    001/*
    002 * Copyright (c) 2007-2016 Concurrent, Inc. All Rights Reserved.
    003 *
    004 * Project and contact information: http://www.cascading.org/
    005 *
    006 * This file is part of the Cascading project.
    007 *
    008 * Licensed under the Apache License, Version 2.0 (the "License");
    009 * you may not use this file except in compliance with the License.
    010 * You may obtain a copy of the License at
    011 *
    012 *     http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing, software
    015 * distributed under the License is distributed on an "AS IS" BASIS,
    016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    017 * See the License for the specific language governing permissions and
    018 * limitations under the License.
    019 */
    020
    021package cascading.flow.planner.rule.partitioner;
    022
    023import cascading.flow.planner.iso.ElementAnnotation;
    024import cascading.flow.planner.iso.expression.ExpressionGraph;
    025import cascading.flow.planner.iso.subgraph.GraphPartitioner;
    026import cascading.flow.planner.iso.subgraph.partitioner.ExpressionGraphPartitioner;
    027import cascading.flow.planner.iso.subgraph.partitioner.UniquePathGraphPartitioner;
    028import cascading.flow.planner.rule.PlanPhase;
    029import cascading.flow.planner.rule.RuleExpression;
    030
    031/**
    032 * Class UniquePathRulePartitioner relies on a {@link cascading.flow.planner.rule.RuleExpression} to identify
    033 * sub-graphs as initial partitions, then will partition the resulting graph into a unique sub-graph for each
    034 * unique path between the head and tail of the graph.
    035 * <p/>
    036 * This partitioner currently requires the matched sub-graph (per the RuleExpression) to have a single head and single
    037 * tail. All paths will between the matched head and tail.
    038 *
    039 * Any remaining elements from the original graph will be included in the final path sub-graph.
    040 *
    041 */
    042public class UniquePathRulePartitioner extends ExpressionRulePartitioner
    043  {
    044  public UniquePathRulePartitioner( PlanPhase phase, RuleExpression ruleExpression )
    045    {
    046    super( phase, ruleExpression );
    047    }
    048
    049  public UniquePathRulePartitioner( PlanPhase phase, RuleExpression ruleExpression, ElementAnnotation... annotations )
    050    {
    051    super( phase, ruleExpression, annotations );
    052    }
    053
    054  public UniquePathRulePartitioner( PlanPhase phase, RuleExpression ruleExpression, Enum... annotationExcludes )
    055    {
    056    super( phase, ruleExpression, annotationExcludes );
    057    }
    058
    059  public UniquePathRulePartitioner( PlanPhase phase, PartitionSource partitionSource, RuleExpression ruleExpression )
    060    {
    061    super( phase, partitionSource, ruleExpression );
    062    }
    063
    064  public UniquePathRulePartitioner( PlanPhase phase, PartitionSource partitionSource, RuleExpression ruleExpression, ElementAnnotation... annotations )
    065    {
    066    super( phase, partitionSource, ruleExpression, annotations );
    067    }
    068
    069  public UniquePathRulePartitioner( PlanPhase phase, PartitionSource partitionSource, RuleExpression ruleExpression, Enum... annotationExcludes )
    070    {
    071    super( phase, partitionSource, ruleExpression, annotationExcludes );
    072    }
    073
    074  protected UniquePathRulePartitioner( PlanPhase phase, GraphPartitioner graphPartitioner )
    075    {
    076    super( phase, graphPartitioner );
    077    }
    078
    079  protected UniquePathRulePartitioner( PlanPhase phase )
    080    {
    081    super( phase );
    082    }
    083
    084  protected UniquePathRulePartitioner()
    085    {
    086    }
    087
    088  @Override
    089  protected ExpressionGraphPartitioner createExpressionGraphPartitioner( ExpressionGraph contractionGraph, ExpressionGraph expressionGraph, ElementAnnotation[] annotations )
    090    {
    091    // include remainders by default
    092    return new UniquePathGraphPartitioner( contractionGraph, expressionGraph, true, annotations );
    093    }
    094  }