Mega Code Archive
LRU Map
<![CDATA[
/*
* @(#)$Id: LRUMap.java 3619 2008-03-26 07:23:03Z yui $
*
* Copyright 2006-2008 Makoto YUI
*
* Licensed 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.
*
* Contributors:
* Makoto YUI - initial implementation
*/
//package xbird.util.collections;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.LinkedHashMap;
import java.util.Map.Entry;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
*/
public class LRUMap<K, V> extends LinkedHashMap<K, V> {
private static final long serialVersionUID = 1L;
protected final int maxCapacity;
public LRUMap(int maxCapacity) {
super(maxCapacity, 1.0f, true);
this.maxCapacity = maxCapacity;
}
@Override
protected boolean removeEldestEntry(Entry<K, V> eldest) {
return size() > maxCapacity;
}
public void writeTo(ObjectOutput out) throws IOException {
out.writeInt(maxCapacity);
int size = size();
out.writeInt(size);
for(Entry<K, V> e : entrySet()) {
out.writeObject(e.getKey());
out.writeObject(e.getValue());
}
}
@SuppressWarnings("unchecked")
public static <K, V> LRUMap<K, V> readFrom(ObjectInput in) throws IOException,
ClassNotFoundException {
int cap = in.readInt();
final LRUMap<K, V> map = new LRUMap<K, V>(cap);
final int size = in.readInt();
for(int i = 0; i < size; i++) {
K key = (K) in.readObject();
V value = (V) in.readObject();
map.put(key, value);
}
return map;
}
}
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