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# Copyright (C) 2017 Nippon Telegraph and Telephone Corporation.
#
# 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.
import functools
import logging
from sqlalchemy.ext.declarative import declarative_base
LOG = logging.getLogger(__name__)
Base = declarative_base()
"""
Base class for Zebra protocol database tables.
"""
def _repr(self):
m = ', '.join(
['%s=%r' % (k, v)
for k, v in self.__dict__.items() if not k.startswith('_')])
return "%s(%s)" % (self.__class__.__name__, m)
Base.__repr__ = _repr
def sql_function(func):
"""
Decorator for wrapping the given function in order to manipulate (CRUD)
the records safely.
For the adding/updating/deleting records function, this decorator
invokes "Session.commit()" after the given function.
If any exception while modifying records raised, this decorator invokes
"Session.rollbacks()".
"""
@functools.wraps(func)
def _wrapper(session, *args, **kwargs):
ret = None
try:
ret = func(session, *args, **kwargs)
if session.dirty:
# If the given function has any update to records,
# commits them.
session.commit()
except Exception as e:
# If any exception raised, rollbacks the transaction.
LOG.error('Error in %s: %s', func.__name__, e)
if session.dirty:
LOG.error('Do rolling back %s table',
session.dirty[0].__tablename__)
session.rollback()
return ret
return _wrapper
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