content: package org.apache.lucene.util;
  
  /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.
   */
  
  
  import java.util.Set;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.Map;
  
  /**
   * Helper class for keeping Lists of Objects associated with keys. <b>WARNING: THIS CLASS IS NOT THREAD SAFE</b>
   * @lucene.internal
   */
  public class MapOfSets<K, V> {
  
    private final Map<K, Set<V>> theMap;
  
    /**
     * @param m the backing store for this object
     */
    public MapOfSets(Map<K, Set<V>> m) {
      theMap = m;
    }
  
    /**
     * @return direct access to the map backing this object.
     */
    public Map<K, Set<V>> getMap() {
      return theMap;
    }
  
    /**
     * Adds val to the Set associated with key in the Map.  If key is not 
     * already in the map, a new Set will first be created.
     * @return the size of the Set associated with key once val is added to it.
     */
    public int put(K key, V val) {
      final Set<V> theSet;
      if (theMap.containsKey(key)) {
        theSet = theMap.get(key);
      } else {
        theSet = new HashSet<V>(23);
        theMap.put(key, theSet);
      }
      theSet.add(val);
      return theSet.size();
    }
     /**
     * Adds multiple vals to the Set associated with key in the Map.  
     * If key is not 
     * already in the map, a new Set will first be created.
     * @return the size of the Set associated with key once val is added to it.
     */
    public int putAll(K key, Collection<? extends V> vals) {
      final Set<V> theSet;
      if (theMap.containsKey(key)) {
        theSet = theMap.get(key);
      } else {
        theSet = new HashSet<V>(23);
        theMap.put(key, theSet);
      }
      theSet.addAll(vals);
      return theSet.size();
    }
   
  }
  