexicographic comparison. */
 typedef struct {
-    robj *min, *max;  /* May be set to shared.(minstring|maxstring) */
+    sds min, max;     /* May be set to shared.(minstring|maxstring) */
     int minex, maxex; /* are min or max exclusive? */
 } zlexrangespec;
 
 zskiplist *zslCreate(void);
 void zslFree(zskiplist *zsl);
-zskiplistNode *zslInsert(zskiplist *zsl, double score, robj *obj);
-unsigned char *zzlInsert(unsigned char *zl, robj *ele, double score);
-int zslDelete(zskiplist *zsl, double score, robj *obj);
+zskiplistNode *zslInsert(zskiplist *zsl, double score, sds ele);
+unsigned char *zzlInsert(unsigned char *zl, sds ele, double score);
+int zslDelete(zskiplist *zsl, double score, sds ele, zskiplistNode **node);
 zskiplistNode *zslFirstInRange(zskiplist *zsl, zrangespec *range);
 zskiplistNode *zslLastInRange(zskiplist *zsl, zrangespec *range);
 double zzlGetScore(unsigned char *sptr);
 void zzlNext(unsigned char *zl, unsigned char **eptr, unsigned char **sptr);
 void zzlPrev(unsigned char *zl, unsigned char **eptr, unsigned char **sptr);
-unsigned int zsetLength(robj *zobj);
+unsigned char *zzlFirstInRange(unsigned char *zl, zrangespec *range);
+unsigned char *zzlLastInRange(unsigned char *zl, zrangespec *range);
+unsigned int zsetLength(const robj *zobj);
 void zsetConvert(robj *zobj, int encoding);
 void zsetConvertToZiplistIfNeeded(robj *zobj, size_t maxelelen);
-int zsetScore(robj *zobj, robj *member, double *score);
-unsigned long zslGetRank(zskiplist *zsl, double score, robj *o);
+int zsetScore(robj *zobj, sds member, double *score);
+unsigned long zslGetRank(zskiplist *zsl, double score, sds o);
+int zsetAdd(robj *zobj, double score, sds ele, int *flags, double *newscore);
+long zsetRank(robj *zobj, sds ele, int reverse);
+int zsetDel(robj *zobj, sds ele);
+sds ziplistGetObject(unsigned char *sptr);
+int zslValueGteMin(double value, zrangespec *spec);
+int zslValueLteMax(double value, zrangespec *spec);
+void zslFreeLexRange(zlexrangespec *spec);
+int zslParseLexRange(robj *min, robj *max, zlexrangespec *spec);
+unsigned char *zzlFirstInLexRange(unsigned char *zl, zlexrangespec *range);
+unsigned char *zzlLastInLexRange(unsigned char *zl, zlexrangespec *range);
+zskiplistNode *zslFirstInLexRange(zskiplist *zsl, zlexrangespec *range);
+zskiplistNode *zslLastInLexRange(zskiplist *zsl, zlexrangespec *range);
+int zzlLexValueGteMin(unsigned char *p, zlexrangespec *spec);
+int zzlLexValueLteMax(unsigned char *p, zlexrangespec *spec);
+int zslLexValueGteMin(sds value, zlexrangespec *spec);
+int zslLexValueLteMax(sds value, zlexrangespec *spec);
 
 /* Core functions */
 int freeMemoryIfNeeded(void);
@@ -1336,6 +1531,8 @@ void updateCachedTime(void);
 void resetServerStats(void);
 unsigned int getLRUClock(void);
 const char *evictPolicyToString(void);
+struct redisMemOverhead *getMemoryOverheadData(void);
+void freeMemoryOverheadData(struct redisMemOverhead *mh);
 
 #define RESTART_SERVER_NONE 0
 #define RESTART_SERVER_GRACEFULLY (1<<0)     /* Do proper shutdown. */
@@ -1343,28 +1540,30 @@ const char *evictPolicyToString(void);
 int restartServer(int flags, mstime_t delay);
 
 /* Set data type */
-robj *setTypeCreate(robj *value);
-int setTypeAdd(robj *subject, robj *value);
-int setTypeRemove(robj *subject, robj *value);
-int setTypeIsMember(robj *subject, robj *value);
+robj *setTypeCreate(sds value);
+int setTypeAdd(robj *subject, sds value);
+int setTypeRemove(robj *subject, sds value);
+int setTypeIsMember(robj *subject, sds value);
 setTypeIterator *setTypeInitIterator(robj *subject);
 void setTypeReleaseIterator(setTypeIterator *si);
-int setTypeNext(setTypeIterator *si, robj **objele, int64_t *llele);
-robj *setTypeNextObject(setTypeIterator *si);
-int setTypeRandomElement(robj *setobj, robj **objele, int64_t *llele);
+int setTypeNext(setTypeIterator *si, sds *sdsele, int64_t *llele);
+sds setTypeNextObject(setTypeIterator *si);
+int setTypeRandomElement(robj *setobj, sds *sdsele, int64_t *llele);
 unsigned long setTypeRandomElements(robj *set, unsigned long count, robj *aux_set);
-unsigned long setTypeSize(robj *subject);
+unsigned long setTypeSize(const robj *subject);
 void setTypeConvert(robj *subject, int enc);
 
 /* Hash data type */
+#define HASH_SET_TAKE_FIELD (1<<0)
+#define HASH_SET_TAKE_VALUE (1<<1)
+#define HASH_SET_COPY 0
+
 void hashTypeConvert(robj *o, int enc);
 void hashTypeTryConversion(robj *subject, robj **argv, int start, int end);
 void hashTypeTryObjectEncoding(robj *subject, robj **o1, robj **o2);
-robj *hashTypeGetObject(robj *o, robj *key);
-int hashTypeExists(robj *o, robj *key);
-int hashTypeSet(robj *o, robj *key, robj *value);
-int hashTypeDelete(robj *o, robj *key);
-unsigned long hashTypeLength(robj *o);
+int hashTypeExists(robj *o, sds key);
+int hashTypeDelete(robj *o, sds key);
+unsigned long hashTypeLength(const robj *o);
 hashTypeIterator *hashTypeInitIterator(robj *subject);
 void hashTypeReleaseIterator(hashTypeIterator *hi);
 int hashTypeNext(hashTypeIterator *hi);
@@ -1372,9 +1571,12 @@ void hashTypeCurrentFromZiplist(hashTypeIterator *hi, int what,
                                 unsigned char **vstr,
                                 unsigned int *vlen,
                                 long long *vll);
-void hashTypeCurrentFromHashTable(hashTypeIterator *hi, int what, robj **dst);
-robj *hashTypeCurrentObject(hashTypeIterator *hi, int what);
+sds hashTypeCurrentFromHashTable(hashTypeIterator *hi, int what);
+void hashTypeCurrentObject(hashTypeIterator *hi, int what, unsigned char **vstr, unsigned int *vlen, long long *vll);
+sds hashTypeCurrentObjectNewSds(hashTypeIterator *hi, int what);
 robj *hashTypeLookupWriteOrCreate(client *c, robj *key);
+robj *hashTypeGetValueObject(robj *o, sds field);
+int hashTypeSet(robj *o, sds field, sds value, int flags);
 
 /* Pub / Sub */
 int pubsubUnsubscribeAllChannels(client *c, int notify);
@@ -1398,7 +1600,7 @@ int rewriteConfig(char *path);
 
 /* db.c -- Keyspace access API */
 int removeExpire(redisDb *db, robj *key);
-void propagateExpire(redisDb *db, robj *key);
+void propagateExpire(redisDb *db, robj *key, int lazy);
 int expireIfNeeded(redisDb *db, robj *key);
 long long getExpire(redisDb *db, robj *key);
 void setExpire(redisDb *db, robj *key, long long when);
@@ -1415,9 +1617,14 @@ void dbOverwrite(redisDb *db, robj *key, robj *val);
 void setKey(redisDb *db, robj *key, robj *val);
 int dbExists(redisDb *db, robj *key);
 robj *dbRandomKey(redisDb *db);
+int dbSyncDelete(redisDb *db, robj *key);
 int dbDelete(redisDb *db, robj *key);
 robj *dbUnshareStringValue(redisDb *db, robj *key, robj *o);
-long long emptyDb(void(callback)(void*));
+
+#define EMPTYDB_NO_FLAGS 0      /* No flags. */
+#define EMPTYDB_ASYNC (1<<0)    /* Reclaim memory in another thread. */
+long long emptyDb(int dbnum, int flags, void(callback)(void*));
+
 int selectDb(client *c, int id);
 void signalModifiedKey(redisDb *db, robj *key);
 void signalFlushedDb(int dbid);
@@ -1427,6 +1634,13 @@ unsigned int delKeysInSlot(unsigned int hashslot);
 int verifyClusterConfigWithData(void);
 void scanGenericCommand(client *c, robj *o, unsigned long cursor);
 int parseScanCursorOrReply(client *c, robj *o, unsigned long *cursor);
+void slotToKeyAdd(robj *key);
+void slotToKeyDel(robj *key);
+void slotToKeyFlush(void);
+int dbAsyncDelete(redisDb *db, robj *key);
+void emptyDbAsync(redisDb *db);
+void slotToKeyFlushAsync(void);
+size_t lazyfreeGetPendingObjectsCount(void);
 
 /* API to get key arguments from commands */
 int *getKeysFromCommand(struct redisCommand *cmd, robj **argv, int argc, int *numkeys);
@@ -1470,6 +1684,15 @@ void replyToBlockedClientTimedOut(client *c);
 int getTimeoutFromObjectOrReply(client *c, robj *object, mstime_t *timeout, int unit);
 void disconnectAllBlockedClients(void);
 
+/* expire.c -- Handling of expired keys */
+void activeExpireCycle(int type);
+
+/* evict.c -- maxmemory handling and LRU eviction. */
+void evictionPoolAlloc(void);
+#define LFU_INIT_VAL 5
+unsigned long LFUGetTimeInMinutes(void);
+uint8_t LFULogIncr(uint8_t value);
+
 /* Git SHA1 */
 char *redisGitSHA1(void);
 char *redisGitDirty(void);
@@ -1486,6 +1709,7 @@ void setexCommand(client *c);
 void psetexCommand(client *c);
 void getCommand(client *c);
 void delCommand(client *c);
+void unlinkCommand(client *c);
 void existsCommand(client *c);
 void setbitCommand(client *c);
 void getbitCommand(client *c);
@@ -1621,6 +1845,7 @@ void readonlyCommand(client *c);
 void readwriteCommand(client *c);
 void dumpCommand(client *c);
 void objectCommand(client *c);
+void memoryCommand(client *c);
 void clientCommand(client *c);
 void evalCommand(client *c);
 void evalShaCommand(client *c);
@@ -1645,6 +1870,7 @@ void pfcountCommand(client *c);
 void pfmergeCommand(client *c);
 void pfdebugCommand(client *c);
 void latencyCommand(client *c);
+void moduleCommand(client *c);
 void securityWarningCommand(client *c);
 
 #if defined(__GNUC__)
@@ -1655,11 +1881,11 @@ void *realloc(void *ptr, size_t size) __attribute__ ((deprecated));
 #endif
 
 /* Debugging stuff */
-void _serverAssertWithInfo(client *c, robj *o, char *estr, char *file, int line);
-void _serverAssert(char *estr, char *file, int line);
-void _serverPanic(char *msg, char *file, int line);
+void _serverAssertWithInfo(const client *c, const robj *o, const char *estr, const char *file, int line);
+void _serverAssert(const char *estr, const char *file, int line);
+void _serverPanic(const char *msg, const char *file, int line);
 void bugReportStart(void);
-void serverLogObjectDebugInfo(robj *o);
+void serverLogObjectDebugInfo(const robj *o);
 void sigsegvHandler(int sig, siginfo_t *info, void *secret);
 sds genRedisInfoString(char *section);
 void enableWatchdog(int period);

src/sort.c

@@ -112,9 +112,9 @@ robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
     if (fieldobj) {
         if (o->type != OBJ_HASH) goto noobj;
 
-        /* Retrieve value from hash by the field name. This operation
-         * already increases the refcount of the returned object. */
-        o = hashTypeGetObject(o, fieldobj);
+        /* Retrieve value from hash by the field name. The returend object
+         * is a new object with refcount already incremented. */
+        o = hashTypeGetValueObject(o, fieldobj->ptr);
     } else {
         if (o->type != OBJ_STRING) goto noobj;
 
@@ -380,9 +380,9 @@ void sortCommand(client *c) {
         listTypeReleaseIterator(li);
     } else if (sortval->type == OBJ_SET) {
         setTypeIterator *si = setTypeInitIterator(sortval);
-        robj *ele;
-        while((ele = setTypeNextObject(si)) != NULL) {
-            vector[j].obj = ele;
+        sds sdsele;
+        while((sdsele = setTypeNextObject(si)) != NULL) {
+            vector[j].obj = createObject(OBJ_STRING,sdsele);
             vector[j].u.score = 0;
             vector[j].u.cmpobj = NULL;
             j++;
@@ -399,7 +399,7 @@ void sortCommand(client *c) {
         zset *zs = sortval->ptr;
         zskiplist *zsl = zs->zsl;
         zskiplistNode *ln;
-        robj *ele;
+        sds sdsele;
         int rangelen = vectorlen;
 
         /* Check if starting point is trivial, before doing log(N) lookup. */
@@ -417,8 +417,8 @@ void sortCommand(client *c) {
 
         while(rangelen--) {
             serverAssertWithInfo(c,sortval,ln != NULL);
-            ele = ln->obj;
-            vector[j].obj = ele;
+            sdsele = ln->ele;
+            vector[j].obj = createStringObject(sdsele,sdslen(sdsele));
             vector[j].u.score = 0;
             vector[j].u.cmpobj = NULL;
             j++;
@@ -431,9 +431,11 @@ void sortCommand(client *c) {
         dict *set = ((zset*)sortval->ptr)->dict;
         dictIterator *di;
         dictEntry *setele;
+        sds sdsele;
         di = dictGetIterator(set);
         while((setele = dictNext(di)) != NULL) {
-            vector[j].obj = dictGetKey(setele);
+            sdsele =  dictGetKey(setele);
+            vector[j].obj = createStringObject(sdsele,sdslen(sdsele));
             vector[j].u.score = 0;
             vector[j].u.cmpobj = NULL;
             j++;
@@ -577,9 +579,9 @@ void sortCommand(client *c) {
     }
 
     /* Cleanup */
-    if (sortval->type == OBJ_LIST || sortval->type == OBJ_SET)
-        for (j = 0; j < vectorlen; j++)
-            decrRefCount(vector[j].obj);
+    for (j = 0; j < vectorlen; j++)
+        decrRefCount(vector[j].obj);
+
     decrRefCount(sortval);
     listRelease(operations);
     for (j = 0; j < vectorlen; j++) {

src/t_hash.c

@@ -52,17 +52,9 @@ void hashTypeTryConversion(robj *o, robj **argv, int start, int end) {
     }
 }
 
-/* Encode given objects in-place when the hash uses a dict. */
-void hashTypeTryObjectEncoding(robj *subject, robj **o1, robj **o2) {
-    if (subject->encoding == OBJ_ENCODING_HT) {
-        if (o1) *o1 = tryObjectEncoding(*o1);
-        if (o2) *o2 = tryObjectEncoding(*o2);
-    }
-}
-
 /* Get the value from a ziplist encoded hash, identified by field.
  * Returns -1 when the field cannot be found. */
-int hashTypeGetFromZiplist(robj *o, robj *field,
+int hashTypeGetFromZiplist(robj *o, sds field,
                            unsigned char **vstr,
                            unsigned int *vlen,
                            long long *vll)
@@ -72,12 +64,10 @@ int hashTypeGetFromZiplist(robj *o, robj *field,
 
     serverAssert(o->encoding == OBJ_ENCODING_ZIPLIST);
 
-    field = getDecodedObject(field);
-
     zl = o->ptr;
     fptr = ziplistIndex(zl, ZIPLIST_HEAD);
     if (fptr != NULL) {
-        fptr = ziplistFind(fptr, field->ptr, sdslen(field->ptr), 1);
+        fptr = ziplistFind(fptr, (unsigned char*)field, sdslen(field), 1);
         if (fptr != NULL) {
             /* Grab pointer to the value (fptr points to the field) */
             vptr = ziplistNext(zl, fptr);
@@ -85,8 +75,6 @@ int hashTypeGetFromZiplist(robj *o, robj *field,
         }
     }
 
-    decrRefCount(field);
-
     if (vptr != NULL) {
         ret = ziplistGet(vptr, vstr, vlen, vll);
         serverAssert(ret);
@@ -97,56 +85,63 @@ int hashTypeGetFromZiplist(robj *o, robj *field,
 }
 
 /* Get the value from a hash table encoded hash, identified by field.
- * Returns -1 when the field cannot be found. */
-int hashTypeGetFromHashTable(robj *o, robj *field, robj **value) {
+ * Returns NULL when the field cannot be found, otherwise the SDS value
+ * is returned. */
+sds hashTypeGetFromHashTable(robj *o, sds field) {
     dictEntry *de;
 
     serverAssert(o->encoding == OBJ_ENCODING_HT);
 
     de = dictFind(o->ptr, field);
-    if (de == NULL) return -1;
-    *value = dictGetVal(de);
-    return 0;
+    if (de == NULL) return NULL;
+    return dictGetVal(de);
 }
 
