Swoole is a high-concurrency network communication framework based on PHP. It can improve the performance and efficiency of PHP in network communication through coroutines. Among them, the swoole_pop3_list function is a commonly used POP3 email protocol operation function in the Swoole framework and can be used to obtain a mailing list. In this article, we will introduce how to use coroutines to implement the highly concurrent swoole_pop3_list function in Swoole.
1. What is the POP3 protocol
POP3 (Post Office Protocol 3) is the third version of the post office protocol and is currently the most widely used mail receiving protocol. The basic function of the POP3 protocol is to collect mails on the user's host computer to the mail server, so that users can connect to the mail server through the Internet to receive mails anytime and anywhere.
2. swoole_pop3_list function
The swoole_pop3_list function is one of the POP3 protocol operation functions provided in the Swoole framework. This function is used to obtain the mailing list. Its basic syntax is as follows:
swoole_pop3_list ( resource $server , callable $callback , string $username , string $password [, string $mailbox = 'INBOX' [, int $options = 0 ]] ) : bool
Parameter description:
Return value description:
3. The concept and function of coroutine
Coroutine is a lightweight thread in user mode, which can realize the concurrent execution of multiple subprograms in one thread. . Coroutines can improve the running efficiency and concurrency performance of the program, and reduce thread switching and resource waste.
In the Swoole framework, coroutines are one of the main means to achieve high concurrency. Coroutines allow one thread to handle multiple client requests at the same time without creating multiple processes and threads, thereby improving the concurrency and efficiency of PHP programs.
4. Use coroutines to implement high-concurrency swoole_pop3_list function
Since the pop3 client in Swoole is not coroutine-based, we need to implement a coroutine version of the pop3 client ourselves. And use coroutines to achieve high-concurrency mailing list acquisition. The specific implementation method is as follows:
connect('pop3.qq.com', 995, true); $server->recv(); $swoole_client = new SwooleCoroutineClient(SWOOLE_SOCK_TCP); if (!$swoole_client->connect('127.0.0.1', 20018, -1)) { exit("connect failed. Error: {$swoole_client->errCode} "); } $username = 'your_email@qq.com'; $password = 'your_password'; $mailbox = 'INBOX'; $options = 0; $client = new Pop3Client($server, $swoole_client, $username, $password, $mailbox, $options); $res = $client->getMails(); var_dump($res); class Pop3Client { private $server; private $swoole_client; private $username; private $password; private $mailbox; private $options; private $timeout = 5; public function __construct($server, $swoole_client, $username, $password, $mailbox, $options = 0) { $this->server = $server; $this->swoole_client = $swoole_client; $this->username = $username; $this->password = $password; $this->mailbox = $mailbox; $this->options = $options; // 配置服务器 $this->server->set(array( 'open_length_check' => false, 'open_eof_check' => true, 'package_eof' => " " )); } // 建立连接 public function connect() { // 连接服务器，获取欢迎信息 if (!$this->server->connect('pop3.qq.com', 995, true, $this->timeout)) { return false; } $str = $this->server->recv(); // 判断是否获取了欢迎信息 if (substr($str, 0, 3) != '+OK') { return false; } // 用户登录 $cmd = 'user ' . $this->username . " "; $this->server->send($cmd); $str = $this->server->recv(); // 判断是否登录成功 if (substr($str, 0, 3) != '+OK') { return false; } // 验证密码 $cmd = 'pass ' . $this->password . " "; $this->server->send($cmd); $str = $this->server->recv(); // 判断是否验证密码成功 if (substr($str, 0, 3) != '+OK') { return false; } // 设置邮箱 $cmd = 'select ' . $this->mailbox . " "; $this->server->send($cmd); $str = $this->server->recv(); // 判断是否设置邮箱成功 if (substr($str, 0, 3) != '+OK') { return false; } return true; } // 获取邮件列表 public function getList() { $cmd = 'list' . " "; $this->server->send($cmd); $str = $this->server->recv(); if (substr($str, 0, 3) != '+OK') { return false; } $list = array(); $i = 0; while (true) { $str = $this->server->recv(); if ($str == ". ") { break; } $i++; $tempArr = explode(' ', trim($str)); $el = array( 'id' => $tempArr[0], 'size' => $tempArr[1], ); $list[] = $el; } return $list; } // 获取所有邮件 public function getMails() { if (!$this->connect()) { return false; } $list = $this->getList(); if (!$list) { return false; } $mails = array(); foreach ($list as $key => $value) { $cmd = 'retr ' . $value['id'] . " "; $this->server->send($cmd); $str = $this->server->recv(); if (substr($str, 0, 3) != '+OK') { return false; } $tmp_mail = ''; $start = false; while (true) { $str = $this->server->recv(); if (substr($str, 0, 1) == '.') { $tmp_mail .= $str; break; } if (substr($str, 0, 6) == 'From: ') { $start = true; } if ($start) { $tmp_mail .= $str; } } $mails[] = $tmp_mail; } return $mails; } }
In the code, we use Swoole's coroutine client to implement the coroutineization of the pop3 client. Specifically, we first established a Swoole TCP client, connected to the POP3 server, and verified the username and password in the welcome message sent by the server, thereby connecting to the POP3 server. Next, we call the getList function to obtain the mailing list, loop through all mail IDs, and call the retr command to obtain the corresponding mail content.
In the implementation of the above code, we implemented a highly concurrent mailing list acquisition function through coroutines, changing the client from a synchronous blocking mode to an asynchronous non-blocking mode, thus improving the code efficiency efficiency and performance. At the same time, through coroutines, we realize the function of processing multiple client requests in one thread, avoiding the waste of resources by creating multiple processes and threads.
5. Summary
This article introduces how to use coroutines to implement the highly concurrent swoole_pop3_list function in Swoole. Through coroutineization, we can avoid blocking and resource occupation, and improve the efficiency and performance of the code. At the same time, coroutines are also the main means for Swoole to achieve high concurrency. We need to be proficient in the use of coroutines in order to better utilize the Swoole framework to complete program development.
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