001/*
002 * Copyright (c) 2007-2022 The Cascading Authors. All Rights Reserved.
003 *
004 * Project and contact information: https://cascading.wensel.net/
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.tez.planner.rule.expressiongraph;
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.Topo;
028import cascading.flow.planner.iso.finder.SearchOrder;
029import cascading.flow.planner.rule.elementexpression.BoundariesElementExpression;
030import cascading.tap.Tap;
031
032import static cascading.flow.planner.iso.expression.AndElementExpression.and;
033import static cascading.flow.planner.iso.expression.NotElementExpression.not;
034
035/**
036 *
037 */
038public class TopDownSplitJoinBoundariesExpressionGraph extends ExpressionGraph
039  {
040  public TopDownSplitJoinBoundariesExpressionGraph()
041    {
042    super( SearchOrder.Topological );
043
044    this.arc(
045      new BoundariesElementExpression( Topo.Split ),
046
047      PathScopeExpression.ANY,
048
049      // don't capture a contracted graph having a tap split to a splice tap (two taps with two edges)
050      // this interferes if there is a logical split and merge
051      and(
052        ElementCapture.Primary,
053        new BoundariesElementExpression( Topo.Splice ),
054        not( new FlowElementExpression( Tap.class ) )
055      )
056    );
057    }
058  }