Making PHP web sites from scratch

Some time ago I chose a library for working with web-based software. On the Internet, I came across articles on the integration of node.js with yii, and almost all articles on websockets in Habré were limited to instructions on how to use phpdaemon.

I studied the libraries phpdaemon and ratchet , they are quite monstrous (and using ratchet to send a message to a specific user it is recommended to use wamp additionally). It was not quite clear to me why use such monsters that require installation of other monsters. After reading the sources of these, as well as other libraries, I figured out how everything works and I wanted to write a simple web server server in php on my own. This helped me to fix the material studied and stumble upon some of the pitfalls that I had no idea about.

So I decided to write the necessary functionality for me from scratch.
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The resulting code and link to the demo chat at the end of the article.

Set goals:

1) deal with server sockets in php
2) deal with the protocol of web sockets
3) write a simple web-based server from scratch

1) Server sockets in php

Up to this point, I had a vague idea of server sockets. Having read the source codes of several libraries for working with websockets, I ran into two schemes for their implementation:

using php "socket" extension:

$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);//  socket_bind($socket, '127.0.0.1', 8000);//    ip   socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1);//       socket_listen($socket);//

or using the php "stream" extension:

 $socket = stream_socket_server("tcp://127.0.0.1:8000", $errno, $errstr);

I preferred the second option because of its brevity.

So, we have created a server socket and now we want to handle new connections to it, for this again there are two options

 while ($connect = stream_socket_accept($socket, -1)) {//   ( ) ... $connect }

An example of a simple http server that responds to all requests: Hello

 #!/usr/bin/env php <?php $socket = stream_socket_server("tcp://0.0.0.0:8000", $errno, $errstr); if (!$socket) { die("$errstr ($errno)\n"); } while ($connect = stream_socket_accept($socket, -1)) { fwrite($connect, "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nConnection: close\r\n\r\n"); fclose($connect); } fclose($socket);

or using stream_select

 $connects = array(); while (true) { //   : $read = $connects; $read[] = $socket; $write = $except = null; if (!stream_select($read, $write, $except, null)) {//     ( ) break; } if (in_array($socket, $read)) {//   $connect = stream_socket_accept($socket, -1);//   $connects[] = $connect;//       unset($read[ array_search($socket, $read) ]); } foreach($read as $connect) {//   ... $connect unset($connects[ array_search($connect, $connects) ]); } }

An example of a simple http server using stream_select, which responds to all requests: Hi

 #!/usr/bin/env php <?php $socket = stream_socket_server("tcp://0.0.0.0:8000", $errno, $errstr); if (!$socket) { die("$errstr ($errno)\n"); } $connects = array(); while (true) { //   : $read = $connects; $read []= $socket; $write = $except = null; if (!stream_select($read, $write, $except, null)) {//     ( ) break; } if (in_array($socket, $read)) {//   $connect = stream_socket_accept($socket, -1);//   $connects[] = $connect;//       unset($read[ array_search($socket, $read) ]); } foreach($read as $connect) {//   $headers = ''; while ($buffer = rtrim(fgets($connect))) { $headers .= $buffer; } fwrite($connect, "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nConnection: close\r\n\r\n"); fclose($connect); unset($connects[ array_search($connect, $connects) ]); } } fclose($server);

Since in the future, we will need to simultaneously process the server socket for new connections, and existing connections for new messages, then we’ll look at the second option.

