gedis：自己实现go语言的redis客户端第三节（redis协议的处理）

素颜马尾好姑娘i 2023-06-17 02:59 15阅读 0赞

redis的通信协议本文不做分析和解读，建议参考redis官方文档或其它博文，我们直接看实现：

redis相关命令及常量定义：

package protocol
    
    const DOLLARBYTE = "$"
    const ASTERISKBYTE = "*"
    const PLUSBYTE = "+"
    const MINUS_BYTE = "-"
    const COLON_BYTE = ":"
    const CRLF = "\r\n"
    const BLANK = ""
    const OK = "+OK\r\n"
    const NONEXIST = "$-1"
    
    const PING = "PING"
    const SET = "SET"
    const GET = "GET"
    const QUIT = "QUIT"
    const EXISTS = "EXISTS"
    const DEL = "DEL"
    const TYPE = "TYPE"
    const FLUSHDB = "FLUSHDB"
    const KEYS = "KEYS"
    const RANDOMKEY = "RANDOMKEY"
    const RENAME = "RENAME"
    const RENAMENX = "RENAMENX"
    const RENAMEX = "RENAMEX"
    const DBSIZE = "DBSIZE"
    const EXPIRE = "EXPIRE"
    const EXPIREAT = "EXPIREAT"
    const TTL = "TTL"
    const SELECT = "SELECT"
    const MOVE = "MOVE"
    const FLUSHALL = "FLUSHALL"
    const GETSET = "GETSET"
    const MGET = "MGET"
    const SETNX = "SETNX"
    const SETEX = "SETEX"
    const MSET = "MSET"
    const MSETNX = "MSETNX"
    const DECRBY = "DECRBY"
    const DECR = "DECR"
    const INCRBY = "INCRBY"
    const INCR = "INCR"
    const APPEND = "APPEND"
    const SUBSTR = "SUBSTR"
    const HSET = "HSET"
    const HGET = "HGET"
    const HSETNX = "HSETNX"
    const HMSET = "HMSET"
    const HMGET = "HMGET"
    const HINCRBY = "HINCRBY"
    const HEXISTS = "HEXISTS"
    const HDEL = "HDEL"
    const HLEN = "HLEN"
    const HKEYS = "HKEYS"
    const HVALS = "HVALS"
    const HGETALL = "HGETALL"
    const RPUSH = "RPUSH"
    const LPUSH = "LPUSH"
    const LLEN = "LLEN"
    const LRANGE = "LRANGE"
    const LTRIM = "LTRIM"
    const LINDEX = "LINDEX"
    const LSET = "LSET"
    const LREM = "LREM"
    const LPOP = "LPOP"
    const RPOP = "RPOP"
    const RPOPLPUSH = "RPOPLPUSH"
    const SADD = "SADD"
    const SMEMBERS = "SMEMBERS"
    const SREM = "SREM"
    const SPOP = "SPOP"
    const SMOVE = "SMOVE"
    const SCARD = "SCARD"
    const SISMEMBER = "SISMEMBER"
    const SINTER = "SINTER"
    const SINTERSTORE = "SINTERSTORE"
    const SUNION = "SUNION"
    const SUNIONSTORE = "SUNIONSTORE"
    const SDIFF = "SDIFF"
    const SDIFFSTORE = "SDIFFSTORE"
    const SRANDMEMBER = "SRANDMEMBER"
    const ZADD = "ZADD"
    const ZRANGE = "ZRANGE"
    const ZREM = "ZREM"
    const ZINCRBY = "ZINCRBY"
    const ZRANK = "ZRANK"
    const ZREVRANK = "ZREVRANK"
    const ZREVRANGE = "ZREVRANGE"
    const ZCARD = "ZCARD"
    const ZSCORE = "ZSCORE"
    const MULTI = "MULTI"
    const DISCARD = "DISCARD"
