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 PercentLimitUsage<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        updateLimitBasedOnPercent();
041    }
042
043    public StoreUsage(StoreUsage parent, String name) {
044        super(parent, name, 1.0f);
045        this.store = parent.store;
046        updateLimitBasedOnPercent();
047    }
048
049    @Override
050    protected long retrieveUsage() {
051        if (store == null)
052            return 0;
053        return store.size();
054    }
055
056    public PersistenceAdapter getStore() {
057        return store;
058    }
059
060    public void setStore(PersistenceAdapter store) {
061        this.store = store;
062        if (percentLimit > 0 && store != null) {
063            //will trigger onLimitChange
064            updateLimitBasedOnPercent();
065        } else {
066            onLimitChange();
067        }
068    }
069
070    @Override
071    public int getPercentUsage() {
072        usageLock.writeLock().lock();
073        try {
074            percentUsage = caclPercentUsage();
075            return super.getPercentUsage();
076        } finally {
077            usageLock.writeLock().unlock();
078        }
079    }
080
081
082    @Override
083    protected void updateLimitBasedOnPercent() {
084        usageLock.writeLock().lock();
085        try {
086            percentLimitFromFile(store != null ? store.getDirectory() : null);
087        } finally {
088            usageLock.writeLock().unlock();
089        }
090    }
091
092    public StoreUsage copy() {
093        StoreUsage storeUsage = new StoreUsage();
094        storeUsage.name = name;
095        storeUsage.parent = parent;
096        storeUsage.total = total;
097        storeUsage.percentLimit = percentLimit;
098        storeUsage.getLimiter().setLimit(getLimiter().getLimit());
099        return storeUsage;
100    }
101}