2abb40f9e9
The client call() and cast() methods take a request context argument which is expected to be a dictionary. The RPC endpoint methods on the server are invoked with a dictionary context argument. However, Nova passes a nova.context.RequestContext on the client side and the oslo-incubator RPC code deserializes that as a amqp.RpcContext which looks vaguely compatible with Nova's RequestContext. Support the serialization and deserialization of RequestContext objects with an additional (de)serialize_context() hook on our Serializer class. Note: this is a backwards incompatible API change because Serializer implementations which do not implement the new abstract methods would no longer be possible to instantiate. Not a problem with this commit, but shows the type of compat concerns we'll need to think about once the API is locked down for good. Change-Id: I20782bad77fa0b0e396d082df852ca355548f9b7
75 lines
2.2 KiB
Python
75 lines
2.2 KiB
Python
# Copyright 2013 IBM Corp.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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__all__ = ['Serializer', 'NoOpSerializer']
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"""Provides the definition of a message serialization handler"""
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import abc
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class Serializer(object):
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"""Generic (de-)serialization definition base class."""
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__metaclass__ = abc.ABCMeta
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@abc.abstractmethod
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def serialize_entity(self, ctxt, entity):
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"""Serialize something to primitive form.
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:param ctxt: Request context, in deserialized form
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:param entity: Entity to be serialized
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:returns: Serialized form of entity
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"""
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@abc.abstractmethod
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def deserialize_entity(self, ctxt, entity):
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"""Deserialize something from primitive form.
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:param ctxt: Request context, in deserialized form
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:param entity: Primitive to be deserialized
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:returns: Deserialized form of entity
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"""
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@abc.abstractmethod
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def serialize_context(self, ctxt):
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"""Serialize a request context into a dictionary.
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:param ctxt: Request context
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:returns: Serialized form of context
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"""
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@abc.abstractmethod
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def deserialize_context(self, ctxt):
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"""Deserialize a dictionary into a request context.
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:param ctxt: Request context dictionary
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:returns: Deserialized form of entity
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"""
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class NoOpSerializer(Serializer):
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"""A serializer that does nothing."""
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def serialize_entity(self, ctxt, entity):
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return entity
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def deserialize_entity(self, ctxt, entity):
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return entity
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def serialize_context(self, ctxt):
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return ctxt
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def deserialize_context(self, ctxt):
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return ctxt
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