PHP study notes: Real-time communication and Web Socket

PHP study notes: Real-time communication and Web Socket

Introduction:
In today's Internet world, real-time communication has become an essential need . Whether it's social networking, online chat, multiplayer games or online collaboration, real-time communication plays an important role. In the past, polling or long polling was often required to achieve real-time communication. This method had problems such as low efficiency and poor real-time performance. The emergence of Web Socket has completely changed this situation. This article will introduce the basic concepts and principles of Web Socket and how to use PHP to achieve real-time communication.

1. The basic concept of Web Socket
Web Socket is a protocol for full-duplex communication on a single TCP connection. It establishes a persistent connection between the client and the server and allows both parties to communicate in real time by sending messages. Compared with the traditional HTTP protocol, Web Socket has a faster response speed and stronger real-time performance.

2. The principle of Web Socket
The handshake process of Web Socket protocol is similar to that of HTTP protocol. However, after the handshake is successful, unlike HTTP protocol, Web Socket will maintain a long connection and can be used for any period of time. Send data to each other. At the same time, the Web Socket protocol uses a special binary data frame for data transmission, which can transmit data more efficiently and reduce header overhead.

3. How to use Web Socket
In PHP, we can use the corresponding library to implement the function of Web Socket. The following is a simple example:

<?php

$host = 'localhost'; // 服务器IP地址
$port = 8888; // 端口号

// 创建一个Socket
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

// 绑定Socket到指定的IP地址和端口
socket_bind($socket, $host, $port);

// 监听连接
socket_listen($socket);

echo "Server running at {$host}:{$port}
";

// 等待客户端连接
$client = socket_accept($socket);

// 接收来自客户端的消息
$message = socket_read($client, 1024);

echo "Received message: {$message}
";

// 向客户端发送消息
$response = "Hello, this is the server response!";
socket_write($client, $response, strlen($response));

// 关闭连接
socket_close($client);
socket_close($socket);

?>

The above code implements a basic Web Socket server, which listens to the specified IP address and port, waiting for the client's connection request. Once the client's connection request is received, the server can begin real-time communication with the client. After receiving the client's message, the server can process the message and send the corresponding response message to the client.

4. Conclusion
Web Socket provides powerful support for real-time communication. In PHP, we can use related libraries to quickly build the Web Socket server. By mastering the basic concepts and principles of Web Socket and using PHP to implement related functions, we can easily achieve real-time communication needs. Hope this article is helpful to everyone!

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