ZlibCompressor.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine\network\mcpe\compression;
 
use pocketmine\network\mcpe\protocol\types\CompressionAlgorithm;
use pocketmine\utils\SingletonTrait;
use pocketmine\utils\Utils;
use function function_exists;
use function libdeflate_deflate_compress;
use function strlen;
use function zlib_decode;
use function zlib_encode;
use const ZLIB_ENCODING_RAW;
 
final class ZlibCompressor implements Compressor{
    use SingletonTrait;
 
    public const DEFAULT_LEVEL = 7;
    public const DEFAULT_THRESHOLD = 256;
    public const DEFAULT_MAX_DECOMPRESSION_SIZE = 8 * 1024 * 1024;
 
    private static function make() : self{
        return new self(self::DEFAULT_LEVEL, self::DEFAULT_THRESHOLD, self::DEFAULT_MAX_DECOMPRESSION_SIZE);
    }
 
    public function __construct(
        private int $level,
        private ?int $minCompressionSize,
        private int $maxDecompressionSize
    ){}
 
    public function getCompressionThreshold() : ?int{
        return $this->minCompressionSize;
    }
 
    public function decompress(string $payload) : string{
        $result = @zlib_decode($payload, $this->maxDecompressionSize);
        if($result === false){
            throw new DecompressionException("Failed to decompress data");
        }
        return $result;
    }
 
    public function compress(string $payload) : string{
        $compressible = $this->minCompressionSize !== null && strlen($payload) >= $this->minCompressionSize;
        $level = $compressible ? $this->level : 0;
 
        return function_exists('libdeflate_deflate_compress') ?
            libdeflate_deflate_compress($payload, $level) :
            Utils::assumeNotFalse(zlib_encode($payload, ZLIB_ENCODING_RAW, $level), "ZLIB compression failed");
    }
 
    public function getNetworkId() : int{
        return CompressionAlgorithm::ZLIB;
    }
}