old_contents: # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  # Copyright (c) 2012 NTT DOCOMO, INC.
  # 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 nova.db.sqlalchemy import session as nova_session
  from nova.openstack.common import cfg
  
  opts = [
      cfg.StrOpt('baremetal_sql_connection',
                 default='sqlite:///$state_path/baremetal_$sqlite_db',
                 help='The SQLAlchemy connection string used to connect to the '
                      'bare-metal database'),
      ]
  
  CONF = cfg.CONF
  CONF.register_opts(opts)
  CONF.import_opt('sqlite_db', 'nova.db.sqlalchemy.session')
  CONF.import_opt('state_path', 'nova.config')
  
  _ENGINE = None
  _MAKER = None
  
  
  def get_session(autocommit=True, expire_on_commit=False):
      """Return a SQLAlchemy session."""
      global _MAKER
  
      if _MAKER is None:
          engine = get_engine()
          _MAKER = nova_session.get_maker(engine, autocommit, expire_on_commit)
  
      session = _MAKER()
      session = nova_session.wrap_session(session)
      return session
  
  
  def get_engine():
      """Return a SQLAlchemy engine."""
      global _ENGINE
      if _ENGINE is None:
          _ENGINE = nova_session.create_engine(CONF.baremetal_sql_connection)
      return _ENGINE
  
new_contents: # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  # Copyright (c) 2012 NTT DOCOMO, INC.
  # 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 nova.db.sqlalchemy import session as nova_session
  from nova.openstack.common import cfg
  
  opts = [
      cfg.StrOpt('baremetal_sql_connection',
                 default='sqlite:///$state_path/baremetal_$sqlite_db',
                 help='The SQLAlchemy connection string used to connect to the '
                      'bare-metal database'),
      ]
  
  CONF = cfg.CONF
  CONF.register_opts(opts)
  CONF.import_opt('sqlite_db', 'nova.db.sqlalchemy.session')
  CONF.import_opt('state_path', 'nova.config')
  
  _ENGINE = None
  _MAKER = None
  
  
  def get_session(autocommit=True, expire_on_commit=False):
      """Return a SQLAlchemy session."""
      global _MAKER
  
      if _MAKER is None:
          engine = get_engine()
          _MAKER = nova_session.get_maker(engine, autocommit, expire_on_commit)
  
      session = _MAKER()
      return session
  
  
  def get_engine():
      """Return a SQLAlchemy engine."""
      global _ENGINE
      if _ENGINE is None:
          _ENGINE = nova_session.create_engine(CONF.baremetal_sql_connection)
      return _ENGINE
  
subject: Remove session.flush() and session.query() monkey patching