2) Protocol of websockets

This article describes the interaction protocol well.
We are interested in two points:

"Handshake" or handshake:

We read the value of Sec-WebSocket-Key from the incoming header from the client, count on the basis of it Sec-WebSocket-Accept and send the final answer:

 $SecWebSocketAccept = base64_encode(pack('H*', sha1($SecWebSocketKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'))); $response = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" . "Upgrade: websocket\r\n" . "Connection: Upgrade\r\n" . "Sec-WebSocket-Accept:$SecWebSocketAccept\r\n\r\n";

An example of the function that does it.

 function handshake($connect) { $info = array(); $line = fgets($connect); $header = explode(' ', $line); $info['method'] = $header[0]; $info['uri'] = $header[1]; //    while ($line = rtrim(fgets($connect))) { if (preg_match('/\A(\S+): (.*)\z/', $line, $matches)) { $info[$matches[1]] = $matches[2]; } else { break; } } $address = explode(':', stream_socket_get_name($connect, true)); //   $info['ip'] = $address[0]; $info['port'] = $address[1]; if (empty($info['Sec-WebSocket-Key'])) { return false; } //     $SecWebSocketAccept = base64_encode(pack('H*', sha1($info['Sec-WebSocket-Key'] . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'))); $upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" . "Upgrade: websocket\r\n" . "Connection: Upgrade\r\n" . "Sec-WebSocket-Accept:$SecWebSocketAccept\r\n\r\n"; fwrite($connect, $upgrade); return $info; }

message exchange

After receiving the data from the web socket, we need to decode it, and encode it when sending it.
Everything in the same article describes message coding well, but in essence we need only two functions: decode and encode.

An example of the implementation of decode and encode

 function decode($data) { $unmaskedPayload = ''; $decodedData = array(); // estimate frame type: $firstByteBinary = sprintf('%08b', ord($data[0])); $secondByteBinary = sprintf('%08b', ord($data[1])); $opcode = bindec(substr($firstByteBinary, 4, 4)); $isMasked = ($secondByteBinary[0] == '1') ? true : false; $payloadLength = ord($data[1]) & 127; // unmasked frame is received: if (!$isMasked) { return array('type' => '', 'payload' => '', 'error' => 'protocol error (1002)'); } switch ($opcode) { // text frame: case 1: $decodedData['type'] = 'text'; break; case 2: $decodedData['type'] = 'binary'; break; // connection close frame: case 8: $decodedData['type'] = 'close'; break; // ping frame: case 9: $decodedData['type'] = 'ping'; break; // pong frame: case 10: $decodedData['type'] = 'pong'; break; default: return array('type' => '', 'payload' => '', 'error' => 'unknown opcode (1003)'); } if ($payloadLength === 126) { $mask = substr($data, 4, 4); $payloadOffset = 8; $dataLength = bindec(sprintf('%08b', ord($data[2])) . sprintf('%08b', ord($data[3]))) + $payloadOffset; } elseif ($payloadLength === 127) { $mask = substr($data, 10, 4); $payloadOffset = 14; $tmp = ''; for ($i = 0; $i < 8; $i++) { $tmp .= sprintf('%08b', ord($data[$i + 2])); } $dataLength = bindec($tmp) + $payloadOffset; unset($tmp); } else { $mask = substr($data, 2, 4); $payloadOffset = 6; $dataLength = $payloadLength + $payloadOffset; } /** * We have to check for large frames here. socket_recv cuts at 1024 bytes * so if websocket-frame is > 1024 bytes we have to wait until whole * data is transferd. */ if (strlen($data) < $dataLength) { return false; } if ($isMasked) { for ($i = $payloadOffset; $i < $dataLength; $i++) { $j = $i - $payloadOffset; if (isset($data[$i])) { $unmaskedPayload .= $data[$i] ^ $mask[$j % 4]; } } $decodedData['payload'] = $unmaskedPayload; } else { $payloadOffset = $payloadOffset - 4; $decodedData['payload'] = substr($data, $payloadOffset); } return $decodedData; } function encode($payload, $type = 'text', $masked = false) { $frameHead = array(); $payloadLength = strlen($payload); switch ($type) { case 'text': // first byte indicates FIN, Text-Frame (10000001): $frameHead[0] = 129; break; case 'close': // first byte indicates FIN, Close Frame(10001000): $frameHead[0] = 136; break; case 'ping': // first byte indicates FIN, Ping frame (10001001): $frameHead[0] = 137; break; case 'pong': // first byte indicates FIN, Pong frame (10001010): $frameHead[0] = 138; break; } // set mask and payload length (using 1, 3 or 9 bytes) if ($payloadLength > 65535) { $payloadLengthBin = str_split(sprintf('%064b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 255 : 127; for ($i = 0; $i < 8; $i++) { $frameHead[$i + 2] = bindec($payloadLengthBin[$i]); } // most significant bit MUST be 0 if ($frameHead[2] > 127) { return array('type' => '', 'payload' => '', 'error' => 'frame too large (1004)'); } } elseif ($payloadLength > 125) { $payloadLengthBin = str_split(sprintf('%016b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 254 : 126; $frameHead[2] = bindec($payloadLengthBin[0]); $frameHead[3] = bindec($payloadLengthBin[1]); } else { $frameHead[1] = ($masked === true) ? $payloadLength + 128 : $payloadLength; } // convert frame-head to string: foreach (array_keys($frameHead) as $i) { $frameHead[$i] = chr($frameHead[$i]); } if ($masked === true) { // generate a random mask: $mask = array(); for ($i = 0; $i < 4; $i++) { $mask[$i] = chr(rand(0, 255)); } $frameHead = array_merge($frameHead, $mask); } $frame = implode('', $frameHead); // append payload to frame: for ($i = 0; $i < $payloadLength; $i++) { $frame .= ($masked === true) ? $payload[$i] ^ $mask[$i % 4] : $payload[$i]; } return $frame; }

