//##header
/*
* *****************************************************************************
* Copyright (C) 2006, International Business Machines Corporation and others.
* All Rights Reserved.
* *****************************************************************************
*/
package com.ibm.icu.impl;
//#ifndef FOUNDATION
import java.util.LinkedHashMap;
//#endif
import java.util.Map;
/*
* Simple LRU (Least Recent Used) Map implementation
*/
public class LRUMap extends LinkedHashMap {
private static final long serialVersionUID = -8178106459089682120L;
private static final int DEFAULT_MAXCAPACITY = 64;
private static final int DEFAULT_INITIALCAPACITY = 16;
private static final float DEFAULT_LOADFACTOR = 0.75F;
private final int maxCapacity;
/**
* Construct a new LRU map with the default initial
* capacity(16) and the maximum capacity(64).
*/
public LRUMap() {
super(DEFAULT_INITIALCAPACITY, DEFAULT_LOADFACTOR, true);
maxCapacity = DEFAULT_MAXCAPACITY;
}
/**
* Construct a new LRU map with the specified initial
* capacity and the maximum capacity
*
* @param initialCapacity initial capacity of the map
* @param maxCapacity maximum capacity of the map
*/
public LRUMap(int initialCapacity, int maxCapacity) {
super(initialCapacity, DEFAULT_LOADFACTOR, true);
this.maxCapacity = maxCapacity;
}
/*
* Delete the eldest entry when the size exceeds the limit
*/
protected boolean removeEldestEntry(Map.Entry eldest) {
return (size() > maxCapacity);
}
}
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