-/* Higher level function of hashTypeGet*() that always returns a Redis
- * object (either new or with refcount incremented), so that the caller
- * can retain a reference or call decrRefCount after the usage.
+/* Higher level function of hashTypeGet*() that returns the hash value
+ * associated with the specified field. If the field is found C_OK
+ * is returned, otherwise C_ERR. The returned object is returned by
+ * reference in either *vstr and *vlen if it's returned in string form,
+ * or stored in *vll if it's returned as a number.
  *
- * The lower level function can prevent copy on write so it is
- * the preferred way of doing read operations. */
-robj *hashTypeGetObject(robj *o, robj *field) {
-    robj *value = NULL;
-
+ * If *vll is populated *vstr is set to NULL, so the caller
+ * can always check the function return by checking the return value
+ * for C_OK and checking if vll (or vstr) is NULL. */
+int hashTypeGetValue(robj *o, sds field, unsigned char **vstr, unsigned int *vlen, long long *vll) {
     if (o->encoding == OBJ_ENCODING_ZIPLIST) {
-        unsigned char *vstr = NULL;
-        unsigned int vlen = UINT_MAX;
-        long long vll = LLONG_MAX;
-
-        if (hashTypeGetFromZiplist(o, field, &vstr, &vlen, &vll) == 0) {
-            if (vstr) {
-                value = createStringObject((char*)vstr, vlen);
-            } else {
-                value = createStringObjectFromLongLong(vll);
-            }
-        }
+        *vstr = NULL;
+        if (hashTypeGetFromZiplist(o, field, vstr, vlen, vll) == 0)
+            return C_OK;
     } else if (o->encoding == OBJ_ENCODING_HT) {
-        robj *aux;
-
-        if (hashTypeGetFromHashTable(o, field, &aux) == 0) {
-            incrRefCount(aux);
-            value = aux;
+        sds value;
+        if ((value = hashTypeGetFromHashTable(o, field)) != NULL) {
+            *vstr = (unsigned char*) value;
+            *vlen = sdslen(value);
+            return C_OK;
         }
     } else {
         serverPanic("Unknown hash encoding");
     }
-    return value;
+    return C_ERR;
+}
+
+/* Like hashTypeGetValue() but returns a Redis object, which is useful for
+ * interaction with the hash type outside t_hash.c.
+ * The function returns NULL if the field is not found in the hash. Otherwise
+ * a newly allocated string object with the value is returned. */
+robj *hashTypeGetValueObject(robj *o, sds field) {
+    unsigned char *vstr;
+    unsigned int vlen;
+    long long vll;
+
+    if (hashTypeGetValue(o,field,&vstr,&vlen,&vll) == C_ERR) return NULL;
+    if (vstr) return createStringObject((char*)vstr,vlen);
+    else return createStringObjectFromLongLong(vll);
 }
 
 /* Higher level function using hashTypeGet*() to return the length of the
  * object associated with the requested field, or 0 if the field does not
  * exist. */
-size_t hashTypeGetValueLength(robj *o, robj *field) {
+size_t hashTypeGetValueLength(robj *o, sds field) {
     size_t len = 0;
     if (o->encoding == OBJ_ENCODING_ZIPLIST) {
         unsigned char *vstr = NULL;
@@ -156,10 +151,10 @@ size_t hashTypeGetValueLength(robj *o, robj *field) {
         if (hashTypeGetFromZiplist(o, field, &vstr, &vlen, &vll) == 0)
             len = vstr ? vlen : sdigits10(vll);
     } else if (o->encoding == OBJ_ENCODING_HT) {
-        robj *aux;
+        sds aux;
 
-        if (hashTypeGetFromHashTable(o, field, &aux) == 0)
-            len = stringObjectLen(aux);
+        if ((aux = hashTypeGetFromHashTable(o, field)) != NULL)
+            len = sdslen(aux);
     } else {
         serverPanic("Unknown hash encoding");
     }
@@ -168,7 +163,7 @@ size_t hashTypeGetValueLength(robj *o, robj *field) {
 
 /* Test if the specified field exists in the given hash. Returns 1 if the field
  * exists, and 0 when it doesn't. */
-int hashTypeExists(robj *o, robj *field) {
+int hashTypeExists(robj *o, sds field) {
     if (o->encoding == OBJ_ENCODING_ZIPLIST) {
         unsigned char *vstr = NULL;
         unsigned int vlen = UINT_MAX;
@@ -176,32 +171,44 @@ int hashTypeExists(robj *o, robj *field) {
 
         if (hashTypeGetFromZiplist(o, field, &vstr, &vlen, &vll) == 0) return 1;
     } else if (o->encoding == OBJ_ENCODING_HT) {
-        robj *aux;
-
-        if (hashTypeGetFromHashTable(o, field, &aux) == 0) return 1;
+        if (hashTypeGetFromHashTable(o, field) != NULL) return 1;
     } else {
         serverPanic("Unknown hash encoding");
     }
     return 0;
 }
 
-/* Add an element, discard the old if the key already exists.
+/* Add a new field, overwrite the old with the new value if it already exists.
  * Return 0 on insert and 1 on update.
- * This function will take care of incrementing the reference count of the
- * retained fields and value objects. */
-int hashTypeSet(robj *o, robj *field, robj *value) {
+ *
+ * By default, the key and value SDS strings are copied if needed, so the
+ * caller retains ownership of the strings passed. However this behavior
+ * can be effected by passing appropriate flags (possibly bitwise OR-ed):
+ *
+ * HASH_SET_TAKE_FIELD -- The SDS field ownership passes to the function.
+ * HASH_SET_TAKE_VALUE -- The SDS value ownership passes to the function.
+ *
+ * When the flags are used the caller does not need to release the passed
+ * SDS string(s). It's up to the function to use the string to create a new
+ * entry or to free the SDS string before returning to the caller.
+ *
+ * HASH_SET_COPY corresponds to no flags passed, and means the default
+ * semantics of copying the values if needed.
+ *
+ */
+#define HASH_SET_TAKE_FIELD (1<<0)
+#define HASH_SET_TAKE_VALUE (1<<1)
+#define HASH_SET_COPY 0
+int hashTypeSet(robj *o, sds field, sds value, int flags) {
     int update = 0;
 
     if (o->encoding == OBJ_ENCODING_ZIPLIST) {
         unsigned char *zl, *fptr, *vptr;
 
-        field = getDecodedObject(field);
-        value = getDecodedObject(value);
-
         zl = o->ptr;
         fptr = ziplistIndex(zl, ZIPLIST_HEAD);
         if (fptr != NULL) {
-            fptr = ziplistFind(fptr, field->ptr, sdslen(field->ptr), 1);
+            fptr = ziplistFind(fptr, (unsigned char*)field, sdslen(field), 1);
             if (fptr != NULL) {
                 /* Grab pointer to the value (fptr points to the field) */
                 vptr = ziplistNext(zl, fptr);
@@ -212,49 +219,73 @@ int hashTypeSet(robj *o, robj *field, robj *value) {
                 zl = ziplistDelete(zl, &vptr);
 
                 /* Insert new value */
-                zl = ziplistInsert(zl, vptr, value->ptr, sdslen(value->ptr));
+                zl = ziplistInsert(zl, vptr, (unsigned char*)value,
+                        sdslen(value));
             }
         }
 
         if (!update) {
             /* Push new field/value pair onto the tail of the ziplist */
-            zl = ziplistPush(zl, field->ptr, sdslen(field->ptr), ZIPLIST_TAIL);
-            zl = ziplistPush(zl, value->ptr, sdslen(value->ptr), ZIPLIST_TAIL);
+            zl = ziplistPush(zl, (unsigned char*)field, sdslen(field),
+                    ZIPLIST_TAIL);
+            zl = ziplistPush(zl, (unsigned char*)value, sdslen(value),
+                    ZIPLIST_TAIL);
         }
         o->ptr = zl;
-        decrRefCount(field);
-        decrRefCount(value);
 
         /* Check if the ziplist needs to be converted to a hash table */
         if (hashTypeLength(o) > server.hash_max_ziplist_entries)
             hashTypeConvert(o, OBJ_ENCODING_HT);
     } else if (o->encoding == OBJ_ENCODING_HT) {
-        if (dictReplace(o->ptr, field, value)) { /* Insert */
-            incrRefCount(field);
-        } else { /* Update */
+        dictEntry *de = dictFind(o->ptr,field);
+        if (de) {
+            sdsfree(dictGetVal(de));
+            if (flags & HASH_SET_TAKE_VALUE) {
+                dictGetVal(de) = value;
+                value = NULL;
+            } else {
+                dictGetVal(de) = sdsdup(value);
+            }
             update = 1;
+        } else {
+            sds f,v;
+            if (flags & HASH_SET_TAKE_FIELD) {
+                f = field;
+                field = NULL;
+            } else {
+                f = sdsdup(field);
+            }
+            if (flags & HASH_SET_TAKE_VALUE) {
+                v = value;
+                value = NULL;
+            } else {
+                v = sdsdup(value);
+            }
+            dictAdd(o->ptr,f,v);
         }
-        incrRefCount(value);
     } else {
         serverPanic("Unknown hash encoding");
     }
+
+    /* Free SDS strings we did not referenced elsewhere if the flags
+     * want this function to be responsible. */
+    if (flags & HASH_SET_TAKE_FIELD && field) sdsfree(field);
+    if (flags & HASH_SET_TAKE_VALUE && value) sdsfree(value);
     return update;
 }
 
 /* Delete an element from a hash.
  * Return 1 on deleted and 0 on not found. */
-int hashTypeDelete(robj *o, robj *field) {
+int hashTypeDelete(robj *o, sds field) {
     int deleted = 0;
 
     if (o->encoding == OBJ_ENCODING_ZIPLIST) {
         unsigned char *zl, *fptr;
 
-        field = getDecodedObject(field);
-
         zl = o->ptr;
         fptr = ziplistIndex(zl, ZIPLIST_HEAD);
         if (fptr != NULL) {
-            fptr = ziplistFind(fptr, field->ptr, sdslen(field->ptr), 1);
+            fptr = ziplistFind(fptr, (unsigned char*)field, sdslen(field), 1);
             if (fptr != NULL) {
                 zl = ziplistDelete(zl,&fptr);
                 zl = ziplistDelete(zl,&fptr);
@@ -262,9 +293,6 @@ int hashTypeDelete(robj *o, robj *field) {
                 deleted = 1;
             }
         }
-
-        decrRefCount(field);
-
     } else if (o->encoding == OBJ_ENCODING_HT) {
         if (dictDelete((dict*)o->ptr, field) == C_OK) {
             deleted = 1;
@@ -276,22 +304,20 @@ int hashTypeDelete(robj *o, robj *field) {
     } else {
         serverPanic("Unknown hash encoding");
     }
-
     return deleted;
 }
 
 /* Return the number of elements in a hash. */
-unsigned long hashTypeLength(robj *o) {
+unsigned long hashTypeLength(const robj *o) {
     unsigned long length = ULONG_MAX;
 
     if (o->encoding == OBJ_ENCODING_ZIPLIST) {
         length = ziplistLen(o->ptr) / 2;
     } else if (o->encoding == OBJ_ENCODING_HT) {
-        length = dictSize((dict*)o->ptr);
+        length = dictSize((const dict*)o->ptr);
     } else {
         serverPanic("Unknown hash encoding");
     }
-
     return length;
 }
 
@@ -308,15 +334,12 @@ hashTypeIterator *hashTypeInitIterator(robj *subject) {
     } else {
         serverPanic("Unknown hash encoding");
     }
-
     return hi;
 }
 
 void hashTypeReleaseIterator(hashTypeIterator *hi) {
-    if (hi->encoding == OBJ_ENCODING_HT) {
+    if (hi->encoding == OBJ_ENCODING_HT)
         dictReleaseIterator(hi->di);
-    }
-
     zfree(hi);
 }
 
@@ -378,41 +401,51 @@ void hashTypeCurrentFromZiplist(hashTypeIterator *hi, int what,
 }
 
 /* Get the field or value at iterator cursor, for an iterator on a hash value
- * encoded as a ziplist. Prototype is similar to `hashTypeGetFromHashTable`. */
-void hashTypeCurrentFromHashTable(hashTypeIterator *hi, int what, robj **dst) {
+ * encoded as a hash table. Prototype is similar to
+ * `hashTypeGetFromHashTable`. */
+sds hashTypeCurrentFromHashTable(hashTypeIterator *hi, int what) {
     serverAssert(hi->encoding == OBJ_ENCODING_HT);
 
     if (what & OBJ_HASH_KEY) {
-        *dst = dictGetKey(hi->de);
+        return dictGetKey(hi->de);
     } else {
-        *dst = dictGetVal(hi->de);
+        return dictGetVal(hi->de);
     }
 }
 
-/* A non copy-on-write friendly but higher level version of hashTypeCurrent*()
- * that returns an object with incremented refcount (or a new object). It is up
- * to the caller to decrRefCount() the object if no reference is retained. */
-robj *hashTypeCurrentObject(hashTypeIterator *hi, int what) {
-    robj *dst;
-
+/* Higher level function of hashTypeCurrent*() that returns the hash value
+ * at current iterator position.
+ *
+ * The returned element is returned by reference in either *vstr and *vlen if
+ * it's returned in string form, or stored in *vll if it's returned as
+ * a number.
+ *
+ * If *vll is populated *vstr is set to NULL, so the caller
+ * can always check the function return by checking the return value
+ * type checking if vstr == NULL. */
+void hashTypeCurrentObject(hashTypeIterator *hi, int what, unsigned char **vstr, unsigned int *vlen, long long *vll) {
     if (hi->encoding == OBJ_ENCODING_ZIPLIST) {
-        unsigned char *vstr = NULL;
-        unsigned int vlen = UINT_MAX;
-        long long vll = LLONG_MAX;
-
-        hashTypeCurrentFromZiplist(hi, what, &vstr, &vlen, &vll);
-        if (vstr) {
-            dst = createStringObject((char*)vstr, vlen);
-        } else {
-            dst = createStringObjectFromLongLong(vll);
-        }
+        *vstr = NULL;
+        hashTypeCurrentFromZiplist(hi, what, vstr, vlen, vll);
     } else if (hi->encoding == OBJ_ENCODING_HT) {
-        hashTypeCurrentFromHashTable(hi, what, &dst);
-        incrRefCount(dst);
+        sds ele = hashTypeCurrentFromHashTable(hi, what);
+        *vstr = (unsigned char*) ele;
+        *vlen = sdslen(ele);
     } else {
         serverPanic("Unknown hash encoding");
     }
-    return dst;
+}
+
+/* Return the key or value at the current iterator position as a new
+ * SDS string. */
+sds hashTypeCurrentObjectNewSds(hashTypeIterator *hi, int what) {
+    unsigned char *vstr;
+    unsigned int vlen;
+    long long vll;
+
+    hashTypeCurrentObject(hi,what,&vstr,&vlen,&vll);
+    if (vstr) return sdsnewlen(vstr,vlen);
+    return sdsfromlonglong(vll);
 }
 
 robj *hashTypeLookupWriteOrCreate(client *c, robj *key) {
@@ -444,26 +477,21 @@ void hashTypeConvertZiplist(robj *o, int enc) {
         dict = dictCreate(&hashDictType, NULL);
 
         while (hashTypeNext(hi) != C_ERR) {
-            robj *field, *value;
+            sds key, value;
 
-            field = hashTypeCurrentObject(hi, OBJ_HASH_KEY);
-            field = tryObjectEncoding(field);
-            value = hashTypeCurrentObject(hi, OBJ_HASH_VALUE);
-            value = tryObjectEncoding(value);
-            ret = dictAdd(dict, field, value);
+            key = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_KEY);
+            value = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_VALUE);
+            ret = dictAdd(dict, key, value);
             if (ret != DICT_OK) {
                 serverLogHexDump(LL_WARNING,"ziplist with dup elements dump",
                     o->ptr,ziplistBlobLen(o->ptr));
-                serverAssert(ret == DICT_OK);
+                serverPanic("Ziplist corruption detected");
             }
         }
-
         hashTypeReleaseIterator(hi);
         zfree(o->ptr);
-
         o->encoding = OBJ_ENCODING_HT;
         o->ptr = dict;
-
     } else {
         serverPanic("Unknown hash encoding");
     }
@@ -489,8 +517,7 @@ void hsetCommand(client *c) {
 
     if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
     hashTypeTryConversion(o,c->argv,2,3);
-    hashTypeTryObjectEncoding(o,&c->argv[2], &c->argv[3]);
-    update = hashTypeSet(o,c->argv[2],c->argv[3]);
+    update = hashTypeSet(o,c->argv[2]->ptr,c->argv[3]->ptr,HASH_SET_COPY);
     addReply(c, update ? shared.czero : shared.cone);
     signalModifiedKey(c->db,c->argv[1]);
     notifyKeyspaceEvent(NOTIFY_HASH,"hset",c->argv[1],c->db->id);
@@ -502,11 +529,10 @@ void hsetnxCommand(client *c) {
     if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
     hashTypeTryConversion(o,c->argv,2,3);
 
