trove/trove/guestagent/strategies/replication/__init__.py

59 lines
2.0 KiB
Python

# Copyright 2014 Tesora, Inc.
# 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.
#
from oslo_log import log as logging
from trove.common import cfg
from trove.common.strategies.strategy import Strategy
LOG = logging.getLogger(__name__)
CONF = cfg.CONF
__replication_instance = None
__replication_manager = None
__replication_namespace = None
__replication_strategy = None
def get_instance(manager):
global __replication_instance
global __replication_manager
global __replication_namespace
if not __replication_instance or manager != __replication_manager:
replication_strategy = get_strategy(manager)
__replication_namespace = CONF.get(manager).replication_namespace
replication_strategy_cls = get_strategy_cls(
replication_strategy, __replication_namespace)
__replication_instance = replication_strategy_cls()
__replication_manager = manager
LOG.debug('Replication instance from: %(namespace)s.%(strategy)s',
{'namespace': __replication_namespace,
'strategy': __replication_strategy})
return __replication_instance
def get_strategy(manager):
global __replication_strategy
if not __replication_strategy or manager != __replication_manager:
__replication_strategy = CONF.get(manager).replication_strategy
return __replication_strategy
def get_strategy_cls(replication_driver, ns=__name__):
return Strategy.get_strategy(replication_driver, ns)