d0edb62b9a
In order to match the directory/module layout of the other pluggable backends better move the persistence base module that defines the base abstract classes up into the parent directory. This makes it easier to look at the taskflow code-base and understand the common layout. Change-Id: I7887cb0241b8fe65cbdfee32c101c3df5f05d27c
127 lines
3.6 KiB
Python
127 lines
3.6 KiB
Python
# -*- coding: utf-8 -*-
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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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from taskflow.persistence import logbook
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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.
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The semantics of this *may* vary depending on the backend. On failure a
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backend specific exception should be raised that will indicate why the
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failure occurred.
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"""
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pass
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@abc.abstractmethod
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def update_atom_details(self, atom_detail):
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"""Updates a given atom 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 atom 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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def _format_atom(atom_detail):
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return {
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'atom': atom_detail.to_dict(),
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'type': logbook.atom_detail_type(atom_detail),
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}
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