cache.py 文件源码

def _decompress_bz2(filename, blocksize=900*1024):
    """
    Decompress .tar.bz2 to .tar on disk (for faster access)

    Use TemporaryFile to guarentee write access.
    """
    if not filename.endswith('.tar.bz2'):
        return filename

    fd, path = mkstemp()
    with os.fdopen(fd, 'wb') as fo:
        with open(filename, 'rb') as fi:
            z = bz2.BZ2Decompressor()

            for block in iter(lambda: fi.read(blocksize), b''):
                fo.write(z.decompress(block))
    return path