55 lines
1.7 KiB
Python
55 lines
1.7 KiB
Python
# Copyright 2015 Mirantis, Inc.
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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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"""
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task should be visited only when predecessors are visited,
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visited node could be only in SUCCESS or ERROR
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task can be scheduled for execution if it is not yet visited, and state
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not in SKIPPED, INPROGRESS
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PENDING - task that is scheduled to be executed
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ERROR - visited node, but failed, can be failed by timeout
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SUCCESS - visited node, successfull
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INPROGRESS - task already scheduled, can be moved to ERROR or SUCCESS
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SKIPPED - not visited, and should be skipped from execution
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NOOP - task wont be executed, but should be treated as visited
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"""
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from enum import Enum
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states = Enum('States', 'SUCCESS ERROR NOOP INPROGRESS SKIPPED PENDING')
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VISITED = (states.SUCCESS.name, states.ERROR.name, states.NOOP.name)
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BLOCKED = (states.INPROGRESS.name, states.SKIPPED.name)
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def traverse(dg):
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visited = set()
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for node in dg:
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data = dg.node[node]
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if data['status'] in VISITED:
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visited.add(node)
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for node in dg:
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data = dg.node[node]
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if node in visited or data['status'] in BLOCKED:
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continue
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if set(dg.predecessors(node)) <= visited:
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yield node
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