Import sqlalchemy session/models/utils
Bring in session, base model, utilities, and tests for sqlalchemy from Nova. Add sqlalchemy to pip-requires and and python-mysql to test-requires. Partially implements blueprint common-db Change-Id: I3e0065cdac87e10c4e0742d66c293c72bb3acbb2
This commit is contained in:
Eric Windisch
parent
4ee08da470
commit
bed94c3b25
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2012 Cloudscaling Group, Inc
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
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# License for the specific language governing permissions and limitations
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# under the License.
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2010 United States Government as represented by the
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# Administrator of the National Aeronautics and Space Administration.
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# All Rights Reserved.
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# Copyright 2012 Cloudscaling Group, Inc
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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from openstack.common.gettextutils import _
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from openstack.common import log as logging
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LOG = logging.getLogger(__name__)
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class Invalid(Exception):
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pass
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class InvalidSortKey(Invalid):
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message = _("Sort key supplied was not valid.")
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class InvalidUnicodeParameter(Invalid):
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message = _("Invalid Parameter: "
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"Unicode is not supported by the current database.")
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class DBError(Exception):
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"""Wraps an implementation specific exception."""
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def __init__(self, inner_exception=None):
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self.inner_exception = inner_exception
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super(DBError, self).__init__(str(inner_exception))
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2012 Cloudscaling Group, Inc
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
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# License for the specific language governing permissions and limitations
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# under the License.
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (c) 2011 X.commerce, a business unit of eBay Inc.
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# Copyright 2010 United States Government as represented by the
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# Administrator of the National Aeronautics and Space Administration.
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# Copyright 2011 Piston Cloud Computing, Inc.
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# Copyright 2012 Cloudscaling Group, Inc.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
|
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#
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# Unless required by applicable law or agreed to in writing, software
|
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""
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SQLAlchemy models.
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"""
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from sqlalchemy import Column, Boolean
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from sqlalchemy import DateTime
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from sqlalchemy.orm import object_mapper
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from openstack.common.db.sqlalchemy.session import get_session
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from openstack.common import timeutils
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class ModelBase(object):
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"""Base class for models."""
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__table_initialized__ = False
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created_at = Column(DateTime, default=timeutils.utcnow)
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updated_at = Column(DateTime, onupdate=timeutils.utcnow)
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metadata = None
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def save(self, session=None):
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"""Save this object."""
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if not session:
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session = get_session()
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# NOTE(boris-42): This part of code should be look like:
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# sesssion.add(self)
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# session.flush()
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# But there is a bug in sqlalchemy and eventlet that
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# raises NoneType exception if there is no running
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# transaction and rollback is called. As long as
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# sqlalchemy has this bug we have to create transaction
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# explicity.
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with session.begin(subtransactions=True):
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session.add(self)
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session.flush()
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def __setitem__(self, key, value):
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setattr(self, key, value)
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def __getitem__(self, key):
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return getattr(self, key)
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def get(self, key, default=None):
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return getattr(self, key, default)
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def __iter__(self):
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columns = dict(object_mapper(self).columns).keys()
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# NOTE(russellb): Allow models to specify other keys that can be looked
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# up, beyond the actual db columns. An example would be the 'name'
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# property for an Instance.
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if hasattr(self, '_extra_keys'):
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columns.extend(self._extra_keys())
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self._i = iter(columns)
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return self
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def next(self):
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n = self._i.next()
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return n, getattr(self, n)
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def update(self, values):
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"""Make the model object behave like a dict."""
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for k, v in values.iteritems():
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setattr(self, k, v)
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def iteritems(self):
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"""Make the model object behave like a dict.
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Includes attributes from joins."""
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local = dict(self)
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joined = dict([(k, v) for k, v in self.__dict__.iteritems()
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if not k[0] == '_'])
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local.update(joined)
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return local.iteritems()
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class SoftDeleteMixin(object):
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deleted_at = Column(DateTime)
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deleted = Column(Boolean, default=False)
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def soft_delete(self, session=None):
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"""Mark this object as deleted."""
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self.deleted = True
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self.deleted_at = timeutils.utcnow()
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self.save(session=session)
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2010 United States Government as represented by the
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# Administrator of the National Aeronautics and Space Administration.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
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# not use this file except in compliance with the License. You may obtain
|
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# a copy of the License at
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#
|
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# http://www.apache.org/licenses/LICENSE-2.0
|
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
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# License for the specific language governing permissions and limitations
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# under the License.
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"""Session Handling for SQLAlchemy backend.
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Initializing:
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* Call set_defaults with the minimal of the following kwargs:
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sql_connection, sqlite_db
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Example:
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session.set_defaults(sql_connection="sqlite:///var/lib/oslo/sqlite.db",
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sqlite_db="/var/lib/oslo/sqlite.db")
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Recommended ways to use sessions within this framework:
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* Don't use them explicitly; this is like running with AUTOCOMMIT=1.
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model_query() will implicitly use a session when called without one
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supplied. This is the ideal situation because it will allow queries
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to be automatically retried if the database connection is interrupted.
