WebSocket library in PHP8.0

With the rapid development of the Internet and the continuous updating of Web technology, more and more Web applications are beginning to use WebSocket technology to achieve real-time communication functions. As one of the most commonly used Web development languages, PHP has always had limited support for WebSocket. However, in the PHP8.0 version, we have seen some new changes, the most important of which is the official introduction of a new WebSocket library, which provides PHP developers with a more convenient, efficient, and reliable real-time communication solution. This article will introduce the WebSocket library in PHP8.0 in detail.

1. Introduction to WebSocket

WebSocket is a network technology that realizes two-way communication between a Web browser and a Web server. After the connection is established, the server can actively send data to the browser without the browser sending a request. This characteristic makes WebSocket widely used in fields such as real-time communication, online games, online chat, and remote desktop.

2. History of PHP WebSocket library

Before PHP, many excellent WebSocket libraries have been born, such as PHPoole's php-websocket, Ratchet, ReactPHP, Swoole, etc. Although these libraries are powerful, they are third-party and cannot be officially supported and maintained by PHP. There may be some compatibility, stability and security issues during use.

Therefore, in order to further improve PHP’s web development ecosystem, PHP version 7.2 introduces a new extension: ext-sockets. This extension provides support for raw Socket and can help PHP developers easily implement Socket-based communication. However, due to some limitations, such as the need to manually handle the HTTP protocol and the inability to detect connection closures, there are still certain difficulties in using it in practical applications.

Finally, in the PHP8.0 version, PHP officially introduced a new WebSocket library: ext-sockets upgraded version. This new library fixes the limitations of the extension and adds more functions, thus providing Better WebScoket support.

3. New features in PHP8.0

The new WebSocket library in PHP8.0, named ext-sockets2, mainly adds the following features:

1. Supports the WebSocket protocol that complies with the RFC 6455 standard

Different from the earlier version of the ext-sockets extension, ext-sockets2 uses the improved WebSocket protocol that complies with the RFC 6455 standard. This means that developers can safely use standard protocols, making it easier to implement WebScoket applications.

2. Automatically parse HTTP handshake requests

Under the hood of the extension, ext-sockets2 automatically parses WebSocket handshake requests and builds appropriate WebSocket frames. This allows developers to easily create WebSocket servers using dedicated creation functions without having to understand the details of the protocol.

3. Support for binary data

In addition to supporting text data, ext-sockets2 also allows developers to handle binary data. This is useful in applications that need to transmit large data streams or contain binary content.

4. Support PING/PONG

In the WebSocket protocol, the server sometimes needs to use PING/PONG heartbeat based on the client's response time or to detect whether the client is online. frames to maintain the connection status. In the ext-sockets2 library, we can easily implement this functionality.

5. Support closing connections

In some cases, the server needs to close the connection with the client, such as when restarting the server, or after the background program completes a task. In ext-sockets2, we can implement this function very conveniently.

4. Installation and initial configuration of the WebSocket library

You need to install this extension before using ext-sockets2. You can use the following command:

pecl install sockets

After the extension installation is completed , you need to add this extension to the php.ini file:

extension=sockets

After completing the installation and configuration of the extension, we can start using WebSocket.

5. Use the WebSocket library to write a simple program

Let's take a look at how to use ext-sockets2 to write a simple program. This program listens for messages from the client and responds to them:

<?php

$address = '127.0.0.1';
$port = 8080;
$server = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_bind($server, $address, $port);
socket_listen($server);
while (true) {
    $client = socket_accept($server);
    while (true) {
        $input = socket_read($client, 1024);
        if (strlen($input) == 0) {
            socket_close($client);
            break;
        }
        echo $input . PHP_EOL;
        socket_write($client, $input);
    }
}

In this program, we use socket_create() to create a socket server and socket_bind() to bind it to the specified IP address and port. Next, we use socket_listen() to start listening for client connections. The first while loop is used to listen for requests from clients, and the second while loop is used to process messages from connected clients.

In the program, we use socket_read() to receive the messages sent by the client, and use socket_write() to return these messages to the client as a response.

6. Summary

WebSocket technology is increasingly used in Internet application development. In the PHP8.0 version, we also saw a brand new WebSocket library officially introduced by PHP - ext-sockets2, which brings many new features, making PHP developers more convenient, efficient and reliable when implementing WebSocket. . When choosing between old and new WebSocket libraries, we might as well try new extensions to better meet the growing needs of real-time communication.

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