    const EXEC = "EXEC"
    const WATCH = "WATCH"
    const UNWATCH = "UNWATCH"
    const SORT = "SORT"
    const BLPOP = "BLPOP"
    const BRPOP = "BRPOP"
    const AUTH = "AUTH"
    const SUBSCRIBE = "SUBSCRIBE"
    const PUBLISH = "PUBLISH"
    const UNSUBSCRIBE = "UNSUBSCRIBE"
    const PSUBSCRIBE = "PSUBSCRIBE"
    const PUNSUBSCRIBE = "PUNSUBSCRIBE"
    const PUBSUB = "PUBSUB"
    const ZCOUNT = "ZCOUNT"
    const ZRANGEBYSCORE = "ZRANGEBYSCORE"
    const ZREVRANGEBYSCORE = "ZREVRANGEBYSCORE"
    const ZREMRANGEBYRANK = "ZREMRANGEBYRANK"
    const ZREMRANGEBYSCORE = "ZREMRANGEBYSCORE"
    const ZUNIONSTORE = "ZUNIONSTORE"
    const ZINTERSTORE = "ZINTERSTORE"
    const ZLEXCOUNT = "ZLEXCOUNT"
    const ZRANGEBYLEX = "ZRANGEBYLEX"
    const ZREVRANGEBYLEX = "ZREVRANGEBYLEX"
    const ZREMRANGEBYLEX = "ZREMRANGEBYLEX"
    const SAVE = "SAVE"
    const BGSAVE = "BGSAVE"
    const BGREWRITEAOF = "BGREWRITEAOF"
    const LASTSAVE = "LASTSAVE"
    const SHUTDOWN = "SHUTDOWN"
    const INFO = "INFO"
    const MONITOR = "MONITOR"
    const SLAVEOF = "SLAVEOF"
    const CONFIG = "CONFIG"
    const STRLEN = "STRLEN"
    const SYNC = "SYNC"
    const LPUSHX = "LPUSHX"
    const PERSIST = "PERSIST"
    const RPUSHX = "RPUSHX"
    const ECHO = "ECHO"
    const LINSERT = "LINSERT"
    const DEBUG = "DEBUG"
    const BRPOPLPUSH = "BRPOPLPUSH"
    const SETBIT = "SETBIT"
    const GETBIT = "GETBIT"
    const BITPOS = "BITPOS"
    const SETRANGE = "SETRANGE"
    const GETRANGE = "GETRANGE"
    const EVAL = "EVAL"
    const EVALSHA = "EVALSHA"
    const SCRIPT = "SCRIPT"
    const SLOWLOG = "SLOWLOG"
    const OBJECT = "OBJECT"
    const BITCOUNT = "BITCOUNT"
    const BITOP = "BITOP"
    const SENTINEL = "SENTINEL"
    const DUMP = "DUMP"
    const RESTORE = "RESTORE"
    const PEXPIRE = "PEXPIRE"
    const PEXPIREAT = "PEXPIREAT"
    const PTTL = "PTTL"
    const INCRBYFLOAT = "INCRBYFLOAT"
    const PSETEX = "PSETEX"
    const CLIENT = "CLIENT"
    const TIME = "TIME"
    const MIGRATE = "MIGRATE"
    const HINCRBYFLOAT = "HINCRBYFLOAT"
    const SCAN = "SCAN"
    const HSCAN = "HSCAN"
    const SSCAN = "SSCAN"
    const ZSCAN = "ZSCAN"
    const WAIT = "WAIT"
    const CLUSTER = "CLUSTER"
    const ASKING = "ASKING"
    const PFADD = "PFADD"
    const PFCOUNT = "PFCOUNT"
    const PFMERGE = "PFMERGE"
    const READONLY = "READONLY"
    const GEOADD = "GEOADD"
    const GEODIST = "GEODIST"
    const GEOHASH = "GEOHASH"
    const GEOPOS = "GEOPOS"
    const GEORADIUS = "GEORADIUS"
    const GEORADIUSBYMEMBER = "GEORADIUSBYMEMBER"
    const BITFIELD = "BITFIELD"

