Files
gantt/nova/rpcclient.py
Mark McLoughlin 5668e57616 Port all rpcapi modules to oslo.messaging interface
Add a temporary nova.rpcclient.RPCClient helper class which translates
oslo.messaging.rpc.RPCClient compatible calls into calls on a RpcProxy
object.

Use this new class to port all of the rpcapi modules over to the new
RPCClient so that the final port of Nova over to oslo.messaging will be
smaller and easier to review.

This patch contains no functional changes at all, except that all client
side RPCs go through this temporary helper class.

blueprint: oslo-messaging
Change-Id: Iee86c36bcc474a604993618b8a2255af8c3d2f48
2013-09-03 21:22:43 +01:00

97 lines
3.3 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2013 Red Hat, Inc.
#
# 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.
"""
A temporary helper which emulates oslo.messaging.rpc.RPCClient.
The most tedious part of porting to oslo.messaging is porting the code which
sub-classes RpcProxy to use RPCClient instead.
This helper method allows us to do that tedious porting as a standalone commit
so that the commit which switches us to oslo.messaging is smaller and easier
to review. This file will be removed as part of that commit.
"""
from nova.openstack.common.rpc import proxy
class RPCClient(object):
def __init__(self, proxy, namespace=None, server_params=None):
super(RPCClient, self).__init__()
self.proxy = proxy
self.namespace = namespace
self.server_params = server_params
self.kwargs = {}
self.fanout = None
def prepare(self, **kwargs):
# Clone ourselves
ret = self.__class__(self.proxy, self.namespace, self.server_params)
ret.kwargs.update(self.kwargs)
ret.fanout = self.fanout
# Update according to supplied kwargs
ret.kwargs.update(kwargs)
server = ret.kwargs.pop('server', None)
if server:
ret.kwargs['topic'] = '%s.%s' % (self.proxy.topic, server)
fanout = ret.kwargs.pop('fanout', None)
if fanout:
ret.fanout = True
return ret
def _invoke(self, cast_or_call, ctxt, method, **kwargs):
try:
msg = self.proxy.make_namespaced_msg(method,
self.namespace,
**kwargs)
return cast_or_call(ctxt, msg, **self.kwargs)
finally:
self.kwargs = {}
self.fanout = None
def cast(self, ctxt, method, **kwargs):
if self.server_params:
def cast_to_server(ctxt, msg, **kwargs):
if self.fanout:
return self.proxy.fanout_cast_to_server(
ctxt, self.server_params, msg, **kwargs)
else:
return self.proxy.cast_to_server(
ctxt, self.server_params, msg, **kwargs)
caster = cast_to_server
else:
caster = self.proxy.fanout_cast if self.fanout else self.proxy.cast
self._invoke(caster, ctxt, method, **kwargs)
def call(self, ctxt, method, **kwargs):
return self._invoke(self.proxy.call, ctxt, method, **kwargs)
def can_send_version(self, version):
return self.proxy.can_send_version(version)
class RpcProxy(proxy.RpcProxy):
def get_client(self, namespace=None, server_params=None):
return RPCClient(self,
namespace=namespace,
server_params=server_params)