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/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
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*
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* Copyright 2011 OpenConcerto, by ILM Informatique. All rights reserved.
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*
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* The contents of this file are subject to the terms of the GNU General Public License Version 3
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* only ("GPL"). You may not use this file except in compliance with the License. You can obtain a
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* copy of the License at http://www.gnu.org/licenses/gpl-3.0.html See the License for the specific
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* language governing permissions and limitations under the License.
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*
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* When distributing the software, include this License Header Notice in each file.
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*/
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package org.openconcerto.utils.cache;
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import java.util.LinkedHashMap;
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public class LRUMap<K, V> extends LinkedHashMap<K, V> {
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static final float DEFAULT_LOAD_FACTOR = 0.75f;
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static final int REHASH_GROWTH = 2;
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private static final int MIN_CAPACITY = 4;
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private static final int SIZE_THRESHOLD = (int) (MIN_CAPACITY * DEFAULT_LOAD_FACTOR * REHASH_GROWTH);
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private int maxSize;
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public LRUMap(final int maxSize) {
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this(maxSize, maxSize <= SIZE_THRESHOLD ? MIN_CAPACITY : (int) (maxSize / DEFAULT_LOAD_FACTOR / REHASH_GROWTH + 1));
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}
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public LRUMap(final int maxSize, final int initialCapacity) {
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this(maxSize, initialCapacity, DEFAULT_LOAD_FACTOR);
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}
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public LRUMap(final int maxSize, int initialCapacity, float loadFactor) {
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super(initialCapacity, loadFactor, true);
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this.setMaxSize(maxSize);
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}
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public final int getMaxSize() {
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return this.maxSize;
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}
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public final void setMaxSize(int maxSize) {
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this.maxSize = maxSize;
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}
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@Override
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protected final boolean removeEldestEntry(java.util.Map.Entry<K, V> eldest) {
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return this.size() > this.getMaxSize();
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}
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}
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