/** Performs the probe asynchronously. */
private void sendProbe() {
final NameServicesChannelMessage message = new NameServicesChannelMessage();
message.agent = Nodel.getAgent();
List<String> discoveryList = new ArrayList<String>(1);
discoveryList.add("*");
List<String> typesList = new ArrayList<String>(2);
typesList.add("tcp");
typesList.add("http");
message.discovery = discoveryList;
message.types = typesList;
_lastProbe.set(System.nanoTime());
// IO is involved so use a thread-pool
_threadPool.execute(
new Runnable() {
@Override
public void run() {
sendMessage(_sendSocket, s_sendSocketLabel, _groupSocketAddress, message);
// check if hard links (direct "multicasting") are enabled for some hosts
if (_hardLinksAddresses != null && _hardLinksSocket != null) {
for (InetSocketAddress socketAddress : _hardLinksAddresses) {
sendMessage(_hardLinksSocket, s_hardLinksSocketlabel, socketAddress, message);
}
}
}
});
}
/** Complete the necessary response, also a timer entry-point. */
private void completeResponse() {
// prepare a message
final NameServicesChannelMessage message = new NameServicesChannelMessage();
message.present = new ArrayList<String>();
// try keep the packets relatively small by roughly guessing how much space
// its JSON advertisement packet might take up
// account for "present"...
// and
// "addresses":["tcp://136.154.27.100:65017","http://136.154.27.100:8085/index.htm?node=%NODE%"]
// so start off with approx. 110 chars
long roughTotalSize = 110;
while (_serviceIterator.hasNext()) {
ServiceItem si = _serviceIterator.next();
String name = si._name.getOriginalName();
// calculate size to be the name, two inverted-commas, and a comma and a possible space in
// between.
int size = name.length() + 4;
roughTotalSize += size;
message.present.add(name);
// make sure we're not going anywhere near UDP MTU (64K),
// in fact, squeeze them into packets similar to size of Ethernet MTU (~1400 MTU)
if (roughTotalSize > 1200) break;
} // (while)
message.addresses = new ArrayList<String>();
message.addresses.add(_nodelAddress);
message.addresses.add(_httpAddress);
// IO is involved so use thread-pool
// (and only send if the 'present' list is not empty)
if (message.present.size() > 0) {
_threadPool.execute(
new Runnable() {
@Override
public void run() {
sendMessage(_sendSocket, s_sendSocketLabel, _recipient, message);
}
});
}
// do we need this completed in the very near future?
// if so, space out by at least 333ms.
if (_serviceIterator.hasNext()) {
_timerThread.schedule(
new TimerTask() {
@Override
public void run() {
completeResponse();
}
},
333);
} else {
synchronized (_responders) {
_responders.remove(_recipient);
}
}
} // (method)
