    001/*
    002 * Copyright (c) 2007-2017 Xplenty, 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.hadoop.planner.rule.expression;
    022
    023import cascading.flow.planner.iso.expression.ElementCapture;
    024import cascading.flow.planner.iso.expression.ExpressionGraph;
    025import cascading.flow.planner.iso.expression.FlowElementExpression;
    026import cascading.flow.planner.iso.expression.PathScopeExpression;
    027import cascading.flow.planner.iso.expression.TypeExpression;
    028import cascading.flow.planner.rule.RuleExpression;
    029import cascading.flow.planner.rule.expressiongraph.SyncPipeExpressionGraph;
    030import cascading.pipe.HashJoin;
    031import cascading.pipe.Pipe;
    032import cascading.tap.Tap;
    033
    034/**
    035 *
    036 */
    037public class BalanceSameSourceStreamedAccumulatedExpression extends RuleExpression
    038  {
    039  private static final FlowElementExpression SHARED_TAP = new FlowElementExpression( Tap.class, TypeExpression.Topo.SplitOnly );
    040  public static final FlowElementExpression SHARED_HASHJOIN_STREAMED = new FlowElementExpression( HashJoin.class );
    041  public static final FlowElementExpression SHARED_HASHJOIN_ACCUMULATED = new FlowElementExpression( HashJoin.class );
    042
    043  public BalanceSameSourceStreamedAccumulatedExpression()
    044    {
    045    super(
    046      new SyncPipeExpressionGraph(),
    047
    048      new ExpressionGraph()
    049        .arc( SHARED_TAP, PathScopeExpression.NON_BLOCKING, SHARED_HASHJOIN_STREAMED )
    050        .arc( SHARED_TAP, PathScopeExpression.BLOCKING, SHARED_HASHJOIN_ACCUMULATED )
    051        .arc( SHARED_HASHJOIN_STREAMED, PathScopeExpression.NON_BLOCKING, SHARED_HASHJOIN_ACCUMULATED ),
    052
    053      new ExpressionGraph()
    054        .arc(
    055          new FlowElementExpression( ElementCapture.Primary, Pipe.class ),
    056          PathScopeExpression.NON_BLOCKING,
    057          new FlowElementExpression( ElementCapture.Secondary, HashJoin.class )
    058        )
    059    );
    060    }
    061  }