gantt/nova/fakerabbit.py
2011-05-25 15:42:49 -07:00

154 lines
4.7 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
# 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.
"""Based a bit on the carrot.backeds.queue backend... but a lot better."""
import Queue as queue
from carrot.backends import base
from eventlet import greenthread
from nova import log as logging
LOG = logging.getLogger("nova.fakerabbit")
EXCHANGES = {}
QUEUES = {}
CONSUMERS = {}
class Message(base.BaseMessage):
pass
class Exchange(object):
def __init__(self, name, exchange_type):
self.name = name
self.exchange_type = exchange_type
self._queue = queue.Queue()
self._routes = {}
def publish(self, message, routing_key=None):
nm = self.name
LOG.debug(_('(%(nm)s) publish (key: %(routing_key)s)'
' %(message)s') % locals())
if routing_key in self._routes:
for f in self._routes[routing_key]:
LOG.debug(_('Publishing to route %s'), f)
f(message, routing_key=routing_key)
def bind(self, callback, routing_key):
self._routes.setdefault(routing_key, [])
self._routes[routing_key].append(callback)
class Queue(object):
def __init__(self, name):
self.name = name
self._queue = queue.Queue()
def __repr__(self):
return '<Queue: %s>' % self.name
def push(self, message, routing_key=None):
self._queue.put(message)
def size(self):
return self._queue.qsize()
def pop(self):
return self._queue.get()
class Backend(base.BaseBackend):
def queue_declare(self, queue, **kwargs):
global QUEUES
if queue not in QUEUES:
LOG.debug(_('Declaring queue %s'), queue)
QUEUES[queue] = Queue(queue)
def exchange_declare(self, exchange, type, *args, **kwargs):
global EXCHANGES
if exchange not in EXCHANGES:
LOG.debug(_('Declaring exchange %s'), exchange)
EXCHANGES[exchange] = Exchange(exchange, type)
def queue_bind(self, queue, exchange, routing_key, **kwargs):
global EXCHANGES
global QUEUES
LOG.debug(_('Binding %(queue)s to %(exchange)s with'
' key %(routing_key)s') % locals())
EXCHANGES[exchange].bind(QUEUES[queue].push, routing_key)
def declare_consumer(self, queue, callback, consumer_tag, *args, **kwargs):
global CONSUMERS
LOG.debug("Adding consumer %s", consumer_tag)
CONSUMERS[consumer_tag] = (queue, callback)
def cancel(self, consumer_tag):
global CONSUMERS
LOG.debug("Removing consumer %s", consumer_tag)
del CONSUMERS[consumer_tag]
def consume(self, limit=None):
global CONSUMERS
num = 0
while True:
for (queue, callback) in CONSUMERS.itervalues():
item = self.get(queue)
if item:
callback(item)
num += 1
yield
if limit and num == limit:
raise StopIteration()
greenthread.sleep(0.1)
def get(self, queue, no_ack=False):
global QUEUES
if not queue in QUEUES or not QUEUES[queue].size():
return None
(message_data, content_type, content_encoding) = QUEUES[queue].pop()
message = Message(backend=self, body=message_data,
content_type=content_type,
content_encoding=content_encoding)
message.result = True
LOG.debug(_('Getting from %(queue)s: %(message)s') % locals())
return message
def prepare_message(self, message_data, delivery_mode,
content_type, content_encoding, **kwargs):
"""Prepare message for sending."""
return (message_data, content_type, content_encoding)
def publish(self, message, exchange, routing_key, **kwargs):
global EXCHANGES
if exchange in EXCHANGES:
EXCHANGES[exchange].publish(message, routing_key=routing_key)
def reset_all():
global EXCHANGES
global QUEUES
global CONSUMERS
EXCHANGES = {}
QUEUES = {}
CONSUMERS = {}