使用PHP实现实时消息推送的技巧解析

<?php
class WebSocketServer {
    private $clients = [];
    private $server;

    public function __construct($host, $port) {
        $this->server = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
        socket_set_option($this->server, SOL_SOCKET, SO_REUSEADDR, 1);
        socket_bind($this->server, $host, $port);
        socket_listen($this->server);
    }

    public function run() {
        while (true) {
            $changed = array_merge([$this->server], $this->clients);
            socket_select($changed, $write, $except, null);

            foreach ($changed as $socket) {
                if ($socket == $this->server) {
                    $client = socket_accept($this->server);
                    $this->clients[] = $client;
                } else {
                    $data = socket_read($socket, 1024);
                    $this->sendMessage($data);

                    $index = array_search($socket, $this->clients);
                    unset($this->clients[$index]);
                    socket_close($socket);
                }
            }
        }
    }

    public function sendMessage($message) {
        foreach ($this->clients as $client) {
            socket_write($client, $message, strlen($message));
        }
    }
}

$server = new WebSocketServer('localhost', 8080);
$server->run();
?>

<?php
while (true) {
    $message = getMessage();

    if ($message) {
        echo $message;
        flush();
        break;
    }

    sleep(1);
}
?>

<?php
header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');
header('Connection: keep-alive');

while (true) {
    $message = getMessage();

    if ($message) {
        echo "data: $message

";
    }

    ob_flush();
    flush();
    sleep(1);
}
?>

var source = new EventSource('stream.php');
source.addEventListener('message', function(event) {
    var message = event.data;
    // 处理消息
});