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OpenStack Study: models.py**** CubicPower OpenStack Study ****
# Copyright (c) 2011 X.commerce, a business unit of eBay Inc. # Copyright 2010 United States Government as represented by the # Administrator of the National Aeronautics and Space Administration. # Copyright 2011 Piston Cloud Computing, Inc. # Copyright 2012 Cloudscaling Group, Inc. # 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. """ SQLAlchemy models. """ import six from sqlalchemy import Column, Integer from sqlalchemy import DateTime from sqlalchemy.orm import object_mapper from keystone.openstack.common import timeutils
**** CubicPower OpenStack Study **** class ModelBase(six.Iterator): """Base class for models.""" __table_initialized__ = False
**** CubicPower OpenStack Study **** def save(self, session): """Save this object.""" # NOTE(boris-42): This part of code should be look like: # session.add(self) # session.flush() # But there is a bug in sqlalchemy and eventlet that # raises NoneType exception if there is no running # transaction and rollback is called. As long as # sqlalchemy has this bug we have to create transaction # explicitly. with session.begin(subtransactions=True): session.add(self) session.flush()
**** CubicPower OpenStack Study **** def __setitem__(self, key, value): setattr(self, key, value)
**** CubicPower OpenStack Study **** def __getitem__(self, key): return getattr(self, key)
**** CubicPower OpenStack Study **** def get(self, key, default=None): return getattr(self, key, default) @property
**** CubicPower OpenStack Study **** def _extra_keys(self): """Specifies custom fields Subclasses can override this property to return a list of custom fields that should be included in their dict representation. For reference check tests/db/sqlalchemy/test_models.py """ return []
**** CubicPower OpenStack Study **** def __iter__(self): columns = dict(object_mapper(self).columns).keys() # NOTE(russellb): Allow models to specify other keys that can be looked # up, beyond the actual db columns. An example would be the 'name' # property for an Instance. columns.extend(self._extra_keys) self._i = iter(columns) return self # In Python 3, __next__() has replaced next().
**** CubicPower OpenStack Study **** def __next__(self): n = six.advance_iterator(self._i) return n, getattr(self, n)
**** CubicPower OpenStack Study **** def next(self): return self.__next__()
**** CubicPower OpenStack Study **** def update(self, values): """Make the model object behave like a dict.""" for k, v in six.iteritems(values): setattr(self, k, v)
**** CubicPower OpenStack Study **** def iteritems(self): """Make the model object behave like a dict. Includes attributes from joins. """ local = dict(self) joined = dict([(k, v) for k, v in six.iteritems(self.__dict__) if not k[0] == '_']) local.update(joined) return six.iteritems(local)
**** CubicPower OpenStack Study **** class TimestampMixin(object): created_at = Column(DateTime,
**** CubicPower OpenStack Study **** class SoftDeleteMixin(object): deleted_at = Column(DateTime) deleted = Column(Integer,
**** CubicPower OpenStack Study **** def soft_delete(self, session): """Mark this object as deleted.""" self.deleted = self.id self.deleted_at = timeutils.utcnow() self.save(session=session)
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