-    if (hashTypeExists(o, c->argv[2])) {
+    if (hashTypeExists(o, c->argv[2]->ptr)) {
         addReply(c, shared.czero);
     } else {
-        hashTypeTryObjectEncoding(o,&c->argv[2], &c->argv[3]);
-        hashTypeSet(o,c->argv[2],c->argv[3]);
+        hashTypeSet(o,c->argv[2]->ptr,c->argv[3]->ptr,HASH_SET_COPY);
         addReply(c, shared.cone);
         signalModifiedKey(c->db,c->argv[1]);
         notifyKeyspaceEvent(NOTIFY_HASH,"hset",c->argv[1],c->db->id);
@@ -526,8 +552,7 @@ void hmsetCommand(client *c) {
     if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
     hashTypeTryConversion(o,c->argv,2,c->argc-1);
     for (i = 2; i < c->argc; i += 2) {
-        hashTypeTryObjectEncoding(o,&c->argv[i], &c->argv[i+1]);
-        hashTypeSet(o,c->argv[i],c->argv[i+1]);
+        hashTypeSet(o,c->argv[i]->ptr,c->argv[i+1]->ptr,HASH_SET_COPY);
     }
     addReply(c, shared.ok);
     signalModifiedKey(c->db,c->argv[1]);
@@ -537,17 +562,20 @@ void hmsetCommand(client *c) {
 
 void hincrbyCommand(client *c) {
     long long value, incr, oldvalue;
-    robj *o, *current, *new;
+    robj *o;
+    sds new;
+    unsigned char *vstr;
+    unsigned int vlen;
 
     if (getLongLongFromObjectOrReply(c,c->argv[3],&incr,NULL) != C_OK) return;
     if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
-    if ((current = hashTypeGetObject(o,c->argv[2])) != NULL) {
-        if (getLongLongFromObjectOrReply(c,current,&value,
-            "hash value is not an integer") != C_OK) {
-            decrRefCount(current);
-            return;
-        }
-        decrRefCount(current);
+    if (hashTypeGetValue(o,c->argv[2]->ptr,&vstr,&vlen,&value) == C_OK) {
+        if (vstr) {
+            if (string2ll((char*)vstr,vlen,&value) == 0) {
+                addReplyError(c,"hash value is not an integer");
+                return;
+            }
+        } /* Else hashTypeGetValue() already stored it into &value */
     } else {
         value = 0;
     }
@@ -559,10 +587,8 @@ void hincrbyCommand(client *c) {
         return;
     }
     value += incr;
-    new = createStringObjectFromLongLong(value);
-    hashTypeTryObjectEncoding(o,&c->argv[2],NULL);
-    hashTypeSet(o,c->argv[2],new);
-    decrRefCount(new);
+    new = sdsfromlonglong(value);
+    hashTypeSet(o,c->argv[2]->ptr,new,HASH_SET_TAKE_VALUE);
     addReplyLongLong(c,value);
     signalModifiedKey(c->db,c->argv[1]);
     notifyKeyspaceEvent(NOTIFY_HASH,"hincrby",c->argv[1],c->db->id);
@@ -570,27 +596,35 @@ void hincrbyCommand(client *c) {
 }
 
 void hincrbyfloatCommand(client *c) {
-    double long value, incr;
-    robj *o, *current, *new, *aux;
+    long double value, incr;
+    long long ll;
+    robj *o;
+    sds new;
+    unsigned char *vstr;
+    unsigned int vlen;
 
     if (getLongDoubleFromObjectOrReply(c,c->argv[3],&incr,NULL) != C_OK) return;
     if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
-    if ((current = hashTypeGetObject(o,c->argv[2])) != NULL) {
-        if (getLongDoubleFromObjectOrReply(c,current,&value,
-            "hash value is not a valid float") != C_OK) {
-            decrRefCount(current);
-            return;
+    if (hashTypeGetValue(o,c->argv[2]->ptr,&vstr,&vlen,&ll) == C_OK) {
+        if (vstr) {
+            if (string2ld((char*)vstr,vlen,&value) == 0) {
+                addReplyError(c,"hash value is not a float");
+                return;
+            }
+        } else {
+            value = (long double)ll;
         }
-        decrRefCount(current);
     } else {
         value = 0;
     }
 
     value += incr;
-    new = createStringObjectFromLongDouble(value,1);
-    hashTypeTryObjectEncoding(o,&c->argv[2],NULL);
-    hashTypeSet(o,c->argv[2],new);
-    addReplyBulk(c,new);
+
+    char buf[256];
+    int len = ld2string(buf,sizeof(buf),value,1);
+    new = sdsnewlen(buf,len);
+    hashTypeSet(o,c->argv[2]->ptr,new,HASH_SET_TAKE_VALUE);
+    addReplyBulkCBuffer(c,buf,len);
     signalModifiedKey(c->db,c->argv[1]);
     notifyKeyspaceEvent(NOTIFY_HASH,"hincrbyfloat",c->argv[1],c->db->id);
     server.dirty++;
@@ -598,14 +632,16 @@ void hincrbyfloatCommand(client *c) {
     /* Always replicate HINCRBYFLOAT as an HSET command with the final value
      * in order to make sure that differences in float pricision or formatting
      * will not create differences in replicas or after an AOF restart. */
+    robj *aux, *newobj;
     aux = createStringObject("HSET",4);
+    newobj = createRawStringObject(buf,len);
     rewriteClientCommandArgument(c,0,aux);
     decrRefCount(aux);
-    rewriteClientCommandArgument(c,3,new);
-    decrRefCount(new);
+    rewriteClientCommandArgument(c,3,newobj);
+    decrRefCount(newobj);
 }
 
-static void addHashFieldToReply(client *c, robj *o, robj *field) {
+static void addHashFieldToReply(client *c, robj *o, sds field) {
     int ret;
 
     if (o == NULL) {
@@ -630,15 +666,11 @@ static void addHashFieldToReply(client *c, robj *o, robj *field) {
         }
 
     } else if (o->encoding == OBJ_ENCODING_HT) {
-        robj *value;
-
-        ret = hashTypeGetFromHashTable(o, field, &value);
-        if (ret < 0) {
+        sds value = hashTypeGetFromHashTable(o, field);
+        if (value == NULL)
             addReply(c, shared.nullbulk);
-        } else {
-            addReplyBulk(c, value);
-        }
-
+        else
+            addReplyBulkCBuffer(c, value, sdslen(value));
     } else {
         serverPanic("Unknown hash encoding");
     }
@@ -650,7 +682,7 @@ void hgetCommand(client *c) {
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
         checkType(c,o,OBJ_HASH)) return;
 
-    addHashFieldToReply(c, o, c->argv[2]);
+    addHashFieldToReply(c, o, c->argv[2]->ptr);
 }
 
 void hmgetCommand(client *c) {
@@ -667,7 +699,7 @@ void hmgetCommand(client *c) {
 
     addReplyMultiBulkLen(c, c->argc-2);
     for (i = 2; i < c->argc; i++) {
-        addHashFieldToReply(c, o, c->argv[i]);
+        addHashFieldToReply(c, o, c->argv[i]->ptr);
     }
 }
 
@@ -679,7 +711,7 @@ void hdelCommand(client *c) {
         checkType(c,o,OBJ_HASH)) return;
 
     for (j = 2; j < c->argc; j++) {
-        if (hashTypeDelete(o,c->argv[j])) {
+        if (hashTypeDelete(o,c->argv[j]->ptr)) {
             deleted++;
             if (hashTypeLength(o) == 0) {
                 dbDelete(c->db,c->argv[1]);
@@ -713,7 +745,7 @@ void hstrlenCommand(client *c) {
 
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,o,OBJ_HASH)) return;
-    addReplyLongLong(c,hashTypeGetValueLength(o,c->argv[2]));
+    addReplyLongLong(c,hashTypeGetValueLength(o,c->argv[2]->ptr));
 }
 
 static void addHashIteratorCursorToReply(client *c, hashTypeIterator *hi, int what) {
@@ -723,18 +755,13 @@ static void addHashIteratorCursorToReply(client *c, hashTypeIterator *hi, int wh
         long long vll = LLONG_MAX;
 
         hashTypeCurrentFromZiplist(hi, what, &vstr, &vlen, &vll);
-        if (vstr) {
+        if (vstr)
             addReplyBulkCBuffer(c, vstr, vlen);
-        } else {
+        else
             addReplyBulkLongLong(c, vll);
-        }
-
     } else if (hi->encoding == OBJ_ENCODING_HT) {
-        robj *value;
-
-        hashTypeCurrentFromHashTable(hi, what, &value);
-        addReplyBulk(c, value);
-
+        sds value = hashTypeCurrentFromHashTable(hi, what);
+        addReplyBulkCBuffer(c, value, sdslen(value));
     } else {
         serverPanic("Unknown hash encoding");
     }
@@ -788,7 +815,7 @@ void hexistsCommand(client *c) {
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,o,OBJ_HASH)) return;
 
-    addReply(c, hashTypeExists(o,c->argv[2]) ? shared.cone : shared.czero);
+    addReply(c, hashTypeExists(o,c->argv[2]->ptr) ? shared.cone : shared.czero);
 }
 
 void hscanCommand(client *c) {

src/t_list.c

@@ -71,7 +71,7 @@ robj *listTypePop(robj *subject, int where) {
     return value;
 }
 
-unsigned long listTypeLength(robj *subject) {
+unsigned long listTypeLength(const robj *subject) {
     if (subject->encoding == OBJ_ENCODING_QUICKLIST) {
         return quicklistCount(subject->ptr);
     } else {
@@ -195,7 +195,7 @@ void listTypeConvert(robj *subject, int enc) {
  *----------------------------------------------------------------------------*/
 
 void pushGenericCommand(client *c, int where) {
-    int j, waiting = 0, pushed = 0;
+    int j, pushed = 0;
     robj *lobj = lookupKeyWrite(c->db,c->argv[1]);
 
     if (lobj && lobj->type != OBJ_LIST) {
@@ -204,7 +204,6 @@ void pushGenericCommand(client *c, int where) {
     }
 
     for (j = 2; j < c->argc; j++) {
-        c->argv[j] = tryObjectEncoding(c->argv[j]);
         if (!lobj) {
             lobj = createQuicklistObject();
             quicklistSetOptions(lobj->ptr, server.list_max_ziplist_size,
@@ -214,7 +213,7 @@ void pushGenericCommand(client *c, int where) {
         listTypePush(lobj,c->argv[j],where);
         pushed++;
     }
-    addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));
+    addReplyLongLong(c, (lobj ? listTypeLength(lobj) : 0));
     if (pushed) {
         char *event = (where == LIST_HEAD) ? "lpush" : "rpush";
 
@@ -232,70 +231,80 @@ void rpushCommand(client *c) {
     pushGenericCommand(c,LIST_TAIL);
 }
 
-void pushxGenericCommand(client *c, robj *refval, robj *val, int where) {
+void pushxGenericCommand(client *c, int where) {
+    int j, pushed = 0;
+    robj *subject;
+
+    if ((subject = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
+        checkType(c,subject,OBJ_LIST)) return;
+
+    for (j = 2; j < c->argc; j++) {
+        listTypePush(subject,c->argv[j],where);
+        pushed++;
+    }
+
+    addReplyLongLong(c,listTypeLength(subject));
+
+    if (pushed) {
+        char *event = (where == LIST_HEAD) ? "lpush" : "rpush";
+        signalModifiedKey(c->db,c->argv[1]);
+        notifyKeyspaceEvent(NOTIFY_LIST,event,c->argv[1],c->db->id);
+    }
+    server.dirty += pushed;
+}
+
+void lpushxCommand(client *c) {
+    pushxGenericCommand(c,LIST_HEAD);
+}
+
+void rpushxCommand(client *c) {
+    pushxGenericCommand(c,LIST_TAIL);
+}
+
+void linsertCommand(client *c) {
+    int where;
     robj *subject;
     listTypeIterator *iter;
     listTypeEntry entry;
     int inserted = 0;
 
+    if (strcasecmp(c->argv[2]->ptr,"after") == 0) {
+        where = LIST_TAIL;
+    } else if (strcasecmp(c->argv[2]->ptr,"before") == 0) {
+        where = LIST_HEAD;
+    } else {
+        addReply(c,shared.syntaxerr);
+        return;
+    }
+
     if ((subject = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,subject,OBJ_LIST)) return;
 
-    if (refval != NULL) {
-        /* Seek refval from head to tail */
-        iter = listTypeInitIterator(subject,0,LIST_TAIL);
-        while (listTypeNext(iter,&entry)) {
-            if (listTypeEqual(&entry,refval)) {
-                listTypeInsert(&entry,val,where);
-                inserted = 1;
-                break;
-            }
+    /* Seek pivot from head to tail */
+    iter = listTypeInitIterator(subject,0,LIST_TAIL);
+    while (listTypeNext(iter,&entry)) {
+        if (listTypeEqual(&entry,c->argv[3])) {
+            listTypeInsert(&entry,c->argv[4],where);
+            inserted = 1;
+            break;
         }
-        listTypeReleaseIterator(iter);
+    }
+    listTypeReleaseIterator(iter);
 
-        if (inserted) {
-            signalModifiedKey(c->db,c->argv[1]);
-            notifyKeyspaceEvent(NOTIFY_LIST,"linsert",
-                                c->argv[1],c->db->id);
-            server.dirty++;
-        } else {
-            /* Notify client of a failed insert */
-            addReply(c,shared.cnegone);
-            return;
-        }
-    } else {
-        char *event = (where == LIST_HEAD) ? "lpush" : "rpush";
-
-        listTypePush(subject,val,where);
+    if (inserted) {
         signalModifiedKey(c->db,c->argv[1]);
-        notifyKeyspaceEvent(NOTIFY_LIST,event,c->argv[1],c->db->id);
+        notifyKeyspaceEvent(NOTIFY_LIST,"linsert",
+                            c->argv[1],c->db->id);
         server.dirty++;
+    } else {
+        /* Notify client of a failed insert */
+        addReply(c,shared.cnegone);
+        return;
     }
 
     addReplyLongLong(c,listTypeLength(subject));
 }
 
-void lpushxCommand(client *c) {
-    c->argv[2] = tryObjectEncoding(c->argv[2]);
-    pushxGenericCommand(c,NULL,c->argv[2],LIST_HEAD);
-}
-
-void rpushxCommand(client *c) {
-    c->argv[2] = tryObjectEncoding(c->argv[2]);
-    pushxGenericCommand(c,NULL,c->argv[2],LIST_TAIL);
-}
-
-void linsertCommand(client *c) {
-    c->argv[4] = tryObjectEncoding(c->argv[4]);
-    if (strcasecmp(c->argv[2]->ptr,"after") == 0) {
-        pushxGenericCommand(c,c->argv[3],c->argv[4],LIST_TAIL);
-    } else if (strcasecmp(c->argv[2]->ptr,"before") == 0) {
-        pushxGenericCommand(c,c->argv[3],c->argv[4],LIST_HEAD);
-    } else {
-        addReply(c,shared.syntaxerr);
-    }
-}
-
 void llenCommand(client *c) {
     robj *o = lookupKeyReadOrReply(c,c->argv[1],shared.czero);
     if (o == NULL || checkType(c,o,OBJ_LIST)) return;

src/t_set.c

@@ -39,26 +39,28 @@ void sunionDiffGenericCommand(client *c, robj **setkeys, int setnum,
 /* Factory method to return a set that *can* hold "value". When the object has
  * an integer-encodable value, an intset will be returned. Otherwise a regular
  * hash table. */
-robj *setTypeCreate(robj *value) {
-    if (isObjectRepresentableAsLongLong(value,NULL) == C_OK)
+robj *setTypeCreate(sds value) {
+    if (isSdsRepresentableAsLongLong(value,NULL) == C_OK)
         return createIntsetObject();
     return createSetObject();
 }
 
-/* Add the specified value into a set. The function takes care of incrementing
- * the reference count of the object if needed in order to retain a copy.
+/* Add the specified value into a set.
  *
  * If the value was already member of the set, nothing is done and 0 is
  * returned, otherwise the new element is added and 1 is returned. */
-int setTypeAdd(robj *subject, robj *value) {
+int setTypeAdd(robj *subject, sds value) {
     long long llval;
     if (subject->encoding == OBJ_ENCODING_HT) {
-        if (dictAdd(subject->ptr,value,NULL) == DICT_OK) {
-            incrRefCount(value);
+        dict *ht = subject->ptr;
+        dictEntry *de = dictAddRaw(ht,value,NULL);
+        if (de) {
+            dictSetKey(ht,de,sdsdup(value));
+            dictSetVal(ht,de,NULL);
             return 1;
         }
     } else if (subject->encoding == OBJ_ENCODING_INTSET) {
-        if (isObjectRepresentableAsLongLong(value,&llval) == C_OK) {
+        if (isSdsRepresentableAsLongLong(value,&llval) == C_OK) {
             uint8_t success = 0;
             subject->ptr = intsetAdd(subject->ptr,llval,&success);
             if (success) {
@@ -74,9 +76,7 @@ int setTypeAdd(robj *subject, robj *value) {
 
