//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.Level;
import java.util.logging.Logger;
import javax.jmdns.impl.DNSConstants;
import javax.jmdns.impl.DNSOutgoing;
import javax.jmdns.impl.DNSState;
import javax.jmdns.impl.JmDNSImpl;
import javax.jmdns.impl.ServiceInfoImpl;
/**
* The Announcer sends an accumulated query of all announces, and advances
* the state of all serviceInfos, for which it has sent an announce.
* The Announcer also sends announcements and advances the state of JmDNS itself.
* <p/>
* When the announcer has run two times, it finishes.
*/
public class Announcer extends TimerTask
{
static Logger logger = Logger.getLogger(Announcer.class.getName());
/**
*
*/
private final JmDNSImpl jmDNSImpl;
/**
* The state of the announcer.
*/
DNSState taskState = DNSState.ANNOUNCING_1;
public Announcer(JmDNSImpl jmDNSImpl)
{
this.jmDNSImpl = jmDNSImpl;
// Associate host to this, if it needs announcing
if (this.jmDNSImpl.getState() == DNSState.ANNOUNCING_1)
{
this.jmDNSImpl.setTask(this);
}
// Associate services to this, if they need announcing
synchronized (this.jmDNSImpl)
{
for (Iterator s = this.jmDNSImpl.getServices().values().iterator(); s.hasNext();)
{
ServiceInfoImpl info = (ServiceInfoImpl) s.next();
if (info.getState() == DNSState.ANNOUNCING_1)
{
info.setTask(this);
}
}
}
}
public void start(Timer timer)
{
timer.schedule(this, DNSConstants.ANNOUNCE_WAIT_INTERVAL, DNSConstants.ANNOUNCE_WAIT_INTERVAL);
}
public boolean cancel()
{
// Remove association from host to this
if (this.jmDNSImpl.getTask() == this)
{
this.jmDNSImpl.setTask(null);
}
// Remove associations from services to this
synchronized (this.jmDNSImpl)
{
for (Iterator i = this.jmDNSImpl.getServices().values().iterator(); i.hasNext();)
{
ServiceInfoImpl info = (ServiceInfoImpl) i.next();
if (info.getTask() == this)
{
info.setTask(null);
}
}
}
return super.cancel();
}
public void run()
{
DNSOutgoing out = null;
try
{
// send probes for JmDNS itself
if (this.jmDNSImpl.getState() == taskState)
{
if (out == null)
{
out = new DNSOutgoing(DNSConstants.FLAGS_QR_RESPONSE | DNSConstants.FLAGS_AA);
}
this.jmDNSImpl.getLocalHost().addAddressRecords(out, false);
this.jmDNSImpl.advanceState();
}
// send announces for services
// Defensively copy the services into a local list,
// to prevent race conditions with methods registerService
// and unregisterService.
List list;
synchronized (this.jmDNSImpl)
{
list = new ArrayList(this.jmDNSImpl.getServices().values());
}
for (Iterator i = list.iterator(); i.hasNext();)
{
ServiceInfoImpl info = (ServiceInfoImpl) i.next();
synchronized (info)
{
if (info.getState() == taskState && info.getTask() == this)
{
info.advanceState();
logger.finer("run() JmDNS announcing " + info.getQualifiedName() + " state " + info.getState());
if (out == null)
{
out = new DNSOutgoing(DNSConstants.FLAGS_QR_RESPONSE | DNSConstants.FLAGS_AA);
}
info.addAnswers(out, DNSConstants.DNS_TTL, this.jmDNSImpl.getLocalHost());
}
}
}
if (out != null)
{
logger.finer("run() JmDNS announcing #" + taskState);
this.jmDNSImpl.send(out);
}
else
{
// If we have nothing to send, another timer taskState ahead
// of us has done the job for us. We can cancel.
cancel();
}
}
catch (Throwable e)
{
logger.log(Level.WARNING, "run() exception ", e);
this.jmDNSImpl.recover();
}
taskState = taskState.advance();
if (!taskState.isAnnouncing())
{
cancel();
this.jmDNSImpl.startRenewer();
}
}
}