query handle on php

queryHandle.php

<?php
/**
 * Created by PhpStorm.
 * User: MakStashkevich
 * Date: 30.08.2018
 * Time: 16:31
 */

class Query
{

    /** @var int */
    const HANDSHAKE = 9;
    const STATISTICS = 0;

    /** @var resource $socket */
    protected $socket;
    /** @var int $timestamp */
    protected $timestamp;

    /**
     * Query constructor.
     * @param string $host
     * @param int $port
     * @param int $timeout
     * @throws \Exception
     */
    function __construct(string $host, int $port, int $timeout = 3)
    {
        $this->socket = fsockopen("udp://" . $host, $port);
        if (!$this->socket) {
            throw new \Exception("Could not create socket.");
        }
        $this->timestamp = time() + rand();
        stream_set_timeout($this->socket, $timeout);
        stream_set_blocking($this->socket, \true);
    }

    /**
     * @param int $request
     * @param string $additional
     */
    private function writeData(int $request, string $additional = "")
    {
        $data = pack("C3N", 0xfe, 0xfd, $request, $this->timestamp) . $additional;
        fwrite($this->socket, $data, strlen($data));
    }


    /**
     * @return bool|string
     */
    private function readData()
    {
        return substr(fread($this->socket, 4096), 5); //skip header & timestamp
    }

    /**
     * @return null|string
     */
    private function getToken()
    {
        $this->writeData(self::HANDSHAKE);
        return ($data = $this->readData()) === \false ? \null : $data;
    }


    /**
     * @param string $token
     * @return array|null
     */
    private function getStatus(string $token)
    {
        $this->writeData(self::STATISTICS, pack("N", $token) . "\xff\xff\xff\x01");
        if (($data = $this->readData()) === false) {
            return \null;
        }
        if (count(($data = explode("\x00\x00\x01player_\x00\x00", substr($data, 11)))) !== 2) {
            return \null;
        }
        $statistics = [
            'players' => array_filter($data[1] === "\x00" ? [] : explode("\x00", $data[1]), function ($v) {
                return $v !== "";
            })
        ];
        foreach (array_chunk(explode("\x00", $data[0]), 2) as $v) {
            $statistics[$v[0]] = $v[1];
        }
        return $statistics;
    }

    /**
     * @return array|null
     */
    function getResult()
    {
        return ($token = $this->getToken()) !== \null && ($status = $this->getStatus($token)) !== \null ? $status : \null;
    }
}