             /* The set *was* an intset and this value is not integer
              * encodable, so dictAdd should always work. */
-            serverAssertWithInfo(NULL,value,
-                                dictAdd(subject->ptr,value,NULL) == DICT_OK);
-            incrRefCount(value);
+            serverAssert(dictAdd(subject->ptr,sdsdup(value),NULL) == DICT_OK);
             return 1;
         }
     } else {
@@ -85,7 +85,7 @@ int setTypeAdd(robj *subject, robj *value) {
     return 0;
 }
 
-int setTypeRemove(robj *setobj, robj *value) {
+int setTypeRemove(robj *setobj, sds value) {
     long long llval;
     if (setobj->encoding == OBJ_ENCODING_HT) {
         if (dictDelete(setobj->ptr,value) == DICT_OK) {
@@ -93,7 +93,7 @@ int setTypeRemove(robj *setobj, robj *value) {
             return 1;
         }
     } else if (setobj->encoding == OBJ_ENCODING_INTSET) {
-        if (isObjectRepresentableAsLongLong(value,&llval) == C_OK) {
+        if (isSdsRepresentableAsLongLong(value,&llval) == C_OK) {
             int success;
             setobj->ptr = intsetRemove(setobj->ptr,llval,&success);
             if (success) return 1;
@@ -104,12 +104,12 @@ int setTypeRemove(robj *setobj, robj *value) {
     return 0;
 }
 
-int setTypeIsMember(robj *subject, robj *value) {
+int setTypeIsMember(robj *subject, sds value) {
     long long llval;
     if (subject->encoding == OBJ_ENCODING_HT) {
         return dictFind((dict*)subject->ptr,value) != NULL;
     } else if (subject->encoding == OBJ_ENCODING_INTSET) {
-        if (isObjectRepresentableAsLongLong(value,&llval) == C_OK) {
+        if (isSdsRepresentableAsLongLong(value,&llval) == C_OK) {
             return intsetFind((intset*)subject->ptr,llval);
         }
     } else {
@@ -141,28 +141,26 @@ void setTypeReleaseIterator(setTypeIterator *si) {
 /* Move to the next entry in the set. Returns the object at the current
  * position.
  *
- * Since set elements can be internally be stored as redis objects or
+ * Since set elements can be internally be stored as SDS strings or
  * simple arrays of integers, setTypeNext returns the encoding of the
  * set object you are iterating, and will populate the appropriate pointer
- * (objele) or (llele) accordingly.
+ * (sdsele) or (llele) accordingly.
  *
- * Note that both the objele and llele pointers should be passed and cannot
+ * Note that both the sdsele and llele pointers should be passed and cannot
  * be NULL since the function will try to defensively populate the non
  * used field with values which are easy to trap if misused.
  *
- * When there are no longer elements -1 is returned.
- * Returned objects ref count is not incremented, so this function is
- * copy on write friendly. */
-int setTypeNext(setTypeIterator *si, robj **objele, int64_t *llele) {
+ * When there are no longer elements -1 is returned. */
+int setTypeNext(setTypeIterator *si, sds *sdsele, int64_t *llele) {
     if (si->encoding == OBJ_ENCODING_HT) {
         dictEntry *de = dictNext(si->di);
         if (de == NULL) return -1;
-        *objele = dictGetKey(de);
+        *sdsele = dictGetKey(de);
         *llele = -123456789; /* Not needed. Defensive. */
     } else if (si->encoding == OBJ_ENCODING_INTSET) {
         if (!intsetGet(si->subject->ptr,si->ii++,llele))
             return -1;
-        *objele = NULL; /* Not needed. Defensive. */
+        *sdsele = NULL; /* Not needed. Defensive. */
     } else {
         serverPanic("Wrong set encoding in setTypeNext");
     }
@@ -170,25 +168,24 @@ int setTypeNext(setTypeIterator *si, robj **objele, int64_t *llele) {
 }
 
 /* The not copy on write friendly version but easy to use version
- * of setTypeNext() is setTypeNextObject(), returning new objects
- * or incrementing the ref count of returned objects. So if you don't
- * retain a pointer to this object you should call decrRefCount() against it.
+ * of setTypeNext() is setTypeNextObject(), returning new SDS
+ * strings. So if you don't retain a pointer to this object you should call
+ * sdsfree() against it.
  *
  * This function is the way to go for write operations where COW is not
- * an issue as the result will be anyway of incrementing the ref count. */
-robj *setTypeNextObject(setTypeIterator *si) {
+ * an issue. */
+sds setTypeNextObject(setTypeIterator *si) {
     int64_t intele;
-    robj *objele;
+    sds sdsele;
     int encoding;
 
-    encoding = setTypeNext(si,&objele,&intele);
+    encoding = setTypeNext(si,&sdsele,&intele);
     switch(encoding) {
         case -1:    return NULL;
         case OBJ_ENCODING_INTSET:
-            return createStringObjectFromLongLong(intele);
+            return sdsfromlonglong(intele);
         case OBJ_ENCODING_HT:
-            incrRefCount(objele);
-            return objele;
+            return sdsdup(sdsele);
         default:
             serverPanic("Unsupported encoding");
     }
@@ -197,7 +194,7 @@ robj *setTypeNextObject(setTypeIterator *si) {
 
 /* Return random element from a non empty set.
  * The returned element can be a int64_t value if the set is encoded
- * as an "intset" blob of integers, or a redis object if the set
+ * as an "intset" blob of integers, or an SDS string if the set
  * is a regular set.
  *
  * The caller provides both pointers to be populated with the right
@@ -205,32 +202,28 @@ robj *setTypeNextObject(setTypeIterator *si) {
  * field of the object and is used by the caller to check if the
  * int64_t pointer or the redis object pointer was populated.
  *
- * Note that both the objele and llele pointers should be passed and cannot
+ * Note that both the sdsele and llele pointers should be passed and cannot
  * be NULL since the function will try to defensively populate the non
- * used field with values which are easy to trap if misused.
- *
- * When an object is returned (the set was a real set) the ref count
- * of the object is not incremented so this function can be considered
- * copy on write friendly. */
-int setTypeRandomElement(robj *setobj, robj **objele, int64_t *llele) {
+ * used field with values which are easy to trap if misused. */
+int setTypeRandomElement(robj *setobj, sds *sdsele, int64_t *llele) {
     if (setobj->encoding == OBJ_ENCODING_HT) {
         dictEntry *de = dictGetRandomKey(setobj->ptr);
-        *objele = dictGetKey(de);
+        *sdsele = dictGetKey(de);
         *llele = -123456789; /* Not needed. Defensive. */
     } else if (setobj->encoding == OBJ_ENCODING_INTSET) {
         *llele = intsetRandom(setobj->ptr);
-        *objele = NULL; /* Not needed. Defensive. */
+        *sdsele = NULL; /* Not needed. Defensive. */
     } else {
         serverPanic("Unknown set encoding");
     }
     return setobj->encoding;
 }
 
-unsigned long setTypeSize(robj *subject) {
+unsigned long setTypeSize(const robj *subject) {
     if (subject->encoding == OBJ_ENCODING_HT) {
-        return dictSize((dict*)subject->ptr);
+        return dictSize((const dict*)subject->ptr);
     } else if (subject->encoding == OBJ_ENCODING_INTSET) {
-        return intsetLen((intset*)subject->ptr);
+        return intsetLen((const intset*)subject->ptr);
     } else {
         serverPanic("Unknown set encoding");
     }
@@ -247,7 +240,7 @@ void setTypeConvert(robj *setobj, int enc) {
     if (enc == OBJ_ENCODING_HT) {
         int64_t intele;
         dict *d = dictCreate(&setDictType,NULL);
-        robj *element;
+        sds element;
 
         /* Presize the dict to avoid rehashing */
         dictExpand(d,intsetLen(setobj->ptr));
@@ -255,9 +248,8 @@ void setTypeConvert(robj *setobj, int enc) {
         /* To add the elements we extract integers and create redis objects */
         si = setTypeInitIterator(setobj);
         while (setTypeNext(si,&element,&intele) != -1) {
-            element = createStringObjectFromLongLong(intele);
-            serverAssertWithInfo(NULL,element,
-                                dictAdd(d,element,NULL) == DICT_OK);
+            element = sdsfromlonglong(intele);
+            serverAssert(dictAdd(d,element,NULL) == DICT_OK);
         }
         setTypeReleaseIterator(si);
 
@@ -275,7 +267,7 @@ void saddCommand(client *c) {
 
     set = lookupKeyWrite(c->db,c->argv[1]);
     if (set == NULL) {
-        set = setTypeCreate(c->argv[2]);
+        set = setTypeCreate(c->argv[2]->ptr);
         dbAdd(c->db,c->argv[1],set);
     } else {
         if (set->type != OBJ_SET) {
@@ -285,8 +277,7 @@ void saddCommand(client *c) {
     }
 
     for (j = 2; j < c->argc; j++) {
-        c->argv[j] = tryObjectEncoding(c->argv[j]);
-        if (setTypeAdd(set,c->argv[j])) added++;
+        if (setTypeAdd(set,c->argv[j]->ptr)) added++;
     }
     if (added) {
         signalModifiedKey(c->db,c->argv[1]);
@@ -304,7 +295,7 @@ void sremCommand(client *c) {
         checkType(c,set,OBJ_SET)) return;
 
     for (j = 2; j < c->argc; j++) {
-        if (setTypeRemove(set,c->argv[j])) {
+        if (setTypeRemove(set,c->argv[j]->ptr)) {
             deleted++;
             if (setTypeSize(set) == 0) {
                 dbDelete(c->db,c->argv[1]);
@@ -328,7 +319,7 @@ void smoveCommand(client *c) {
     robj *srcset, *dstset, *ele;
     srcset = lookupKeyWrite(c->db,c->argv[1]);
     dstset = lookupKeyWrite(c->db,c->argv[2]);
-    ele = c->argv[3] = tryObjectEncoding(c->argv[3]);
+    ele = c->argv[3];
 
     /* If the source key does not exist return 0 */
     if (srcset == NULL) {
@@ -343,12 +334,13 @@ void smoveCommand(client *c) {
 
     /* If srcset and dstset are equal, SMOVE is a no-op */
     if (srcset == dstset) {
-        addReply(c,setTypeIsMember(srcset,ele) ? shared.cone : shared.czero);
+        addReply(c,setTypeIsMember(srcset,ele->ptr) ?
+            shared.cone : shared.czero);
         return;
     }
 
     /* If the element cannot be removed from the src set, return 0. */
-    if (!setTypeRemove(srcset,ele)) {
+    if (!setTypeRemove(srcset,ele->ptr)) {
         addReply(c,shared.czero);
         return;
     }
@@ -362,7 +354,7 @@ void smoveCommand(client *c) {
 
     /* Create the destination set when it doesn't exist */
     if (!dstset) {
-        dstset = setTypeCreate(ele);
+        dstset = setTypeCreate(ele->ptr);
         dbAdd(c->db,c->argv[2],dstset);
     }
 
@@ -371,7 +363,7 @@ void smoveCommand(client *c) {
     server.dirty++;
 
     /* An extra key has changed when ele was successfully added to dstset */
-    if (setTypeAdd(dstset,ele)) {
+    if (setTypeAdd(dstset,ele->ptr)) {
         server.dirty++;
         notifyKeyspaceEvent(NOTIFY_SET,"sadd",c->argv[2],c->db->id);
     }
@@ -384,8 +376,7 @@ void sismemberCommand(client *c) {
     if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,set,OBJ_SET)) return;
 
-    c->argv[2] = tryObjectEncoding(c->argv[2]);
-    if (setTypeIsMember(set,c->argv[2]))
+    if (setTypeIsMember(set,c->argv[2]->ptr))
         addReply(c,shared.cone);
     else
         addReply(c,shared.czero);
@@ -458,7 +449,7 @@ void spopWithCountCommand(client *c) {
         return;
     }
 
-    /* Case 2 and 3 require to replicate SPOP as a set of SERM commands.
+    /* Case 2 and 3 require to replicate SPOP as a set of SREM commands.
      * Prepare our replication argument vector. Also send the array length
      * which is common to both the code paths. */
     robj *propargv[3];
@@ -467,6 +458,7 @@ void spopWithCountCommand(client *c) {
     addReplyMultiBulkLen(c,count);
 
     /* Common iteration vars. */
+    sds sdsele;
     robj *objele;
     int encoding;
     int64_t llele;
@@ -481,17 +473,18 @@ void spopWithCountCommand(client *c) {
      * the set. */
     if (remaining*SPOP_MOVE_STRATEGY_MUL > count) {
         while(count--) {
-            encoding = setTypeRandomElement(set,&objele,&llele);
+            /* Emit and remove. */
+            encoding = setTypeRandomElement(set,&sdsele,&llele);
             if (encoding == OBJ_ENCODING_INTSET) {
+                addReplyBulkLongLong(c,llele);
                 objele = createStringObjectFromLongLong(llele);
+                set->ptr = intsetRemove(set->ptr,llele,NULL);
             } else {
-                incrRefCount(objele);
+                addReplyBulkCBuffer(c,sdsele,sdslen(sdsele));
+                objele = createStringObject(sdsele,sdslen(sdsele));
+                setTypeRemove(set,sdsele);
             }
 
-            /* Return the element to the client and remove from the set. */
-            addReplyBulk(c,objele);
-            setTypeRemove(set,objele);
-
             /* Replicate/AOF this command as an SREM operation */
             propargv[2] = objele;
             alsoPropagate(server.sremCommand,c->db->id,propargv,3,
@@ -511,16 +504,16 @@ void spopWithCountCommand(client *c) {
 
         /* Create a new set with just the remaining elements. */
         while(remaining--) {
-            encoding = setTypeRandomElement(set,&objele,&llele);
+            encoding = setTypeRandomElement(set,&sdsele,&llele);
             if (encoding == OBJ_ENCODING_INTSET) {
-                objele = createStringObjectFromLongLong(llele);
+                sdsele = sdsfromlonglong(llele);
             } else {
-                incrRefCount(objele);
+                sdsele = sdsdup(sdsele);
             }
-            if (!newset) newset = setTypeCreate(objele);
-            setTypeAdd(newset,objele);
-            setTypeRemove(set,objele);
-            decrRefCount(objele);
+            if (!newset) newset = setTypeCreate(sdsele);
+            setTypeAdd(newset,sdsele);
+            setTypeRemove(set,sdsele);
+            sdsfree(sdsele);
         }
 
         /* Assign the new set as the key value. */
@@ -530,19 +523,19 @@ void spopWithCountCommand(client *c) {
         /* Tranfer the old set to the client and release it. */
         setTypeIterator *si;
         si = setTypeInitIterator(set);
-        while((encoding = setTypeNext(si,&objele,&llele)) != -1) {
+        while((encoding = setTypeNext(si,&sdsele,&llele)) != -1) {
             if (encoding == OBJ_ENCODING_INTSET) {
+                addReplyBulkLongLong(c,llele);
                 objele = createStringObjectFromLongLong(llele);
             } else {
-                incrRefCount(objele);
+                addReplyBulkCBuffer(c,sdsele,sdslen(sdsele));
+                objele = createStringObject(sdsele,sdslen(sdsele));
             }
-            addReplyBulk(c,objele);
 
             /* Replicate/AOF this command as an SREM operation */
             propargv[2] = objele;
             alsoPropagate(server.sremCommand,c->db->id,propargv,3,
                 PROPAGATE_AOF|PROPAGATE_REPL);
-
             decrRefCount(objele);
         }
         setTypeReleaseIterator(si);
@@ -561,6 +554,7 @@ void spopWithCountCommand(client *c) {
 
 void spopCommand(client *c) {
     robj *set, *ele, *aux;
+    sds sdsele;
     int64_t llele;
     int encoding;
 
@@ -578,15 +572,15 @@ void spopCommand(client *c) {
         checkType(c,set,OBJ_SET)) return;
 
     /* Get a random element from the set */
-    encoding = setTypeRandomElement(set,&ele,&llele);
+    encoding = setTypeRandomElement(set,&sdsele,&llele);
 
     /* Remove the element from the set */
     if (encoding == OBJ_ENCODING_INTSET) {
         ele = createStringObjectFromLongLong(llele);
         set->ptr = intsetRemove(set->ptr,llele,NULL);
     } else {
-        incrRefCount(ele);
-        setTypeRemove(set,ele);
+        ele = createStringObject(sdsele,sdslen(sdsele));
+        setTypeRemove(set,ele->ptr);
     }
 
     notifyKeyspaceEvent(NOTIFY_SET,"spop",c->argv[1],c->db->id);
@@ -594,11 +588,11 @@ void spopCommand(client *c) {
     /* Replicate/AOF this command as an SREM operation */
     aux = createStringObject("SREM",4);
     rewriteClientCommandVector(c,3,aux,c->argv[1],ele);
-    decrRefCount(ele);
     decrRefCount(aux);
 
     /* Add the element to the reply */
     addReplyBulk(c,ele);
+    decrRefCount(ele);
 
