//Copyright 2003-2005 Arthur van Hoff, Rick Blair
//Licensed under Apache License version 2.0
//Original license LGPL
package javax.jmdns.impl.tasks;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
//import java.util.logging.Logger;
import javax.jmdns.impl.DNSCache;
import javax.jmdns.impl.DNSConstants;
import javax.jmdns.impl.DNSRecord;
import javax.jmdns.impl.DNSState;
import javax.jmdns.impl.JmDNSImpl;
/**
* Periodicaly removes expired entries from the cache.
*/
public class RecordReaper extends TimerTask
{
// static Logger logger = Logger.getLogger(RecordReaper.class.getName());
/**
*
*/
private final JmDNSImpl jmDNSImpl;
/**
* @param jmDNSImpl
*/
public RecordReaper(JmDNSImpl jmDNSImpl)
{
this.jmDNSImpl = jmDNSImpl;
}
public void start(Timer timer)
{
timer.schedule(this, DNSConstants.RECORD_REAPER_INTERVAL, DNSConstants.RECORD_REAPER_INTERVAL);
}
public void run()
{
synchronized (this.jmDNSImpl)
{
if (this.jmDNSImpl.getState() == DNSState.CANCELED)
{
return;
}
// logger.finest("run() JmDNS reaping cache");
// Remove expired answers from the cache
// -------------------------------------
// To prevent race conditions, we defensively copy all cache
// entries into a list.
List list = new ArrayList();
synchronized (this.jmDNSImpl.getCache())
{
for (Iterator i = this.jmDNSImpl.getCache().iterator(); i.hasNext();)
{
for (DNSCache.CacheNode n = (DNSCache.CacheNode) i.next(); n != null; n = n.next())
{
list.add(n.getValue());
}
}
}
// Now, we remove them.
long now = System.currentTimeMillis();
for (Iterator i = list.iterator(); i.hasNext();)
{
DNSRecord c = (DNSRecord) i.next();
if (c.isExpired(now))
{
this.jmDNSImpl.updateRecord(now, c);
this.jmDNSImpl.getCache().remove(c);
}
}
}
}
}