001/*
002 * Copyright (c) 2007-2015 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
021/*
022 * See package LICENSE.txt for additional license information.
023 */
024
025package cascading.util.jgrapht;
026
027import java.util.HashMap;
028import java.util.Map;
029
030public class IntegerNameProvider<V> implements VertexNameProvider<V>
031  {
032  private int nextID = 1;
033  private final Map<V, Integer> idMap = new HashMap<V, Integer>();
034
035  public void clear()
036    {
037    nextID = 1;
038    idMap.clear();
039    }
040
041  @Override
042  public String getVertexName( V vertex )
043    {
044    Integer id = idMap.get( vertex );
045    if( id == null )
046      {
047      id = nextID++;
048      idMap.put( vertex, id );
049      }
050
051    return id.toString();
052    }
053  }