     /* Delete the set if it's empty */
     if (setTypeSize(set) == 0) {
@@ -623,7 +617,8 @@ void srandmemberWithCountCommand(client *c) {
     long l;
     unsigned long count, size;
     int uniq = 1;
-    robj *set, *ele;
+    robj *set;
+    sds ele;
     int64_t llele;
     int encoding;
 
@@ -660,7 +655,7 @@ void srandmemberWithCountCommand(client *c) {
             if (encoding == OBJ_ENCODING_INTSET) {
                 addReplyBulkLongLong(c,llele);
             } else {
-                addReplyBulk(c,ele);
+                addReplyBulkCBuffer(c,ele,sdslen(ele));
             }
         }
         return;
@@ -675,7 +670,7 @@ void srandmemberWithCountCommand(client *c) {
     }
 
     /* For CASE 3 and CASE 4 we need an auxiliary dictionary. */
-    d = dictCreate(&setDictType,NULL);
+    d = dictCreate(&objectKeyPointerValueDictType,NULL);
 
     /* CASE 3:
      * The number of elements inside the set is not greater than
@@ -697,7 +692,7 @@ void srandmemberWithCountCommand(client *c) {
             if (encoding == OBJ_ENCODING_INTSET) {
                 retval = dictAdd(d,createStringObjectFromLongLong(llele),NULL);
             } else {
-                retval = dictAdd(d,dupStringObject(ele),NULL);
+                retval = dictAdd(d,createStringObject(ele,sdslen(ele)),NULL);
             }
             serverAssert(retval == DICT_OK);
         }
@@ -720,21 +715,22 @@ void srandmemberWithCountCommand(client *c) {
      * to reach the specified count. */
     else {
         unsigned long added = 0;
+        robj *objele;
 
         while(added < count) {
             encoding = setTypeRandomElement(set,&ele,&llele);
             if (encoding == OBJ_ENCODING_INTSET) {
-                ele = createStringObjectFromLongLong(llele);
+                objele = createStringObjectFromLongLong(llele);
             } else {
-                ele = dupStringObject(ele);
+                objele = createStringObject(ele,sdslen(ele));
             }
             /* Try to add the object to the dictionary. If it already exists
              * free it, otherwise increment the number of objects we have
              * in the result dictionary. */
-            if (dictAdd(d,ele,NULL) == DICT_OK)
+            if (dictAdd(d,objele,NULL) == DICT_OK)
                 added++;
             else
-                decrRefCount(ele);
+                decrRefCount(objele);
         }
     }
 
@@ -753,7 +749,8 @@ void srandmemberWithCountCommand(client *c) {
 }
 
 void srandmemberCommand(client *c) {
-    robj *set, *ele;
+    robj *set;
+    sds ele;
     int64_t llele;
     int encoding;
 
@@ -772,7 +769,7 @@ void srandmemberCommand(client *c) {
     if (encoding == OBJ_ENCODING_INTSET) {
         addReplyBulkLongLong(c,llele);
     } else {
-        addReplyBulk(c,ele);
+        addReplyBulkCBuffer(c,ele,sdslen(ele));
     }
 }
 
@@ -792,7 +789,8 @@ void sinterGenericCommand(client *c, robj **setkeys,
                           unsigned long setnum, robj *dstkey) {
     robj **sets = zmalloc(sizeof(robj*)*setnum);
     setTypeIterator *si;
-    robj *eleobj, *dstset = NULL;
+    robj *dstset = NULL;
+    sds elesds;
     int64_t intobj;
     void *replylen = NULL;
     unsigned long j, cardinality = 0;
@@ -842,7 +840,7 @@ void sinterGenericCommand(client *c, robj **setkeys,
      * the element against all the other sets, if at least one set does
      * not include the element it is discarded */
     si = setTypeInitIterator(sets[0]);
-    while((encoding = setTypeNext(si,&eleobj,&intobj)) != -1) {
+    while((encoding = setTypeNext(si,&elesds,&intobj)) != -1) {
         for (j = 1; j < setnum; j++) {
             if (sets[j] == sets[0]) continue;
             if (encoding == OBJ_ENCODING_INTSET) {
@@ -855,25 +853,15 @@ void sinterGenericCommand(client *c, robj **setkeys,
                  * have to use the generic function, creating an object
                  * for this */
                 } else if (sets[j]->encoding == OBJ_ENCODING_HT) {
-                    eleobj = createStringObjectFromLongLong(intobj);
-                    if (!setTypeIsMember(sets[j],eleobj)) {
-                        decrRefCount(eleobj);
+                    elesds = sdsfromlonglong(intobj);
+                    if (!setTypeIsMember(sets[j],elesds)) {
+                        sdsfree(elesds);
                         break;
                     }
-                    decrRefCount(eleobj);
+                    sdsfree(elesds);
                 }
             } else if (encoding == OBJ_ENCODING_HT) {
-                /* Optimization... if the source object is integer
-                 * encoded AND the target set is an intset, we can get
-                 * a much faster path. */
-                if (eleobj->encoding == OBJ_ENCODING_INT &&
-                    sets[j]->encoding == OBJ_ENCODING_INTSET &&
-                    !intsetFind((intset*)sets[j]->ptr,(long)eleobj->ptr))
-                {
-                    break;
-                /* else... object to object check is easy as we use the
-                 * type agnostic API here. */
-                } else if (!setTypeIsMember(sets[j],eleobj)) {
+                if (!setTypeIsMember(sets[j],elesds)) {
                     break;
                 }
             }
@@ -883,17 +871,17 @@ void sinterGenericCommand(client *c, robj **setkeys,
         if (j == setnum) {
             if (!dstkey) {
                 if (encoding == OBJ_ENCODING_HT)
-                    addReplyBulk(c,eleobj);
+                    addReplyBulkCBuffer(c,elesds,sdslen(elesds));
                 else
                     addReplyBulkLongLong(c,intobj);
                 cardinality++;
             } else {
                 if (encoding == OBJ_ENCODING_INTSET) {
-                    eleobj = createStringObjectFromLongLong(intobj);
-                    setTypeAdd(dstset,eleobj);
-                    decrRefCount(eleobj);
+                    elesds = sdsfromlonglong(intobj);
+                    setTypeAdd(dstset,elesds);
+                    sdsfree(elesds);
                 } else {
-                    setTypeAdd(dstset,eleobj);
+                    setTypeAdd(dstset,elesds);
                 }
             }
         }
@@ -940,7 +928,8 @@ void sunionDiffGenericCommand(client *c, robj **setkeys, int setnum,
                               robj *dstkey, int op) {
     robj **sets = zmalloc(sizeof(robj*)*setnum);
     setTypeIterator *si;
-    robj *ele, *dstset = NULL;
+    robj *dstset = NULL;
+    sds ele;
     int j, cardinality = 0;
     int diff_algo = 1;
 
@@ -1006,7 +995,7 @@ void sunionDiffGenericCommand(client *c, robj **setkeys, int setnum,
             si = setTypeInitIterator(sets[j]);
             while((ele = setTypeNextObject(si)) != NULL) {
                 if (setTypeAdd(dstset,ele)) cardinality++;
-                decrRefCount(ele);
+                sdsfree(ele);
             }
             setTypeReleaseIterator(si);
         }
@@ -1031,7 +1020,7 @@ void sunionDiffGenericCommand(client *c, robj **setkeys, int setnum,
                 setTypeAdd(dstset,ele);
                 cardinality++;
             }
-            decrRefCount(ele);
+            sdsfree(ele);
         }
         setTypeReleaseIterator(si);
     } else if (op == SET_OP_DIFF && sets[0] && diff_algo == 2) {
@@ -1052,7 +1041,7 @@ void sunionDiffGenericCommand(client *c, robj **setkeys, int setnum,
                 } else {
                     if (setTypeRemove(dstset,ele)) cardinality--;
                 }
-                decrRefCount(ele);
+                sdsfree(ele);
             }
             setTypeReleaseIterator(si);
 
@@ -1067,8 +1056,8 @@ void sunionDiffGenericCommand(client *c, robj **setkeys, int setnum,
         addReplyMultiBulkLen(c,cardinality);
         si = setTypeInitIterator(dstset);
         while((ele = setTypeNextObject(si)) != NULL) {
-            addReplyBulk(c,ele);
-            decrRefCount(ele);
+            addReplyBulkCBuffer(c,ele,sdslen(ele));
+            sdsfree(ele);
         }
         setTypeReleaseIterator(si);
         decrRefCount(dstset);

src/util.c

@@ -274,7 +274,7 @@ uint32_t sdigits10(int64_t v) {
  *
  * Modified in order to handle signed integers since the original code was
  * designed for unsigned integers. */
-int ll2string(char* dst, size_t dstlen, long long svalue) {
+int ll2string(char *dst, size_t dstlen, long long svalue) {
     static const char digits[201] =
         "0001020304050607080910111213141516171819"
         "2021222324252627282930313233343536373839"
@@ -330,7 +330,16 @@ int ll2string(char* dst, size_t dstlen, long long svalue) {
 
 /* Convert a string into a long long. Returns 1 if the string could be parsed
  * into a (non-overflowing) long long, 0 otherwise. The value will be set to
- * the parsed value when appropriate. */
+ * the parsed value when appropriate.
+ *
+ * Note that this function demands that the string strictly represents
+ * a long long: 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. */
 int string2ll(const char *s, size_t slen, long long *value) {
     const char *p = s;
     size_t plen = 0;
@@ -410,8 +419,40 @@ int string2l(const char *s, size_t slen, long *lval) {
     return 1;
 }
 
+/* Convert a string into a double. Returns 1 if the string could be parsed
+ * into a (non-overflowing) double, 0 otherwise. The value will be set to
+ * the parsed value when appropriate.
+ *
+ * Note that this function demands that the string strictly represents
+ * a double: no spaces or other characters before or after the string
+ * representing the number are accepted. */
+int string2ld(const char *s, size_t slen, long double *dp) {
+    char buf[256];
+    long double value;
+    char *eptr;
+
+    if (slen >= sizeof(buf)) return 0;
+    memcpy(buf,s,slen);
+    buf[slen] = '\0';
+
+    errno = 0;
+    value = strtold(buf, &eptr);
+    if (isspace(buf[0]) || eptr[0] != '\0' ||
+        (errno == ERANGE &&
+            (value == HUGE_VAL || value == -HUGE_VAL || value == 0)) ||
+        errno == EINVAL ||
+        isnan(value))
+        return 0;
+
+    if (dp) *dp = value;
+    return 1;
+}
+
 /* Convert a double to a string representation. Returns the number of bytes
- * required. The representation should always be parsable by strtod(3). */
+ * required. The representation should always be parsable by strtod(3).
+ * This function does not support human-friendly formatting like ld2string
+ * does. It is intented mainly to be used inside t_zset.c when writing scores
+ * into a ziplist representing a sorted set. */
 int d2string(char *buf, size_t len, double value) {
     if (isnan(value)) {
         len = snprintf(buf,len,"nan");
@@ -449,6 +490,52 @@ int d2string(char *buf, size_t len, double value) {
     return len;
 }
 
+/* Convert a long double into a string. If humanfriendly is non-zero
+ * it does not use exponential format and trims trailing zeroes at the end,
+ * however this results in loss of precision. Otherwise exp format is used
+ * and the output of snprintf() is not modified.
+ *
+ * The function returns the length of the string or zero if there was not
+ * enough buffer room to store it. */
+int ld2string(char *buf, size_t len, long double value, int humanfriendly) {
+    size_t l;
+
+    if (isinf(value)) {
+        /* Libc in odd systems (Hi Solaris!) will format infinite in a
+         * different way, so better to handle it in an explicit way. */
+        if (len < 5) return 0; /* No room. 5 is "-inf\0" */
+        if (value > 0) {
+            memcpy(buf,"inf",3);
+            l = 3;
+        } else {
+            memcpy(buf,"-inf",4);
+            l = 4;
+        }
+    } else if (humanfriendly) {
+        /* We use 17 digits precision since with 128 bit floats that precision
+         * after rounding is able to represent most small decimal numbers in a
+         * way that is "non surprising" for the user (that is, most small
+         * decimal numbers will be represented in a way that when converted
+         * back into a string are exactly the same as what the user typed.) */
+        l = snprintf(buf,len,"%.17Lf", value);
+        if (l+1 > len) return 0; /* No room. */
+        /* Now remove trailing zeroes after the '.' */
+        if (strchr(buf,'.') != NULL) {
+            char *p = buf+l-1;
+            while(*p == '0') {
+                p--;
+                l--;
+            }
+            if (*p == '.') l--;
+        }
+    } else {
+        l = snprintf(buf,len,"%.17Lg", value);
+        if (l+1 > len) return 0; /* No room. */
+    }
+    buf[l] = '\0';
+    return l;
+}
+
 /* Generate the Redis "Run ID", a SHA1-sized random number that identifies a
  * given execution of Redis, so that if you are talking with an instance
  * having run_id == A, and you reconnect and it has run_id == B, you can be

src/util.h

@@ -41,7 +41,9 @@ uint32_t sdigits10(int64_t v);
 int ll2string(char *s, size_t len, long long value);
 int string2ll(const char *s, size_t slen, long long *value);
 int string2l(const char *s, size_t slen, long *value);
+int string2ld(const char *s, size_t slen, long double *dp);
 int d2string(char *buf, size_t len, double value);
+int ld2string(char *buf, size_t len, long double value, int humanfriendly);
 sds getAbsolutePath(char *filename);
 int pathIsBaseName(char *path);
 

src/version.h

@@ -1 +1 @@
-#define REDIS_VERSION "3.2.8"
+#define REDIS_VERSION "999.999.999"

src/ziplist.c

@@ -180,7 +180,7 @@ typedef struct zlentry {
 void ziplistRepr(unsigned char *zl);
 
 /* Return bytes needed to store integer encoded by 'encoding' */
-unsigned int zipIntSize(unsigned char encoding) {
+static unsigned int zipIntSize(unsigned char encoding) {
     switch(encoding) {
     case ZIP_INT_8B:  return 1;
     case ZIP_INT_16B: return 2;
@@ -195,7 +195,7 @@ unsigned int zipIntSize(unsigned char encoding) {
 
 /* Encode the length 'rawlen' writing it in 'p'. If p is NULL it just returns
  * the amount of bytes required to encode such a length. */
-unsigned int zipEncodeLength(unsigned char *p, unsigned char encoding, unsigned int rawlen) {
+static unsigned int zipEncodeLength(unsigned char *p, unsigned char encoding, unsigned int rawlen) {
     unsigned char len = 1, buf[5];
 
     if (ZIP_IS_STR(encoding)) {
@@ -259,7 +259,7 @@ unsigned int zipEncodeLength(unsigned char *p, unsigned char encoding, unsigned
 
 /* Encode the length of the previous entry and write it to "p". Return the
  * number of bytes needed to encode this length if "p" is NULL. */
-unsigned int zipPrevEncodeLength(unsigned char *p, unsigned int len) {
+static unsigned int zipPrevEncodeLength(unsigned char *p, unsigned int len) {
     if (p == NULL) {
         return (len < ZIP_BIGLEN) ? 1 : sizeof(len)+1;
     } else {
@@ -277,7 +277,7 @@ unsigned int zipPrevEncodeLength(unsigned char *p, unsigned int len) {
 
 /* Encode the length of the previous entry and write it to "p". This only
  * uses the larger encoding (required in __ziplistCascadeUpdate). */
-void zipPrevEncodeLengthForceLarge(unsigned char *p, unsigned int len) {
+static void zipPrevEncodeLengthForceLarge(unsigned char *p, unsigned int len) {
     if (p == NULL) return;
     p[0] = ZIP_BIGLEN;
     memcpy(p+1,&len,sizeof(len));
@@ -309,14 +309,14 @@ void zipPrevEncodeLengthForceLarge(unsigned char *p, unsigned int len) {
 
 /* Return the difference in number of bytes needed to store the length of the
  * previous element 'len', in the entry pointed to by 'p'. */
-int zipPrevLenByteDiff(unsigned char *p, unsigned int len) {
+static int zipPrevLenByteDiff(unsigned char *p, unsigned int len) {
     unsigned int prevlensize;
     ZIP_DECODE_PREVLENSIZE(p, prevlensize);
     return zipPrevEncodeLength(NULL, len) - prevlensize;
 }
 
 /* Return the total number of bytes used by the entry pointed to by 'p'. */
-unsigned int zipRawEntryLength(unsigned char *p) {
+static unsigned int zipRawEntryLength(unsigned char *p) {
     unsigned int prevlensize, encoding, lensize, len;
     ZIP_DECODE_PREVLENSIZE(p, prevlensize);
     ZIP_DECODE_LENGTH(p + prevlensize, encoding, lensize, len);
@@ -325,7 +325,7 @@ unsigned int zipRawEntryLength(unsigned char *p) {
 
 /* Check if string pointed to by 'entry' can be encoded as an integer.
  * Stores the integer value in 'v' and its encoding in 'encoding'. */
-int zipTryEncoding(unsigned char *entry, unsigned int entrylen, long long *v, unsigned char *encoding) {
+static int zipTryEncoding(unsigned char *entry, unsigned int entrylen, long long *v, unsigned char *encoding) {
     long long value;
 
     if (entrylen >= 32 || entrylen == 0) return 0;
@@ -352,7 +352,7 @@ int zipTryEncoding(unsigned char *entry, unsigned int entrylen, long long *v, un
 }
 
