node/vms/rpcchainvm/rpchttp/rpcreader/reader_server.go

//go:build grpc

// Copyright (C) 2019-2025, Lux Industries Inc. All rights reserved.
// See the file LICENSE for licensing terms.

package rpcreader

import (
	"context"
	"io"

	readerpb "github.com/luxfi/node/proto/pb/io/reader"
)

var _ readerpb.ReaderServer = (*Server)(nil)

// Server is an io.Reader that is managed over RPC.
type Server struct {
	readerpb.UnsafeReaderServer
	reader io.Reader
}

// NewServer returns an io.Reader instance managed remotely
func NewServer(reader io.Reader) *Server {
	return &Server{reader: reader}
}

func (s *Server) Read(_ context.Context, req *readerpb.ReadRequest) (*readerpb.ReadResponse, error) {
	buf := make([]byte, int(req.Length))
	n, err := s.reader.Read(buf)
	resp := &readerpb.ReadResponse{
		Read: buf[:n],
	}
	if err != nil {
		resp.Error = &readerpb.Error{
			Message: err.Error(),
		}

		// Sentinel errors must be special-cased through an error code
		if err == io.EOF {
			resp.Error.ErrorCode = readerpb.ErrorCode_ERROR_CODE_EOF
		}
	}
	return resp, nil
}