76641d86b8
In order to make it possible to have a symbol tree we need to relax and remove the constraints that are being imposed by the unordered constraints and later move those constraint checks and validations into the engines compilation stage. Part of blueprint taskflow-improved-scoping Change-Id: I80718b4bc01fbf0dce6a95cd2fac7e6e2e1814d1
62 lines
2.0 KiB
Python
62 lines
2.0 KiB
Python
# -*- coding: utf-8 -*-
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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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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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"""
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def __init__(self, name, retry=None):
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super(Flow, self).__init__(name, retry)
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# NOTE(imelnikov): A unordered flow is unordered, so we use
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# set instead of list to save children, children so that
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# people using it don't depend on the ordering.
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self._children = set()
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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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self._children.update(items)
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return self
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def __len__(self):
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return len(self._children)
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def __iter__(self):
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for child in self._children:
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yield child
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def iter_links(self):
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# NOTE(imelnikov): children in unordered flow have no dependencies
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# between each other due to invariants retained during construction.
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return iter(())
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@property
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def requires(self):
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requires = set()
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retry_provides = set()
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if self._retry is not None:
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requires.update(self._retry.requires)
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retry_provides.update(self._retry.provides)
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for item in self:
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item_requires = item.requires - retry_provides
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requires.update(item_requires)
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return frozenset(requires)
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