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.planner.iso.transformer; 022 023import cascading.flow.planner.graph.ElementGraph; 024import cascading.flow.planner.iso.expression.ExpressionGraph; 025import cascading.util.ProcessLogger; 026 027/** 028 * 029 */ 030public abstract class MutateGraphTransformer extends RecursiveGraphTransformer<ElementGraph> 031 { 032 protected final GraphTransformer graphTransformer; 033 034 public MutateGraphTransformer( ExpressionGraph filter ) 035 { 036 super( filter ); 037 this.graphTransformer = null; 038 } 039 040 public MutateGraphTransformer( GraphTransformer graphTransformer, ExpressionGraph filter ) 041 { 042 super( filter ); 043 this.graphTransformer = graphTransformer; 044 } 045 046 @Override 047 protected boolean requiresRecursiveSearch() 048 { 049 return graphTransformer != null || super.requiresRecursiveSearch(); 050 } 051 052 @Override 053 protected ElementGraph prepareForMatch( ProcessLogger processLogger, Transformed<ElementGraph> transformed, ElementGraph graph ) 054 { 055 if( graphTransformer == null ) 056 return graph; 057 058 if( processLogger.isDebugEnabled() ) 059 processLogger.logDebug( "transforming with: {}", graphTransformer.getClass().getSimpleName() ); 060 061 Transformed child = graphTransformer.transform( transformed.getPlannerContext(), graph ); 062 063 transformed.addChildTransform( child ); 064 065 return child.getEndGraph(); 066 } 067 }