Simple webbox server

So, we have all the necessary information.
Using the code of a simple http server from the first part, as well as the handshake, decode and encode functions from the second, we can build a simple web socket server.

An example implementation of a simple web socket server

 #!/usr/bin/env php <?php $socket = stream_socket_server("tcp://0.0.0.0:8000", $errno, $errstr); if (!$socket) { die("$errstr ($errno)\n"); } $connects = array(); while (true) { //   : $read = $connects; $read []= $socket; $write = $except = null; if (!stream_select($read, $write, $except, null)) {//     ( ) break; } if (in_array($socket, $read)) {//   //     : if (($connect = stream_socket_accept($socket, -1)) && $info = handshake($connect)) { $connects[] = $connect;//       onOpen($connect, $info);//   } unset($read[ array_search($socket, $read) ]); } foreach($read as $connect) {//   $data = fread($connect, 100000); if (!$data) { //   fclose($connect); unset($connects[ array_search($connect, $connects) ]); onClose($connect);//   continue; } onMessage($connect, $data);//   } } fclose($server); function handshake($connect) { $info = array(); $line = fgets($connect); $header = explode(' ', $line); $info['method'] = $header[0]; $info['uri'] = $header[1]; //    while ($line = rtrim(fgets($connect))) { if (preg_match('/\A(\S+): (.*)\z/', $line, $matches)) { $info[$matches[1]] = $matches[2]; } else { break; } } $address = explode(':', stream_socket_get_name($connect, true)); //   $info['ip'] = $address[0]; $info['port'] = $address[1]; if (empty($info['Sec-WebSocket-Key'])) { return false; } //     $SecWebSocketAccept = base64_encode(pack('H*', sha1($info['Sec-WebSocket-Key'] . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'))); $upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" . "Upgrade: websocket\r\n" . "Connection: Upgrade\r\n" . "Sec-WebSocket-Accept:$SecWebSocketAccept\r\n\r\n"; fwrite($connect, $upgrade); return $info; } function encode($payload, $type = 'text', $masked = false) { $frameHead = array(); $payloadLength = strlen($payload); switch ($type) { case 'text': // first byte indicates FIN, Text-Frame (10000001): $frameHead[0] = 129; break; case 'close': // first byte indicates FIN, Close Frame(10001000): $frameHead[0] = 136; break; case 'ping': // first byte indicates FIN, Ping frame (10001001): $frameHead[0] = 137; break; case 'pong': // first byte indicates FIN, Pong frame (10001010): $frameHead[0] = 138; break; } // set mask and payload length (using 1, 3 or 9 bytes) if ($payloadLength > 65535) { $payloadLengthBin = str_split(sprintf('%064b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 255 : 127; for ($i = 0; $i < 8; $i++) { $frameHead[$i + 2] = bindec($payloadLengthBin[$i]); } // most significant bit MUST be 0 if ($frameHead[2] > 127) { return array('type' => '', 'payload' => '', 'error' => 'frame too large (1004)'); } } elseif ($payloadLength > 125) { $payloadLengthBin = str_split(sprintf('%016b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 