c#实现redis客户端(一)

  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:

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];

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

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";

            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];
            //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:

 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";

            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();
        }     

 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

posted @ 2015-01-12 08:55  蘑菇先生  阅读(...)  评论(...编辑  收藏