HTML5的TCP和UDP Web Socket API草案定稿

这是在 Web 上实现 UDP/TCP API 的草案，沿未形成标准。该标准的一大亮点就是使用内置 Promise 设计模式，替代了传统 JavaScript 中的事件触发回调。不过各大浏览器厂商会不会这样实现还要打一个问号，毕竟编写标准的学院派和实现标准的行业派很难达到完全统一。

　　以下内容来自： http://www.w3.org/TR/2014/WD-tcp-udp-sockets-20141202/

　　接口标准提供对原始 UDP 套接字(Socket)，TCP 客户端套接字和 TCP 服务器套接字 API 的定义。

　　简介

　　这部分沿未形成规范。您可以使用该 API 来发送和接收数据，并使用 TCP 或 UDP 网络。

　　使用此 API 的部分用例：

• 能够与 SMTP, POP3 和 IMAP 服务器进行通信的邮件服务器。
• 一个能与 IRC 服务器进行通信的 IRC 客户端 （注* IRC 是一种通过网络的即时聊天方式。其主要用于群组聊天。）
• 实现一个 SSH 应用程序
• 与现有的消费硬件产品进行通信，如互联网电视
• 游戏服务器
• 端到端应用程序（注* P2P 或对等网络应用）
• 本地网络多播服务（multicast service）发掘，例如 UPnP/ SSDP 和 mDNS

　　一个 UDP 的例子：

 // // This example shows a simple implementation of UPnP-SSDP M-SEARCH  // discovery using a multicast UDPSocket   //   var address = '239.255.255.250',      port = '1900',      serviceType = 'upnp:rootdevice',      rn = '\r\n',      search = '';    //  Create a new UDP client socket var mySocket = new UDPSocket ();    // Build an SSDP M-SEARCH multicast message search += 'M-SEARCH * HTTP/1.1' + rn;  search += 'ST: ' + serviceType + rn;  search += 'MAN: "ssdp:discover"' + rn;  search += 'HOST: ' + address + ':' + port + rn;  search += 'MX: 10';      // Receive and log SSDP M-SEARCH response messages function receiveMSearchResponses () {               // While data in buffer, read and log UDP message while (mySocket.readable.state === "readable") {                  var msg = mySocket.readable.read ();      console.log ('Remote address: ' + msg.remoteAddress + ' Remote port: ' + msg.remotePort + 'Message: ' + ab2str (msg.data));         // ArrayBuffer to string conversion could also be done by piping         // through a transform stream. To be updated when the Streams API        // specification has been stabilized on this point.    }              // Wait for SSDP M-SEARCH responses to arrive        mySocket.readable.wait () .then (      receiveMSearchResponses,                e => console.error ("Receiving error: ", e);    );       }    // Join SSDP multicast group mySocket.joinMulticast (address);    // Send SSDP M-SEARCH multicast message mySocket.writeable.write (    {data : str2ab (search),     remoteAddress : address,     remotePort : port    }) .then (      () => {        // Data sent sucessfully, wait for response console.log ('M-SEARCH Sent');        receiveMSearchResponses ();      },      e => console.error ("Sending error: ", e);  );    // Log result of UDP socket setup.  mySocket.opened.then (    () => {      console.log ("UDP socket created sucessfully");    },    e =>console.error ("UDP socket setup failed due to error: ", e);  );    // Handle UDP socket closed, either as a result of the application   // calling mySocket.close () or an error causing the socket to be     closed.  mySocket.closed.then (    () => {       console.log ("Socket has been cleanly closed");    },    e => console.error ("Socket closed due to error: ", e);  );    　　相比 UDP，TCP 的示例代码显得简单一些    // // This example shows a simple TCP echo client.   // The client will send "Hello World" to the server on port 6789 and log   // what has been received from the server.  // //  Create a new TCP client socket and connect to remote host      var mySocket = new TCPSocket ("127.0.0.1", 6789);    // Send data to server mySocket.writeable.write ("Hello World") .then (      () => {                    // Data sent sucessfully, wait for response console.log ("Data has been sent to server");          mySocket.readable.wait () .then (              () => {                                // Data in buffer, read it console.log ("Data received from server:" + mySocket.readable.read ());                    // Close the TCP connection                 mySocket.close ();              },                             e => console.error ("Receiving error: ", e);          );      },      e => console.error ("Sending error: ", e);  );    // Signal that we won't be writing any more and can close the write half of the connection. mySocket.halfClose ();    // Log result of TCP connection attempt.  mySocket.opened.then (    () => {      console.log ("TCP connection established sucessfully");    },    e =>console.error ("TCP connection setup failed due to error: ", e);  );    // Handle TCP connection closed, either as a result of the application   // calling mySocket.close () or the other side closed the TCP    // connection or an error causing the TCP connection to be closed. mySocket.closed.then (    () => {       console.log ("TCP socket has been cleanly closed");    },    e => console.error ("TCP socket closed due to error: ", e);  );

　　有什么问题可在 Github 上面给他们开 Issues:， 不过关注者廖廖（14 个 star 目前）： https://github.com/sysapps/tcp-udp-sockets/issues