// Copyright (c) 2003-2012, Jodd Team (jodd.org). All Rights Reserved.
package jodd.cache;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Timer;
import java.util.TimerTask;
/**
* Timed cache. Not limited by size, objects are removed only when they are expired.
* Prune is not invoked explicitly by standard {@link Cache} methods, however,
* it is possible to schedule prunes on fined-rate delays.
*/
public class TimedCache<K, V> extends AbstractCacheMap<K, V> {
public TimedCache(long timeout) {
this.cacheSize = 0;
this.timeout = timeout;
cacheMap = new HashMap<K, CacheObject<K,V>>();
}
// ---------------------------------------------------------------- prune
/**
* Prunes expired elements from the cache. Returns the number of removed objects.
*/
@Override
protected int pruneCache() {
int count = 0;
Iterator<CacheObject<K,V>> values = cacheMap.values().iterator();
while (values.hasNext()) {
CacheObject co = values.next();
if (co.isExpired() == true) {
values.remove();
count++;
}
}
return count;
}
// ---------------------------------------------------------------- auto prune
protected Timer pruneTimer;
/**
* Schedules prune.
*/
public void schedulePrune(long delay) {
if (pruneTimer != null) {
pruneTimer.cancel();
}
pruneTimer = new Timer();
pruneTimer.schedule(
new TimerTask() {
@Override
public void run() {
prune();
}
}, delay, delay
);
}
/**
* Cancels prune schedules.
*/
public void cancelPruneSchedule() {
if (pruneTimer != null) {
pruneTimer.cancel();
pruneTimer = null;
}
}
}
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