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Note: Automatic retry will be enabled in a future patch.
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It is generally fine to issue several queries in a row like this. Even though
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they may be run in separate transactions and/or separate sessions, each one
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will see the data from the prior calls. If needed, undo- or rollback-like
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functionality should be handled at a logical level. For an example, look at
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the code around quotas and reservation_rollback().
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Examples:
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def get_foo(context, foo):
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return model_query(context, models.Foo).\
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filter_by(foo=foo).\
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first()
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def update_foo(context, id, newfoo):
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model_query(context, models.Foo).\
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filter_by(id=id).\
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update({'foo': newfoo})
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def create_foo(context, values):
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foo_ref = models.Foo()
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foo_ref.update(values)
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foo_ref.save()
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return foo_ref
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* Within the scope of a single method, keeping all the reads and writes within
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the context managed by a single session. In this way, the session's __exit__
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handler will take care of calling flush() and commit() for you.
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If using this approach, you should not explicitly call flush() or commit().
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Any error within the context of the session will cause the session to emit
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a ROLLBACK. If the connection is dropped before this is possible, the
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database will implicitly rollback the transaction.
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Note: statements in the session scope will not be automatically retried.
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If you create models within the session, they need to be added, but you
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do not need to call model.save()
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def create_many_foo(context, foos):
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session = get_session()
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with session.begin():
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for foo in foos:
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foo_ref = models.Foo()
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foo_ref.update(foo)
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session.add(foo_ref)
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def update_bar(context, foo_id, newbar):
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session = get_session()
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with session.begin():
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foo_ref = model_query(context, models.Foo, session).\
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filter_by(id=foo_id).\
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first()
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model_query(context, models.Bar, session).\
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filter_by(id=foo_ref['bar_id']).\
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update({'bar': newbar})
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Note: update_bar is a trivially simple example of using "with session.begin".
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Whereas create_many_foo is a good example of when a transaction is needed,
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it is always best to use as few queries as possible. The two queries in
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update_bar can be better expressed using a single query which avoids
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the need for an explicit transaction. It can be expressed like so:
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def update_bar(context, foo_id, newbar):
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subq = model_query(context, models.Foo.id).\
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filter_by(id=foo_id).\
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limit(1).\
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subquery()
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model_query(context, models.Bar).\
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filter_by(id=subq.as_scalar()).\
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update({'bar': newbar})
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For reference, this emits approximagely the following SQL statement:
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UPDATE bar SET bar = ${newbar}
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WHERE id=(SELECT bar_id FROM foo WHERE id = ${foo_id} LIMIT 1);
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* Passing an active session between methods. Sessions should only be passed
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to private methods. The private method must use a subtransaction; otherwise
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SQLAlchemy will throw an error when you call session.begin() on an existing
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transaction. Public methods should not accept a session parameter and should
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not be involved in sessions within the caller's scope.
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Note that this incurs more overhead in SQLAlchemy than the above means
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due to nesting transactions, and it is not possible to implicitly retry
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failed database operations when using this approach.
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This also makes code somewhat more difficult to read and debug, because a
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single database transaction spans more than one method. Error handling
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becomes less clear in this situation. When this is needed for code clarity,
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it should be clearly documented.
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def myfunc(foo):
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session = get_session()
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with session.begin():
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# do some database things
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bar = _private_func(foo, session)
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return bar
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def _private_func(foo, session=None):
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if not session:
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session = get_session()
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with session.begin(subtransaction=True):
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# do some other database things
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return bar
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There are some things which it is best to avoid:
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* Don't keep a transaction open any longer than necessary.
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This means that your "with session.begin()" block should be as short
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as possible, while still containing all the related calls for that
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transaction.
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* Avoid "with_lockmode('UPDATE')" when possible.
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In MySQL/InnoDB, when a "SELECT ... FOR UPDATE" query does not match
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any rows, it will take a gap-lock. This is a form of write-lock on the
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"gap" where no rows exist, and prevents any other writes to that space.
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This can effectively prevent any INSERT into a table by locking the gap
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at the end of the index. Similar problems will occur if the SELECT FOR UPDATE
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has an overly broad WHERE clause, or doesn't properly use an index.
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One idea proposed at ODS Fall '12 was to use a normal SELECT to test the
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number of rows matching a query, and if only one row is returned,
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then issue the SELECT FOR UPDATE.
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The better long-term solution is to use INSERT .. ON DUPLICATE KEY UPDATE.
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However, this can not be done until the "deleted" columns are removed and
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proper UNIQUE constraints are added to the tables.
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Enabling soft deletes:
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* To use/enable soft-deletes, the SoftDeleteMixin must be added
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to your model class. For example:
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class NovaBase(models.SoftDeleteMixin, models.ModelBase):
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pass
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Efficient use of soft deletes:
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* There are two possible ways to mark a record as deleted:
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model.soft_delete() and query.soft_delete().
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model.soft_delete() method works with single already fetched entry.
