def decode_path(encoded_path):
""" Parse a Cassandra-encoded reference path.
Args:
encoded_path: A string specifying the encoded path.
Returns:
An entity_pb.Path object.
"""
path = entity_pb.Path()
for element in encoded_path.split(dbconstants.KIND_SEPARATOR):
# For some reason, encoded keys have a trailing separator, so ignore the
# last empty element.
if not element:
continue
kind, identifier = element.split(dbconstants.ID_SEPARATOR)
new_element = path.add_element()
new_element.set_type(kind)
# Encoded paths do not differentiate between IDs and names, so we can only
# guess which one it is. IDs often exceed the ID_KEY_LENGTH.
if len(identifier) >= ID_KEY_LENGTH and identifier.isdigit():
new_element.set_id(int(identifier))
else:
new_element.set_name(identifier)
return path
def encode_path_from_filter(query_filter):
""" Encode a reference path from a query filter.
Args:
query_filter: A datastore_pb.Query_Filter.
Returns:
A string containing an encoded reference path.
"""
path = entity_pb.Path()
ref_value = query_filter.property(0).value().referencevalue()
for element in ref_value.pathelement_list():
path.add_element().MergeFrom(element)
return str(encode_index_pb(path))
def decode(flat_path, reference_value=False):
""" Converts a tuple to a key path protobuf object. """
if reference_value:
path = entity_pb.PropertyValue_ReferenceValue()
else:
path = entity_pb.Path()
for index in range(0, len(flat_path), 2):
if reference_value:
element = path.add_pathelement()
else:
element = path.add_element()
element.set_type(flat_path[index])
id_or_name = flat_path[index + 1]
if isinstance(id_or_name, int):
element.set_id(id_or_name)
else:
element.set_name(id_or_name.encode('utf-8'))
return path
def group(self):
group = entity_pb.Path()
group.add_element().MergeFrom(Path.decode_element(self.path[:2]))
return group
