001/*
002 * Copyright (c) 2016-2017 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.transformer;
023
024import cascading.flow.planner.iso.expression.ElementCapture;
025import cascading.flow.planner.rule.transformer.BoundaryElementFactory;
026import cascading.flow.planner.rule.transformer.RuleInsertionTransformer;
027import cascading.flow.tez.planner.rule.expression.BalanceSplitToStreamedHashJoinExpression;
028
029import static cascading.flow.planner.rule.PlanPhase.BalanceAssembly;
030
031/**
032 * Inserts Boundary after split that joins back into a HashJoin.
033 * <p>
034 * this allows testGroupBySplitGroupByJoin to pass, and simplifies testJoinSamePipeAroundGroupBy by preventing
035 * the upstream operations to duplicate processing in parallel nodes
036 */
037public class BoundaryBalanceSplitToStreamedHashJoinTransformer extends RuleInsertionTransformer
038  {
039  public BoundaryBalanceSplitToStreamedHashJoinTransformer()
040    {
041    super(
042      BalanceAssembly,
043      new BalanceSplitToStreamedHashJoinExpression(),
044      ElementCapture.Secondary,
045      BoundaryElementFactory.BOUNDARY_PIPE
046    );
047    }
048  }