 /* Store integer 'value' at 'p', encoded as 'encoding' */
-void zipSaveInteger(unsigned char *p, int64_t value, unsigned char encoding) {
+static void zipSaveInteger(unsigned char *p, int64_t value, unsigned char encoding) {
     int16_t i16;
     int32_t i32;
     int64_t i64;
@@ -382,7 +382,7 @@ void zipSaveInteger(unsigned char *p, int64_t value, unsigned char encoding) {
 }
 
 /* Read integer encoded as 'encoding' from 'p' */
-int64_t zipLoadInteger(unsigned char *p, unsigned char encoding) {
+static int64_t zipLoadInteger(unsigned char *p, unsigned char encoding) {
     int16_t i16;
     int32_t i32;
     int64_t i64, ret = 0;
@@ -414,7 +414,7 @@ int64_t zipLoadInteger(unsigned char *p, unsigned char encoding) {
 }
 
 /* Return a struct with all information about an entry. */
-void zipEntry(unsigned char *p, zlentry *e) {
+static void zipEntry(unsigned char *p, zlentry *e) {
 
     ZIP_DECODE_PREVLEN(p, e->prevrawlensize, e->prevrawlen);
     ZIP_DECODE_LENGTH(p + e->prevrawlensize, e->encoding, e->lensize, e->len);
@@ -434,7 +434,7 @@ unsigned char *ziplistNew(void) {
 }
 
 /* Resize the ziplist. */
-unsigned char *ziplistResize(unsigned char *zl, unsigned int len) {
+static unsigned char *ziplistResize(unsigned char *zl, unsigned int len) {
     zl = zrealloc(zl,len);
     ZIPLIST_BYTES(zl) = intrev32ifbe(len);
     zl[len-1] = ZIP_END;
@@ -461,7 +461,7 @@ unsigned char *ziplistResize(unsigned char *zl, unsigned int len) {
  *
  * The pointer "p" points to the first entry that does NOT need to be
  * updated, i.e. consecutive fields MAY need an update. */
-unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *p) {
+static unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *p) {
     size_t curlen = intrev32ifbe(ZIPLIST_BYTES(zl)), rawlen, rawlensize;
     size_t offset, noffset, extra;
     unsigned char *np;
@@ -523,7 +523,7 @@ unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *p) {
 }
 
 /* Delete "num" entries, starting at "p". Returns pointer to the ziplist. */
-unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsigned int num) {
+static unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsigned int num) {
     unsigned int i, totlen, deleted = 0;
     size_t offset;
     int nextdiff = 0;
@@ -583,7 +583,7 @@ unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsigned int
 }
 
 /* Insert item at "p". */
-unsigned char *__ziplistInsert(unsigned char *zl, unsigned char *p, unsigned char *s, unsigned int slen) {
+static unsigned char *__ziplistInsert(unsigned char *zl, unsigned char *p, unsigned char *s, unsigned int slen) {
     size_t curlen = intrev32ifbe(ZIPLIST_BYTES(zl)), reqlen;
     unsigned int prevlensize, prevlen = 0;
     size_t offset;
@@ -621,12 +621,7 @@ unsigned char *__ziplistInsert(unsigned char *zl, unsigned char *p, unsigned cha
     /* When the insert position is not equal to the tail, we need to
      * make sure that the next entry can hold this entry's length in
      * its prevlen field. */
-    int forcelarge = 0;
     nextdiff = (p[0] != ZIP_END) ? zipPrevLenByteDiff(p,reqlen) : 0;
-    if (nextdiff == -4 && reqlen < 4) {
-        nextdiff = 0;
-        forcelarge = 1;
-    }
 
     /* Store offset because a realloc may change the address of zl. */
     offset = p-zl;
@@ -639,10 +634,7 @@ unsigned char *__ziplistInsert(unsigned char *zl, unsigned char *p, unsigned cha
         memmove(p+reqlen,p-nextdiff,curlen-offset-1+nextdiff);
 
         /* Encode this entry's raw length in the next entry. */
-        if (forcelarge)
-            zipPrevEncodeLengthForceLarge(p+reqlen,reqlen);
-        else
-            zipPrevEncodeLength(p+reqlen,reqlen);
+        zipPrevEncodeLength(p+reqlen,reqlen);
 
         /* Update offset for tail */
         ZIPLIST_TAIL_OFFSET(zl) =

src/zmalloc.c

@@ -43,6 +43,7 @@ void zlibc_free(void *ptr) {
 #include <pthread.h>
 #include "config.h"
 #include "zmalloc.h"
+#include "atomicvar.h"
 
 #ifdef HAVE_MALLOC_SIZE
 #define PREFIX_SIZE (0)
@@ -67,32 +68,11 @@ void zlibc_free(void *ptr) {
 #define free(ptr) je_free(ptr)
 #endif
 
-#if defined(__ATOMIC_RELAXED)
-#define update_zmalloc_stat_add(__n) __atomic_add_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
-#define update_zmalloc_stat_sub(__n) __atomic_sub_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
-#elif defined(HAVE_ATOMIC)
-#define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
-#define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
-#else
-#define update_zmalloc_stat_add(__n) do { \
-    pthread_mutex_lock(&used_memory_mutex); \
-    used_memory += (__n); \
-    pthread_mutex_unlock(&used_memory_mutex); \
-} while(0)
-
-#define update_zmalloc_stat_sub(__n) do { \
-    pthread_mutex_lock(&used_memory_mutex); \
-    used_memory -= (__n); \
-    pthread_mutex_unlock(&used_memory_mutex); \
-} while(0)
-
-#endif
-
 #define update_zmalloc_stat_alloc(__n) do { \
     size_t _n = (__n); \
     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
     if (zmalloc_thread_safe) { \
-        update_zmalloc_stat_add(_n); \
+        atomicIncr(used_memory,__n,used_memory_mutex); \
     } else { \
         used_memory += _n; \
     } \
@@ -102,7 +82,7 @@ void zlibc_free(void *ptr) {
     size_t _n = (__n); \
     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
     if (zmalloc_thread_safe) { \
-        update_zmalloc_stat_sub(_n); \
+        atomicDecr(used_memory,__n,used_memory_mutex); \
     } else { \
         used_memory -= _n; \
     } \
@@ -222,18 +202,10 @@ size_t zmalloc_used_memory(void) {
     size_t um;
 
     if (zmalloc_thread_safe) {
-#if defined(__ATOMIC_RELAXED) || defined(HAVE_ATOMIC)
-        um = update_zmalloc_stat_add(0);
-#else
-        pthread_mutex_lock(&used_memory_mutex);
-        um = used_memory;
-        pthread_mutex_unlock(&used_memory_mutex);
-#endif
-    }
-    else {
+        atomicGet(used_memory,um,used_memory_mutex);
+    } else {
         um = used_memory;
     }
-
     return um;
 }
 
@@ -332,14 +304,26 @@ float zmalloc_get_fragmentation_ratio(size_t rss) {
  * /proc/self/smaps. The field must be specified with trailing ":" as it
  * apperas in the smaps output.
  *
- * Example: zmalloc_get_smap_bytes_by_field("Rss:");
+ * If a pid is specified, the information is extracted for such a pid,
+ * otherwise if pid is -1 the information is reported is about the
+ * current process.
+ *
+ * Example: zmalloc_get_smap_bytes_by_field("Rss:",-1);
  */
 #if defined(HAVE_PROC_SMAPS)
-size_t zmalloc_get_smap_bytes_by_field(char *field) {
+size_t zmalloc_get_smap_bytes_by_field(char *field, long pid) {
     char line[1024];
     size_t bytes = 0;
-    FILE *fp = fopen("/proc/self/smaps","r");
     int flen = strlen(field);
+    FILE *fp;
+
+    if (pid == -1) {
+        fp = fopen("/proc/self/smaps","r");
+    } else {
+        char filename[128];
+        snprintf(filename,sizeof(filename),"/proc/%ld/smaps",pid);
+        fp = fopen(filename,"r");
+    }
 
     if (!fp) return 0;
     while(fgets(line,sizeof(line),fp) != NULL) {
@@ -355,14 +339,15 @@ size_t zmalloc_get_smap_bytes_by_field(char *field) {
     return bytes;
 }
 #else
-size_t zmalloc_get_smap_bytes_by_field(char *field) {
+size_t zmalloc_get_smap_bytes_by_field(char *field, long pid) {
     ((void) field);
+    ((void) pid);
     return 0;
 }
 #endif
 
-size_t zmalloc_get_private_dirty(void) {
-    return zmalloc_get_smap_bytes_by_field("Private_Dirty:");
+size_t zmalloc_get_private_dirty(long pid) {
+    return zmalloc_get_smap_bytes_by_field("Private_Dirty:",pid);
 }
 
 /* Returns the size of physical memory (RAM) in bytes.

src/zmalloc.h

@@ -75,8 +75,8 @@ void zmalloc_enable_thread_safeness(void);
 void zmalloc_set_oom_handler(void (*oom_handler)(size_t));
 float zmalloc_get_fragmentation_ratio(size_t rss);
 size_t zmalloc_get_rss(void);
-size_t zmalloc_get_private_dirty(void);
-size_t zmalloc_get_smap_bytes_by_field(char *field);
+size_t zmalloc_get_private_dirty(long pid);
+size_t zmalloc_get_smap_bytes_by_field(char *field, long pid);
 size_t zmalloc_get_memory_size(void);
 void zlibc_free(void *ptr);
 

tests/cluster/tests/04-resharding.tcl

@@ -59,6 +59,7 @@ array set content {}
 set tribpid {}
 
 test "Cluster consistency during live resharding" {
+    set ele 0
     for {set j 0} {$j < $numops} {incr j} {
         # Trigger the resharding once we execute half the ops.
         if {$tribpid ne {} &&
@@ -86,7 +87,7 @@ test "Cluster consistency during live resharding" {
         # Write random data to random list.
         set listid [randomInt $numkeys]
         set key "key:$listid"
-        set ele [randomValue]
+        incr ele
         # We write both with Lua scripts and with plain commands.
         # This way we are able to stress Lua -> Redis command invocation
         # as well, that has tests to prevent Lua to write into wrong
@@ -115,7 +116,9 @@ test "Cluster consistency during live resharding" {
 test "Verify $numkeys keys for consistency with logical content" {
     # Check that the Redis Cluster content matches our logical content.
     foreach {key value} [array get content] {
-        assert {[$cluster lrange $key 0 -1] eq $value}
+        if {[$cluster lrange $key 0 -1] ne $value} {
+            fail "Key $key expected to hold '$value' but actual content is [$cluster lrange $key 0 -1]"
+        }
     }
 }
 
@@ -133,7 +136,9 @@ test "Cluster should eventually be up again" {
 test "Verify $numkeys keys after the crash & restart" {
     # Check that the Redis Cluster content matches our logical content.
     foreach {key value} [array get content] {
-        assert {[$cluster lrange $key 0 -1] eq $value}
+        if {[$cluster lrange $key 0 -1] ne $value} {
+            fail "Key $key expected to hold '$value' but actual content is [$cluster lrange $key 0 -1]"
+        }
     }
 }
 

tests/support/cluster.tcl

@@ -58,7 +58,8 @@ proc ::redis_cluster::__method__refresh_nodes_map {id} {
     set idx 0; # Index of the node that will respond.
     set errmsg {}
     foreach start_node $::redis_cluster::startup_nodes($id) {
-        lassign [split $start_node :] start_host start_port
+        set ip_port [lindex [split $start_node @] 0]
+        lassign [split $ip_port :] start_host start_port
         if {[catch {
             set r {}
             set r [redis $start_host $start_port]
@@ -68,7 +69,7 @@ proc ::redis_cluster::__method__refresh_nodes_map {id} {
             if {$r ne {}} {catch {$r close}}
             incr idx
             if {[string length $errmsg] < 200} {
-                append errmsg " $start_node: $e"
+                append errmsg " $ip_port: $e"
             }
             continue ; # Try next.
         } else {
@@ -98,6 +99,7 @@ proc ::redis_cluster::__method__refresh_nodes_map {id} {
         set args [split $line " "]
         lassign $args nodeid addr flags slaveof pingsent pongrecv configepoch linkstate
         set slots [lrange $args 8 end]
+        set addr [lindex [split $addr @] 0]
         if {$addr eq {:0}} {
             set addr $start_host:$start_port
         }

tests/support/server.tcl

@@ -213,6 +213,8 @@ proc start_server {options {code undefined}} {
 
     if {$::valgrind} {
         set pid [exec valgrind --track-origins=yes --suppressions=src/valgrind.sup --show-reachable=no --show-possibly-lost=no --leak-check=full src/redis-server $config_file > $stdout 2> $stderr &]
+    } elseif ($::stack_logging) {
+        set pid [exec /usr/bin/env MallocStackLogging=1 MallocLogFile=/tmp/malloc_log.txt src/redis-server $config_file > $stdout 2> $stderr &]
     } else {
         set pid [exec src/redis-server $config_file > $stdout 2> $stderr &]
     }

tests/test_helper.tcl

@@ -54,6 +54,7 @@ set ::all_tests {
     unit/geo
     unit/memefficiency
     unit/hyperloglog
+    unit/lazyfree
 }
 # Index to the next test to run in the ::all_tests list.
 set ::next_test 0
@@ -62,6 +63,7 @@ set ::host 127.0.0.1
 set ::port 21111
 set ::traceleaks 0
 set ::valgrind 0
+set ::stack_logging 0
 set ::verbose 0
 set ::quiet 0
 set ::denytags {}
@@ -394,6 +396,7 @@ proc send_data_packet {fd status data} {
 proc print_help_screen {} {
     puts [join {
         "--valgrind         Run the test over valgrind."
+        "--stack-logging    Enable OSX leaks/malloc stack logging."
         "--accurate         Run slow randomized tests for more iterations."
         "--quiet            Don't show individual tests."
         "--single <unit>    Just execute the specified unit (see next option)."
@@ -420,6 +423,10 @@ for {set j 0} {$j < [llength $argv]} {incr j} {
         incr j
     } elseif {$opt eq {--valgrind}} {
         set ::valgrind 1
+    } elseif {$opt eq {--stack-logging}} {
+        if {[string match {*Darwin*} [exec uname -a]]} {
+            set ::stack_logging 1
+        }
     } elseif {$opt eq {--quiet}} {
         set ::quiet 1
     } elseif {$opt eq {--host}} {

tests/unit/aofrw.tcl

@@ -4,60 +4,63 @@ start_server {tags {"aofrw"}} {
     r config set auto-aof-rewrite-percentage 0 ; # Disable auto-rewrite.
     waitForBgrewriteaof r
 
-    test {AOF rewrite during write load} {
-        # Start a write load for 10 seconds
-        set master [srv 0 client]
-        set master_host [srv 0 host]
-        set master_port [srv 0 port]
-        set load_handle0 [start_write_load $master_host $master_port 10]
-        set load_handle1 [start_write_load $master_host $master_port 10]
-        set load_handle2 [start_write_load $master_host $master_port 10]
-        set load_handle3 [start_write_load $master_host $master_port 10]
-        set load_handle4 [start_write_load $master_host $master_port 10]
+    foreach rdbpre {yes no} {
+        r config set aof-use-rdb-preamble $rdbpre
+        test "AOF rewrite during write load: RDB preamble=$rdbpre" {
+            # Start a write load for 10 seconds
+            set master [srv 0 client]
+            set master_host [srv 0 host]
+            set master_port [srv 0 port]
+            set load_handle0 [start_write_load $master_host $master_port 10]
+            set load_handle1 [start_write_load $master_host $master_port 10]
+            set load_handle2 [start_write_load $master_host $master_port 10]
+            set load_handle3 [start_write_load $master_host $master_port 10]
+            set load_handle4 [start_write_load $master_host $master_port 10]
 
