/**

  * Copyright 2005-2013 Dozer Project

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *      http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.dozer;

 import java.util.ArrayList;

 import java.util.HashMap;

 import java.util.IdentityHashMap;

 import java.util.List;

 import java.util.Map;

 /**

  * Keeps track of mapped object during this mapping process execution.

  * Objects, which are referenced multiple types in object hierarchy will be fetched from here

  * to retain referential integrity of resulting object graph.

  *

  * @author dmitry.buzdin

  */

 public class MappedFieldsTracker {

   // Hash Code is ignored as it can serve application specific needs

   // <srcObject, <hashCodeOfDestination, mappedDestinationObject>>

   private final Map<Object, Map<Integer,Object>> mappedFields = new IdentityHashMap<Object, Map<Integer,Object>>();

   public void put(Object src, Object dest) {

     int destId = System.identityHashCode(dest);

     Map<Integer,Object> mappedTo = mappedFields.get(src);

     if (mappedTo == null) {

       mappedTo = new HashMap<Integer, Object>();

       mappedFields.put(src, mappedTo);

     }

     if (!mappedTo.containsKey(destId)) {

       mappedTo.put(destId, dest);

     }

   }

   public Object getMappedValue(Object src, Class<?> destType) {

     Map<Integer,Object> alreadyMappedValues = mappedFields.get(src);

     if (alreadyMappedValues != null) {

       for (Object alreadyMappedValue : alreadyMappedValues.values()) {

         if (alreadyMappedValue != null) {

           // 1664984 - bi-directionnal mapping with sets & subclasses

           if (destType.isAssignableFrom(alreadyMappedValue.getClass())) {

             // Source value has already been mapped to the required destFieldType.

             return alreadyMappedValue;

           }

         }

       }

     }

     return null;

   }

 }