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query.soft_delete() makes only one db request for all entries that correspond
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to query.
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* In almost all cases you should use query.soft_delete(). Some examples:
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def soft_delete_bar():
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count = model_query(BarModel).find(some_condition).soft_delete()
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if count == 0:
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raise Exception("0 entries were soft deleted")
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def complex_soft_delete_with_synchronization_bar(session=None):
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if session is None:
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session = get_session()
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with session.begin(subtransactions=True):
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count = model_query(BarModel).\
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find(some_condition).\
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soft_delete(synchronize_session=True)
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# Here synchronize_session is required, because we
|
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# don't know what is going on in outer session.
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if count == 0:
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raise Exception("0 entries were soft deleted")
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|
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* There is only one situation where model.soft_delete() is appropriate: when
|
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you fetch a single record, work with it, and mark it as deleted in the same
|
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transaction.
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|
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def soft_delete_bar_model():
|
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session = get_session()
|
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with session.begin():
|
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bar_ref = model_query(BarModel).find(some_condition).first()
|
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# Work with bar_ref
|
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bar_ref.soft_delete(session=session)
|
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|
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However, if you need to work with all entries that correspond to query and
|
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then soft delete them you should use query.soft_delete() method:
|
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|
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def soft_delete_multi_models():
|
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session = get_session()
|
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with session.begin():
|
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query = model_query(BarModel, session=session).\
|
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find(some_condition)
|
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model_refs = query.all()
|
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# Work with model_refs
|
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query.soft_delete(synchronize_session=False)
|
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# synchronize_session=False should be set if there is no outer
|
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# session and these entries are not used after this.
|
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|
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When working with many rows, it is very important to use query.soft_delete,
|
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which issues a single query. Using model.soft_delete(), as in the following
|
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example, is very inefficient.
|
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|
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for bar_ref in bar_refs:
|
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bar_ref.soft_delete(session=session)
|
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# This will produce count(bar_refs) db requests.
|
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"""
|
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|
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import os.path
|
||||
import re
|
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import time
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|
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from eventlet import db_pool
|
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from eventlet import greenthread
|
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try:
|
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import MySQLdb
|
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HAS_MYSQLDB = True
|
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except ImportError:
|
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HAS_MYSQLDB = None
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from sqlalchemy.exc import DisconnectionError, OperationalError, IntegrityError
|
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import sqlalchemy.interfaces
|
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import sqlalchemy.orm
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from sqlalchemy.pool import NullPool, StaticPool
|
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from sqlalchemy.sql.expression import literal_column
|
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|
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import openstack.common.db.common as db_common
|
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from openstack.common import cfg
|
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import openstack.common.log as logging
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from openstack.common.gettextutils import _
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from openstack.common import timeutils
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|
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|
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sql_opts = [
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cfg.StrOpt('sql_connection',
|
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default='sqlite:///' +
|
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os.path.abspath(os.path.join(os.path.dirname(__file__),
|
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'../', '$sqlite_db')),
|
||||
help='The SQLAlchemy connection string used to connect to the '
|
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'database'),
|
||||
cfg.StrOpt('sqlite_db',
|
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default='oslo.sqlite',
|
||||
help='the filename to use with sqlite'),
|
||||
cfg.IntOpt('sql_idle_timeout',
|
||||
default=3600,
|
||||
help='timeout before idle sql connections are reaped'),
|
||||
cfg.BoolOpt('sqlite_synchronous',
|
||||
default=True,
|
||||
help='If passed, use synchronous mode for sqlite'),
|
||||
cfg.IntOpt('sql_min_pool_size',
|
||||
default=1,
|
||||
help='Minimum number of SQL connections to keep open in a '
|
||||
'pool'),
|
||||
cfg.IntOpt('sql_max_pool_size',
|
||||
default=5,
|
||||
help='Maximum number of SQL connections to keep open in a '
|
||||
'pool'),
|
||||
cfg.IntOpt('sql_max_retries',
|
||||
default=10,
|
||||
help='maximum db connection retries during startup. '
|
||||
'(setting -1 implies an infinite retry count)'),
|
||||
cfg.IntOpt('sql_retry_interval',
|
||||
default=10,
|
||||
help='interval between retries of opening a sql connection'),
|
||||
cfg.IntOpt('sql_max_overflow',
|
||||
default=None,
|
||||
help='If set, use this value for max_overflow with sqlalchemy'),
|
||||
cfg.IntOpt('sql_connection_debug',
|
||||
default=0,
|
||||
help='Verbosity of SQL debugging information. 0=None, '
|
||||
'100=Everything'),
|
||||
cfg.BoolOpt('sql_connection_trace',
|
||||
default=False,
|
||||
help='Add python stack traces to SQL as comment strings'),
|
||||
cfg.IntOpt('sql_dbpool_enable',
|
||||
default=False,
|
||||
help="enable the use of eventlet's db_pool for MySQL"),
|
||||
cfg.BoolOpt('sql_connection_trace',
|
||||
default=False,
|
||||
help='Add python stack traces to SQL as comment strings'),
|
||||
cfg.BoolOpt('sql_dbpool_enable',
|
||||
default=False,
|
||||
help="enable the use of eventlet's db_pool for MySQL"),
|
||||
]
|
||||
|
||||
CONF = cfg.CONF
|
||||
CONF.register_opts(sql_opts)
|
||||
LOG = logging.getLogger(__name__)
|
||||
|
||||
_ENGINE = None
|
||||
_MAKER = None
|
||||
|
||||
|
||||
def set_defaults(**kwargs):
|
||||
"""Set defaults for configuration variables."""
