Remove line containing comment - # vim: tabstop=4 shiftwidth=4 softtabstop=4 Change-Id: I7581cc88b8de433d5609ed06c6570b0b45c13573 Closes-Bug:#1229324
		
			
				
	
	
		
			95 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
# -*- coding: utf-8 -*-
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#    Copyright (C) 2013 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 six
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from taskflow import states as st
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class GraphAnalyzer(object):
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    """Analyzes a execution graph to get the next nodes for execution or
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    reversion by utilizing the graphs nodes and edge relations and comparing
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    the node state against the states stored in storage.
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    """
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    def __init__(self, graph, storage):
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        self._graph = graph
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        self._storage = storage
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    @property
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    def execution_graph(self):
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        return self._graph
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    def browse_nodes_for_execute(self, node=None):
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        """Browse next nodes to execute for given node if specified and
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        for whole graph otherwise.
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        """
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        if node:
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            nodes = self._graph.successors(node)
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        else:
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            nodes = self._graph.nodes_iter()
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        available_nodes = []
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        for node in nodes:
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            if self._is_ready_for_execute(node):
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                available_nodes.append(node)
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        return available_nodes
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    def browse_nodes_for_revert(self, node=None):
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        """Browse next nodes to revert for given node if specified and
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        for whole graph otherwise.
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        """
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        if node:
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            nodes = self._graph.predecessors(node)
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        else:
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            nodes = self._graph.nodes_iter()
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        available_nodes = []
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        for node in nodes:
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            if self._is_ready_for_revert(node):
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                available_nodes.append(node)
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        return available_nodes
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    def _is_ready_for_execute(self, task):
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        """Checks if task is ready to be executed."""
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        state = self._storage.get_task_state(task.name)
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        if not st.check_task_transition(state, st.RUNNING):
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            return False
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        task_names = []
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        for prev_task in self._graph.predecessors(task):
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            task_names.append(prev_task.name)
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        task_states = self._storage.get_tasks_states(task_names)
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        return all(state == st.SUCCESS
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                   for state in six.itervalues(task_states))
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    def _is_ready_for_revert(self, task):
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        """Checks if task is ready to be reverted."""
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        state = self._storage.get_task_state(task.name)
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        if not st.check_task_transition(state, st.REVERTING):
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            return False
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        task_names = []
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        for prev_task in self._graph.successors(task):
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            task_names.append(prev_task.name)
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        task_states = self._storage.get_tasks_states(task_names)
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        return all(state in (st.PENDING, st.REVERTED)
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                   for state in six.itervalues(task_states))
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