001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.usage;
018
019import org.apache.activemq.store.PersistenceAdapter;
020
021/**
022 * Used to keep track of how much of something is being used so that a
023 * productive working set usage can be controlled. Main use case is manage
024 * memory usage.
025 *
026 * @org.apache.xbean.XBean
027 *
028 */
029public class StoreUsage extends Usage<StoreUsage> {
030
031    private PersistenceAdapter store;
032
033    public StoreUsage() {
034        super(null, null, 1.0f);
035    }
036
037    public StoreUsage(String name, PersistenceAdapter store) {
038        super(null, name, 1.0f);
039        this.store = store;
040    }
041
042    public StoreUsage(StoreUsage parent, String name) {
043        super(parent, name, 1.0f);
044        this.store = parent.store;
045    }
046
047    @Override
048    protected long retrieveUsage() {
049        if (store == null)
050            return 0;
051        return store.size();
052    }
053
054    public PersistenceAdapter getStore() {
055        return store;
056    }
057
058    public void setStore(PersistenceAdapter store) {
059        this.store = store;
060        onLimitChange();
061    }
062
063    @Override
064    public int getPercentUsage() {
065        usageLock.writeLock().lock();
066        try {
067            percentUsage = caclPercentUsage();
068            return super.getPercentUsage();
069        } finally {
070            usageLock.writeLock().unlock();
071        }
072    }
073
074    @Override
075    public boolean waitForSpace(long timeout, int highWaterMark) throws InterruptedException {
076        if (parent != null) {
077            if (parent.waitForSpace(timeout, highWaterMark)) {
078                return true;
079            }
080        }
081
082        return super.waitForSpace(timeout, highWaterMark);
083    }
084}