134 lines
4.5 KiB
Python
134 lines
4.5 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2010 United States Government as represented by the
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# Administrator of the National Aeronautics and Space Administration.
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# All Rights Reserved.
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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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""" Based a bit on the carrot.backeds.queue backend... but a lot better """
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from carrot.backends import base
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import logging
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import Queue as queue
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class Message(base.BaseMessage):
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pass
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class Exchange(object):
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def __init__(self, name, exchange_type):
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self.name = name
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self.exchange_type = exchange_type
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self._queue = queue.Queue()
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self._routes = {}
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def publish(self, message, routing_key=None):
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logging.debug('(%s) publish (key: %s) %s',
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self.name, routing_key, message)
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if routing_key in self._routes:
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for f in self._routes[routing_key]:
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logging.debug('Publishing to route %s', f)
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f(message, routing_key=routing_key)
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def bind(self, callback, routing_key):
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self._routes.setdefault(routing_key, [])
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self._routes[routing_key].append(callback)
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class Queue(object):
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def __init__(self, name):
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self.name = name
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self._queue = queue.Queue()
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def __repr__(self):
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return '<Queue: %s>' % self.name
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def push(self, message, routing_key=None):
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self._queue.put(message)
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def size(self):
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return self._queue.qsize()
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def pop(self):
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return self._queue.get()
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class Backend(object):
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""" Singleton backend for testing """
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class __impl(base.BaseBackend):
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def __init__(self, *args, **kwargs):
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#super(__impl, self).__init__(*args, **kwargs)
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self._exchanges = {}
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self._queues = {}
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def _reset_all(self):
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self._exchanges = {}
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self._queues = {}
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def queue_declare(self, queue, **kwargs):
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if queue not in self._queues:
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logging.debug('Declaring queue %s', queue)
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self._queues[queue] = Queue(queue)
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def exchange_declare(self, exchange, type, *args, **kwargs):
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if exchange not in self._exchanges:
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logging.debug('Declaring exchange %s', exchange)
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self._exchanges[exchange] = Exchange(exchange, type)
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def queue_bind(self, queue, exchange, routing_key, **kwargs):
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logging.debug('Binding %s to %s with key %s',
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queue, exchange, routing_key)
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self._exchanges[exchange].bind(self._queues[queue].push,
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routing_key)
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def get(self, queue, no_ack=False):
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if not queue in self._queues or not self._queues[queue].size():
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return None
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(message_data, content_type, content_encoding) = \
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self._queues[queue].pop()
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message = Message(backend=self, body=message_data,
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content_type=content_type,
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content_encoding=content_encoding)
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logging.debug('Getting from %s: %s', queue, message)
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return message
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def prepare_message(self, message_data, delivery_mode,
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content_type, content_encoding, **kwargs):
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"""Prepare message for sending."""
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return (message_data, content_type, content_encoding)
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def publish(self, message, exchange, routing_key, **kwargs):
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if exchange in self._exchanges:
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self._exchanges[exchange].publish(
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message, routing_key=routing_key)
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__instance = None
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def __init__(self, *args, **kwargs):
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if Backend.__instance is None:
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Backend.__instance = Backend.__impl(*args, **kwargs)
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self.__dict__['_Backend__instance'] = Backend.__instance
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def __getattr__(self, attr):
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return getattr(self.__instance, attr)
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def __setattr__(self, attr, value):
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return setattr(self.__instance, attr, value)
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def reset_all():
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Backend()._reset_all()
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