001/*
002 * Copyright (c) 2016 Chris K Wensel <chris@wensel.net>. All Rights Reserved.
003 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
004 *
005 * Project and contact information: http://www.cascading.org/
006 *
007 * This file is part of the Cascading project.
008 *
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *     http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 */
021
022package cascading.flow.tez.planner.rule.expressiongraph;
023
024import cascading.flow.planner.iso.expression.ElementCapture;
025import cascading.flow.planner.iso.expression.ExpressionGraph;
026import cascading.flow.planner.iso.expression.FlowElementExpression;
027import cascading.flow.planner.iso.expression.PathScopeExpression;
028import cascading.flow.planner.iso.expression.TypeExpression.Topo;
029import cascading.flow.planner.iso.finder.SearchOrder;
030import cascading.flow.planner.rule.elementexpression.BoundariesElementExpression;
031import cascading.tap.Tap;
032
033import static cascading.flow.planner.iso.expression.AndElementExpression.and;
034import static cascading.flow.planner.iso.expression.NotElementExpression.not;
035
036/**
037 *
038 */
039public class TopDownSplitJoinBoundariesExpressionGraph extends ExpressionGraph
040  {
041  public TopDownSplitJoinBoundariesExpressionGraph()
042    {
043    super( SearchOrder.Topological );
044
045    this.arc(
046      new BoundariesElementExpression( Topo.Split ),
047
048      PathScopeExpression.ANY,
049
050      // don't capture a contracted graph having a tap split to a splice tap (two taps with two edges)
051      // this interferes if there is a logical split and merge
052      and(
053        ElementCapture.Primary,
054        new BoundariesElementExpression( Topo.Splice ),
055        not( new FlowElementExpression( Tap.class ) )
056      )
057    );
058    }
059  }