001/* 002 * Copyright (c) 2016 Chris K Wensel <chris@wensel.net>. 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.hadoop.planner.rule.expression; 022 023import cascading.flow.planner.iso.expression.ElementCapture; 024import cascading.flow.planner.iso.expression.ElementExpression; 025import cascading.flow.planner.iso.expression.ExpressionGraph; 026import cascading.flow.planner.iso.expression.FlowElementExpression; 027import cascading.flow.planner.iso.expression.ScopeExpression; 028import cascading.flow.planner.iso.expression.TypeExpression.Topo; 029import cascading.flow.planner.rule.RuleExpression; 030import cascading.flow.planner.rule.expressiongraph.SyncPipeExpressionGraph; 031import cascading.pipe.Checkpoint; 032import cascading.pipe.Group; 033import cascading.pipe.HashJoin; 034import cascading.pipe.Pipe; 035import cascading.tap.Tap; 036 037import static cascading.flow.planner.iso.expression.OrElementExpression.or; 038 039/** 040 * 041 */ 042public class BalanceGroupSplitTriangleExpression extends RuleExpression 043 { 044 public static final FlowElementExpression SHARED_GROUP = new FlowElementExpression( Group.class, Topo.Split ); 045 public static final ElementExpression SHARED_LHS = or( new FlowElementExpression( HashJoin.class ), new FlowElementExpression( Group.class ), new FlowElementExpression( Tap.class ), new FlowElementExpression( Checkpoint.class ) ); 046 public static final ElementExpression SHARED_RHS = or( new FlowElementExpression( HashJoin.class ), new FlowElementExpression( Group.class ), new FlowElementExpression( Tap.class ), new FlowElementExpression( Checkpoint.class ) ); 047 048 public BalanceGroupSplitTriangleExpression() 049 { 050 super( 051 new SyncPipeExpressionGraph(), 052 053 new ExpressionGraph() 054 .arc( 055 SHARED_GROUP, 056 ScopeExpression.ANY, 057 SHARED_LHS 058 ) 059 060 .arc( 061 SHARED_GROUP, 062 ScopeExpression.ANY, 063 SHARED_RHS 064 ) 065 066 .arc( 067 SHARED_LHS, 068 ScopeExpression.ANY, 069 SHARED_RHS 070 ), 071 072 // sub-graph to match has out degree captured above 073 new ExpressionGraph() 074 .arcs( 075 new FlowElementExpression( ElementCapture.Primary, Pipe.class, Topo.SplitOnly ) 076 ) 077 ); 078 } 079 }