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.planner.iso.expression; 022 023import java.util.Set; 024 025import cascading.flow.FlowElement; 026import cascading.flow.planner.PlannerContext; 027import cascading.flow.planner.Scope; 028import cascading.flow.planner.graph.ElementGraph; 029 030/** 031 * 032 */ 033public class JoinEdgesSameSourceScopeExpression extends ScopeExpression 034 { 035 public static final JoinEdgesSameSourceScopeExpression ALL_SAME_SOURCE = new JoinEdgesSameSourceScopeExpression(); 036 037 public JoinEdgesSameSourceScopeExpression() 038 { 039 } 040 041 @Override 042 public boolean applies( PlannerContext plannerContext, ElementGraph elementGraph, Scope scope ) 043 { 044 FlowElement edgeSource = elementGraph.getEdgeSource( scope ); 045 FlowElement edgeTarget = elementGraph.getEdgeTarget( scope ); 046 Set<Scope> allEdgesBetween = elementGraph.getAllEdges( edgeSource, edgeTarget ); 047 048 if( allEdgesBetween.size() == 1 ) 049 return false; 050 051 return allEdgesBetween.equals( elementGraph.incomingEdgesOf( edgeTarget ) ); 052 } 053 }