c#实现redis客户端(一)

c#实现redis客户端(一)
https://www.cnblogs.com/mushroom/p/4217541.html

  最近项目使用中要改造redis客户端，看了下文档，总结分享一下。

阅读目录：

1. 协议规范
2. 基础通信
3. 状态命令
4. set、get命令
5. 管道、事务
6. 总结

协议规范

redis允许客户端以TCP方式连接，默认6379端口。传输数据都以\r\n结尾。

请求格式

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

例：*1\r\n$4\r\nINFO\r\n

响应格式

1：简单字符串，非二进制安全字符串，一般是状态回复。  +开头，例：+OK\r\n 

2: 错误信息。　　　　　　　　　　-开头， 例：-ERR unknown command 'mush'\r\n

3: 整型数字。                            :开头， 例：:1\r\n

4：大块回复值，最大512M。           $开头+数据长度。 例：$4\r\mush\r\n

5：多条回复。                           *开头， 例：*2\r\n$3\r\nfoo\r\n$3\r\nbar\r\n

基础通信

定义配置类：

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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;         }     }

实现socket连接：

 public class RedisBaseClient
    {
        //配置文件
        private Configuration configuration;
        //通信socket
        private Socket socket;
        //接收字节数组
        private byte[] ReceiveBuffer = new byte[100000];
    </span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> RedisBaseClient(Configuration config)
    {
        configuration </span>=<span style="color: rgba(0, 0, 0, 1)"> config;
    }

    </span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> RedisBaseClient()
        : </span><span style="color: rgba(0, 0, 255, 1)">this</span>(<span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Configuration())
    {
    }

    </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> Connect()
    {
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (socket != <span style="color: rgba(0, 0, 255, 1)">null</span> &amp;&amp;<span style="color: rgba(0, 0, 0, 1)"> socket.Connected)
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)">;
        socket </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        {
            NoDelay </span>=<span style="color: rgba(0, 0, 0, 1)"> configuration.NoDelaySocket
        };
        socket.Connect(configuration.Host, configuration.Port);
        </span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (socket.Connected)
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)">;
        Close();
    }

    </span><span style="color: rgba(128, 128, 128, 1)">///</span> <span style="color: rgba(128, 128, 128, 1)">&lt;summary&gt;</span>
    <span style="color: rgba(128, 128, 128, 1)">///</span><span style="color: rgba(0, 128, 0, 1)"> 关闭client
    </span><span style="color: rgba(128, 128, 128, 1)">///</span> <span style="color: rgba(128, 128, 128, 1)">&lt;/summary&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> Close()
    {
        socket.Disconnect(</span><span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">);
        socket.Close();
    }
}</span></pre>

调用：

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

服务端成功响应：

　　

状态命令

定义Redis命令枚举：

public enum RedisCommand
    {
        GET, //获取一个key的值
        INFO, //Redis信息。  
        SET, //添加一个值
        EXPIRE, //设置过期时间
        MULTI, //标记一个事务块开始
        EXEC, //执行所有 MULTI 之后发的命令
    }

发送命令构建：

  public string SendCommand(RedisCommand command, params string[] args)
        {
            //请求头部格式， *<number of arguments>\r\n
            const string headstr = "*{0}\r\n";
            //参数信息       $<number of bytes of argument N>\r\n<argument data>\r\n
            const string bulkstr = "${0}\r\n{1}\r\n";
        </span><span style="color: rgba(0, 0, 255, 1)">var</span> sb = <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> StringBuilder();
        sb.AppendFormat(headstr, args.Length </span>+ <span style="color: rgba(128, 0, 128, 1)">1</span><span style="color: rgba(0, 0, 0, 1)">);

        </span><span style="color: rgba(0, 0, 255, 1)">var</span> cmd =<span style="color: rgba(0, 0, 0, 1)"> command.ToString();
        sb.AppendFormat(bulkstr, cmd.Length, cmd);

