    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  }