1 # Copyright (C) 2021 Wind River Systems, Inc.
3 # Licensed under the Apache License, Version 2.0 (the "License");
4 # you may not use this file except in compliance with the License.
5 # You may obtain a copy of the License at
7 # http://www.apache.org/licenses/LICENSE-2.0
9 # Unless required by applicable law or agreed to in writing, software
10 # distributed under the License is distributed on an "AS IS" BASIS,
11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 # See the License for the specific language governing permissions and
13 # limitations under the License.
15 # pylint: disable=attribute-defined-outside-init
16 from __future__ import annotations
18 from sqlalchemy import create_engine
19 from sqlalchemy.orm import sessionmaker
20 from sqlalchemy.orm.session import Session
23 from o2ims import config
24 from o2ims.adapter import ocloud_repository
27 class AbstractUnitOfWork(abc.ABC):
28 oclouds: ocloud_repository.OcloudRepository
30 def __enter__(self) -> AbstractUnitOfWork:
33 def __exit__(self, *args):
39 def collect_new_events(self):
40 for ocloud in self.oclouds.seen:
42 yield ocloud.events.pop(0)
46 raise NotImplementedError
50 raise NotImplementedError
53 DEFAULT_SESSION_FACTORY = sessionmaker(
55 config.get_postgres_uri(),
56 isolation_level="REPEATABLE READ",
61 class SqlAlchemyUnitOfWork(AbstractUnitOfWork):
62 def __init__(self, session_factory=DEFAULT_SESSION_FACTORY):
63 self.session_factory = session_factory
66 self.session = self.session_factory() # type: Session
67 self.oclouds = ocloud_repository.OcloudSqlAlchemyRepository(self.session)
68 return super().__enter__()
70 def __exit__(self, *args):
71 super().__exit__(*args)
78 self.session.rollback()