|
||||
cfg.set_defaults(sql_opts, **kwargs)
|
||||
|
||||
|
||||
def get_session(autocommit=True, expire_on_commit=False):
|
||||
"""Return a SQLAlchemy session."""
|
||||
global _MAKER
|
||||
|
||||
if _MAKER is None:
|
||||
engine = get_engine()
|
||||
_MAKER = get_maker(engine, autocommit, expire_on_commit)
|
||||
|
||||
session = _MAKER()
|
||||
return session
|
||||
|
||||
|
||||
# note(boris-42): In current versions of DB backends unique constraint
|
||||
# violation messages follow the structure:
|
||||
#
|
||||
# sqlite:
|
||||
# 1 column - (IntegrityError) column c1 is not unique
|
||||
# N columns - (IntegrityError) column c1, c2, ..., N are not unique
|
||||
#
|
||||
# postgres:
|
||||
# 1 column - (IntegrityError) duplicate key value violates unique
|
||||
# constraint "users_c1_key"
|
||||
# N columns - (IntegrityError) duplicate key value violates unique
|
||||
# constraint "name_of_our_constraint"
|
||||
#
|
||||
# mysql:
|
||||
# 1 column - (IntegrityError) (1062, "Duplicate entry 'value_of_c1' for key
|
||||
# 'c1'")
|
||||
# N columns - (IntegrityError) (1062, "Duplicate entry 'values joined
|
||||
# with -' for key 'name_of_our_constraint'")
|
||||
_RE_DB = {
|
||||
"sqlite": re.compile(r"^.*columns?([^)]+)(is|are)\s+not\s+unique$"),
|
||||
"postgresql": re.compile(r"^.*duplicate\s+key.*\"([^\"]+)\"\s*\n.*$"),
|
||||
"mysql": re.compile(r"^.*\(1062,.*'([^\']+)'\"\)$")
|
||||
}
|
||||
|
||||
|
||||
def raise_if_duplicate_entry_error(integrity_error, engine_name):
|
||||
"""
|
||||
In this function will be raised DBDuplicateEntry exception if integrity
|
||||
error wrap unique constraint violation.
|
||||
"""
|
||||
|
||||
def get_columns_from_uniq_cons_or_name(columns):
|
||||
# note(boris-42): UniqueConstraint name convention: "uniq_c1_x_c2_x_c3"
|
||||
# means that columns c1, c2, c3 are in UniqueConstraint.
|
||||
uniqbase = "uniq_"
|
||||
if not columns.startswith(uniqbase):
|
||||
if engine_name == "postgresql":
|
||||
return [columns[columns.index("_") + 1:columns.rindex("_")]]
|
||||
return [columns]
|
||||
return columns[len(uniqbase):].split("_x_")
|
||||
|
||||
if engine_name not in ["mysql", "sqlite", "postgresql"]:
|
||||
return
|
||||
|
||||
m = _RE_DB[engine_name].match(integrity_error.message)
|
||||
if not m:
|
||||
return
|
||||
columns = m.group(1)
|
||||
|
||||
if engine_name == "sqlite":
|
||||
columns = columns.strip().split(", ")
|
||||
else:
|
||||
columns = get_columns_from_uniq_cons_or_name(columns)
|
||||
raise db_common.DBDuplicateEntry(columns, integrity_error)
|
||||
|
||||
|
||||
def wrap_db_error(f):
|
||||
def _wrap(*args, **kwargs):
|
||||
try:
|
||||
return f(*args, **kwargs)
|
||||
except UnicodeEncodeError:
|
||||
raise db_common.InvalidUnicodeParameter()
|
||||
# note(boris-42): We should catch unique constraint violation and
|
||||
# wrap it by our own DBDuplicateEntry exception. Unique constraint
|
||||
# violation is wrapped by IntegrityError.
|
||||
except IntegrityError, e:
|
||||
# note(boris-42): SqlAlchemy doesn't unify errors from different
|
||||
# DBs so we must do this. Also in some tables (for example
|
||||
# instance_types) there are more than one unique constraint. This
|
||||
# means we should get names of columns, which values violate
|
||||
# unique constraint, from error message.
|
||||
raise_if_duplicate_entry_error(e, get_engine().name)
|
||||
raise db_common.DBError(e)
|
||||
except Exception, e:
|
||||
LOG.exception(_('DB exception wrapped.'))
