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.TypeExpression; 027import cascading.flow.planner.rule.RuleExpression; 028import cascading.flow.planner.rule.elementexpression.BoundariesElementExpression; 029import cascading.flow.planner.rule.expressiongraph.SyncPipeExpressionGraph; 030import cascading.pipe.HashJoin; 031import cascading.pipe.Pipe; 032 033/** 034 * 035 */ 036public class BalanceJoinSplitExpression extends RuleExpression 037 { 038 public static final FlowElementExpression SHARED_JOIN = new FlowElementExpression( HashJoin.class ); 039 040 public BalanceJoinSplitExpression() 041 { 042 super( 043 new SyncPipeExpressionGraph(), 044 045 // in order to capture out degree in sub-graph, we need to capture at least two successors 046 new ExpressionGraph() 047 .arcs( SHARED_JOIN, new BoundariesElementExpression() ) 048 .arcs( SHARED_JOIN, new BoundariesElementExpression() ), 049 050 // sub-graph to match has out degree captured above 051 new ExpressionGraph() 052 .arcs( 053 new FlowElementExpression( ElementCapture.Primary, Pipe.class, TypeExpression.Topo.SplitOnly ) 054 ) 055 ); 056 } 057 }