c#實現redis客戶端(一)

時間 2019-11-11

標籤 c# 實現 redis 客戶端欄目 C# 简体版

原文原文鏈接

最近項目使用中要改造redis客戶端，看了下文檔，總結分享一下。git

閱讀目錄：

協議規範

redis容許客戶端以TCP方式鏈接，默認6379端口。傳輸數據都以\r\n結尾。github

請求格式

*<number of arguments>\r\n$<number of bytes of argument 1>\r\n<argument data>\r\nredis

例：*1\r\n$4\r\nINFO\r\n算法

響應格式

1：簡單字符串，非二進制安全字符串，通常是狀態回覆。 +開頭，例：+OK\r\n 數組

2: 錯誤信息。　　　　　　　　　　-開頭，例：-ERR unknown command 'mush'\r\n安全

3: 整型數字。 :開頭，例：:1\r\nsocket

4：大塊回覆值，最大512M。 $開頭+數據長度。例：$4\r\mush\r\nui

5：多條回覆。 *開頭，例：*2\r\n$3\r\nfoo\r\n$3\r\nbar\r\nthis

基礎通訊

定義配置類：spa

public class Configuration
    {
        public string Host { get; set; }
        public int Port { get; set; }
        /// <summary>
        /// Socket 是否正在使用 Nagle 算法。
        /// </summary>
        public bool NoDelaySocket { get; set; }

        public Configuration()
        {
            Host = "localhost";
            Port = 6379;
            NoDelaySocket = false;
        }
    }

實現socket鏈接：

 public class RedisBaseClient
    {
        //配置文件
        private Configuration configuration;
        //通訊socket
        private Socket socket;
        //接收字節數組
        private byte[] ReceiveBuffer = new byte[100000];

        public RedisBaseClient(Configuration config)
        {
            configuration = config;
        }

        public RedisBaseClient()
            : this(new Configuration())
        {
        }

        public void Connect()
        {
            if (socket != null && socket.Connected)
                return;
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
            {
                NoDelay = configuration.NoDelaySocket
            };
            socket.Connect(configuration.Host, configuration.Port);
            if (socket.Connected)
                return;
            Close();
        }

        /// <summary>
        /// 關閉client
        /// </summary>
        public void Close()
        {
            socket.Disconnect(false);
            socket.Close();
        }
    }

調用：

RedisBaseClient redis = new RedisBaseClient();
redis.Connect();

服務端成功響應：

狀態命令

定義Redis命令枚舉：

public enum RedisCommand
    {
        GET, //獲取一個key的值
        INFO, //Redis信息。  
        SET, //添加一個值
        EXPIRE, //設置過時時間
        MULTI, //標記一個事務塊開始
        EXEC, //執行全部 MULTI 以後發的命令
    }

發送命令構建：

  public string SendCommand(RedisCommand command, params string[] args)
        {
            //請求頭部格式， *<number of arguments>\r\n
            const string headstr = "*{0}\r\n";
            //參數信息       $<number of bytes of argument N>\r\n<argument data>\r\n
            const string bulkstr = "${0}\r\n{1}\r\n";

            var sb = new StringBuilder();
            sb.AppendFormat(headstr, args.Length + 1);

            var cmd = command.ToString();
            sb.AppendFormat(bulkstr, cmd.Length, cmd);

            foreach (var arg in args)
            {
                sb.AppendFormat(bulkstr, arg.Length, arg);
            }
            byte[] c = Encoding.UTF8.GetBytes(sb.ToString());
            try
            {
                Connect();
                socket.Send(c);

                socket.Receive(ReceiveBuffer);
                Close();
                return ReadData();
            }
            catch (SocketException e)
            {
                Close();
            }
            return null;
        }
   private string ReadData()
        {
            var data = Encoding.UTF8.GetString(ReceiveBuffer);
            char c = data[0];
            //錯誤消息檢查。
            if (c == '-') //異常處理。
                throw new Exception(data);
            //狀態回覆。
            if (c == '+')
                return data;
            return data;
        }

調用：

 private void button1_Click(object sender, EventArgs e)
        {
            RedisBaseClient redis = new RedisBaseClient();
            var result = redis.SendCommand(RedisCommand.INFO);
            richTextBox1.Text = result;
        }

輸出響應，其$937是數據包的長度。

set、get命令

調用：

   private void button2_Click(object sender, EventArgs e)
        {
            RedisBaseClient redis = new RedisBaseClient();
            var result = redis.SendCommand(RedisCommand.SET, "msg", "testvalue");
            richTextBox1.Text = result.ToString();
        }
        private void button3_Click(object sender, EventArgs e)
        {
            RedisBaseClient redis = new RedisBaseClient();
            var result = redis.SendCommand(RedisCommand.GET, "msg");
            richTextBox1.Text = result.ToString();
        }

輸出

管道、事務

兩者都是走的MULTI，EXEC命令，原子操做。管道就是發送命令(無需等上次命令回覆)，進入命令隊列，而後多條命令一次執行，並返回客戶端結果。

日常使用ServiceStack.Redis客戶端都直接set了，實際上是set、expire 2個命令。簡單實現以下：

        public void CreatePipeline()
        {
            SendCommand(RedisCommand.MULTI, new string[] {}, true);
        }
        public string EnqueueCommand(RedisCommand command, params string[] args)
        {
            return SendCommand(command, args, true);
        }
        public string FlushPipeline()
        {
            var result = SendCommand(RedisCommand.EXEC, new string[] {}, true);
            Close();
            return result;
        }
        public string SendCommand(RedisCommand command, string[] args, bool isPipeline=false)
        {
            //請求頭部格式， *<number of arguments>\r\n
            const string headstr = "*{0}\r\n";
            //參數信息       $<number of bytes of argument N>\r\n<argument data>\r\n
            const string bulkstr = "${0}\r\n{1}\r\n";

            var sb = new StringBuilder();
            sb.AppendFormat(headstr, args.Length + 1);

            var cmd = command.ToString();
            sb.AppendFormat(bulkstr, cmd.Length, cmd);

            foreach (var arg in args)
            {
                sb.AppendFormat(bulkstr, arg.Length, arg);
            }
            byte[] c = Encoding.UTF8.GetBytes(sb.ToString());
            try
            {
                Connect();
                socket.Send(c);
                
                socket.Receive(ReceiveBuffer);
                if (!isPipeline)
                {
                    Close();
                }
                return ReadData();
            }
            catch (SocketException e)
            {
                Close();
            }
            return null;
        }
        public string SetByPipeline(string key, string value, int second)
        {
            this.CreatePipeline();
            this.EnqueueCommand(RedisCommand.SET, key, value);
            this.EnqueueCommand(RedisCommand.EXPIRE, key, second.ToString());
            return this.FlushPipeline();
        }

調用：

  private void button4_Click(object sender, EventArgs e)
        {
            RedisBaseClient redis = new RedisBaseClient();
            richTextBox1.Text = redis.SetByPipeline("cnblogs", "mushroom", 1000);
        }