|
||||
raise db_common.DBError(e)
|
||||
_wrap.func_name = f.func_name
|
||||
return _wrap
|
||||
|
||||
|
||||
def get_engine():
|
||||
"""Return a SQLAlchemy engine."""
|
||||
global _ENGINE
|
||||
if _ENGINE is None:
|
||||
_ENGINE = create_engine(CONF.sql_connection)
|
||||
return _ENGINE
|
||||
|
||||
|
||||
def synchronous_switch_listener(dbapi_conn, connection_rec):
|
||||
"""Switch sqlite connections to non-synchronous mode."""
|
||||
dbapi_conn.execute("PRAGMA synchronous = OFF")
|
||||
|
||||
|
||||
def add_regexp_listener(dbapi_con, con_record):
|
||||
"""Add REGEXP function to sqlite connections."""
|
||||
|
||||
def regexp(expr, item):
|
||||
reg = re.compile(expr)
|
||||
return reg.search(unicode(item)) is not None
|
||||
dbapi_con.create_function('regexp', 2, regexp)
|
||||
|
||||
|
||||
def greenthread_yield(dbapi_con, con_record):
|
||||
"""
|
||||
Ensure other greenthreads get a chance to execute by forcing a context
|
||||
switch. With common database backends (eg MySQLdb and sqlite), there is
|
||||
no implicit yield caused by network I/O since they are implemented by
|
||||
C libraries that eventlet cannot monkey patch.
|
||||
"""
|
||||
greenthread.sleep(0)
|
||||
|
||||
|
||||
def ping_listener(dbapi_conn, connection_rec, connection_proxy):
|
||||
"""
|
||||
Ensures that MySQL connections checked out of the
|
||||
pool are alive.
|
||||
|
||||
Borrowed from:
|
||||
http://groups.google.com/group/sqlalchemy/msg/a4ce563d802c929f
|
||||
"""
|
||||
try:
|
||||
dbapi_conn.cursor().execute('select 1')
|
||||
except dbapi_conn.OperationalError, ex:
|
||||
if ex.args[0] in (2006, 2013, 2014, 2045, 2055):
|
||||
LOG.warn(_('Got mysql server has gone away: %s'), ex)
|
||||
raise DisconnectionError("Database server went away")
|
||||
else:
|
||||
raise
|
||||
|
||||
|
||||
def is_db_connection_error(args):
|
||||
"""Return True if error in connecting to db."""
|
||||
# NOTE(adam_g): This is currently MySQL specific and needs to be extended
|
||||
# to support Postgres and others.
|
||||
conn_err_codes = ('2002', '2003', '2006')
|
||||
for err_code in conn_err_codes:
|
||||
if args.find(err_code) != -1:
|
||||
return True
|
||||
return False
|
||||
|
||||
|
||||
def create_engine(sql_connection):
|
||||
"""Return a new SQLAlchemy engine."""
|
||||
connection_dict = sqlalchemy.engine.url.make_url(sql_connection)
|
||||
|
||||
engine_args = {
|
||||
"pool_recycle": CONF.sql_idle_timeout,
|
||||
"echo": False,
|
||||
'convert_unicode': True,
|
||||
}
|
||||
|
||||
# Map our SQL debug level to SQLAlchemy's options
|
||||
if CONF.sql_connection_debug >= 100:
|
||||
engine_args['echo'] = 'debug'
|
||||
elif CONF.sql_connection_debug >= 50:
|
||||
engine_args['echo'] = True
|
||||
|
||||
if "sqlite" in connection_dict.drivername:
|
||||
engine_args["poolclass"] = NullPool
|
||||
|
||||
if CONF.sql_connection == "sqlite://":
|
||||
engine_args["poolclass"] = StaticPool
|
||||
engine_args["connect_args"] = {'check_same_thread': False}
|
||||
elif all((CONF.sql_dbpool_enable, HAS_MYSQLDB,
|
||||
"mysql" in connection_dict.drivername)):
|
||||
LOG.info(_("Using mysql/eventlet db_pool."))
|
||||
# MySQLdb won't accept 'None' in the password field
|
||||
password = connection_dict.password or ''
|
||||
pool_args = {
|
||||
'db': connection_dict.database,
|
||||
'passwd': password,
|
||||
'host': connection_dict.host,
|
||||
'user': connection_dict.username,
|
||||
'min_size': CONF.sql_min_pool_size,
|
||||
'max_size': CONF.sql_max_pool_size,
|
||||
'max_idle': CONF.sql_idle_timeout}
|
||||
creator = db_pool.ConnectionPool(MySQLdb, **pool_args)
|
||||
engine_args['creator'] = creator.create
|
||||
else:
|
||||
engine_args['pool_size'] = CONF.sql_max_pool_size
|
||||
if CONF.sql_max_overflow is not None:
|
||||
engine_args['max_overflow'] = CONF.sql_max_overflow
|
||||
|
||||
engine = sqlalchemy.create_engine(sql_connection, **engine_args)
|
||||
|
||||
sqlalchemy.event.listen(engine, 'checkin', greenthread_yield)
|
||||
|
||||
if 'mysql' in connection_dict.drivername:
|
||||
sqlalchemy.event.listen(engine, 'checkout', ping_listener)
|
||||
elif 'sqlite' in connection_dict.drivername:
|
||||
if not CONF.sqlite_synchronous:
|
||||
sqlalchemy.event.listen(engine, 'connect',
|
||||
synchronous_switch_listener)
|
||||
sqlalchemy.event.listen(engine, 'connect', add_regexp_listener)
|
||||
|
||||
if (CONF.sql_connection_trace and
|
||||
engine.dialect.dbapi.__name__ == 'MySQLdb'):
|
||||
patch_mysqldb_with_stacktrace_comments()
|
||||
|
||||
try:
|
||||
engine.connect()
|
||||
except OperationalError, e:
|
||||
if not is_db_connection_error(e.args[0]):
|
||||
raise
|
||||
|
||||
remaining = CONF.sql_max_retries
|
||||
if remaining == -1:
|
||||
remaining = 'infinite'
|
||||
while True:
|
||||
msg = _('SQL connection failed. %s attempts left.')
