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     */
017    package org.apache.activemq.usage;
018    
019    import 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     */
029    public 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        protected long retrieveUsage() {
048            if (store == null)
049                return 0;
050            return store.size();
051        }
052    
053        public PersistenceAdapter getStore() {
054            return store;
055        }
056    
057        public void setStore(PersistenceAdapter store) {
058            this.store = store;
059            onLimitChange();
060        }
061    
062        @Override
063        public int getPercentUsage() {
064            synchronized (usageMutex) {
065                percentUsage = caclPercentUsage();
066                return super.getPercentUsage();
067            }
068        }
069    
070        @Override
071        public boolean waitForSpace(long timeout, int highWaterMark) throws InterruptedException {
072            if (parent != null) {
073                if (parent.waitForSpace(timeout, highWaterMark)) {
074                    return true;
075                }
076            }
077    
078            return super.waitForSpace(timeout, highWaterMark);
079        }
080    }