56 lines
1.7 KiB
Python
56 lines
1.7 KiB
Python
# Copyright 2014 Huawei Technologies Co. Ltd
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain 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,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Module to provide util for actions
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.. moduleauthor:: Xiaodong Wang ,xiaodongwang@huawei.com>
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"""
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import logging
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import redis
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from contextlib import contextmanager
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from compass.db.api import database
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from compass.db import models
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@contextmanager
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def lock(lock_name, blocking=True, timeout=10):
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redis_instance = redis.Redis()
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instance_lock = redis_instance.lock(lock_name, timeout=timeout)
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owned = False
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try:
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locked = instance_lock.acquire(blocking=blocking)
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if locked:
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owned = True
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logging.debug('acquired lock %s', lock_name)
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yield instance_lock
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else:
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logging.info('lock %s is already hold', lock_name)
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yield None
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except Exception as error:
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logging.info(
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'redis fails to acquire the lock %s', lock_name)
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logging.exception(error)
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yield None
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finally:
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if owned:
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instance_lock.acquired_until = 0
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instance_lock.release()
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logging.debug('released lock %s', lock_name)
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else:
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logging.debug('nothing to release %s', lock_name)
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