PHP implements socket push technology

This article mainly introduces the socket push technology implemented in PHP. It has certain reference value. Now I share it with everyone. Friends in need can refer to it.

There were already ajax timing requests before the socket appeared. Long polling and other solutions, but none of them can meet the needs, so socket was born.

Socket basic function socket

Summary of commonly used socket functions

Server side: socket_create creates a socket and sets basic parameters

socket_bind binds ip and port number

socket_listen listens

socket_accept client connection

socket_read reads client data

socket_write sends data to a single client

socket_close Close the connection

Client: socket_create Create socket and set basic parameters

socket_connect Connect socket

socket_write Send data to the server

socket_read Read server data

socket_close closes the connection

H5websocketNo more talk, go to the link

OK, start posting the code~

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Server code:

<?php
class WS {
    var $master;
    var $sockets = array();
    var $debug = false;//true为调试模式，输出log日志
    var $handshake = array();

    function __construct($address, $port){
        $this->master=socket_create(AF_INET, SOCK_STREAM, SOL_TCP)     or die("socket_create() failed");
        socket_set_option($this->master, SOL_SOCKET, SO_REUSEADDR, 1)  or die("socket_option() failed");
        socket_bind($this->master, $address, $port)                    or die("socket_bind() failed");
        socket_listen($this->master,20)                                or die("socket_listen() failed");
        
        $this->sockets[] = $this->master;
        $this->say("Server Started : ".date(&#39;Y-m-d H:i:s&#39;));
        $this->say("Listening on   : ".$address." port ".$port);
        $this->say("Master socket  : ".$this->master."\n");
        
        while(true){
            $socketArr = $this->sockets;
            $write = NULL;
            $except = NULL;
            socket_select($socketArr, $write, $except, NULL);  //自动选择来消息的socket 如果是握手 自动选择主机
            foreach ($socketArr as $socket){
                if ($socket == $this->master){  //主机
                    $client = socket_accept($this->master);
                    if ($client < 0){
                        $this->log("socket_accept() failed");
                        continue;
                    } else{
                        $this->connect($client);
                    }
                } else {
                    $bytes = @socket_recv($socket,$buffer,2048,0);
                    if ($bytes == 0){
                        $this->disConnect($socket);
                    }
                    else{
                        $key = array_search($socket, $this->sockets);
                        if (empty($this->handshake) || !isset($this->handshake[$key]) || !$this->handshake[$key]){
                            $this->doHandShake($socket, $buffer, $key);
                        }
                        else{
                            $buffer = $this->decode($buffer);
                            echo $buffer.PHP_EOL;
                            $key = array_search($socket, $this->sockets);
                            $arr = $this->sockets;
                            array_shift($arr);
                            foreach ($arr as $s){
                                $this->send($s, $buffer);
                            }
                        }
                    }
                }
            }
        }
    }
    
    function send($client, $msg){
        $msg = $this->frame($msg);
        socket_write($client, $msg, strlen($msg));
    }
    function connect($socket){
        array_push($this->sockets, $socket);
        $this->say("\n" . $socket . " CONNECTED!");
        $this->say(date("Y-n-d H:i:s"));
    }
    function disConnect($socket){
        $index = array_search($socket, $this->sockets);
        socket_close($socket);
        $this->say($socket . " DISCONNECTED!");
        if ($index >= 0){
            echo &#39;unset index is:&#39;.PHP_EOL;
            unset($this->sockets[$index]);
        }
    }
    function doHandShake($socket, $buffer, $handKey){
        $this->log("\nRequesting handshake...");
        $this->log($buffer);
        list($resource, $host, $origin, $key) = $this->getHeaders($buffer);
        $this->log("Handshaking...");
        $upgrade  = "HTTP/1.1 101 Switching Protocol\r\n" .
                    "Upgrade: websocket\r\n" .
                    "Connection: Upgrade\r\n" .
                    "Sec-WebSocket-Accept: " . $this->calcKey($key) . "\r\n\r\n";  //必须以两个回车结尾
        $this->log($upgrade);
        $sent = socket_write($socket, $upgrade, strlen($upgrade));
        $this->handshake[$handKey]=true;
        $this->log("Done handshaking...");
        return true;
    }

    function getHeaders($req){
        $r = $h = $o = $key = null;
        if (preg_match("/GET (.*) HTTP/"              ,$req,$match)) { $r = $match[1]; }
        if (preg_match("/Host: (.*)\r\n/"             ,$req,$match)) { $h = $match[1]; }
        if (preg_match("/Origin: (.*)\r\n/"           ,$req,$match)) { $o = $match[1]; }
        if (preg_match("/Sec-WebSocket-Key: (.*)\r\n/",$req,$match)) { $key = $match[1]; }
        return array($r, $h, $o, $key);
    }

    function calcKey($key){
        //基于websocket version 13
        $accept = base64_encode(sha1($key . &#39;258EAFA5-E914-47DA-95CA-C5AB0DC85B11&#39;, true));
        return $accept;
    }

    function decode($buffer) {
        $len = $masks = $data = $decoded = null;
        $len = ord($buffer[1]) & 127;

        if ($len === 126) {
            $masks = substr($buffer, 4, 4);
            $data = substr($buffer, 8);
        } 
        else if ($len === 127) {
            $masks = substr($buffer, 10, 4);
            $data = substr($buffer, 14);
        } 
        else {
            $masks = substr($buffer, 2, 4);
            $data = substr($buffer, 6);
        }
        for ($index = 0; $index < strlen($data); $index++) {
            $decoded .= $data[$index] ^ $masks[$index % 4];
        }
        return $decoded;
    }

    function frame($s){
        $a = str_split($s, 125);
        if (count($a) == 1){
            return "\x81" . chr(strlen($a[0])) . $a[0];
        }
        $ns = "";
        foreach ($a as $o){
            $ns .= "\x81" . chr(strlen($o)) . $o;
        }
        return $ns;
    }

    
    function say($msg = ""){
        echo $msg . "\n";
    }
    function log($msg = ""){
        if ($this->debug){
            echo $msg . "\n";
        } 
    }
}
    

new WS(&#39;localhost&#39;, 4000);

Client code (H5):

<html>
    <head>
        <title>demo</title>
        <script src="https://cdn.bootcss.com/jquery/1.9.1/jquery.min.js"></script>
    </head>
    <body>
    <input type="text" id="content">
    <input type="button" value="send" id="send">
        <script type="text/javascript">                    var ws = new WebSocket("ws://localhost:4000");
            ws.onopen = function(){
                console.log("握手成功");
            }
            ws.onmessage = function(e){
                console.log("message:" + e.data);
            }
            ws.onerror = function(){
                console.log("error");
            }
            $("#send").click(function(){
                content = $("#content").val();
                console.log(content);
                ws.send(content);
            })        </script>
    </body>
</html>

Then execute php demo.php to open the socket (steal a trick from the operation and maintenance, execute nohup php demo.php under Linux & can be executed in the background) , the browser can open multiple index.html, and communication can be established.

Code analysis:

1. The attribute $sockets array saves each accept connection (I don’t know if this description is correct);

2. Attribute The $handshake array saves whether the connection is in the connected state;

The above is the entire content of this article. I hope it will be helpful to everyone's learning. For more related content, please pay attention to the PHP Chinese website!

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