oslo.messaging/oslo_messaging/serializer.py

82 lines
2.4 KiB
Python

# Copyright 2013 IBM Corp.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Provides the definition of a message serialization handler"""
import abc
from oslo_serialization import jsonutils
__all__ = ['Serializer', 'NoOpSerializer', 'JsonPayloadSerializer']
class Serializer(object, metaclass=abc.ABCMeta):
"""Generic (de-)serialization definition base class."""
@abc.abstractmethod
def serialize_entity(self, ctxt, entity):
"""Serialize something to primitive form.
:param ctxt: Request context, in deserialized form
:param entity: Entity to be serialized
:returns: Serialized form of entity
"""
@abc.abstractmethod
def deserialize_entity(self, ctxt, entity):
"""Deserialize something from primitive form.
:param ctxt: Request context, in deserialized form
:param entity: Primitive to be deserialized
:returns: Deserialized form of entity
"""
@abc.abstractmethod
def serialize_context(self, ctxt):
"""Serialize a request context into a dictionary.
:param ctxt: Request context
:returns: Serialized form of context
"""
@abc.abstractmethod
def deserialize_context(self, ctxt):
"""Deserialize a dictionary into a request context.
:param ctxt: Request context dictionary
:returns: Deserialized form of entity
"""
class NoOpSerializer(Serializer):
"""A serializer that does nothing."""
def serialize_entity(self, ctxt, entity):
return entity
def deserialize_entity(self, ctxt, entity):
return entity
def serialize_context(self, ctxt):
return ctxt
def deserialize_context(self, ctxt):
return ctxt
class JsonPayloadSerializer(NoOpSerializer):
@staticmethod
def serialize_entity(context, entity):
return jsonutils.to_primitive(entity, convert_instances=True)