254 : 126; $frameHead[2] = bindec($payloadLengthBin[0]); $frameHead[3] = bindec($payloadLengthBin[1]); } else { $frameHead[1] = ($masked === true) ? $payloadLength + 128 : $payloadLength; } // convert frame-head to string: foreach (array_keys($frameHead) as $i) { $frameHead[$i] = chr($frameHead[$i]); } if ($masked === true) { // generate a random mask: $mask = array(); for ($i = 0; $i < 4; $i++) { $mask[$i] = chr(rand(0, 255)); } $frameHead = array_merge($frameHead, $mask); } $frame = implode('', $frameHead); // append payload to frame: for ($i = 0; $i < $payloadLength; $i++) { $frame .= ($masked === true) ? $payload[$i] ^ $mask[$i % 4] : $payload[$i]; } return $frame; } function decode($data) { $unmaskedPayload = ''; $decodedData = array(); // estimate frame type: $firstByteBinary = sprintf('%08b', ord($data[0])); $secondByteBinary = sprintf('%08b', ord($data[1])); $opcode = bindec(substr($firstByteBinary, 4, 4)); $isMasked = ($secondByteBinary[0] == '1') ? true : false; $payloadLength = ord($data[1]) & 127; // unmasked frame is received: if (!$isMasked) { return array('type' => '', 'payload' => '', 'error' => 'protocol error (1002)'); } switch ($opcode) { // text frame: case 1: $decodedData['type'] = 'text'; break; case 2: $decodedData['type'] = 'binary'; break; // connection close frame: case 8: $decodedData['type'] = 'close'; break; // ping frame: case 9: $decodedData['type'] = 'ping'; break; // pong frame: case 10: $decodedData['type'] = 'pong'; break; default: return array('type' => '', 'payload' => '', 'error' => 'unknown opcode (1003)'); } if ($payloadLength === 126) { $mask = substr($data, 4, 4); $payloadOffset = 8; $dataLength = bindec(sprintf('%08b', ord($data[2])) . sprintf('%08b', ord($data[3]))) + $payloadOffset; } elseif ($payloadLength === 127) { $mask = substr($data, 10, 4); $payloadOffset = 14; $tmp = ''; for ($i = 0; $i < 8; $i++) { $tmp .= sprintf('%08b', ord($data[$i + 2])); } $dataLength = bindec($tmp) + $payloadOffset; unset($tmp); } else { $mask = substr($data, 2, 4); $payloadOffset = 6; $dataLength = $payloadLength + $payloadOffset; } /** * We have to check for large frames here. socket_recv cuts at 1024 bytes * so if websocket-frame is > 1024 bytes we have to wait until whole * data is transferd. */ if (strlen($data) < $dataLength) { return false; } if ($isMasked) { for ($i = $payloadOffset; $i < $dataLength; $i++) { $j = $i - $payloadOffset; if (isset($data[$i])) { $unmaskedPayload .= $data[$i] ^ $mask[$j % 4]; } } $decodedData['payload'] = $unmaskedPayload; } else { $payloadOffset = $payloadOffset - 4; $decodedData['payload'] = substr($data, $payloadOffset); } return $decodedData; } // : function onOpen($connect, $info) { echo "open\n"; fwrite($connect, encode('')); } function onClose($connect) { echo "close\n"; } function onMessage($connect, $data) { echo decode($data)['payload'] . "\n"; }

In the given example, you can change user scripts onOpen, onClose and onMessage to implement the necessary functionality.

