/*
* FindBugs - Find Bugs in Java programs
* Copyright (C) 2005, University of Maryland
*
* 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
*/
package edu.umd.cs.findbugs.util;
import java.util.LinkedHashMap;
import java.util.Map;
import org.apache.bcel.classfile.JavaClass;
/**
* Provide a HashMap that can only grow to a specified maximum capacity,
* with entries discarded using a LRU policy to keep the size of the HashMap
* within that bound.
*
* @author pugh
*/
public class MapCache<K,V> extends LinkedHashMap<K,V> {
private static final long serialVersionUID = 0L;
int maxCapacity;
/**
* Create a new MapCache
* @param maxCapacity - maximum number of entries in the map
*/
public MapCache(int maxCapacity) {
super(4*maxCapacity/3+5, 0.75f, true);
this.maxCapacity = maxCapacity;
}
@Override
protected boolean removeEldestEntry(Map.Entry<K,V> eldest) {
boolean result = size() > maxCapacity;
if (false && result && eldest.getKey() instanceof JavaClass)
System.out.println("Dropping " + ((JavaClass)eldest.getKey()).getClassName());
return result;
}
}