package org.mortbay.cometd.ext;
import java.util.Map;
import org.cometd.Bayeux;
import org.cometd.Client;
import org.cometd.Extension;
import org.cometd.Message;
import org.mortbay.cometd.ClientImpl;
import org.mortbay.log.Log;
import org.mortbay.util.ajax.JSON;
/**
* Acknowledged Messages extension.
*
* Installing this extension in a bayeux server allows it to handle the ack
* extension if a client also supports it.
*
* The main role of this extension is to install the
* {@link AcknowledgedMessagesClientExtension} on the {@link Client} instances
* created during handshake for clients that also support the ack extension.
*
*/
public class AcknowledgedMessagesExtension implements Extension
{
JSON.Literal _replyExt=new JSON.Literal("{\"ack\":true}");
public Message rcv(Client from, Message message)
{
return message;
}
public Message rcvMeta(Client from, Message message)
{
return message;
}
public Message send(Client from, Message message)
{
return message;
}
public Message sendMeta(Client from, Message message)
{
if (message.getChannel() == null)
return message;
if (message.getChannel().equals(Bayeux.META_HANDSHAKE) && Boolean.TRUE.equals(message.get(Bayeux.SUCCESSFUL_FIELD)))
{
Message rcv=message.getAssociated();
Map<String,Object> ext=rcv.getExt(false);
boolean clientRequestedAcks=ext != null && ext.get("ack") == Boolean.TRUE;
if (clientRequestedAcks && from != null)
{
Log.info("Enabled message acknowledgement for client " + from);
from.addExtension(new AcknowledgedMessagesClientExtension(from));
((ClientImpl)from).setMetaConnectDeliveryOnly(true);
}
message.put(Bayeux.EXT_FIELD,_replyExt);
}
return message;
}
}