protected function skipbytes($bytes)
    {
        if ($this->comptype === Archive::COMPRESS_GZIP) {
            @gzseek($this->fh, $bytes, SEEK_CUR);
        } elseif ($this->comptype === Archive::COMPRESS_BZIP) {
            // there is no seek in bzip2, we simply read on
            // bzread allows to read a max of 8kb at once
            while($bytes) {
                $toread = min(8192, $bytes);
                @bzread($this->fh, $toread);
                $bytes -= $toread;
            }
        } else {
            @fseek($this->fh, $bytes, SEEK_CUR);
        }
    }