|
||||
LOG.warn(msg % remaining)
|
||||
if remaining != 'infinite':
|
||||
remaining -= 1
|
||||
time.sleep(CONF.sql_retry_interval)
|
||||
try:
|
||||
engine.connect()
|
||||
break
|
||||
except OperationalError, e:
|
||||
if (remaining != 'infinite' and remaining == 0) or \
|
||||
not is_db_connection_error(e.args[0]):
|
||||
raise
|
||||
return engine
|
||||
|
||||
|
||||
class Query(sqlalchemy.orm.query.Query):
|
||||
"""Subclass of sqlalchemy.query with soft_delete() method."""
|
||||
def soft_delete(self, synchronize_session='evaluate'):
|
||||
return self.update({'deleted': True,
|
||||
'updated_at': literal_column('updated_at'),
|
||||
'deleted_at': timeutils.utcnow()},
|
||||
synchronize_session=synchronize_session)
|
||||
|
||||
|
||||
class Session(sqlalchemy.orm.session.Session):
|
||||
"""Custom Session class to avoid SqlAlchemy Session monkey patching."""
|
||||
@wrap_db_error
|
||||
def query(self, *args, **kwargs):
|
||||
return super(Session, self).query(*args, **kwargs)
|
||||
|
||||
@wrap_db_error
|
||||
def flush(self, *args, **kwargs):
|
||||
return super(Session, self).flush(*args, **kwargs)
|
||||
|
||||
|
||||
def get_maker(engine, autocommit=True, expire_on_commit=False):
|
||||
"""Return a SQLAlchemy sessionmaker using the given engine."""
|
||||
return sqlalchemy.orm.sessionmaker(bind=engine,
|
||||
class_=Session,
|
||||
autocommit=autocommit,
|
||||
expire_on_commit=expire_on_commit,
|
||||
query_cls=Query)
|
||||
|
||||
|
||||
def patch_mysqldb_with_stacktrace_comments():
|
||||
"""Adds current stack trace as a comment in queries by patching
|
||||
MySQLdb.cursors.BaseCursor._do_query.
|
||||
"""
|
||||
import MySQLdb.cursors
|
||||
import traceback
|
||||
|
||||
old_mysql_do_query = MySQLdb.cursors.BaseCursor._do_query
|
||||
|
||||
def _do_query(self, q):
|
||||
stack = ''
|
||||
for file, line, method, function in traceback.extract_stack():
|
||||
# exclude various common things from trace
|
||||
if file.endswith('session.py') and method == '_do_query':
|
||||
continue
|
||||
if file.endswith('api.py') and method == 'wrapper':
|
||||
continue
|
||||
if file.endswith('utils.py') and method == '_inner':
|
||||
continue
|
||||
if file.endswith('exception.py') and method == '_wrap':
|
||||
continue
|
||||
# db/api is just a wrapper around db/sqlalchemy/api
|
||||
if file.endswith('db/api.py'):
|
||||
continue
|
||||
# only trace inside oslo
|
||||
index = file.rfind('oslo')
|
||||
if index == -1:
|
||||
continue
|
||||
stack += "File:%s:%s Method:%s() Line:%s | " \
|
||||
% (file[index:], line, method, function)
|
||||
|
||||
# strip trailing " | " from stack
|
||||
if stack:
|
||||
stack = stack[:-3]
|
||||
qq = "%s /* %s */" % (q, stack)
|
||||
else:
|
||||
qq = q
|
||||
old_mysql_do_query(self, qq)
|
||||
|
||||
setattr(MySQLdb.cursors.BaseCursor, '_do_query', _do_query)
|
||||
|
|
@ -0,0 +1,129 @@
|
|||
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
||||
|
||||
# Copyright 2010 United States Government as represented by the
|
||||
# Administrator of the National Aeronautics and Space Administration.
|
||||
# Copyright 2010-2011 OpenStack LLC.
|
||||
# Copyright 2012 Justin Santa Barbara
|
||||
# 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.
|
||||
|
||||
"""Implementation of paginate query."""