请求参数进行编码：

package handler
    
    import "protocol"
    
    func HandleMultiBulkRequest(key string, elements []string) [][]byte{
    	bytes := make([][]byte, len(elements)+1)
    	bytes[0] = protocol.SafeEncode(key)
    	for i := 0; i < len(elements); i++ {
    		bytes[i+1] = protocol.SafeEncode(elements[i])
    	}
    	return bytes
    }
    
    func HandleBulkRequest(elements []string) [][]byte{
    	bytes := make([][]byte, len(elements))
    	for i := 0; i < len(elements); i++ {
    		bytes[i] = protocol.SafeEncode(elements[i])
    	}
    	return bytes
    }

package protocol
    
    import "strconv"
    
    func SafeEncode(arg string) []byte {
    	return []byte(arg)
    }
    
    func SafeEncodeInt(arg int64) []byte {
    	return SafeEncode(strconv.FormatInt(arg, 10))
    }

消息发送模块：

package client
    
    import (
    	"net"
    	"bytes"
    	"protocol"
    	"strconv"
    	"fmt"
    	"os"
    )
    
    func SendCommand(conn *net.TCPConn, cmd string, a ...[]byte) string {
    	var buffer bytes.Buffer
    	buffer.Write(protocol.SafeEncode(protocol.ASTERISKBYTE))
    	buffer.Write(protocol.SafeEncode(strconv.Itoa(len(a) + 1)))
    	buffer.Write(protocol.SafeEncode(protocol.CRLF))
    	buffer.Write(protocol.SafeEncode(protocol.DOLLARBYTE))
    	buffer.Write(protocol.SafeEncode(strconv.Itoa(len(cmd))))
    	buffer.Write(protocol.SafeEncode(protocol.CRLF))
    	buffer.Write(protocol.SafeEncode(cmd))
    	buffer.Write(protocol.SafeEncode(protocol.CRLF))
    
    	for _, arg := range a {
    		buffer.Write(protocol.SafeEncode(protocol.DOLLARBYTE))
    		buffer.Write(protocol.SafeEncode(strconv.Itoa(len(arg))))
    		buffer.Write(protocol.SafeEncode(protocol.CRLF))
    		buffer.Write(arg)
    		buffer.Write(protocol.SafeEncode(protocol.CRLF))
    	}
    	return send(conn, buffer)
    }
    
    func send(conn *net.TCPConn, content bytes.Buffer) string {
    	//send to server
    	_, err := conn.Write(content.Bytes())
    
    	if err != nil {
    		fmt.Println(conn.RemoteAddr().String(), "server response")
    		os.Exit(1)
    	}
    
    	buffer := make([]byte, 1024)
    	//receive server info
    	msg, err := conn.Read(buffer)
    	if err != nil {
    		fmt.Println(conn.RemoteAddr().String(), "server response:"+err.Error())
    		os.Exit(1)
    	}
    	return string(buffer[:msg])
    }

消息接收处理模块：

package handler
    
    import (
    	"strings"
    	"protocol"
    	"fmt"
    	"github.com/emirpasic/gods/lists/arraylist"
    )
    
    /**
     * 处理redis响应的结果
     * 1、复杂的*...
     * 2、:数字
     * 3、简单的$...
     * 4、+OK
     * 5、-ERR(WRONGTYPE...)
     */
    func HandleReply(result string) (interface{}, error) {
    	if strings.HasPrefix(result, protocol.MINUS_BYTE) {
    		return handleMinusReply(result)
    	}
    
    	if strings.HasPrefix(result, protocol.PLUSBYTE) {
    		return handlePlusReply(result)
    	}
    
    	if strings.HasPrefix(result, protocol.COLON_BYTE) {
    		return handleColonReply(result)
    	}
    
    	if strings.HasPrefix(result, protocol.DOLLARBYTE) {
    		return handleDollarReply(result)
    	}
    
    	if strings.HasPrefix(result, protocol.ASTERISKBYTE) {
    		return HandleAsteriskReply(result)
    	}
    	return nil, fmt.Errorf("reply handle err")
    }
    
    func HandleAsteriskReply(result string) (interface{}, error) {
    	array := strings.Split(result, protocol.CRLF)
    	results := arraylist.New()
    	for i := 1; i < len(array)-1; i++ {
    		if array[i] == protocol.NONEXIST {
    			results.Add(nil)
    			continue
    		}
    		results.Add(array[i+1])
    		i++
    		if i > len(array)-2 {
    			break
    		}
    	}
    	return results.Values(), nil
    }
    
    func handlePlusReply(result string) (interface{}, error) {
    	if result != protocol.OK {
    		return nil, fmt.Errorf(result)
    	}
    	return strings.ReplaceAll(strings.ReplaceAll(result, protocol.CRLF, protocol.BLANK), protocol.PLUSBYTE, protocol.BLANK), nil
    }
    
    func handleDollarReply(result string) (interface{}, error) {
    	if strings.HasPrefix(result, protocol.NONEXIST) {
    		return nil, nil
    	}
    
    	if !strings.HasPrefix(result, protocol.DOLLARBYTE) {
    		return nil, fmt.Errorf(result)
    	}
    	array := strings.Split(result, protocol.CRLF)
    	return array[1], nil
    }
    
    func handleColonReply(result string) (interface{}, error) {
    	return strings.ReplaceAll(strings.ReplaceAll(result, protocol.CRLF, protocol.BLANK), protocol.COLON_BYTE, protocol.BLANK), nil
    }
    
    func handleMinusReply(result string) (interface{}, error) {
    	return strings.ReplaceAll(strings.ReplaceAll(result, protocol.CRLF, protocol.BLANK), protocol.MINUS_BYTE, protocol.BLANK), nil
    }

项目地址：

[https://github.com/zhangxiaomin1993/gedis][https_github.com_zhangxiaomin1993_gedis]

[https_github.com_zhangxiaomin1993_gedis]: https://github.com/zhangxiaomin1993/gedis