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# 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.
"""
Session Handling for SQLAlchemy backend
"""
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from nova import flags
FLAGS = flags.FLAGS
_ENGINE = None
_MAKER = None
def get_session(autocommit=True, expire_on_commit=False):
"""Helper method to grab session"""
global _ENGINE
global _MAKER
if not _MAKER:
if not _ENGINE:
_ENGINE = create_engine(FLAGS.sql_connection,
pool_recycle=FLAGS.sql_idle_timeout,
echo=False)
_MAKER = (sessionmaker(bind=_ENGINE,
autocommit=autocommit,
expire_on_commit=expire_on_commit))
session = _MAKER()
return session
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