The goals are achieved.
If this material seems interesting to you, then in the next article I will describe how you can run several processes to handle connections (one master and several workers), interprocess communication, integration with your framework using the example of the yii component.

demo chat with the above functions

Demo chat code

 #!/usr/bin/env php <?php class WebsocketServer { public function __construct($config) { $this->config = $config; } public function start() { //   $server = stream_socket_server("tcp://{$this->config['host']}:{$this->config['port']}", $errorNumber, $errorString); if (!$server) { die("error: stream_socket_server: $errorString ($errorNumber)\r\n"); } list($pid, $master, $workers) = $this->spawnWorkers();//   if ($pid) {// fclose($server);//         $WebsocketMaster = new WebsocketMaster($workers);//      $WebsocketMaster->start(); } else {// $WebsocketHandler = new WebsocketHandler($server, $master); $WebsocketHandler->start(); } } protected function spawnWorkers() { $master = null; $workers = array(); $i = 0; while ($i < $this->config['workers']) { $i++; //  ,        $pair = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP); $pid = pcntl_fork();//  if ($pid == -1) { die("error: pcntl_fork\r\n"); } elseif ($pid) { // fclose($pair[0]); $workers[$pid] = $pair[1];//      } else { // fclose($pair[1]); $master = $pair[0];//   break; } } return array($pid, $master, $workers); } } class WebsocketMaster { protected $workers = array(); protected $clients = array(); public function __construct($workers) { $this->clients = $this->workers = $workers; } public function start() { while (true) { //   ,    $read = $this->clients; stream_select($read, $write, $except, null);//  ,    if ($read) {//     foreach ($read as $client) { $data = fread($client, 1000); if (!$data) { //   unset($this->clients[intval($client)]); @fclose($client); continue; } foreach ($this->workers as $worker) {//     if ($worker !== $client) { fwrite($worker, $data); } } } } } } } abstract class WebsocketWorker { protected $clients = array(); protected $server; protected $master; protected $pid; protected $handshakes = array(); protected $ips = array(); public function __construct($server, $master) { $this->server = $server; $this->master = $master; $this->pid = posix_getpid(); } public function start() { while (true) { //   ,    $read = $this->clients; $read[] = $this->server; $read[] = $this->master; $write = array(); if ($this->handshakes) { foreach ($this->handshakes as $clientId => $clientInfo) { if ($clientInfo) { $write[] = $this->clients[$clientId]; } } } stream_select($read, $write, $except, null);//  ,    if (in_array($this->server, $read)) { //        //     ,    if ($client = stream_socket_accept($this->server, -1)) { $address = explode(':', stream_socket_get_name($client, true)); if (isset($this->ips[$address[0]]) && $this->ips[$address[0]] > 5) {//      ip @fclose($client); } else { @$this->ips[$address[0]]++; $this->clients[intval($client)] = $client; $this->handshakes[intval($client)] = array();//,     } } //    ,          unset($read[array_search($this->server, $read)]); } if (in_array($this->master, $read)) { //    $data = fread($this->master, 1000); $this->onSend($data);//   //   ,          unset($read[array_search($this->master, $read)]); } if ($read) {//     foreach ($read as $client) { if (isset($this->handshakes[intval($client)])) { if ($this->handshakes[intval($client)]) {//       continue;//            } if (!$this->handshake($client)) { unset($this->clients[intval($client)]); unset($this->handshakes[intval($client)]); $address = explode(':', stream_socket_get_name($client, true)); if (isset($this->ips[$address[0]]) && $this->ips[$address[0]] > 0) { @$this->ips[$address[0]]--; } @fclose($client); } } else { $data = fread($client, 1000); if (!