|
||||
|
||||
import sqlalchemy
|
||||
|
||||
from openstack.common.db import common as db_common
|
||||
from openstack.common.gettextutils import _
|
||||
from openstack.common import log as logging
|
||||
|
||||
|
||||
LOG = logging.getLogger(__name__)
|
||||
|
||||
|
||||
# copy from glance/db/sqlalchemy/api.py
|
||||
def paginate_query(query, model, limit, sort_keys, marker=None,
|
||||
sort_dir=None, sort_dirs=None):
|
||||
"""Returns a query with sorting / pagination criteria added.
|
||||
|
||||
Pagination works by requiring a unique sort_key, specified by sort_keys.
|
||||
(If sort_keys is not unique, then we risk looping through values.)
|
||||
We use the last row in the previous page as the 'marker' for pagination.
|
||||
So we must return values that follow the passed marker in the order.
|
||||
With a single-valued sort_key, this would be easy: sort_key > X.
|
||||
With a compound-values sort_key, (k1, k2, k3) we must do this to repeat
|
||||
the lexicographical ordering:
|
||||
(k1 > X1) or (k1 == X1 && k2 > X2) or (k1 == X1 && k2 == X2 && k3 > X3)
|
||||
|
||||
We also have to cope with different sort_directions.
|
||||
|
||||
Typically, the id of the last row is used as the client-facing pagination
|
||||
marker, then the actual marker object must be fetched from the db and
|
||||
passed in to us as marker.
|
||||
|
||||
:param query: the query object to which we should add paging/sorting
|
||||
:param model: the ORM model class
|
||||
:param limit: maximum number of items to return
|
||||
:param sort_keys: array of attributes by which results should be sorted
|
||||
:param marker: the last item of the previous page; we returns the next
|
||||
results after this value.
|
||||
:param sort_dir: direction in which results should be sorted (asc, desc)
|
||||
:param sort_dirs: per-column array of sort_dirs, corresponding to sort_keys
|
||||
|
||||
:rtype: sqlalchemy.orm.query.Query
|
||||
:return: The query with sorting/pagination added.
|
||||
"""
|
||||
|
||||
if 'id' not in sort_keys:
|
||||
# TODO(justinsb): If this ever gives a false-positive, check
|
||||
# the actual primary key, rather than assuming its id
|
||||
LOG.warn(_('Id not in sort_keys; is sort_keys unique?'))
|
||||
|
||||
assert(not (sort_dir and sort_dirs))
|
||||
|
||||
# Default the sort direction to ascending
|
||||
if sort_dirs is None and sort_dir is None:
|
||||
sort_dir = 'asc'
|
||||
|
||||
# Ensure a per-column sort direction
|
||||
if sort_dirs is None:
|
||||
sort_dirs = [sort_dir for _sort_key in sort_keys]
|
||||
|
||||
assert(len(sort_dirs) == len(sort_keys))
|
||||
|
||||
# Add sorting
|
||||
for current_sort_key, current_sort_dir in zip(sort_keys, sort_dirs):
|
||||
sort_dir_func = {
|
||||
'asc': sqlalchemy.asc,
|
||||
'desc': sqlalchemy.desc,
|
||||
}[current_sort_dir]
|
||||
|
||||
try:
|
||||
sort_key_attr = getattr(model, current_sort_key)
|
||||
except AttributeError:
|
||||
raise db_common.InvalidSortKey()
|
||||
query = query.order_by(sort_dir_func(sort_key_attr))
|
||||
|
||||
# Add pagination
|
||||
if marker is not None:
|
||||
marker_values = []
|
||||
for sort_key in sort_keys:
|
||||
v = getattr(marker, sort_key)
|
||||
marker_values.append(v)
|
||||
|
||||
# Build up an array of sort criteria as in the docstring
|
||||
criteria_list = []
|
||||
for i in xrange(0, len(sort_keys)):
|
||||
crit_attrs = []
|
||||
for j in xrange(0, i):
|
||||
model_attr = getattr(model, sort_keys[j])
|
||||
crit_attrs.append((model_attr == marker_values[j]))
|
||||
|
||||
model_attr = getattr(model, sort_keys[i])
|
||||
if sort_dirs[i] == 'desc':
|
||||
crit_attrs.append((model_attr < marker_values[i]))
|
||||
elif sort_dirs[i] == 'asc':
|
||||
crit_attrs.append((model_attr > marker_values[i]))
|
||||
else:
|
||||
raise ValueError(_("Unknown sort direction, "
|
||||
"must be 'desc' or 'asc'"))
|
||||
|
||||
criteria = sqlalchemy.sql.and_(*crit_attrs)
|
||||
criteria_list.append(criteria)
|
||||
|
||||
f = sqlalchemy.sql.or_(*criteria_list)
|
||||
query = query.filter(f)
|
||||
|
||||
if limit is not None:
|
||||
query = query.limit(limit)
