Websocket Client in PHP

ws_client.php

<?php

namespace common\components;

class WebSocketClient {

    private $_Socket = null;

    public function __construct($host, $port) {
        $this->_connect($host, $port);
    }

    public function __destruct() {
        $this->_disconnect();
    }

    public function sendData($data, $final=true) {
        // Assamble header: FINal 0x80 | Opcode 0x02
        $header=chr(($final?0x80:0) | 0x02); // 0x02 binary
        // Mask 0x80 | payload length (0-125)
        if(strlen($data)<126) $header.=chr(0x80 | strlen($data));
        elseif (strlen($data)<0xFFFF) $header.=chr(0x80 | 126) . pack("n",strlen($data));
        else $header.=chr(0x80 | 127) . pack("N",0) . pack("N",strlen($data));
        // Add mask
        $mask=pack("N",rand(1,0x7FFFFFFF));
        $header.=$mask;
        // Mask application data.
        for($i = 0; $i < strlen($data); $i++)
            $data[$i]=chr(ord($data[$i]) ^ ord($mask[$i % 4]));
        return fwrite($this->_Socket,$header.$data);
    }

    private function _connect($host='',$port=80,$headers='',&$error_string='',$timeout=10,$ssl=false){
        // Generate a key (to convince server that the update is not random)
        // The key is for the server to prove it i websocket aware. (We know it is)
        $key=base64_encode(openssl_random_pseudo_bytes(16));
        $header = "GET /ws/faculty_profile/cms/ HTTP/1.1\r\n"
          ."Host: $host\r\n"
          ."pragma: no-cache\r\n"
          ."Upgrade: WebSocket\r\n"
          ."Connection: Upgrade\r\n"
          ."Sec-WebSocket-Key: $key\r\n"
          ."Sec-WebSocket-Version: 13\r\n";
        // Add extra headers
        if(!empty($headers)) foreach($headers as $h) $header.=$h."\r\n";
        // Add end of header marker
        $header.="\r\n";
        // Connect to server
        $host = $host ? $host : "127.0.0.1";
        $port = $port <1 ? 80 : $port;
        $address = ($ssl ? 'ssl://' : '') . $host . ':' . $port;
        $this->_Socket = stream_socket_client($address, $errno, $errstr, $timeout);
        if(!$this->_Socket){
          $error_string = "Unable to connect to websocket server: $errstr ($errno)";
          return false;
        }
        // Set timeouts
        stream_set_timeout($this->_Socket,$timeout);
        //Request upgrade to websocket
        $rc = fwrite($this->_Socket,$header);
        if(!$rc){
          $error_string
            = "Unable to send upgrade header to websocket server: $errstr ($errno)";
          return false;
        }
        // Read response into an assotiative array of headers. Fails if upgrade failes.
        $reaponse_header=fread($this->_Socket, 1024);
        // status code 101 indicates that the WebSocket handshake has completed.
        if(!strpos($reaponse_header," 101 ")
          || !strpos($reaponse_header,'Sec-WebSocket-Accept: ')){
          $error_string = "Server did not accept to upgrade connection to websocket."
            .$reaponse_header. E_USER_ERROR;
          return false;
        }
        // The key we send is returned, concatenate with "258EAFA5-E914-47DA-95CA-
        // C5AB0DC85B11" and then base64-encoded. one can verify if one feels the need...
        return true;
    }

    private function _disconnect() {
        fclose($this->_Socket);
    }
}