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.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;
028import cascading.flow.planner.iso.finder.SearchOrder;
029import cascading.pipe.Boundary;
030import cascading.pipe.Group;
031import cascading.pipe.HashJoin;
032import cascading.pipe.Merge;
033import cascading.tap.Tap;
034
035import static cascading.flow.planner.iso.expression.OrElementExpression.or;
036
037/**
038 * Captures the source when the pipeline only has a single source and its streamed.
039 */
040public class StreamedSelfJoinSourcesExpressionGraph extends ExpressionGraph
041  {
042  public StreamedSelfJoinSourcesExpressionGraph()
043    {
044    super( SearchOrder.Depth, true );
045
046    FlowElementExpression intermediate = new FlowElementExpression( HashJoin.class, TypeExpression.Topo.Linear );
047
048    this.arc(
049      or( ElementCapture.Primary,
050        new FlowElementExpression( Tap.class, TypeExpression.Topo.LinearOut ),
051        new FlowElementExpression( Boundary.class, TypeExpression.Topo.LinearOut ),
052        new FlowElementExpression( Group.class, TypeExpression.Topo.LinearOut )
053      ),
054      PathScopeExpression.ALL,
055      intermediate
056    );
057
058    this.arc(
059      intermediate,
060      PathScopeExpression.ALL,
061      or(
062        new FlowElementExpression( Tap.class ),
063        new FlowElementExpression( Boundary.class ),
064        new FlowElementExpression( Merge.class ),
065        new FlowElementExpression( Group.class )
066      )
067    );
068    }
069  }