Source code for taskflow.persistence.base
# -*- coding: utf-8 -*-
# Copyright (C) 2013 Rackspace Hosting 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 abc
import six
from taskflow.persistence import models
@six.add_metaclass(abc.ABCMeta)
[docs]class Backend(object):
"""Base class for persistence backends."""
def __init__(self, conf):
if not conf:
conf = {}
if not isinstance(conf, dict):
raise TypeError("Configuration dictionary expected not '%s' (%s)"
% (conf, type(conf)))
self._conf = conf
@abc.abstractmethod
[docs] def get_connection(self):
"""Return a Connection instance based on the configuration settings."""
@abc.abstractmethod
[docs] def close(self):
"""Closes any resources this backend has open."""
@six.add_metaclass(abc.ABCMeta)
[docs]class Connection(object):
"""Base class for backend connections."""
@abc.abstractproperty
[docs] def backend(self):
"""Returns the backend this connection is associated with."""
@abc.abstractmethod
[docs] def close(self):
"""Closes any resources this connection has open."""
@abc.abstractmethod
[docs] def upgrade(self):
"""Migrate the persistence backend to the most recent version."""
@abc.abstractmethod
[docs] def clear_all(self):
"""Clear all entries from this backend."""
@abc.abstractmethod
[docs] def validate(self):
"""Validates that a backend is still ok to be used.
The semantics of this *may* vary depending on the backend. On failure a
backend specific exception should be raised that will indicate why the
failure occurred.
"""
@abc.abstractmethod
[docs] def update_atom_details(self, atom_detail):
"""Updates a given atom details and returns the updated version.
NOTE(harlowja): the details that is to be updated must already have
been created by saving a flow details with the given atom detail inside
of it.
"""
@abc.abstractmethod
[docs] def update_flow_details(self, flow_detail):
"""Updates a given flow details and returns the updated version.
NOTE(harlowja): the details that is to be updated must already have
been created by saving a logbook with the given flow detail inside
of it.
"""
@abc.abstractmethod
[docs] def save_logbook(self, book):
"""Saves a logbook, and all its contained information."""
@abc.abstractmethod
[docs] def destroy_logbook(self, book_uuid):
"""Deletes/destroys a logbook matching the given uuid."""
@abc.abstractmethod
[docs] def get_logbook(self, book_uuid, lazy=False):
"""Fetches a logbook object matching the given uuid."""
@abc.abstractmethod
[docs] def get_logbooks(self, lazy=False):
"""Return an iterable of logbook objects."""
@abc.abstractmethod
[docs] def get_flows_for_book(self, book_uuid):
"""Return an iterable of flowdetails for a given logbook uuid."""
@abc.abstractmethod
[docs] def get_flow_details(self, fd_uuid, lazy=False):
"""Fetches a flowdetails object matching the given uuid."""
@abc.abstractmethod
[docs] def get_atom_details(self, ad_uuid):
"""Fetches a atomdetails object matching the given uuid."""
@abc.abstractmethod
[docs] def get_atoms_for_flow(self, fd_uuid):
"""Return an iterable of atomdetails for a given flowdetails uuid."""
def _format_atom(atom_detail):
return {
'atom': atom_detail.to_dict(),
'type': models.atom_detail_type(atom_detail),
}