cache_key = "~".join((filename, size, md5sum, repr(location_id)));
if not files_id_cache.has_key(cache_key):
files_id_serial += 1
cache_key = "~".join((filename, size, md5sum, repr(location_id)));
if not files_id_cache.has_key(cache_key):
files_id_serial += 1