php实现socket推送技术

在socket出现之前已经有ajax定时请求、长轮询等方案，但都不能满足需求，socket就应用而生了。

socket基本函数socket

总结下常用的socket函数

服务端： socket_create 创建socket设置基本参数

　　　　 socket_bind 绑定ip和端口号

　　　　 socket_listen 监听

　　　　 socket_accept 客户端的连接

　　　　 socket_read 读取客户端的数据

　　　　 socket_write 给单独客户端发送数据

　　　　 socket_close 关闭连接

客户端：socket_create 创建socket设置基本参数

　　　　 socket_connect 连接socket

　　　　 socket_write 给服务端发送数据

　　　　 socket_read 读取服务端数据

　　　　 socket_close 关闭连接

H5websocket不多说了，上链接

OK，开始贴代码~

----------------------------------------------------------分割线

服务端代码：

 <?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('Y-m-d H:i:s'));
         $this->say("Listening on   : ".$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 ($index >= 0){
             echo 'unset index is:'.PHP_EOL;
             unset($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 . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11', 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('localhost', 4000);

客户端代码（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>

然后执行php demo.php 开启socket（从运维那偷学一招，linux下执行nohup php demo.php &可以在后台执行），浏览器打开多个index.html，就能建立通讯了。

代码解析：

1.属性$sockets数组保存每个accept连接（不知道这么描述对不对）;

2.属性$handshake数组保存连接是否在连接状态;