-        # Make sure the instance is really receiving data
-        wait_for_condition 50 100 {
-            [r dbsize] > 0
-        } else {
-            fail "No write load detected."
+            # Make sure the instance is really receiving data
+            wait_for_condition 50 100 {
+                [r dbsize] > 0
+            } else {
+                fail "No write load detected."
+            }
+
+            # After 3 seconds, start a rewrite, while the write load is still
+            # active.
+            after 3000
+            r bgrewriteaof
+            waitForBgrewriteaof r
+
+            # Let it run a bit more so that we'll append some data to the new
+            # AOF.
+            after 1000
+
+            # Stop the processes generating the load if they are still active
+            stop_write_load $load_handle0
+            stop_write_load $load_handle1
+            stop_write_load $load_handle2
+            stop_write_load $load_handle3
+            stop_write_load $load_handle4
+
+            # Make sure that we remain the only connected client.
+            # This step is needed to make sure there are no pending writes
+            # that will be processed between the two "debug digest" calls.
+            wait_for_condition 50 100 {
+                [llength [split [string trim [r client list]] "\n"]] == 1
+            } else {
+                puts [r client list]
+                fail "Clients generating loads are not disconnecting"
+            }
+
+            # Get the data set digest
+            set d1 [r debug digest]
+
+            # Load the AOF
+            r debug loadaof
+            set d2 [r debug digest]
+
+            # Make sure they are the same
+            assert {$d1 eq $d2}
         }
-
-        # After 3 seconds, start a rewrite, while the write load is still
-        # active.
-        after 3000
-        r bgrewriteaof
-        waitForBgrewriteaof r
-
-        # Let it run a bit more so that we'll append some data to the new
-        # AOF.
-        after 1000
-
-        # Stop the processes generating the load if they are still active
-        stop_write_load $load_handle0
-        stop_write_load $load_handle1
-        stop_write_load $load_handle2
-        stop_write_load $load_handle3
-        stop_write_load $load_handle4
-
-        # Make sure that we remain the only connected client.
-        # This step is needed to make sure there are no pending writes
-        # that will be processed between the two "debug digest" calls.
-        wait_for_condition 50 100 {
-            [llength [split [string trim [r client list]] "\n"]] == 1
-        } else {
-            puts [r client list]
-            fail "Clients generating loads are not disconnecting"
-        }
-
-        # Get the data set digest
-        set d1 [r debug digest]
-
-        # Load the AOF
-        r debug loadaof
-        set d2 [r debug digest]
-
-        # Make sure they are the same
-        assert {$d1 eq $d2}
     }
 }
 

tests/unit/bitfield.tcl

@@ -189,13 +189,4 @@ start_server {tags {"bitops"}} {
         r set bits 1
         r bitfield bits get u1 0
     } {0}
-
-    test {BITFIELD regression for #3564} {
-        for {set j 0} {$j < 10} {incr j} {
-            r del mystring
-            set res [r BITFIELD mystring SET i8 0 10 SET i8 64 10 INCRBY i8 10 99900]
-            assert {$res eq {0 0 60}}
-        }
-        r del mystring
-    }
 }

tests/unit/geo.tcl

@@ -221,26 +221,18 @@ start_server {tags {"geo"}} {
     }
 
     test {GEOADD + GEORANGE randomized test} {
-        set attempt 30
+        set attempt 20
         while {[incr attempt -1]} {
             set rv [lindex $regression_vectors $rv_idx]
             incr rv_idx
 
             unset -nocomplain debuginfo
-            set srand_seed [clock milliseconds]
+            set srand_seed [randomInt 1000000]
             if {$rv ne {}} {set srand_seed [lindex $rv 0]}
             lappend debuginfo "srand_seed is $srand_seed"
             expr {srand($srand_seed)} ; # If you need a reproducible run
             r del mypoints
-
-            if {[randomInt 10] == 0} {
-                # From time to time use very big radiuses
-                set radius_km [expr {[randomInt 50000]+10}]
-            } else {
-                # Normally use a few - ~200km radiuses to stress
-                # test the code the most in edge cases.
-                set radius_km [expr {[randomInt 200]+10}]
-            }
+            set radius_km [expr {[randomInt 200]+10}]
             if {$rv ne {}} {set radius_km [lindex $rv 1]}
             set radius_m [expr {$radius_km*1000}]
             geo_random_point search_lon search_lat

tests/unit/introspection.tcl

@@ -6,16 +6,17 @@ start_server {tags {"introspection"}} {
     test {MONITOR can log executed commands} {
         set rd [redis_deferring_client]
         $rd monitor
+        assert_match {*OK*} [$rd read]
         r set foo bar
         r get foo
-        list [$rd read] [$rd read] [$rd read]
-    } {*OK*"set" "foo"*"get" "foo"*}
+        list [$rd read] [$rd read]
+    } {*"set" "foo"*"get" "foo"*}
 
     test {MONITOR can log commands issued by the scripting engine} {
         set rd [redis_deferring_client]
         $rd monitor
-        r eval {redis.call('set',KEYS[1],ARGV[1])} 1 foo bar
         $rd read ;# Discard the OK
+        r eval {redis.call('set',KEYS[1],ARGV[1])} 1 foo bar
         assert_match {*eval*} [$rd read]
         assert_match {*lua*"set"*"foo"*"bar"*} [$rd read]
     }

tests/unit/lazyfree.tcl

@@ -0,0 +1,39 @@
+start_server {tags {"lazyfree"}} {
+    test "UNLINK can reclaim memory in background" {
+        set orig_mem [s used_memory]
+        set args {}
+        for {set i 0} {$i < 100000} {incr i} {
+            lappend args $i
+        }
+        r sadd myset {*}$args
+        assert {[r scard myset] == 100000}
+        set peak_mem [s used_memory]
+        assert {[r unlink myset] == 1}
+        assert {$peak_mem > $orig_mem+1000000}
+        wait_for_condition 50 100 {
+            [s used_memory] < $peak_mem &&
+            [s used_memory] < $orig_mem*2
+        } else {
+            fail "Memory is not reclaimed by UNLINK"
+        }
+    }
+
+    test "FLUSHDB ASYNC can reclaim memory in background" {
+        set orig_mem [s used_memory]
+        set args {}
+        for {set i 0} {$i < 100000} {incr i} {
+            lappend args $i
+        }
+        r sadd myset {*}$args
+        assert {[r scard myset] == 100000}
+        set peak_mem [s used_memory]
+        r flushdb async
+        assert {$peak_mem > $orig_mem+1000000}
+        wait_for_condition 50 100 {
+            [s used_memory] < $peak_mem &&
+            [s used_memory] < $orig_mem*2
+        } else {
+            fail "Memory is not reclaimed by FLUSHDB ASYNC"
+        }
+    }
+}

tests/unit/scripting.tcl

@@ -330,7 +330,7 @@ start_server {tags {"scripting"}} {
     test {Globals protection reading an undeclared global variable} {
         catch {r eval {return a} 0} e
         set e
-    } {*ERR*attempted to access unexisting global*}
+    } {*ERR*attempted to access * global*}
 
     test {Globals protection setting an undeclared global*} {
         catch {r eval {a=10} 0} e

tests/unit/type/hash.tcl

@@ -515,4 +515,22 @@ start_server {tags {"hash"}} {
             assert {[r object encoding myhash] eq {hashtable}}
         }
     }
+
+    # The following test can only be executed if we don't use Valgrind, and if
+    # we are using x86_64 architecture, because:
+    #
+    # 1) Valgrind has floating point limitations, no support for 80 bits math.
+    # 2) Other archs may have the same limits.
+    #
+    # 1.23 cannot be represented correctly with 64 bit doubles, so we skip
+    # the test, since we are only testing pretty printing here and is not
+    # a bug if the program outputs things like 1.299999...
+    if {!$::valgrind || ![string match *x86_64* [exec uname -a]]} {
+        test {Test HINCRBYFLOAT for correct float representation (issue #2846)} {
+            r del myhash
+            assert {[r hincrbyfloat myhash float 1.23] eq {1.23}}
+            assert {[r hincrbyfloat myhash float 0.77] eq {2}}
+            assert {[r hincrbyfloat myhash float -0.1] eq {1.9}}
+        }
+    }
 }

tests/unit/type/list.tcl

@@ -507,7 +507,9 @@ start_server {
             create_list xlist "$large c"
             assert_equal 3 [r rpushx xlist d]
             assert_equal 4 [r lpushx xlist a]
-            assert_equal "a $large c d" [r lrange xlist 0 -1]
+            assert_equal 6 [r rpushx xlist 42 x]
+            assert_equal 9 [r lpushx xlist y3 y2 y1]
+            assert_equal "y1 y2 y3 a $large c d 42 x" [r lrange xlist 0 -1]
         }
 
         test "LINSERT - $type" {

utils/graphs/commits-over-time/README.md

@@ -0,0 +1,16 @@
+This Tcl script is what I used in order to generate the graph you
+can find at http://antirez.com/news/98. It's really quick & dirty, more
+a trow away program than anything else, but probably could be reused or
+modified in the future in order to visualize other similar data or an
+updated version of the same data.
+
+The usage is trivial:
+
+    ./genhtml.tcl > output.html
+
+The generated HTML is quite broken but good enough to grab a screenshot
+from the browser. Feel free to improve it if you got time / interest.
+
+Note that the code filtering the tags, and the hardcoded branch name, does
+not make the script, as it is, able to analyze a different repository.
+However the changes needed are trivial.

utils/graphs/commits-over-time/genhtml.tcl

@@ -0,0 +1,96 @@
+#!/usr/bin/env tclsh
+
+# Load commits history as "sha1 unixtime".
+set commits [exec git log unstable {--pretty="%H %at"}]
+set raw_tags [exec git tag]
+
+# Load all the tags that are about stable releases.
+foreach tag $raw_tags {
+    if {[string match v*-stable $tag]} {
+        set tag [string range $tag 1 end-7]
+        puts $tag
+    }
+    if {[regexp {^[0-9]+.[0-9]+.[0-9]+$} $tag]} {
+        lappend tags $tag
+    }
+}
+
+# For each tag, create a list of "name unixtime"
+foreach tag $tags {
+    set taginfo [exec git log $tag -n 1 "--pretty=\"$tag %at\""]
+    set taginfo [string trim $taginfo {"}]
+    lappend labels $taginfo
+}
+
+# For each commit, check the amount of code changed and create an array
+# mapping the commit to the number of lines affected.
+foreach c $commits {
+    set stat [exec git show --oneline --numstat [lindex $c 0]]
+    set linenum 0
+    set affected 0
+    foreach line [split $stat "\n"] {
+        incr linenum
+        if {$linenum == 1 || [string match *deps/* $line]} continue
+        if {[catch {llength $line} numfields]} continue
+        if {$numfields == 0} continue
+        catch {
+            incr affected [lindex $line 0]
+            incr affected [lindex $line 1]
+        }
+    }
+    set commit_to_affected([lindex $c 0]) $affected
+}
+
+set base_time [lindex [lindex $commits end] 1]
+puts [clock format $base_time]
+
+# Generate a graph made of HTML DIVs.
+puts {<html>
+<style>
+.box {
+    position:absolute;
+    width:10px;
+    height:5px;
+    border:1px black solid;
+    background-color:#44aa33;
+    opacity: 0.04;
+}
+.label {
+    position:absolute;
+    background-color:#dddddd;
+    font-family:helvetica;
+    font-size:12px;
+    padding:2px;
+    color:#666;
+    border:1px #aaa solid;
+    border-radius: 5px;
+}
+#outer {
+    position:relative;
+    width:1500;
+    height:500;
+    border:1px #aaa solid;
+}
+</style>
+<div id="outer">
+}
+foreach c $commits {
+    set sha [lindex $c 0]
+    set t [expr {([lindex $c 1]-$base_time)/(3600*24*2)}]
+    set affected [expr $commit_to_affected($sha)]
+    set left $t
+    set height [expr {log($affected)*20}]
+    puts "<div class=\"box\" style=\"left:$left; bottom:0; height:$height\"></div>"
+}
+
+set bottom -30
+foreach l $labels {
+    set name [lindex $l 0]
+    set t [expr {([lindex $l 1]-$base_time)/(3600*24*2)}]
+    set left $t
+    if {$left < 0} continue
+    incr bottom -20
+    if  {$bottom == -210} {set bottom -30}
+    puts "<div class=\"label\" style=\"left:$left; bottom:$bottom\">$name</div>"
+}
+puts {</div></html>}

utils/install_server.sh

@@ -25,9 +25,25 @@
 #
 ################################################################################
 #
-# Interactive service installer for redis server
-# this generates a redis config file and an /etc/init.d script, and installs them
-# this scripts should be run as root
+# Service installer for redis server, runs interactively by default.
+#
+# To run this script non-interactively (for automation/provisioning purposes),
+# feed the variables into the script. Any missing variables will be prompted!
+# Tip: Environment variables also support command substitution (see REDIS_EXECUTABLE)
+#
+# Example:
+#
+# sudo REDIS_PORT=1234 \
+# 		 REDIS_CONFIG_FILE=/etc/redis/1234.conf \
+# 		 REDIS_LOG_FILE=/var/log/redis_1234.log \
+# 		 REDIS_DATA_DIR=/var/lib/redis/1234 \
+# 		 REDIS_EXECUTABLE=`command -v redis-server` ./utils/install_server.sh
+#
+# This generates a redis config file and an /etc/init.d script, and installs them.
+#
+# /!\ This script should be run as root
+#
+################################################################################
 
 die () {
 	echo "ERROR: $1. Aborting!"
@@ -42,6 +58,7 @@ SCRIPTPATH=$(dirname $SCRIPT)
 
 #Initial defaults
 _REDIS_PORT=6379
+_MANUAL_EXECUTION=false
 
 echo "Welcome to the redis service installer"
 echo "This script will help you easily set up a running redis server"
@@ -53,47 +70,61 @@ if [ "$(id -u)" -ne 0 ] ; then
 	exit 1
 fi
 
-#Read the redis port
-read  -p "Please select the redis port for this instance: [$_REDIS_PORT] " REDIS_PORT
 if ! echo $REDIS_PORT | egrep -q '^[0-9]+$' ; then
-	echo "Selecting default: $_REDIS_PORT"
-	REDIS_PORT=$_REDIS_PORT
+	_MANUAL_EXECUTION=true
+	#Read the redis port
+	read  -p "Please select the redis port for this instance: [$_REDIS_PORT] " REDIS_PORT
+	if ! echo $REDIS_PORT | egrep -q '^[0-9]+$' ; then
+		echo "Selecting default: $_REDIS_PORT"
+		REDIS_PORT=$_REDIS_PORT
+	fi
 fi
 
-#read the redis config file
-_REDIS_CONFIG_FILE="/etc/redis/$REDIS_PORT.conf"
-read -p "Please select the redis config file name [$_REDIS_CONFIG_FILE] " REDIS_CONFIG_FILE
 if [ -z "$REDIS_CONFIG_FILE" ] ; then
-	REDIS_CONFIG_FILE=$_REDIS_CONFIG_FILE
-	echo "Selected default - $REDIS_CONFIG_FILE"
+	_MANUAL_EXECUTION=true
+	#read the redis config file
+	_REDIS_CONFIG_FILE="/etc/redis/$REDIS_PORT.conf"
+	read -p "Please select the redis config file name [$_REDIS_CONFIG_FILE] " REDIS_CONFIG_FILE
+	if [ -z "$REDIS_CONFIG_FILE" ] ; then
+		REDIS_CONFIG_FILE=$_REDIS_CONFIG_FILE
+		echo "Selected default - $REDIS_CONFIG_FILE"
+	fi
 fi
 
-#read the redis log file path
-_REDIS_LOG_FILE="/var/log/redis_$REDIS_PORT.log"
-read -p "Please select the redis log file name [$_REDIS_LOG_FILE] " REDIS_LOG_FILE
 if [ -z "$REDIS_LOG_FILE" ] ; then
-	REDIS_LOG_FILE=$_REDIS_LOG_FILE
-	echo "Selected default - $REDIS_LOG_FILE"
+	_MANUAL_EXECUTION=true
+	#read the redis log file path
+	_REDIS_LOG_FILE="/var/log/redis_$REDIS_PORT.log"
+	read -p "Please select the redis log file name [$_REDIS_LOG_FILE] " REDIS_LOG_FILE
+	if [ -z "$REDIS_LOG_FILE" ] ; then
+		REDIS_LOG_FILE=$_REDIS_LOG_FILE
+		echo "Selected default - $REDIS_LOG_FILE"
+	fi
 fi
 
-
-#get the redis data directory
-_REDIS_DATA_DIR="/var/lib/redis/$REDIS_PORT"
-read -p "Please select the data directory for this instance [$_REDIS_DATA_DIR] " REDIS_DATA_DIR
 if [ -z "$REDIS_DATA_DIR" ] ; then
-	REDIS_DATA_DIR=$_REDIS_DATA_DIR
-	echo "Selected default - $REDIS_DATA_DIR"
+	_MANUAL_EXECUTION=true
+	#get the redis data directory
+	_REDIS_DATA_DIR="/var/lib/redis/$REDIS_PORT"
+	read -p "Please select the data directory for this instance [$_REDIS_DATA_DIR] " REDIS_DATA_DIR
+	if [ -z "$REDIS_DATA_DIR" ] ; then
+		REDIS_DATA_DIR=$_REDIS_DATA_DIR
+		echo "Selected default - $REDIS_DATA_DIR"
+	fi
 fi
 
-#get the redis executable path
-_REDIS_EXECUTABLE=`command -v redis-server`
-read -p "Please select the redis executable path [$_REDIS_EXECUTABLE] " REDIS_EXECUTABLE
 if [ ! -x "$REDIS_EXECUTABLE" ] ; then
-	REDIS_EXECUTABLE=$_REDIS_EXECUTABLE
-
+	_MANUAL_EXECUTION=true
+	#get the redis executable path
+	_REDIS_EXECUTABLE=`command -v redis-server`
+	read -p "Please select the redis executable path [$_REDIS_EXECUTABLE] " REDIS_EXECUTABLE
 	if [ ! -x "$REDIS_EXECUTABLE" ] ; then
-		echo "Mmmmm...  it seems like you don't have a redis executable. Did you run make install yet?"
-		exit 1
+		REDIS_EXECUTABLE=$_REDIS_EXECUTABLE
+
+		if [ ! -x "$REDIS_EXECUTABLE" ] ; then
+			echo "Mmmmm...  it seems like you don't have a redis executable. Did you run make install yet?"
+			exit 1
+		fi
 	fi
 fi
 
@@ -112,7 +143,9 @@ echo "Data dir       : $REDIS_DATA_DIR"
 echo "Executable     : $REDIS_EXECUTABLE"
 echo "Cli Executable : $CLI_EXEC"
 
-read -p "Is this ok? Then press ENTER to go on or Ctrl-C to abort." _UNUSED_
+if $_MANUAL_EXECUTION == true ; then
+	read -p "Is this ok? Then press ENTER to go on or Ctrl-C to abort." _UNUSED_
+fi
 
 mkdir -p `dirname "$REDIS_CONFIG_FILE"` || die "Could not create redis config directory"
 mkdir -p `dirname "$REDIS_LOG_FILE"` || die "Could not create redis log dir"

utils/lru/README

@@ -3,11 +3,17 @@ Redis approximated LRU algorithm against the theoretical output of true
 LRU algorithm.
 
