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:
- 协议规范
- 基础通信
- 状态命令
- set、get命令
- 管道、事务
- 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:
</span><span >public</span><span > RedisBaseClient(Configuration config)
{
configuration </span>=<span > config;
}
</span><span >public</span><span > RedisBaseClient()
: </span><span >this</span>(<span >new</span><span > Configuration())
{
}
</span><span >public</span> <span >void</span><span > Connect()
{
</span><span >if</span> (socket != <span >null</span> &&<span > socket.Connected)
</span><span >return</span><span >;
socket </span>= <span >new</span><span > Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
{
NoDelay </span>=<span > configuration.NoDelaySocket
};
socket.Connect(configuration.Host, configuration.Port);
</span><span >if</span><span > (socket.Connected)
</span><span >return</span><span >;
Close();
}
</span><span style="color: rgba(128, 128, 128, 1)">///</span> <span style="color: rgba(128, 128, 128, 1)"><summary></span>
<span style="color: rgba(128, 128, 128, 1)">///</span><span > 关闭client
</span><span style="color: rgba(128, 128, 128, 1)">///</span> <span style="color: rgba(128, 128, 128, 1)"></summary></span>
<span >public</span> <span >void</span><span > Close()
{
socket.Disconnect(</span><span >false</span><span >);
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:
</span><span >var</span> sb = <span >new</span><span > StringBuilder();
sb.AppendFormat(headstr, args.Length </span>+ <span >1</span><span >);
</span><span >var</span> cmd =<span > command.ToString();
sb.AppendFormat(bulkstr, cmd.Length, cmd);
</span><span >foreach</span> (<span >var</span> arg <span >in</span><span > args)
{
sb.AppendFormat(bulkstr, arg.Length, arg);
}
</span><span >byte</span>[] c =<span > Encoding.UTF8.GetBytes(sb.ToString());
</span><span >try</span><span >
{
Connect();
socket.Send(c);
socket.Receive(ReceiveBuffer);
Close();
</span><span >return</span><span > ReadData();
}
</span><span >catch</span><span > (SocketException e)
{
Close();
}
</span><span >return</span> <span >null</span><span >;
}
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
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。
,其实是set、expire 2个命令。
</span><span >var</span> sb = <span >new</span><span > StringBuilder();
sb.AppendFormat(headstr, args.Length </span>+ <span >1</span><span >);
</span><span >var</span> cmd =<span > command.ToString();
sb.AppendFormat(bulkstr, cmd.Length, cmd);
</span><span >foreach</span> (<span >var</span> arg <span >in</span><span > args)
{
sb.AppendFormat(bulkstr, arg.Length, arg);
}
</span><span >byte</span>[] c =<span > Encoding.UTF8.GetBytes(sb.ToString());
</span><span >try</span><span >
{
Connect();
socket.Send(c);
socket.Receive(ReceiveBuffer);
</span><span >if</span> (!<span >isPipeline)
{
Close();
}
</span><span >return</span><span > ReadData();
}
</span><span >catch</span><span > (SocketException e)
{
Close();
}
</span><span >return</span> <span >null</span><span >;
}
</span><span >public</span> <span >string</span> SetByPipeline(<span >string</span> key, <span >string</span> value, <span >int</span><span > second)
{
</span><span >this</span><span >.CreatePipeline();
</span><span >this</span><span >.EnqueueCommand(RedisCommand.SET, key, value);
</span><span >this</span><span >.EnqueueCommand(RedisCommand.EXPIRE, key, second.ToString());
</span><span >return</span> <span >this</span><span >.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