$data) { //   unset($this->clients[intval($client)]); unset($this->handshakes[intval($client)]); $address = explode(':', stream_socket_get_name($client, true)); if (isset($this->ips[$address[0]]) && $this->ips[$address[0]] > 0) { @$this->ips[$address[0]]--; } @fclose($client); $this->onClose($client);//   continue; } $this->onMessage($client, $data);//   } } } if ($write) { foreach ($write as $client) { if (!$this->handshakes[intval($client)]) {//        continue;//      } $info = $this->handshake($client); $this->onOpen($client, $info);//   } } } } protected function handshake($client) { $key = $this->handshakes[intval($client)]; if (!$key) { //    $headers = fread($client, 10000); preg_match("/Sec-WebSocket-Key: (.*)\r\n/", $headers, $match); if (empty($match[1])) { return false; } $key = $match[1]; $this->handshakes[intval($client)] = $key; } else { //     $SecWebSocketAccept = base64_encode(pack('H*', sha1($key . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'))); $upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" . "Upgrade: websocket\r\n" . "Connection: Upgrade\r\n" . "Sec-WebSocket-Accept:$SecWebSocketAccept\r\n\r\n"; fwrite($client, $upgrade); unset($this->handshakes[intval($client)]); } return $key; } protected function encode($payload, $type = 'text', $masked = false) { $frameHead = array(); $payloadLength = strlen($payload); switch ($type) { case 'text': // first byte indicates FIN, Text-Frame (10000001): $frameHead[0] = 129; break; case 'close': // first byte indicates FIN, Close Frame(10001000): $frameHead[0] = 136; break; case 'ping': // first byte indicates FIN, Ping frame (10001001): $frameHead[0] = 137; break; case 'pong': // first byte indicates FIN, Pong frame (10001010): $frameHead[0] = 138; break; } // set mask and payload length (using 1, 3 or 9 bytes) if ($payloadLength > 65535) { $payloadLengthBin = str_split(sprintf('%064b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 255 : 127; for ($i = 0; $i < 8; $i++) { $frameHead[$i + 2] = bindec($payloadLengthBin[$i]); } // most significant bit MUST be 0 if ($frameHead[2] > 127) { return array('type' => '', 'payload' => '', 'error' => 'frame too large (1004)'); } } elseif ($payloadLength > 125) { $payloadLengthBin = str_split(sprintf('%016b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 254 : 126; $frameHead[2] = bindec($payloadLengthBin[0]); $frameHead[3] = bindec($payloadLengthBin[1]); } else { $frameHead[1] = ($masked === true) ? $payloadLength + 128 : $payloadLength; } // convert frame-head to string: foreach (array_keys($frameHead) as $i) { $frameHead[$i] = chr($frameHead[$i]); } if ($masked === true) { // generate a random mask: $mask = array(); for ($i = 0; $i < 4; $i++) { $mask[$i] = chr(rand(0, 255)); } $frameHead = array_merge($frameHead, $mask); } $frame = implode('', $frameHead); // append payload to frame: for ($i = 0; $i < $payloadLength; $i++) { $frame .= ($masked === true) ? $payload[$i] ^ $mask[$i % 4] : $payload[$i]; } return $frame; } protected function decode($data) { $unmaskedPayload = ''; $decodedData = array(); // estimate frame type: $firstByteBinary = sprintf('%08b', ord($data[0])); $secondByteBinary = sprintf('%08b', ord($data[1])); $opcode = bindec(substr($firstByteBinary, 4, 4)); $isMasked = ($secondByteBinary[0] == '1') ? true : false; $payloadLength = ord($data[1]) & 127; // unmasked frame is received: if (!