def _DecodeCompiledCursor(self, query, compiled_cursor):
"""Converts a compiled_cursor into a cursor_entity.
Returns:
(cursor_entity, inclusive): a datastore.Entity and if it should be
included in the result set.
"""
assert len(compiled_cursor.position_list()) == 1
position = compiled_cursor.position(0)
entity_pb = datastore_pb.EntityProto()
(query_info_encoded,
entity_encoded) = position.start_key().split(_CURSOR_CONCAT_STR, 1)
query_info_pb = datastore_pb.Query()
query_info_pb.ParseFromString(query_info_encoded)
self._ValidateQuery(query, query_info_pb)
entity_pb.ParseFromString(entity_encoded)
return (datastore.Entity._FromPb(entity_pb,
True), position.start_inclusive())
def _MinimalEntityInfo(self, entity_proto, query):
"""Extract the minimal set of information that preserves entity order.
Args:
entity_proto: datastore_pb.EntityProto instance from which to extract
information
query: datastore_pb.Query instance for which ordering must be preserved.
Returns:
datastore_pb.EntityProto instance suitable for matching against a list of
results when finding cursor positions.
"""
entity_info = datastore_pb.EntityProto();
order_names = [o.property() for o in query.order_list()]
entity_info.mutable_key().MergeFrom(entity_proto.key())
entity_info.mutable_entity_group().MergeFrom(entity_proto.entity_group())
for prop in entity_proto.property_list():
if prop.name() in order_names:
entity_info.add_property().MergeFrom(prop)
return entity_info;