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com.hfg xml, html, svg, and bioinformatics utility library
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package com.hfg.util.collection;

import java.util.HashMap;
import java.util.Map;


//------------------------------------------------------------------------------
/**
 Simple implementation of a bi-directional map.
 
 @author J. Alex Taylor, hairyfatguy.com
 
 */
//------------------------------------------------------------------------------
// com.hfg Library
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// J. Alex Taylor, President, Founder, CEO, COO, CFO, OOPS hairyfatguy.com
// [email protected]
//------------------------------------------------------------------------------

public class BiHashMap extends HashMap implements BiMap
{
   private Map mReverseMap;

   //##########################################################################
   // CONSTRUCTORS
   //##########################################################################

   //--------------------------------------------------------------------------
   public BiHashMap()
   {
      super();
      init(null);
   }

   //--------------------------------------------------------------------------
   public BiHashMap(int inInitialSize)
   {
      super(inInitialSize);
      init(inInitialSize);
   }

   //--------------------------------------------------------------------------
   private void init(Integer inInitialSize)
   {
      if (inInitialSize != null)
      {
         mReverseMap = new HashMap<>(inInitialSize);
      }
      else
      {
         mReverseMap = new HashMap<>();
      }
   }

   //##########################################################################
   // PUBLIC METHODS
   //##########################################################################

   //--------------------------------------------------------------------------
   /**
    Performs a reverse lookup on the Map.
    * @param inValue the value to use
    * @return the key associated with the value
    */
   public K getKey(V inValue)
   {
      return mReverseMap.get(inValue);
   }

   //--------------------------------------------------------------------------
   @Override
   public V put(K inKey, V inValue)
   {
      mReverseMap.put(inValue, inKey);
      return super.put(inKey, inValue);
   }

   //--------------------------------------------------------------------------
   @Override
   public void putAll(Map inValues)
   {
      if (CollectionUtil.hasValues(inValues))
      {
         for (K key : inValues.keySet())
         {
            mReverseMap.put(inValues.get(key), key);
         }
      }

      super.putAll(inValues);
   }

   //--------------------------------------------------------------------------
   @Override
   public V putIfAbsent(K inKey, V inValue)
   {
      mReverseMap.putIfAbsent(inValue, inKey);
      return super.putIfAbsent(inKey, inValue);
   }

   //--------------------------------------------------------------------------
   @Override
   public void clear()
   {
      mReverseMap.clear();
      super.clear();
   }

   //--------------------------------------------------------------------------
   @Override
   public V remove(Object inKey)
   {
      mReverseMap.remove(get(inKey));
      return super.remove(inKey);
   }

   //--------------------------------------------------------------------------
   @Override
   public V replace(K inKey, V inValue)
   {
      mReverseMap.remove(get(inKey));
      mReverseMap.put(inValue, inKey);
      return super.replace(inKey, inValue);
   }

   //--------------------------------------------------------------------------
   @Override
   public boolean containsValue(Object inValue)
   {
      return mReverseMap.containsKey(inValue);
   }

}