trove/reddwarf/db/sqlalchemy/mappers.py

49 lines
1.6 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 OpenStack LLC.
# 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 sqlalchemy import MetaData
from sqlalchemy import Table
from sqlalchemy import orm
from sqlalchemy.orm import exc as orm_exc
def map(engine, models):
meta = MetaData()
meta.bind = engine
if mapping_exists(models['instance']):
return
orm.mapper(models['instance'], Table('instances', meta, autoload=True))
orm.mapper(models['root_enabled_history'],
Table('root_enabled_history', meta, autoload=True))
orm.mapper(models['service_image'],
Table('service_images', meta, autoload=True))
orm.mapper(models['service_statuses'],
Table('service_statuses', meta, autoload=True))
orm.mapper(models['dns_records'],
Table('dns_records', meta, autoload=True))
orm.mapper(models['agent_heartbeats'],
Table('agent_heartbeats', meta, autoload=True))
def mapping_exists(model):
try:
orm.class_mapper(model)
return True
except orm_exc.UnmappedClassError:
return False