/***************************************************************************
* Copyright (C) 2012 by H-Store Project *
* Brown University *
* Massachusetts Institute of Technology *
* Yale University *
* *
* http://hstore.cs.brown.edu/ *
* *
* Permission is hereby granted, free of charge, to any person obtaining *
* a copy of this software and associated documentation files (the *
* "Software"), to deal in the Software without restriction, including *
* without limitation the rights to use, copy, modify, merge, publish, *
* distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to *
* the following conditions: *
* *
* The above copyright notice and this permission notice shall be *
* included in all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, *
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
* OTHER DEALINGS IN THE SOFTWARE. *
***************************************************************************/
package edu.brown.utils;
import java.util.Comparator;
import java.util.Map;
/**
* @author pavlo
* @param <K>
* @param <V>
*/
public class MapValueComparator<K, V extends Comparable<V>> implements Comparator<K> {
private final Map<K, V> data;
private final boolean reverse;
public MapValueComparator(Map<K, V> data, boolean reverse) {
this.data = data;
this.reverse = reverse;
}
public MapValueComparator(Map<K, V> data) {
this(data, false);
}
public int compare(K key0, K key1) {
V v0 = this.data.get(key0);
V v1 = this.data.get(key1);
if (v0 == null && v1 == null)
return (0);
if (v0 == null)
return (1);
return (this.reverse ? v1.compareTo(v0) : v0.compareTo(v1));
};
}