    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;
    022
    023import java.util.Collection;
    024
    025import cascading.flow.FlowElement;
    026import cascading.flow.planner.PlannerContext;
    027import cascading.flow.planner.graph.ElementGraph;
    028import cascading.flow.planner.iso.subgraph.GraphPartitioner;
    029import cascading.flow.planner.iso.subgraph.Partitions;
    030
    031/**
    032 * The RulePartitioner class is responsible for partitioning an element graph into smaller sub-graphs.
    033 * <p/>
    034 * It may also re-partition a given graph, in place replacing it with its children, if any.
    035 */
    036public abstract class RulePartitioner implements Rule
    037  {
    038  public abstract Enum[] getAnnotationExcludes();
    039
    040  public enum PartitionSource
    041    {
    042      /**
    043       * Partition the parent into children.
    044       */
    045      PartitionParent,
    046
    047      /**
    048       * Partition a given child into more children, removing the original child.
    049       */
    050      PartitionCurrent
    051    }
    052
    053  protected PlanPhase phase;
    054  protected PartitionSource partitionSource = PartitionSource.PartitionParent;
    055  protected GraphPartitioner graphPartitioner;
    056
    057  public RulePartitioner( PlanPhase phase, PartitionSource partitionSource, GraphPartitioner graphPartitioner )
    058    {
    059    this.phase = phase;
    060    this.partitionSource = partitionSource;
    061    this.graphPartitioner = graphPartitioner;
    062    }
    063
    064  public RulePartitioner()
    065    {
    066    }
    067
    068  @Override
    069  public PlanPhase getRulePhase()
    070    {
    071    return phase;
    072    }
    073
    074  public PartitionSource getPartitionSource()
    075    {
    076    return partitionSource;
    077    }
    078
    079  protected GraphPartitioner getGraphPartitioner()
    080    {
    081    return graphPartitioner;
    082    }
    083
    084  public Partitions partition( PlannerContext plannerContext, ElementGraph elementGraph )
    085    {
    086    return partition( plannerContext, elementGraph, null );
    087    }
    088
    089  public Partitions partition( PlannerContext plannerContext, ElementGraph elementGraph, Collection<FlowElement> excludes )
    090    {
    091    Partitions partition = getGraphPartitioner().partition( plannerContext, elementGraph, excludes );
    092
    093    if( partition != null )
    094      partition.setRulePartitioner( this );
    095
    096    return partition;
    097    }
    098
    099  @Override
    100  public String getRuleName()
    101    {
    102    return getClass().getSimpleName().replaceAll( "^(.*)[]A-Z][a-z]*Rule$", "$1" );
    103    }
    104
    105  @Override
    106  public String toString()
    107    {
    108    return getRuleName();
    109    }
    110  }