    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.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  }