'Return a unique name for a blob dbfile.
This is used as the filename for the dbfile for this blob.'

def bhash_from_blob_info(self, res_path, lang, blobname):

    s = ':'.join([res_path, lang, blobname])
    if isinstance(s, unicode):
        s = s.encode(sys.getfilesystemencoding())
    return md5(s).hexdigest()
