/*
* 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.codehaus.groovy.runtime.memoize;
import org.apache.groovy.util.concurrentlinkedhashmap.ConcurrentLinkedHashMap;
import java.lang.ref.SoftReference;
import java.util.Iterator;
import java.util.Map;
/**
* A cache backed by a ConcurrentLinkedHashMap
*
* @author Vaclav Pech
* @author <a href="mailto:realbluesun@hotmail.com">Daniel.Sun</a>
*/
public final class LRUCache implements MemoizeCache<Object, Object> {
private final Map<Object, Object> cache;
public LRUCache(final int maxCacheSize) {
// cache = Collections.synchronizedMap(new LRUProtectionStorage(maxCacheSize));
cache = new ConcurrentLinkedHashMap.Builder<>()
.maximumWeightedCapacity(maxCacheSize)
.build();
}
public Object put(final Object key, final Object value) {
return cache.put(key, value);
}
public Object get(final Object key) {
return cache.get(key);
}
/**
* Remove all entries holding SoftReferences to gc-evicted objects.
*/
public void cleanUpNullReferences() {
synchronized (cache) {
final Iterator<Map.Entry<Object, Object>> iterator = cache.entrySet().iterator();
while (iterator.hasNext()) {
final Map.Entry<Object, Object> entry = iterator.next();
final Object value = entry.getValue();
if (!(value instanceof SoftReference)) continue;
if (((SoftReference) value).get() == null) iterator.remove();
}
}
}
}