|
||||
|
||||
return query
|
||||
|
|
@ -0,0 +1,16 @@
|
|||
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
||||
|
||||
# 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.
|
||||
|
|
@ -0,0 +1,16 @@
|
|||
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
||||
|
||||
# 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.
|
||||
|
|
@ -0,0 +1,72 @@
|
|||
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
||||
|
||||
# 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.
|
||||
|
||||
import openstack.common.db.sqlalchemy.models as models
|
||||
from tests import utils as test_utils
|
||||
|
||||
|
||||
class ModelBaseTest(test_utils.BaseTestCase):
|
||||
|
||||
def test_modelbase_has_dict_methods(self):
|
||||
dict_methods = ('__getitem__',
|
||||
'__setitem__',
|
||||
'__iter__',
|
||||
'get',
|
||||
'next',
|
||||
'update',
|
||||
'iteritems')
|
||||
for method in dict_methods:
|
||||
self.assertTrue(hasattr(models.ModelBase, method))
|
||||
|
||||
def test_modelbase_set(self):
|
||||
mb = models.ModelBase()
|
||||
mb['world'] = 'hello'
|
||||
self.assertEqual(mb['world'], 'hello')
|
||||
|
||||
def test_modelbase_update(self):
|
||||
mb = models.ModelBase()
|
||||
h = {'a': '1', 'b': '2'}
|
||||
mb.update(h)
|
||||
for key in h.keys():
|
||||
self.assertEqual(mb[key], h[key])
|
||||
|
||||
def test_modelbase_iteritems(self):
|
||||
self.skipTest("Requires DB")
|
||||
mb = models.ModelBase()
|
||||
h = {'a': '1', 'b': '2'}
|
||||
mb.update(h)
|
||||
for key, value in mb.iteritems():
|
||||
self.assertEqual(h[key], value)
|
||||
|
||||
def test_modelbase_iter(self):
|
||||
self.skipTest("Requires DB")
|
||||
mb = models.ModelBase()
|
||||
h = {'a': '1', 'b': '2'}
|
||||
mb.update(h)
|
||||
i = iter(mb)
|
||||
|
||||
min_items = len(h)
|
||||
found_items = 0
|
||||
while True:
|
||||
r = next(i, None)
|
||||
if r is None:
|
||||
break
|
||||
|
||||
self.assertTrue(r in h)
|
||||
found_items += 1
|
||||
|
||||
self.assertEqual(min_items, found_items)
|
||||
|
|
@ -0,0 +1,72 @@
|
|||
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
||||
# Copyright (c) 2012 Rackspace Hosting
|
||||
# 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.
|
||||
|
||||
"""Unit tests for SQLAlchemy specific code."""
|
||||
|
||||
from eventlet import db_pool
|
||||
try:
|
||||
import MySQLdb
|
||||
HAS_MYSQLDB = True
|
||||
except ImportError:
|
||||
HAS_MYSQLDB = False
|
||||
|
||||
from openstack.common import context
|
||||
from openstack.common import exception
|
||||
from openstack.common.db.sqlalchemy import session
|
||||
from tests import utils as test_utils
|
||||
|
||||
|
||||
class TestException(exception.OpenstackException):
|
||||
pass
|
||||
|
||||
|
||||
class DbPoolTestCase(test_utils.BaseTestCase):
|
||||
def setUp(self):
|
||||
super(DbPoolTestCase, self).setUp()
|
||||
if not HAS_MYSQLDB:
|
||||
self.skipTest("Required module MySQLdb missing.")
|
||||
self.config(sql_dbpool_enable=True)
|
||||
self.user_id = 'fake'
|
||||
self.project_id = 'fake'
|
||||
self.context = context.RequestContext(self.user_id, self.project_id)
|
||||
|
||||
def test_db_pool_option(self):
|
||||
self.config(sql_idle_timeout=11, sql_min_pool_size=21,
|
||||
sql_max_pool_size=42)
|
||||
|
||||
info = {}
|
||||
|
||||
class FakeConnectionPool(db_pool.ConnectionPool):
|
||||
def __init__(self, mod_name, **kwargs):
|
||||
info['module'] = mod_name
|
||||
info['kwargs'] = kwargs
|
||||
super(FakeConnectionPool, self).__init__(mod_name,
|
||||
**kwargs)
|
||||
|
||||
def connect(self, *args, **kwargs):
|
||||
raise TestException()
|
||||
|
||||
self.stubs.Set(db_pool, 'ConnectionPool',
|
||||
FakeConnectionPool)
|
||||
|
||||
sql_connection = 'mysql://user:pass@127.0.0.1/nova'
|
||||
self.assertRaises(TestException, session.create_engine,
|
||||
sql_connection)
|
||||
|
||||
self.assertEqual(info['module'], MySQLdb)
|
||||
self.assertEqual(info['kwargs']['max_idle'], 11)
|
||||
self.assertEqual(info['kwargs']['min_size'], 21)
|
||||
self.assertEqual(info['kwargs']['max_size'], 42)
|
||||
Loading…
Reference in New Issue