29e44f39b8
Now that all backends implement a validate that can be called to check if the backend is still useable we can add a base method to the base class that defines exactly what this new method does. Change-Id: Ica4571970bad2de16ce2071a645abf24c25c110b
118 lines
3.4 KiB
Python
118 lines
3.4 KiB
Python
# -*- coding: utf-8 -*-
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (C) 2013 Rackspace Hosting Inc. 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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import abc
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import six
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@six.add_metaclass(abc.ABCMeta)
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class Backend(object):
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"""Base class for persistence backends."""
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def __init__(self, conf):
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if not conf:
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conf = {}
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if not isinstance(conf, dict):
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raise TypeError("Configuration dictionary expected not: %s"
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% type(conf))
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self._conf = conf
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@abc.abstractmethod
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def get_connection(self):
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"""Return a Connection instance based on the configuration settings."""
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pass
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@abc.abstractmethod
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def close(self):
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"""Closes any resources this backend has open."""
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pass
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@six.add_metaclass(abc.ABCMeta)
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class Connection(object):
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"""Base class for backend connections."""
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@abc.abstractproperty
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def backend(self):
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"""Returns the backend this connection is associated with."""
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pass
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@abc.abstractmethod
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def close(self):
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"""Closes any resources this connection has open."""
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pass
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@abc.abstractmethod
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def upgrade(self):
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"""Migrate the persistence backend to the most recent version."""
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pass
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@abc.abstractmethod
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def clear_all(self):
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"""Clear all entries from this backend."""
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pass
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@abc.abstractmethod
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def validate(self):
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"""Validates that a backend is still ok to be used (the semantics
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of this vary depending on the backend). On failure a backend specific
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exception is raised that will indicate why the failure occurred.
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"""
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pass
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@abc.abstractmethod
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def update_task_details(self, task_detail):
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"""Updates a given task details and returns the updated version.
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NOTE(harlowja): the details that is to be updated must already have
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been created by saving a flow details with the given task detail inside
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of it.
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"""
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pass
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@abc.abstractmethod
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def update_flow_details(self, flow_detail):
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"""Updates a given flow details and returns the updated version.
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NOTE(harlowja): the details that is to be updated must already have
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been created by saving a logbook with the given flow detail inside
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of it.
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"""
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pass
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@abc.abstractmethod
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def save_logbook(self, book):
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"""Saves a logbook, and all its contained information."""
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pass
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@abc.abstractmethod
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def destroy_logbook(self, book_uuid):
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"""Deletes/destroys a logbook matching the given uuid."""
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pass
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@abc.abstractmethod
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def get_logbook(self, book_uuid):
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"""Fetches a logbook object matching the given uuid."""
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pass
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@abc.abstractmethod
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def get_logbooks(self):
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"""Return an iterable of logbook objects."""
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pass
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