79 lines
2.3 KiB
Python
79 lines
2.3 KiB
Python
# Copyright 2014 OpenStack Foundation
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# Copyright 2017 Red Hat, Inc.
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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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import collections
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import threading
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class MergedQueue(object):
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def __init__(self):
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self.queue = collections.deque()
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self.lock = threading.RLock()
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self.condition = threading.Condition(self.lock)
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self.join_condition = threading.Condition(self.lock)
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self.tasks = 0
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def qsize(self):
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return len(self.queue)
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def empty(self):
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return self.qsize() == 0
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def put(self, item):
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# Returns the original item if added, or an updated equivalent
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# item if already enqueued.
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self.condition.acquire()
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ret = None
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try:
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for x in self.queue:
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if item == x:
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ret = x
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if hasattr(ret, 'merge'):
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ret.merge(item)
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if ret is None:
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ret = item
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self.queue.append(item)
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self.condition.notify()
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finally:
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self.condition.release()
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return ret
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def get(self):
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self.condition.acquire()
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try:
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while True:
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try:
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ret = self.queue.popleft()
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self.join_condition.acquire()
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self.tasks += 1
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self.join_condition.release()
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return ret
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except IndexError:
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self.condition.wait()
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finally:
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self.condition.release()
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def task_done(self):
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self.join_condition.acquire()
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self.tasks -= 1
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self.join_condition.notify()
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self.join_condition.release()
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def join(self):
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self.join_condition.acquire()
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while self.tasks:
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self.join_condition.wait()
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self.join_condition.release()
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