 In order to use the program you need to recompile Redis setting the define
-REDIS_LRU_CLOCK_RESOLUTION to 1, by editing redis.h.
+REDIS_LRU_CLOCK_RESOLUTION to 1, by editing the file server.h.
 This allows to execute the program in a fast way since the 1 ms resolution
 is enough for all the objects to have a different enough time stamp during
 the test.
 
 The program is executed like this:
 
-    ruby test-lru.rb > /tmp/lru.html
+    ruby test-lru.rb /tmp/lru.html
+
+You can optionally specify a number of times to run, so that the program
+will output averages of different runs, by adding an additional argument.
+For instance in order to run the test 10 times use:
+
+    ruby test-lru.rb /tmp/lru.html 10

utils/lru/lfu-simulation.c

@@ -0,0 +1,158 @@
+#include <stdio.h>
+#include <time.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+int decr_every = 1;
+int keyspace_size = 1000000;
+time_t switch_after = 30; /* Switch access pattern after N seconds. */
+
+struct entry {
+    /* Field that the LFU Redis implementation will have (we have
+     * 24 bits of total space in the object->lru field). */
+    uint8_t counter;    /* Logarithmic counter. */
+    uint16_t decrtime;  /* (Reduced precision) time of last decrement. */
+
+    /* Fields only useful for visualization. */
+    uint64_t hits;      /* Number of real accesses. */
+    time_t ctime;       /* Key creation time. */
+};
+
+#define to_16bit_minutes(x) ((x/60) & 65535)
+#define COUNTER_INIT_VAL 5
+
+/* Compute the difference in minutes between two 16 bit minutes times
+ * obtained with to_16bit_minutes(). Since they can wrap around if
+ * we detect the overflow we account for it as if the counter wrapped
+ * a single time. */
+uint16_t minutes_diff(uint16_t now, uint16_t prev) {
+    if (now >= prev) return now-prev;
+    return 65535-prev+now;
+}
+
+/* Increment a couter logaritmically: the greatest is its value, the
+ * less likely is that the counter is really incremented.
+ * The maximum value of the counter is saturated at 255. */
+uint8_t log_incr(uint8_t counter) {
+    if (counter == 255) return counter;
+    double r = (double)rand()/RAND_MAX;
+    double baseval = counter-COUNTER_INIT_VAL;
+    if (baseval < 0) baseval = 0;
+    double limit = 1.0/(baseval*10+1);
+    if (r < limit) counter++;
+    return counter;
+}
+
+/* Simulate an access to an entry. */
+void access_entry(struct entry *e) {
+    e->counter = log_incr(e->counter);
+    e->hits++;
+}
+
+/* Return the entry LFU value and as a side effect decrement the
+ * entry value if the decrement time was reached. */
+uint8_t scan_entry(struct entry *e) {
+    if (minutes_diff(to_16bit_minutes(time(NULL)),e->decrtime)
+        >= decr_every)
+    {
+        if (e->counter) {
+            if (e->counter > COUNTER_INIT_VAL*2) {
+                e->counter /= 2;
+            } else {
+                e->counter--;
+            }
+        }
+        e->decrtime = to_16bit_minutes(time(NULL));
+    }
+    return e->counter;
+}
+
+/* Print the entry info. */
+void show_entry(long pos, struct entry *e) {
+    char *tag = "normal       ";
+
+    if (pos >= 10 && pos <= 14) tag = "new no access";
+    if (pos >= 15 && pos <= 19) tag = "new accessed ";
+    if (pos >= keyspace_size -5) tag= "old no access";
+
+    printf("%ld] <%s> frequency:%d decrtime:%d [%lu hits | age:%ld sec]\n",
+        pos, tag, e->counter, e->decrtime, (unsigned long)e->hits,
+            time(NULL) - e->ctime);
+}
+
+int main(void) {
+    time_t start = time(NULL);
+    time_t new_entry_time = start;
+    time_t display_time = start;
+    struct entry *entries = malloc(sizeof(*entries)*keyspace_size);
+    long j;
+
+    /* Initialize. */
+    for (j = 0; j < keyspace_size; j++) {
+        entries[j].counter = COUNTER_INIT_VAL;
+        entries[j].decrtime = to_16bit_minutes(start);
+        entries[j].hits = 0;
+        entries[j].ctime = time(NULL);
+    }
+
+    while(1) {
+        time_t now = time(NULL);
+        long idx;
+
+        /* Scan N random entries (simulates the eviction under maxmemory). */
+        for (j = 0; j < 3; j++) {
+            scan_entry(entries+(rand()%keyspace_size));
+        }
+
+        /* Access a random entry: use a power-law access pattern up to
+         * 'switch_after' seconds. Then revert to flat access pattern. */
+        if (now-start < switch_after) {
+            /* Power law. */
+            idx = 1;
+            while((rand() % 21) != 0 && idx < keyspace_size) idx *= 2;
+            if (idx > keyspace_size) idx = keyspace_size;
+            idx = rand() % idx;
+        } else {
+            /* Flat. */
+            idx = rand() % keyspace_size;
+        }
+
+        /* Never access entries between position 10 and 14, so that
+         * we simulate what happens to new entries that are never
+         * accessed VS new entries which are accessed in positions
+         * 15-19.
+         *
+         * Also never access last 5 entry, so that we have keys which
+         * are never recreated (old), and never accessed. */
+        if ((idx < 10 || idx > 14) && (idx < keyspace_size-5))
+            access_entry(entries+idx);
+
+        /* Simulate the addition of new entries at positions between
+         * 10 and 19, a random one every 10 seconds. */
+        if (new_entry_time <= now) {
+            idx = 10+(rand()%10);
+            entries[idx].counter = COUNTER_INIT_VAL;
+            entries[idx].decrtime = to_16bit_minutes(time(NULL));
+            entries[idx].hits = 0;
+            entries[idx].ctime = time(NULL);
+            new_entry_time = now+10;
+        }
+
+        /* Show the first 20 entries and the last 20 entries. */
+        if (display_time != now) {
+            printf("=============================\n");
+            printf("Current minutes time: %d\n", (int)to_16bit_minutes(now));
+            printf("Access method: %s\n",
+                (now-start < switch_after) ? "power-law" : "flat");
+
+            for (j = 0; j < 20; j++)
+                show_entry(j,entries+j);
+
+            for (j = keyspace_size-20; j < keyspace_size; j++)
+                show_entry(j,entries+j);
+            display_time = now;
+        }
+    }
+    return 0;
+}
+

utils/lru/test-lru.rb

@@ -1,112 +1,223 @@
 require 'rubygems'
 require 'redis'
 
-r = Redis.new
-r.config("SET","maxmemory","2000000")
-r.config("SET","maxmemory-policy","allkeys-lru")
-r.config("SET","maxmemory-samples",5)
-r.config("RESETSTAT")
-r.flushall
+$runs = []; # Remember the error rate of each run for average purposes.
+$o = {};    # Options set parsing arguments
 
-puts <<EOF
-<html>
-<body>
-<style>
-.box {
-    width:5px;
-    height:5px;
-    float:left;
-    margin: 1px;
-}
-
-.old {
-    border: 1px black solid;
-}
-
-.new {
-    border: 1px green solid;
-}
-
-.ex {
-    background-color: #666;
-}
-</style>
-<pre>
-EOF
-
-# Fill
-oldsize = r.dbsize
-id = 0
-while true
-    id += 1
-    r.set(id,"foo")
-    newsize = r.dbsize
-    break if newsize == oldsize
-    oldsize = newsize
-end
-
-inserted = r.dbsize
-first_set_max_id = id
-puts "#{r.dbsize} keys inserted"
-
-# Access keys sequentially
-
-puts "Access keys sequentially"
-(1..first_set_max_id).each{|id|
-    r.get(id)
-#    sleep 0.001
-}
-
-# Insert more 50% keys. We expect that the new keys
-half = inserted/2
-puts "Insert enough keys to evict half the keys we inserted"
-add = 0
-while true
-    add += 1
-    id += 1
-    r.set(id,"foo")
-    break if r.info['evicted_keys'].to_i >= half
-end
-
-puts "#{add} additional keys added."
-puts "#{r.dbsize} keys in DB"
-
-# Check if evicted keys respect LRU
-# We consider errors from 1 to N progressively more serious as they violate
-# more the access pattern.
-
-errors = 0
-e = 1
-edecr = 1.0/(first_set_max_id/2)
-(1..(first_set_max_id/2)).each{|id|
-    e -= edecr if e > 0
-    e = 0 if e < 0
-    if r.exists(id)
-        errors += e
-    end
-}
-
-puts "#{errors} errors!"
-puts "</pre>"
-
-# Generate the graphical representation
-(1..id).each{|id|
-    # Mark first set and added items in a different way.
-    c = "box"
-    if id <= first_set_max_id
-        c << " old"
+def testit(filename)
+    r = Redis.new
+    r.config("SET","maxmemory","2000000")
+    if $o[:ttl]
+        r.config("SET","maxmemory-policy","volatile-ttl")
     else
-        c << " new"
+        r.config("SET","maxmemory-policy","allkeys-lru")
+    end
+    r.config("SET","maxmemory-samples",5)
+    r.config("RESETSTAT")
+    r.flushall
+
+    html = ""
+    html << <<EOF
+    <html>
+    <body>
+    <style>
+    .box {
+        width:5px;
+        height:5px;
+        float:left;
+        margin: 1px;
+    }
+
+    .old {
+        border: 1px black solid;
+    }
+
+    .new {
+        border: 1px green solid;
+    }
+
+    .otherdb {
+        border: 1px red solid;
+    }
+
+    .ex {
+        background-color: #666;
+    }
+    </style>
+    <pre>
+EOF
+
+    # Fill the DB up to the first eviction.
+    oldsize = r.dbsize
+    id = 0
+    while true
+        id += 1
+        begin
+            r.set(id,"foo")
+        rescue
+            break
+        end
+        newsize = r.dbsize
+        break if newsize == oldsize # A key was evicted? Stop.
+        oldsize = newsize
     end
 
-    # Add class if exists
-    c << " ex" if r.exists(id)
-    puts "<div class=\"#{c}\"></div>"
-}
+    inserted = r.dbsize
+    first_set_max_id = id
+    html << "#{r.dbsize} keys inserted.\n"
 
-# Close HTML page
+    # Access keys sequentially, so that in theory the first part will be expired
+    # and the latter part will not, according to perfect LRU.
 
-puts <<EOF
-</body>
-</html>
+    if $o[:ttl]
+        STDERR.puts "Set increasing expire value"
+        (1..first_set_max_id).each{|id|
+            r.expire(id,1000+id)
+            STDERR.print(".") if (id % 150) == 0
+        }
+    else
+        STDERR.puts "Access keys sequentially"
+        (1..first_set_max_id).each{|id|
+            r.get(id)
+            sleep 0.001
+            STDERR.print(".") if (id % 150) == 0
+        }
+    end
+    STDERR.puts
+
+    # Insert more 50% keys. We expect that the new keys will rarely be expired
+    # since their last access time is recent compared to the others.
+    #
+    # Note that we insert the first 100 keys of the new set into DB1 instead
+    # of DB0, so that we can try how cross-DB eviction works.
+    half = inserted/2
+    html << "Insert enough keys to evict half the keys we inserted.\n"
+    add = 0
+
+    otherdb_start_idx = id+1
+    otherdb_end_idx = id+100
+    while true
+        add += 1
+        id += 1
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            r.select(1)
+            r.set(id,"foo")
+            r.select(0)
+        else
+            r.set(id,"foo")
+        end
+        break if r.info['evicted_keys'].to_i >= half
+    end
+
+    html << "#{add} additional keys added.\n"
+    html << "#{r.dbsize} keys in DB.\n"
+
+    # Check if evicted keys respect LRU
+    # We consider errors from 1 to N progressively more serious as they violate
+    # more the access pattern.
+
+    errors = 0
+    e = 1
+    error_per_key = 100000.0/first_set_max_id
+    half_set_size = first_set_max_id/2
+    maxerr = 0
+    (1..(first_set_max_id/2)).each{|id|
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            r.select(1)
+            exists = r.exists(id)
+            r.select(0)
+        else
+            exists = r.exists(id)
+        end
+        if id < first_set_max_id/2
+            thiserr = error_per_key * ((half_set_size-id).to_f/half_set_size)
+            maxerr += thiserr
+            errors += thiserr if exists
+        elsif id >= first_set_max_id/2
+            thiserr = error_per_key * ((id-half_set_size).to_f/half_set_size)
+            maxerr += thiserr
+            errors += thiserr if !exists
+        end
+    }
+    errors = errors*100/maxerr
+
+    STDERR.puts "Test finished with #{errors}% error! Generating HTML on stdout."
+
+    html << "#{errors}% error!\n"
+    html << "</pre>"
+    $runs << errors
+
+    # Generate the graphical representation
+    (1..id).each{|id|
+        # Mark first set and added items in a different way.
+        c = "box"
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            c << " otherdb"
+        elsif id <= first_set_max_id
+            c << " old"
+        else
+            c << " new"
+        end
+
+        # Add class if exists
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            r.select(1)
+            exists = r.exists(id)
+            r.select(0)
+        else
+            exists = r.exists(id)
+        end
+
+        c << " ex" if exists
+        html << "<div title=\"#{id}\" class=\"#{c}\"></div>"
+    }
+
+    # Close HTML page
+
+    html << <<EOF
+    </body>
+    </html>
 EOF
+
+    f = File.open(filename,"w")
+    f.write(html)
+    f.close
+end
+
+def print_avg
+    avg = ($runs.reduce {|a,b| a+b}) / $runs.length
+    puts "#{$runs.length} runs, AVG is #{avg}"
+end
+
+if ARGV.length < 1
+    STDERR.puts "Usage: ruby test-lru.rb <html-output-filename> [--runs <count>] [--ttl]"
+    STDERR.puts "Options:"
+    STDERR.puts "  --runs <count>    Execute the test <count> times."
+    STDERR.puts "  --ttl             Set keys with increasing TTL values"
+    STDERR.puts "                    (starting from 1000 seconds) in order to"
+    STDERR.puts "                    test the volatile-lru policy."
+    exit 1
+end
+
+filename = ARGV[0]
+$o[:numruns] = 1
+
+# Options parsing
+i = 1
+while i < ARGV.length
+    if ARGV[i] == '--runs'
+        $o[:numruns] = ARGV[i+1].to_i
+        i+= 1
+    elsif ARGV[i] == '--ttl'
+        $o[:ttl] = true
+    else
+        STDERR.puts "Unknown option #{ARGV[i]}"
+        exit 1
+    end
+    i+= 1
+end
+
+$o[:numruns].times {
+    testit(filename)
+    print_avg if $o[:numruns] != 1
+}

utils/releasetools/03_test_release.sh

@@ -13,6 +13,8 @@ ssh antirez@metal "export TERM=xterm;
                    cd /tmp;
                    rm -rf test_release_tmp_dir;
                    cd test_release_tmp_dir;
+                   rm -f $TARNAME;
+                   rm -rf redis-${TAG};
                    wget $DOWNLOADURL;
                    tar xvzf $TARNAME;
                    cd redis-${TAG};

utils/releasetools/changelog.tcl

@@ -0,0 +1,30 @@
+#!/usr/bin/env tclsh
+
+if {[llength $::argv] != 2} {
+    puts "Usage: $::argv0 <branch> <version>"
+    exit 1
+}
+
+set branch [lindex $::argv 0]
+set ver [lindex $::argv 1]
+
+set template {
+================================================================================
+Redis %ver%     Released %date%
+================================================================================
+
+Upgrade urgency <URGENCY>: <DESCRIPTION>
+}
+
+set template [string trim $template]
+append template "\n\n"
+set date [clock format [clock seconds]]
+set template [string map [list %ver% $ver %date% $date] $template]
+
+append template [exec git log $branch~30..$branch "--format=format:%an in commit %h:%n %s" --shortstat]
+
+#Older, more verbose version.
+#
+#append template [exec git log $branch~30..$branch "--format=format:+-------------------------------------------------------------------------------%n| %s%n| By %an, %ai%n+--------------------------------------------------------------------------------%nhttps://github.com/antirez/redis/commit/%H%n%n%b" --stat]
+
+puts $template