oslo.messaging/oslo/messaging/_executors/base.py

63 lines
2.0 KiB
Python

# Copyright 2013 New Dream Network, LLC (DreamHost)
#
# 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 abc
import logging
import sys
import six
from oslo import messaging
_LOG = logging.getLogger(__name__)
@six.add_metaclass(abc.ABCMeta)
class ExecutorBase(object):
def __init__(self, conf, listener, callback):
self.conf = conf
self.listener = listener
self.callback = callback
def _dispatch(self, incoming):
try:
incoming.reply(self.callback(incoming.ctxt, incoming.message))
except messaging.ExpectedException as e:
_LOG.debug('Expected exception during message handling (%s)' %
e.exc_info[1])
incoming.reply(failure=e.exc_info, log_failure=False)
except Exception as e:
# sys.exc_info() is deleted by LOG.exception().
exc_info = sys.exc_info()
_LOG.error('Exception during message handling: %s', e,
exc_info=exc_info)
incoming.reply(failure=exc_info)
# NOTE(dhellmann): Remove circular object reference
# between the current stack frame and the traceback in
# exc_info.
del exc_info
@abc.abstractmethod
def start(self):
"Start polling for incoming messages."
@abc.abstractmethod
def stop(self):
"Stop polling for messages."
@abc.abstractmethod
def wait(self):
"Wait until the executor has stopped polling."