HTML5的TCP和UDP Web Socket API草案定稿

這是在Web上實現UDP/TCP API的草案，沿未形成標准。該標准的一大亮點就是使用內置Promise設計模式，替代了傳統JavaScript中的事件觸發回調。不過各大瀏覽器廠商會不會這樣實現還要打一個問號，畢竟編寫標准的學院派和實現標准的行業派很難達到完全統一。

 

以下內容來自：  http://www.w3.org/TR/2014/WD-tcp-udp-sockets-20141202/

 

接口標准提供對原始UDP套接字(Socket)，TCP客戶端套接字和TCP服務器套接字API的定義。

 

 

簡介

 

這部分沿未形成規范。您可以使用該API來發送和接收數據，並使用TCP或UDP網絡。

 

使用此API的部分用例：

 

• 能夠與SMTP, POP3 和 IMAP 服務器進行通信的郵件服務器。
• 一個能與IRC服務器進行通信的IRC客戶端 （注* IRC是一種通過網絡的即時聊天方式。其主要用於群組聊天。）
• 實現一個SSH應用程序
• 與現有的消費硬件產品進行通信，如互聯網電視
• 游戲服務器
• 端到端應用程序（注* P2P或對等網絡應用）
• 本地網絡多播服務（multicast service）發掘，例如UPnP/ SSDP和mDNS

一個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的示例代碼顯得簡單一些

// 
// 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);
);

有什么問題可在Github上面給他們開Issues:， 不過關注者廖廖（14個star目前）：  https://github.com/sysapps/tcp-udp-sockets/issues