57 lines
1.6 KiB
Python
57 lines
1.6 KiB
Python
#!/usr/bin/env python
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# Copyright (c) 2016 Hewlett Packard Enterprise Development Company, L.P.
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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 monasca_analytics.banana.typeck.type_util as type_util
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class DagNode(object):
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def __init__(self, typec):
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"""
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Create a DAGNode.
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:param typec: The type of the node.
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"""
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self.parents = []
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self.children = []
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self.typec = typec
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self._visited = False
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self._seen_sink = False
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def visit(self):
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"""
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Visit this nodes and all of its connections.
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"""
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if not self._visited:
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self._visited = True
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if isinstance(self.typec, type_util.Sink):
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self.visit_parents()
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return
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for child in self.children:
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child.visit()
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def visit_parents(self):
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"""
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Visit the parent to tell them that we've seen a Sink.
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"""
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if not self._seen_sink:
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self._seen_sink = True
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for parent in self.parents:
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parent.visit_parents()
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def is_alive(self):
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return self._visited and self._seen_sink
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