Example explanation of how to implement socket push technology in PHP

<?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);

<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>