$isMasked) { return array('type' => '', 'payload' => '', 'error' => 'protocol error (1002)'); } switch ($opcode) { // text frame: case 1: $decodedData['type'] = 'text'; break; case 2: $decodedData['type'] = 'binary'; break; // connection close frame: case 8: $decodedData['type'] = 'close'; break; // ping frame: case 9: $decodedData['type'] = 'ping'; break; // pong frame: case 10: $decodedData['type'] = 'pong'; break; default: return array('type' => '', 'payload' => '', 'error' => 'unknown opcode (1003)'); } if ($payloadLength === 126) { $mask = substr($data, 4, 4); $payloadOffset = 8; $dataLength = bindec(sprintf('%08b', ord($data[2])) . sprintf('%08b', ord($data[3]))) + $payloadOffset; } elseif ($payloadLength === 127) { $mask = substr($data, 10, 4); $payloadOffset = 14; $tmp = ''; for ($i = 0; $i < 8; $i++) { $tmp .= sprintf('%08b', ord($data[$i + 2])); } $dataLength = bindec($tmp) + $payloadOffset; unset($tmp); } else { $mask = substr($data, 2, 4); $payloadOffset = 6; $dataLength = $payloadLength + $payloadOffset; } /** * We have to check for large frames here. socket_recv cuts at 1024 bytes * so if websocket-frame is > 1024 bytes we have to wait until whole * data is transferd. */ if (strlen($data) < $dataLength) { return false; } if ($isMasked) { for ($i = $payloadOffset; $i < $dataLength; $i++) { $j = $i - $payloadOffset; if (isset($data[$i])) { $unmaskedPayload .= $data[$i] ^ $mask[$j % 4]; } } $decodedData['payload'] = $unmaskedPayload; } else { $payloadOffset = $payloadOffset - 4; $decodedData['payload'] = substr($data, $payloadOffset); } return $decodedData; } abstract protected function onOpen($client, $info); abstract protected function onClose($client); abstract protected function onMessage($client, $data); abstract protected function onSend($data); abstract protected function send($data); } //   class WebsocketHandler extends WebsocketWorker { protected function onOpen($client, $info) {//      } protected function onClose($client) {//     } protected function onMessage($client, $data) {//      $data = $this->decode($data); if (!$data['payload']) { return; } if (!mb_check_encoding($data['payload'], 'utf-8')) { return; } //var_export($data); //  ,  ,      $message = ' #' . intval($client) . ' (' . $this->pid . '): ' . strip_tags($data['payload']); $this->send($message); $this->sendHelper($message); } protected function onSend($data) {//      $this->sendHelper($data); } protected function send($message) {//   ,        @fwrite($this->master, $message); } private function sendHelper($data) { $data = $this->encode($data); $write = $this->clients; if (stream_select($read, $write, $except, 0)) { foreach ($write as $client) { @fwrite($client, $data); } } } } $config = array( 'host' => '0.0.0.0', 'port' => 8000, 'workers' => 1, ); $WebsocketServer = new WebsocketServer($config); $WebsocketServer->start();

Update (best of comments):

one connection takes about 9kb of memory
If you use fgets() when working with open sockets, you can get a "hang" (the function will wait for the end of the line or timeout), because the message does not end with a line break according to the web socket protocol. use fread()
when writing a response to the socket with the fwrite() function (the function returns the number of bytes written), it is necessary to check that all data has been written to the socket
when responding from the server, you need to check the client's readiness to receive data using the stream_socket_accept() function
if on the server to write characters to the socket that are missing in utf-8, then the client will disconnect the connection with an error:
WebSocket connection to 'ws://sharoid.ru:8000/' failed: Could not decode a text frame as UTF-8.
when checking that the client has not sent any data and need to close the socket, use !strlen($data) , and not !$data
nginx can be placed in front of the webbox server

The second part of the article: IPC. Interprocess communication
The third part of the article: From chat to game: Battle City
The source code of the library and examples is on github and is available under the MIT license.

Source: https://habr.com/ru/post/209864/

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