        </span><span style="color: rgba(0, 0, 255, 1)">foreach</span> (<span style="color: rgba(0, 0, 255, 1)">var</span> arg <span style="color: rgba(0, 0, 255, 1)">in</span><span style="color: rgba(0, 0, 0, 1)"> args)
        {
            sb.AppendFormat(bulkstr, arg.Length, arg);
        }
        </span><span style="color: rgba(0, 0, 255, 1)">byte</span>[] c =<span style="color: rgba(0, 0, 0, 1)"> Encoding.UTF8.GetBytes(sb.ToString());
        </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)">
        {
            Connect();
            socket.Send(c);

            socket.Receive(ReceiveBuffer);
            Close();
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> ReadData();
        }
        </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (SocketException e)
        {
            Close();
        }
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    }

private string ReadData()

{

var data = Encoding.UTF8.GetString(ReceiveBuffer);

char c = data[0];

//错误消息检查。

if (c == '-') //异常处理。

throw new Exception(data);

//状态回复。

if (c == '+')

return data;

return data;

}

 调用：

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

输出响应，其$937是数据包的长度。

 

set、get命令

调用：

   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();
        }

输出

管道、事务

 二者都是走的MULTI，EXEC命令，原子操作。管道就是发送命令(无需等上次命令回复)，进入命令队列，然后多条命令一次执行，并返回客户端结果。 

 平常使用ServiceStack.Redis客户端都直接set了，其实是set、expire 2个命令。 简单实现如下：

        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)
        {
            //请求头部格式， *<number of arguments>\r\n
            const string headstr = "*{0}\r\n";
            //参数信息       $<number of bytes of argument N>\r\n<argument data>\r\n
            const string bulkstr = "${0}\r\n{1}\r\n";
        </span><span style="color: rgba(0, 0, 255, 1)">var</span> sb = <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> StringBuilder();
        sb.AppendFormat(headstr, args.Length </span>+ <span style="color: rgba(128, 0, 128, 1)">1</span><span style="color: rgba(0, 0, 0, 1)">);

        </span><span style="color: rgba(0, 0, 255, 1)">var</span> cmd =<span style="color: rgba(0, 0, 0, 1)"> command.ToString();
        sb.AppendFormat(bulkstr, cmd.Length, cmd);

        </span><span style="color: rgba(0, 0, 255, 1)">foreach</span> (<span style="color: rgba(0, 0, 255, 1)">var</span> arg <span style="color: rgba(0, 0, 255, 1)">in</span><span style="color: rgba(0, 0, 0, 1)"> args)
        {
            sb.AppendFormat(bulkstr, arg.Length, arg);
        }
        </span><span style="color: rgba(0, 0, 255, 1)">byte</span>[] c =<span style="color: rgba(0, 0, 0, 1)"> Encoding.UTF8.GetBytes(sb.ToString());
        </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)">
        {
            Connect();
            socket.Send(c);
            
            socket.Receive(ReceiveBuffer);
            </span><span style="color: rgba(0, 0, 255, 1)">if</span> (!<span style="color: rgba(0, 0, 0, 1)">isPipeline)
            {
                Close();
            }
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> ReadData();
        }
        </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (SocketException e)
        {
            Close();
        }
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    }
    </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">string</span> SetByPipeline(<span style="color: rgba(0, 0, 255, 1)">string</span> key, <span style="color: rgba(0, 0, 255, 1)">string</span> value, <span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> second)
    {
        </span><span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">.CreatePipeline();
        </span><span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">.EnqueueCommand(RedisCommand.SET, key, value);
        </span><span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">.EnqueueCommand(RedisCommand.EXPIRE, key, second.ToString());
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">.FlushPipeline();
    }     <br></span></pre>

 调用：

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

输出：

*2 表示2条回复。

+2 表示命令执行OK。

:1  表示命令执行的结果

总结

本文只是简单的实现，有兴趣的同学，可以继续下去。

客户端实现这块，Socket连接池管理相较复杂些。

参考资源：

http://redis.io/topics/protocol

https://github.com/ServiceStack/ServiceStack.Redis