001 /*
002 * Copyright 2001-2004 The Apache Software Foundation
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016 package org.apache.commons.cache;
017
018 import java.util.NoSuchElementException;
019 import java.io.Serializable;
020
021 /**
022 * tk.
023 * @version $Id: StaleObjectEvictor.java 155435 2005-02-26 13:17:27Z dirkv $
024 * @author Rodney Waldhoff
025 */
026 public class StaleObjectEvictor implements Runnable, Serializable {
027 public transient static final int DEFAULT_OBJECTS_BETWEEN_NAPS;
028 static {
029 int objsTweenNaps = 10;
030 try {
031 objsTweenNaps = Integer.parseInt(System.getProperty("org.apache.commons.cache.StaleObjectEvictor.objs-between-naps","10"));
032 } catch(Exception e) {
033 objsTweenNaps = 10;
034 }
035 DEFAULT_OBJECTS_BETWEEN_NAPS = objsTweenNaps;
036 }
037
038 public transient static final long DEFAULT_SLEEP_TIME_MILLIS;
039 static {
040 long sleepTime = 10000;
041 try {
042 sleepTime = Long.parseLong(System.getProperty("org.apache.commons.cache.StaleObjectEvictor.sleep-time-millis","10000"));
043 } catch(Exception e) {
044 sleepTime = 10000;
045 }
046 DEFAULT_SLEEP_TIME_MILLIS = sleepTime;
047 }
048
049 protected int _objsBetweenNaps = DEFAULT_OBJECTS_BETWEEN_NAPS;
050 protected long _sleepTimeMillis = DEFAULT_SLEEP_TIME_MILLIS;
051 protected CachedObjectIterator _iterator;
052 protected boolean _cancelled = false;
053
054 public StaleObjectEvictor(CachedObjectIterator it) {
055 this(it,DEFAULT_OBJECTS_BETWEEN_NAPS,DEFAULT_SLEEP_TIME_MILLIS);
056 }
057
058 public StaleObjectEvictor(CachedObjectIterator it, int objsBetweenNaps) {
059 this(it,objsBetweenNaps,DEFAULT_SLEEP_TIME_MILLIS);
060 }
061
062 public StaleObjectEvictor(CachedObjectIterator it, long sleepTimeMillis) {
063 this(it,DEFAULT_OBJECTS_BETWEEN_NAPS,sleepTimeMillis);
064 }
065
066 public StaleObjectEvictor(CachedObjectIterator it, int objsBetweenNaps, long sleepTimeMillis) {
067 _iterator = it;
068 _objsBetweenNaps = objsBetweenNaps;
069 _sleepTimeMillis = sleepTimeMillis;
070 }
071
072 public void cancel() {
073 _cancelled = true;
074 }
075
076 public void run() {
077 while(!_cancelled) {
078 for(int i=0;i<_objsBetweenNaps;i++) {
079 CachedObjectInfo info = null;
080 try {
081 info = _iterator.getNext();
082 } catch(NoSuchElementException e) {
083 info = null;
084 }
085 if(null != info) {
086 Long expiry = info.getExpirationTs();
087 if(null != expiry) {
088 if(System.currentTimeMillis() >= expiry.longValue()) {
089 try {
090 _iterator.remove();
091 } catch(Exception e) {
092 // ignored
093 }
094 }
095 }
096 } else {
097 break;
098 }
099 }
100 try {
101 Thread.sleep(_sleepTimeMillis);
102 } catch(InterruptedException e) {
103 // ignored
104 }
105 }
106 }
107
108 /*
109 public void passivate() {
110 _cancelled = true;
111 }
112
113 public void activate() {
114 _cancelled = false;
115 }
116 */
117
118
119 }