WebsocketGeneric.php

<?php

abstract class WebsocketGeneric
{
    const SOCKET_BUFFER_SIZE = 1024;
    const MAX_SOCKET_BUFFER_SIZE = 10240;
    const MAX_SOCKETS = 1000;
    const SOCKET_MESSAGE_DELIMITER = "\n";
    protected $clients = array();
    protected $_server = null;
    protected $_services = array();
    protected $_read = array();//буферы чтения
    protected $_write = array();//буферы заииси
    public $timer = null;

    public function start() {
        if ($this->timer) {
            $timer = $this->_createTimer();
        }

        while (true) {
            //подготавливаем массив всех сокетов, которые нужно обработать
            $read = $this->_services + $this->clients;

            if ($this->_server) {
                $read[] = $this->_server;
            }

            if ($this->timer) {
                $read[] = $timer;
            }

            if (!$read) {
                return;
            }

            $write = array();

            if ($this->_write) {
                foreach ($this->_write as $connectionId => $buffer) {
                    if ($buffer) {
                        $write[] = $this->getConnectionById($connectionId);
                    }
                }
            }

            $except = $read;

            stream_select($read, $write, $except, null);//обновляем массив сокетов, которые можно обработать

            if ($this->timer && in_array($timer, $read)) {
                unset($read[array_search($timer, $read)]);
                fread($timer, self::SOCKET_BUFFER_SIZE);
                $this->onTimer();
            }

            if ($read) {//пришли данные от подключенных клиентов
                foreach ($read as $client) {
                    if ($this->_server == $client) { //на серверный сокет пришёл запрос от нового клиента
                        if ((count($this->clients) < self::MAX_SOCKETS) && ($client = @stream_socket_accept($this->_server, 0))) {
                            stream_set_blocking($client, 0);
                            $clientId = $this->getIdByConnection($client);
                            $this->clients[$clientId] = $client;
                            $this->_onOpen($clientId);
                        }
                    } else {
                        $connectionId = $this->getIdByConnection($client);
                        if (in_array($client, $this->_services)) {
                            if (is_null($this->_read($connectionId))) { //соединение было закрыто
                                $this->close($connectionId);
                                continue;
                            }

                            while ($data = $this->_readFromBuffer($connectionId)) {
                                $this->_onService($connectionId, $data); //вызываем пользовательский сценарий
                            }
                        } else {
                            if (!$this->_read($connectionId)) { //соединение было закрыто или превышен размер буфера
                                $this->close($connectionId);
                                continue;
                            }

                            $this->_onMessage($connectionId);
                        }
                    }
                }
            }

            if ($write) {
                foreach ($write as $client) {
                    if (is_resource($client)) {//проверяем, что мы его ещё не закрыли во время чтения
                        $this->_sendBuffer($client);
                    }
                }
            }

            if ($except) {
                foreach ($except as $client) {
                    $this->_onError($this->getIdByConnection($client));
                }
            }
        }
    }

    protected function _onError($connectionId) {
        echo "An error has occurred: $connectionId\n";
    }

    protected function close($connectionId) {
        @fclose($this->getConnectionById($connectionId));

        if (isset($this->clients[$connectionId])) {
            unset($this->clients[$connectionId]);
        } elseif (isset($this->_services[$connectionId])) {
            unset($this->_services[$connectionId]);
        } elseif($this->getConnectionById($connectionId) == $this->_server) {
            unset($this->_server);
        }

        unset($this->_write[$connectionId]);
        unset($this->_read[$connectionId]);
    }

    protected function _write($connectionId, $data, $delimiter = '') {
        @$this->_write[$connectionId] .=  $data . $delimiter;
    }

    protected function _sendBuffer($connect) {
        $connectionId = $this->getIdByConnection($connect);
        $written = fwrite($connect, $this->_write[$connectionId], self::SOCKET_BUFFER_SIZE);
        $this->_write[$connectionId] = substr($this->_write[$connectionId], $written);
    }

    protected function _readFromBuffer($connectionId) {
        $data = '';

        if (false !== ($pos = strpos($this->_read[$connectionId], self::SOCKET_MESSAGE_DELIMITER))) {
            $data = substr($this->_read[$connectionId], 0, $pos);
            $this->_read[$connectionId] = substr($this->_read[$connectionId], $pos + strlen(self::SOCKET_MESSAGE_DELIMITER));
        }

        return $data;
    }

    protected function _read($connectionId) {
        $data = fread($this->getConnectionById($connectionId), self::SOCKET_BUFFER_SIZE);

        if (!strlen($data)) return;

        @$this->_read[$connectionId] .= $data;//добавляем полученные данные в буфер чтения
        return strlen($this->_read[$connectionId]) < self::MAX_SOCKET_BUFFER_SIZE;
    }

    protected function getConnectionById($connectionId) {
        return isset($this->clients[$connectionId]) ? $this->clients[$connectionId] :
            (isset($this->_services[$connectionId]) ? $this->_services[$connectionId] : $this->_server);
    }

    protected function getIdByConnection($connection) {
        return intval($connection);
    }

    protected function _createTimer() {
        $pair = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);

        $pid = pcntl_fork();//создаём форк

        if ($pid == -1) {
            die("error: pcntl_fork\r\n");
        } elseif ($pid) { //родитель
            fclose($pair[0]);
            return $pair[1];//один из пары будет в родителе
        } else { //дочерний процесс
            fclose($pair[1]);
            $parent = $pair[0];//второй в дочернем процессе

            while (true) {
                fwrite($parent, '1');

                usleep($this->timer * 1000000);
            }
        }
    }

    abstract protected function _onMessage($connectionId);

    abstract protected function _onService($connectionId, $data);

    abstract protected function _onOpen($connectionId);
}