c#实现redis客户端(一)。
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*\r\n$\r\n\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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 public class Configuration { public string Host { get; set; } public int Port { get; set; } /// /// Socket 是否正在使用 Nagle 算法。 /// 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(); } /// /// 关闭client /// 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, *\r\n const string headstr = "*{0}\r\n"; //参数信息 $\r\n\r\n const string bulkstr = "${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:
1 2 3 4 5 6 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。