84 lines
3.0 KiB
Python
84 lines
3.0 KiB
Python
# Copyright 2011 OpenStack Foundation.
|
|
# All Rights Reserved.
|
|
# Copyright 2013 eNovance
|
|
#
|
|
# 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.
|
|
|
|
import itertools
|
|
import logging
|
|
|
|
from oslo.messaging import localcontext
|
|
from oslo.messaging import serializer as msg_serializer
|
|
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
PRIORITIES = ['audit', 'debug', 'info', 'warn', 'error', 'critical', 'sample']
|
|
|
|
|
|
class NotificationDispatcher(object):
|
|
"""A message dispatcher which understands Notification messages.
|
|
|
|
A MessageHandlingServer is constructed by passing a callable dispatcher
|
|
which is invoked with context and message dictionaries each time a message
|
|
is received.
|
|
|
|
NotifcationDispatcher is one such dispatcher which pass a raw notification
|
|
message to the endpoints
|
|
"""
|
|
|
|
def __init__(self, targets, endpoints, serializer):
|
|
self.targets = targets
|
|
self.endpoints = endpoints
|
|
self.serializer = serializer or msg_serializer.NoOpSerializer()
|
|
|
|
self._callbacks_by_priority = {}
|
|
for endpoint, prio in itertools.product(endpoints, PRIORITIES):
|
|
if hasattr(endpoint, prio):
|
|
method = getattr(endpoint, prio)
|
|
self._callbacks_by_priority.setdefault(prio, []).append(method)
|
|
|
|
priorities = self._callbacks_by_priority.keys()
|
|
self._targets_priorities = set(itertools.product(self.targets,
|
|
priorities))
|
|
|
|
def _listen(self, transport):
|
|
return transport._listen_for_notifications(self._targets_priorities)
|
|
|
|
def __call__(self, ctxt, message):
|
|
"""Dispatch an RPC message to the appropriate endpoint method.
|
|
|
|
:param ctxt: the request context
|
|
:type ctxt: dict
|
|
:param message: the message payload
|
|
:type message: dict
|
|
"""
|
|
ctxt = self.serializer.deserialize_context(ctxt)
|
|
|
|
publisher_id = message.get('publisher_id')
|
|
event_type = message.get('event_type')
|
|
priority = message.get('priority', '').lower()
|
|
if priority not in PRIORITIES:
|
|
LOG.warning('Unknown priority "%s"' % priority)
|
|
return
|
|
|
|
payload = self.serializer.deserialize_entity(ctxt,
|
|
message.get('payload'))
|
|
|
|
for callback in self._callbacks_by_priority.get(priority, []):
|
|
localcontext.set_local_context(ctxt)
|
|
try:
|
|
callback(ctxt, publisher_id, event_type, payload)
|
|
finally:
|
|
localcontext.clear_local_context()
|