| /** |
| * 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.activemq.memory; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| import org.apache.activemq.usage.MemoryUsage; |
| |
| /** |
| * Simple CacheFilter that increases/decreases usage on a UsageManager as |
| * objects are added/removed from the Cache. |
| * |
| * |
| */ |
| public class UsageManagerCacheFilter extends CacheFilter { |
| |
| private final AtomicLong totalUsage = new AtomicLong(0); |
| private final MemoryUsage usage; |
| |
| public UsageManagerCacheFilter(Cache next, MemoryUsage um) { |
| super(next); |
| this.usage = um; |
| } |
| |
| public Object put(Object key, Object value) { |
| long usageValue = getUsageOfAddedObject(value); |
| Object rc = super.put(key, value); |
| if (rc != null) { |
| usageValue -= getUsageOfRemovedObject(rc); |
| } |
| totalUsage.addAndGet(usageValue); |
| usage.increaseUsage(usageValue); |
| return rc; |
| } |
| |
| public Object remove(Object key) { |
| Object rc = super.remove(key); |
| if (rc != null) { |
| long usageValue = getUsageOfRemovedObject(rc); |
| totalUsage.addAndGet(-usageValue); |
| usage.decreaseUsage(usageValue); |
| } |
| return rc; |
| } |
| |
| protected long getUsageOfAddedObject(Object value) { |
| return 1; |
| } |
| |
| protected long getUsageOfRemovedObject(Object value) { |
| return 1; |
| } |
| |
| public void close() { |
| usage.decreaseUsage(totalUsage.get()); |
| } |
| } |