23dfff4105
In order to move away from the existing flows having their own implementation of running, start moving the existing flows to be patterns that only structure tasks (and impose constraints about how the group of tasks can run) in useful ways. Let the concept of running those patterns be handled by an engine instead of being handled by the flow itself. This will allow for varying engines to be able to run flows in whichever way the engine chooses (as long as the constraints set up by the flow are observed). Currently threaded flow and graph flow are broken by this commit, since they have not been converted to being a structure of tasks + constraints. The existing engine has not yet been modified to run those structures either, work is underway to remediate this. Part of: blueprint patterns-and-engines Followup bugs that must be addressed: Bug: 1221448 Bug: 1221505 Change-Id: I3a8b96179f336d1defe269728ebae0caa3d832d7
56 lines
1.8 KiB
Python
56 lines
1.8 KiB
Python
# -*- coding: utf-8 -*-
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (C) 2012 Yahoo! 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 collections
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from taskflow import flow
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class Flow(flow.Flow):
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""""Unordered Flow pattern.
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A unordered (potentially nested) flow of *tasks/flows* that can be
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executed in any order as one unit and rolled back as one unit.
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NOTE(harlowja): Since the flow is unordered there can *not* be any
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dependency between task inputs and task outputs.
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"""
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def __init__(self, name, uuid=None):
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super(Flow, self).__init__(name, uuid)
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# A unordered flow is unordered so use a dict that is indexed by
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# names instead of a list so that people using this flow don't depend
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# on the ordering.
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self._children = collections.defaultdict(list)
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self._count = 0
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def add(self, *items):
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"""Adds a given task/tasks/flow/flows to this flow."""
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for e in [self._extract_item(item) for item in items]:
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self._children[e.name].append(e)
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self._count += 1
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return self
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def __len__(self):
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return self._count
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def __iter__(self):
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for _n, group in self._children.iteritems():
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for g in group:
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yield g
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