Gran Turismo File System (GTFS): PHP parsing library

<?php
// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

namespace {
    class GranTurismoVol extends \Kaitai\Struct\Struct {
        public function __construct(\Kaitai\Struct\Stream $_io, \Kaitai\Struct\Struct $_parent = null, \GranTurismoVol $_root = null) {
            parent::__construct($_io, $_parent, $_root);
            $this->_read();
        }

        private function _read() {
            $this->_m_magic = $this->_io->readBytes(8);
            if (!($this->magic() == "\x47\x54\x46\x53\x00\x00\x00\x00")) {
                throw new \Kaitai\Struct\Error\ValidationNotEqualError("\x47\x54\x46\x53\x00\x00\x00\x00", $this->magic(), $this->_io(), "/seq/0");
            }
            $this->_m_numFiles = $this->_io->readU2le();
            $this->_m_numEntries = $this->_io->readU2le();
            $this->_m_reserved = $this->_io->readBytes(4);
            if (!($this->reserved() == "\x00\x00\x00\x00")) {
                throw new \Kaitai\Struct\Error\ValidationNotEqualError("\x00\x00\x00\x00", $this->reserved(), $this->_io(), "/seq/3");
            }
            $this->_m_offsets = [];
            $n = $this->numFiles();
            for ($i = 0; $i < $n; $i++) {
                $this->_m_offsets[] = $this->_io->readU4le();
            }
        }
        protected $_m_ofsDir;
        public function ofsDir() {
            if ($this->_m_ofsDir !== null)
                return $this->_m_ofsDir;
            $this->_m_ofsDir = $this->offsets()[1];
            return $this->_m_ofsDir;
        }
        protected $_m_files;
        public function files() {
            if ($this->_m_files !== null)
                return $this->_m_files;
            $_pos = $this->_io->pos();
            $this->_io->seek(($this->ofsDir() & 4294965248));
            $this->_m_files = [];
            $n = $this->_root()->numEntries();
            for ($i = 0; $i < $n; $i++) {
                $this->_m_files[] = new \GranTurismoVol\FileInfo($this->_io, $this, $this->_root);
            }
            $this->_io->seek($_pos);
            return $this->_m_files;
        }
        protected $_m_magic;
        protected $_m_numFiles;
        protected $_m_numEntries;
        protected $_m_reserved;
        protected $_m_offsets;
        public function magic() { return $this->_m_magic; }
        public function numFiles() { return $this->_m_numFiles; }
        public function numEntries() { return $this->_m_numEntries; }
        public function reserved() { return $this->_m_reserved; }
        public function offsets() { return $this->_m_offsets; }
    }
}

namespace GranTurismoVol {
    class FileInfo extends \Kaitai\Struct\Struct {
        public function __construct(\Kaitai\Struct\Stream $_io, \GranTurismoVol $_parent = null, \GranTurismoVol $_root = null) {
            parent::__construct($_io, $_parent, $_root);
            $this->_read();
        }

        private function _read() {
            $this->_m_timestamp = $this->_io->readU4le();
            $this->_m_offsetIdx = $this->_io->readU2le();
            $this->_m_flags = $this->_io->readU1();
            $this->_m_name = \Kaitai\Struct\Stream::bytesToStr(\Kaitai\Struct\Stream::bytesTerminate(\Kaitai\Struct\Stream::bytesStripRight($this->_io->readBytes(25), 0), 0, false), "ASCII");
        }
        protected $_m_size;
        public function size() {
            if ($this->_m_size !== null)
                return $this->_m_size;
            $this->_m_size = (($this->_root()->offsets()[($this->offsetIdx() + 1)] & 4294965248) - $this->_root()->offsets()[$this->offsetIdx()]);
            return $this->_m_size;
        }
        protected $_m_body;
        public function body() {
            if ($this->_m_body !== null)
                return $this->_m_body;
            if (!($this->isDir())) {
                $_pos = $this->_io->pos();
                $this->_io->seek(($this->_root()->offsets()[$this->offsetIdx()] & 4294965248));
                $this->_m_body = $this->_io->readBytes($this->size());
                $this->_io->seek($_pos);
            }
            return $this->_m_body;
        }
        protected $_m_isDir;
        public function isDir() {
            if ($this->_m_isDir !== null)
                return $this->_m_isDir;
            $this->_m_isDir = ($this->flags() & 1) != 0;
            return $this->_m_isDir;
        }
        protected $_m_isLastEntry;
        public function isLastEntry() {
            if ($this->_m_isLastEntry !== null)
                return $this->_m_isLastEntry;
            $this->_m_isLastEntry = ($this->flags() & 128) != 0;
            return $this->_m_isLastEntry;
        }
        protected $_m_timestamp;
        protected $_m_offsetIdx;
        protected $_m_flags;
        protected $_m_name;
        public function timestamp() { return $this->_m_timestamp; }
        public function offsetIdx() { return $this->_m_offsetIdx; }
        public function flags() { return $this->_m_flags; }
        public function name() { return $this->_m_name; }
    }
}