    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.PathScopeExpression;
    026import cascading.flow.planner.iso.expression.TypeExpression;
    027import cascading.flow.planner.iso.finder.SearchOrder;
    028import cascading.flow.planner.rule.elementexpression.BoundariesElementExpression;
    029
    030/**
    031 * Captures the source when the pipeline only has a single source and its streamed.
    032 */
    033public class StreamedOnlySourcesExpressionGraph extends ExpressionGraph
    034  {
    035  public StreamedOnlySourcesExpressionGraph()
    036    {
    037    super( SearchOrder.Depth );
    038
    039    this.arc(
    040      new BoundariesElementExpression( ElementCapture.Primary, TypeExpression.Topo.LinearOut ),
    041
    042      PathScopeExpression.ALL_NON_BLOCKING,
    043
    044      new BoundariesElementExpression()
    045    );
    046    }
    047  }