Add generic serialization support

This adds a generic serialization model that the RpcProxy and
RpcDispatcher will use to serialize and deserialize arguments
and return values. The base definition is provided, as well
as a default NoOpSerializer which performs no special
action (retaining the existing behavior).

Related to blueprint rpc-object-serialization

Change-Id: I0a33baddee3e28dfc47100eb3216b679558b0bdd

1 files changed, 52 insertions, 0 deletions

diff --git a/openstack/common/rpc/serializer.py b/openstack/common/rpc/serializer.py
new file mode 100644
index 0000000..0a2c9c4
--- /dev/null
+++ b/openstack/common/rpc/serializer.py
@@ -0,0 +1,52 @@
+#    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 an RPC serialization handler"""
+
+import abc
+
+
+class Serializer(object):
+    """Generic (de-)serialization definition base class"""
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractmethod
+    def serialize_entity(self, context, entity):
+        """Serialize something to primitive form.
+
+        :param context: Security context
+        :param entity: Entity to be serialized
+        :returns: Serialized form of entity
+        """
+        pass
+
+    @abc.abstractmethod
+    def deserialize_entity(self, context, entity):
+        """Deserialize something from primitive form.
+
+        :param context: Security context
+        :param entity: Primitive to be deserialized
+        :returns: Deserialized form of entity
+        """
+        pass
+
+
+class NoOpSerializer(Serializer):
+    """A serializer that does nothing"""
+
+    def serialize_entity(self, context, entity):
+        return entity
+
+    def deserialize_entity(self, context, entity):
+        return entity