001/* 002 * Copyright (c) 2007-2016 Concurrent, 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.planner.iso.transformer; 022 023import java.util.Set; 024 025import cascading.flow.FlowElement; 026import cascading.flow.planner.PlannerContext; 027import cascading.flow.planner.graph.ElementGraph; 028import cascading.flow.planner.graph.ElementGraphs; 029import cascading.flow.planner.graph.ElementMultiGraph; 030import cascading.flow.planner.iso.expression.ElementCapture; 031import cascading.flow.planner.iso.expression.ExpressionGraph; 032import cascading.flow.planner.iso.finder.Match; 033 034/** 035 * 036 */ 037public class ContractedTransformer extends RecursiveGraphTransformer<ElementGraph> 038 { 039 public ContractedTransformer( ExpressionGraph expression ) 040 { 041 super( expression ); 042 } 043 044 @Override 045 public Transformed<ElementGraph> transform( PlannerContext plannerContext, ElementGraph rootGraph ) 046 { 047 return super.transform( plannerContext, new ElementMultiGraph( rootGraph ) ); 048 } 049 050 @Override 051 protected boolean transformGraphInPlaceUsing( Transformed<ElementGraph> transformed, ElementGraph graph, Match match ) 052 { 053 Set<FlowElement> remove = match.getCapturedElements( ElementCapture.Primary ); 054 055 if( remove.isEmpty() ) 056 return false; 057 058 for( FlowElement flowElement : remove ) 059 ElementGraphs.removeAndContract( graph, flowElement ); 060 061 return true; 062 } 063 }