def _convert_display_size(size):
    """
    Convert filesize into human-readable size using unit suffixes
    """
    unit_gigabyte = 1024 * 1024 * 1024.0
    unit_megabyte = 1024 * 1024.0
    unit_kilobyte = 1024.0

    if size > unit_gigabyte:
        return "{:.2f} GB".format(
            size / unit_gigabyte)
    elif size > unit_megabyte:
        return "{:.2f} MB".format(
            size / unit_megabyte)
    elif size > unit_kilobyte:
        return "{:.1f} KB".format(
            size / unit_kilobyte)

    return "{0} bytes".format(size)