if b.uint32() != 1 { // total number of disks
		return -1, nil // the file is not a valid zip64-file
	}
	return int64(p), nil
}

// readDirectory64End reads the zip64 directory end and updates the
// directory end with the zip64 directory end values.
func readDirectory64End(r io.ReaderAt, offset int64, d *directoryEnd) (err error) {
	buf := make([]byte, directory64EndLen)

		tr.curr = &sparseFileReader{tr.curr, sph, 0}
	}
	return err
}

// readGNUSparsePAXHeaders checks the PAX headers for GNU sparse headers.
// If they are found, then this function reads the sparse map and returns it.
// This assumes that 0.0 headers have already been converted to 0.1 headers
// by the PAX header parsing logic.
func (tr *Reader) readGNUSparsePAXHeaders(hdr *Header) (sparseDatas, error) {