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Diffstat (limited to '')
-rw-r--r-- | sca-java-2.x/tags/2.0.1-RC1/modules/common-java/src/main/java/org/apache/tuscany/sca/common/java/collection/LRUCache.java | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/common-java/src/main/java/org/apache/tuscany/sca/common/java/collection/LRUCache.java b/sca-java-2.x/tags/2.0.1-RC1/modules/common-java/src/main/java/org/apache/tuscany/sca/common/java/collection/LRUCache.java new file mode 100644 index 0000000000..41286aa0f9 --- /dev/null +++ b/sca-java-2.x/tags/2.0.1-RC1/modules/common-java/src/main/java/org/apache/tuscany/sca/common/java/collection/LRUCache.java @@ -0,0 +1,89 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ +package org.apache.tuscany.sca.common.java.collection; + +import java.util.LinkedHashMap; +import java.util.Map; + +/** + * A Simple LRU Cache + * + * @version $Revision$ + * @param <K> + * @param <V> + * @tuscany.spi.extension.asclient + */ + +public class LRUCache<K, V> extends LinkedHashMap<K, V> { + private static final long serialVersionUID = -342098639681884413L; + protected int maxCacheSize = 4096; + + /** + * Default constructor for an LRU Cache The default capacity is 4096 + */ + public LRUCache() { + this(0, 4096, 0.75f, true); + } + + /** + * Constructs a LRUCache with a maximum capacity + * + * @param maximumCacheSize + */ + public LRUCache(int maximumCacheSize) { + this(0, maximumCacheSize, 0.75f, true); + } + + /** + * Constructs an empty <tt>LRUCache</tt> instance with the specified + * initial capacity, maximumCacheSize,load factor and ordering mode. + * + * @param initialCapacity the initial capacity. + * @param maximumCacheSize + * @param loadFactor the load factor. + * @param accessOrder the ordering mode - <tt>true</tt> for access-order, + * <tt>false</tt> for insertion-order. + * @throws IllegalArgumentException if the initial capacity is negative or + * the load factor is non-positive. + */ + + public LRUCache(int initialCapacity, int maximumCacheSize, float loadFactor, boolean accessOrder) { + super(initialCapacity, loadFactor, accessOrder); + this.maxCacheSize = maximumCacheSize; + } + + /** + * @return Returns the maxCacheSize. + */ + public int getMaxCacheSize() { + return maxCacheSize; + } + + /** + * @param maxCacheSize The maxCacheSize to set. + */ + public void setMaxCacheSize(int maxCacheSize) { + this.maxCacheSize = maxCacheSize; + } + + @Override + protected boolean removeEldestEntry(Map.Entry<K, V> eldest) { + return size() > maxCacheSize; + } +} |