pocketmine\level\format\mcregion\RegionLoader::cleanGarbage PHP Метод

    private function cleanGarbage()
    {
        $sectors = [];
        foreach ($this->locationTable as $index => $data) {
            //Calculate file usage
            if ($data[0] === 0 or $data[1] === 0) {
                $this->locationTable[$index] = [0, 0, 0];
                continue;
            }
            for ($i = 0; $i < $data[1]; ++$i) {
                $sectors[$data[0]] = $index;
            }
        }
        if (count($sectors) === $this->lastSector - 2) {
            //No collection needed
            return 0;
        }
        ksort($sectors);
        $shift = 0;
        $lastSector = 1;
        //First chunk - 1
        fseek($this->filePointer, 8192);
        $sector = 2;
        foreach ($sectors as $sector => $index) {
            if ($sector - $lastSector > 1) {
                $shift += $sector - $lastSector - 1;
            }
            if ($shift > 0) {
                fseek($this->filePointer, $sector << 12);
                $old = fread($this->filePointer, 4096);
                fseek($this->filePointer, $sector - $shift << 12);
                fwrite($this->filePointer, $old, 4096);
            }
            $this->locationTable[$index][0] -= $shift;
            $lastSector = $sector;
        }
        ftruncate($this->filePointer, $sector + 1 << 12);
        //Truncate to the end of file written
        return $shift;
    }