How to implement WebSocket sending and receiving UDP messages on the front end (multi-threaded mode)

Introduction:

This article will continue to introduce how to use WebSocket technology to send and receive UDP messages in front-end applications, and introduce multi-threading mode to improve sending efficiency and performance. We will use JavaScript language to write code, and combine WebSocket API, UDP data packet, Web Workers and UDP message listener to realize this function.

Step 1: Create a WebSocket Connection

First, we need to establish a WebSocket connection in the front-end application to communicate with the server. The following code can be used to create a WebSocket connection:

const socket = new WebSocket('ws://服务器地址');

explain:

• const socket: Create a WebSocket object.
• new WebSocket('ws://服务器地址'): Create a WebSocket connection by specifying the server address.

Step 2: Create Web Workers

Web Workers allow us to run JavaScript code in the background without blocking the main thread. We will use two Web Workers, one for sending UDP messages and one for receiving UDP messages.

First, we need to write a JavaScript file to define the Web Worker logic for sending UDP messages. Create a udpSendWorker.jsfile called and add the following code:

self.addEventListener('message', function (event) {
    
    
  // 获取要发送的数据
  const data = event.data;

  // 创建UDP数据包
  const udpPacket = new ArrayBuffer(4);
  const view = new DataView(udpPacket);
  view.setUint32(0, data);

  // 发送UDP数据包
  self.postMessage(udpPacket);
});

Then, we create another JavaScript file to define the Web Worker logic to receive UDP messages. Create a udpReceiveWorker.jsfile called and add the following code:

self.addEventListener('message', function (event) {
    
    
  // 获取UDP数据包
  const udpPacket = event.data;

  // 解析UDP数据包
  const view = new DataView(udpPacket);
  const data = view.getUint32(0);

  // 处理接收到的UDP消息
  self.postMessage(data);
});

explain:

• self.addEventListener('message', function (event) { ... }): When the Web Worker receives a message, execute the code block in the callback function.
• const data = event.data: Get the data sent from the main thread.
• const udpPacket = new ArrayBuffer(4): Creates a binary data buffer of length 4.
• const view = new DataView(udpPacket): Create a view for manipulating binary data.
• view.setUint32(0, data): Writes the data received from the main thread to the first position in the buffer.
• self.postMessage(udpPacket): Send processed UDP packets to the main thread.

Step 3: Send and receive UDP messages (multithreaded mode)

Now, we will use Web Workers in the front-end application to send and receive UDP messages. Modify the previous code and add the following code socket.addEventListener('open', function (event) { ... })inside :

// 创建发送UDP消息的Web Worker
const sendWorker = new Worker('udpSendWorker.js');

socket.addEventListener('open', function (event) {
    
    
  // 发送UDP数据
  sendWorker.postMessage(12345);
});

sendWorker.addEventListener('message', function (event) {
    
    
  // 接收来自Web Worker的处理后的UDP数据包
  const udpPacket = event.data;

  // 发送UDP数据包
  socket.send(udpPacket);
});

// 创建接收UDP消息的Web Worker
const receiveWorker = new Worker('udpReceiveWorker.js');

receiveWorker.addEventListener('message', function (event) {
    
    
  // 接收来自Web Worker的解析后的UDP消息
  const data = event.data;

  // 处理接收到的UDP消息
  console.log('接收到UDP消息:', data);
});

explain:

• const sendWorker = new Worker('udpSendWorker.js'): Create a Web Worker object for sending UDP messages, specifying the JavaScript file to load.

• sendWorker.postMessage(12345): Send the data to be sent to the Web Worker that sends the UDP message.

• sendWorker.addEventListener('message', function (event) { ... }): When the Web Worker that sends a UDP message sends a message to the main thread, execute the code block in the callback function.

• const udpPacket = event.data: Get the processed UDP packet from the Web Worker that sent the UDP message.

• socket.send(udpPacket): Send UDP packets over WebSocket.

• const receiveWorker = new Worker('udpReceiveWorker.js'): Create a Web Worker object for receiving UDP messages, specifying the JavaScript file to load.

• receiveWorker.addEventListener('message', function (event) { ... }): When the Web Worker receiving the UDP message sends the message to the main thread, execute the code block in the callback function.

• const data = event.data: Get the parsed UDP message from the Web Worker that received the UDP message.

• console.log('接收到UDP消息:', data): Print the received UDP message on the console.

Conclusion:

By introducing multi-threading mode and using Web Workers, we have realized the front-end function of sending and receiving UDP messages using WebSocket. One of the Web Workers is used to send UDP messages and the other Web Worker is used to receive UDP messages. I hope this article can help you implement this feature and improve the efficiency and performance of your front-end applications. If you have any questions, please feel free to ask.