| package org.apache.commons.jcs3.auxiliary.disk.jdbc; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.Iterator; |
| import java.util.concurrent.CopyOnWriteArraySet; |
| |
| import org.apache.commons.jcs3.log.Log; |
| import org.apache.commons.jcs3.log.LogManager; |
| import org.apache.commons.jcs3.utils.timing.ElapsedTimer; |
| |
| /** |
| * Calls delete expired on the disk caches. The shrinker is run by a clock daemon. The shrinker |
| * calls delete on each region. It pauses between calls. |
| * <p> |
| * @author Aaron Smuts |
| */ |
| public class ShrinkerThread |
| implements Runnable |
| { |
| /** The logger. */ |
| private static final Log log = LogManager.getLog( ShrinkerThread.class ); |
| |
| /** A set of JDBCDiskCache objects to call deleteExpired on. */ |
| private final CopyOnWriteArraySet<JDBCDiskCache<?, ?>> shrinkSet = |
| new CopyOnWriteArraySet<>(); |
| |
| /** Default time period to use. */ |
| private static final long DEFAULT_PAUSE_BETWEEN_REGION_CALLS_MILLIS = 5000; |
| |
| /** |
| * How long should we wait between calls to deleteExpired when we are iterating through the list |
| * of regions. Delete can lock the table. We want to give clients a chance to get some work |
| * done. |
| */ |
| private long pauseBetweenRegionCallsMillis = DEFAULT_PAUSE_BETWEEN_REGION_CALLS_MILLIS; |
| |
| /** |
| * Does nothing special. |
| */ |
| protected ShrinkerThread() |
| { |
| } |
| |
| /** |
| * Adds a JDBC disk cache to the set of disk cache to shrink. |
| * <p> |
| * @param diskCache |
| */ |
| public void addDiskCacheToShrinkList( final JDBCDiskCache<?, ?> diskCache ) |
| { |
| // the set will prevent dupes. |
| // we could also just add these to a hashmap by region name |
| // but that might cause a problem if you wanted to use two different |
| // jbdc disk caches for the same region. |
| shrinkSet.add( diskCache ); |
| } |
| |
| /** |
| * Calls deleteExpired on each item in the set. It pauses between each call. |
| */ |
| @Override |
| public void run() |
| { |
| try |
| { |
| deleteExpiredFromAllRegisteredRegions(); |
| } |
| catch ( final Throwable e ) |
| { |
| log.error( "Caught an exception while trying to delete expired items.", e ); |
| } |
| } |
| |
| /** |
| * Deletes the expired items from all the registered regions. |
| */ |
| private void deleteExpiredFromAllRegisteredRegions() |
| { |
| log.info( "Running JDBC disk cache shrinker. Number of regions [{0}]", |
| () -> shrinkSet.size() ); |
| |
| for (final Iterator<JDBCDiskCache<?, ?>> i = shrinkSet.iterator(); i.hasNext();) |
| { |
| final JDBCDiskCache<?, ?> cache = i.next(); |
| final ElapsedTimer timer = new ElapsedTimer(); |
| final int deleted = cache.deleteExpired(); |
| |
| log.info( "Deleted [{0}] expired for region [{1}] for table [{2}] in {3} ms.", |
| deleted, cache.getCacheName(), cache.getTableName(), timer.getElapsedTime() ); |
| |
| // don't pause after the last call to delete expired. |
| if ( i.hasNext() ) |
| { |
| log.info( "Pausing for [{0}] ms before shrinking the next region.", |
| this.getPauseBetweenRegionCallsMillis() ); |
| |
| try |
| { |
| Thread.sleep( this.getPauseBetweenRegionCallsMillis() ); |
| } |
| catch ( final InterruptedException e ) |
| { |
| log.warn( "Interrupted while waiting to delete expired for the next region." ); |
| } |
| } |
| } |
| } |
| |
| /** |
| * How long should we wait between calls to deleteExpired when we are iterating through the list |
| * of regions. |
| * <p> |
| * @param pauseBetweenRegionCallsMillis The pauseBetweenRegionCallsMillis to set. |
| */ |
| public void setPauseBetweenRegionCallsMillis( final long pauseBetweenRegionCallsMillis ) |
| { |
| this.pauseBetweenRegionCallsMillis = pauseBetweenRegionCallsMillis; |
| } |
| |
| /** |
| * How long should we wait between calls to deleteExpired when we are iterating through the list |
| * of regions. |
| * <p> |
| * @return Returns the pauseBetweenRegionCallsMillis. |
| */ |
| public long getPauseBetweenRegionCallsMillis() |
| { |
| return pauseBetweenRegionCallsMillis; |
| } |
| } |