Centrifugo Redis proto support

redis.go

package libcentrifugo

import (
	"encoding/json"
	"strings"

	"github.com/FZambia/go-logger"
	"github.com/tidwall/redcon"
)

var addr = ":6380"

type connMeta struct {
	inPipe      bool
	pipeCounter int
}

func (app *Application) startRedisServer() error {

	logger.INFO.Printf("Started Redis protocol compatible API server at %s", ":6380")

	conns := map[redcon.Conn]*connMeta{}

	err := redcon.ListenAndServe(":6380",
		func(conn redcon.Conn, commands [][]string) {
			c := conns[conn]
			for _, args := range commands {
				switch strings.ToLower(args[0]) {
				default:
					conn.WriteError("ERR unknown command '" + args[0] + "'")
				case "ping":
					conn.WriteString("PONG")
				case "quit":
					conn.WriteString("OK")
					conn.Close()
				case "multi":
					conn.WriteString("OK")
					c.inPipe = true
				case "exec":
					conn.WriteArray(c.pipeCounter)
					for i := 0; i < c.pipeCounter; i++ {
						conn.WriteString("OK")
					}
					c.inPipe = false
					c.pipeCounter = 0
				case "set":
					if len(args) != 3 {
						conn.WriteError("ERR wrong number of arguments for '" + args[0] + "' command")
						continue
					}
					if !c.inPipe {
						conn.WriteString("OK")
					} else {
						conn.WriteString("QUEUED")
						c.pipeCounter += 1
					}
					cmd := apiCommand{
						Method: args[1],
						Params: json.RawMessage([]byte(args[2])),
					}
					_, err := app.apiCmd(cmd)
					if err != nil {
						logger.ERROR.Println(err)
					}
				case "get":
					if len(args) != 2 {
						conn.WriteError("ERR wrong number of arguments for '" + args[0] + "' command")
						continue
					}
					conn.WriteNull()
				}
			}
		},
		func(conn redcon.Conn) bool {
			conns[conn] = &connMeta{}
			logger.INFO.Printf("Accept connection to Redis compatible API server: %s", conn.RemoteAddr())
			return true
		},
		func(conn redcon.Conn, err error) {
			delete(conns, conn)
			logger.INFO.Printf("Connection to Redis compatible API server closed: %s, err: %v", conn.RemoteAddr(), err)
		},
	)
	if err != nil {
		logger.FATAL.Fatal(err)
	}
	return nil
}