/** Attempts to send a QUERY_CONNECT for a new long distance link. */
private void getNewLongDistance() {
if (!alreadyInOutcommingSet) symphony.retriesNewLongDistance = 0;
else {
symphony.retriesNewLongDistance++;
if (symphony.retriesNewLongDistance
>= ((SymphonyProperties) Properties.overlayPropertiesInstance)
.maxRetriesNewLongDistance) {
return;
}
}
newQueryConnect = symphony.getNewLongDistance();
if (newQueryConnect != null) symphony.sendMessage(newQueryConnect);
}
/**
* Given a RouteMessage and a Node as input, onMessage's method do execution steps for the
* behaviour. Node should be casted to Node's class in order to manage data structures and
* protocol of designed overlay.
*
* @param msg RouteMessage taken as input.
* @param node Node taken as input.
*/
public void onMessage(RouteMessage msg, Node node) {
symphony = (SymphonyNode) node;
outcommingSet = symphony.getOutcommingSet();
incommingSet = symphony.getIncommingSet();
/* We suppose long links are bidireccional TCP connections.
*/
longHandle = msg.getSource();
alreadyInOutcommingSet = outcommingSet.contains(longHandle);
/* If this new long distance is accepted, the remote node only may contain
* this local node in its incomming set (this local node only may contain the
* remote node in the neighbour set or outcomming set).
* If this new long distance already exists in the neighbour set,
* the long distance is closed and attempt to find a new long distance.
*/
if (symphony.neighbourSetContains(longHandle)) {
symphony.sendMessage(
symphony.buildMessage(
symphony.getLocalHandle(),
longHandle,
SymphonyNode.CLOSE_LONG_CONNECT,
SymphonyNode.REFRESH,
null));
getNewLongDistance();
return;
} else {
if (incommingSet.contains(longHandle)) {
// this case only occurs when two nodes simultaneously send
// a QUERY_CONNECT to the other one in the same step.
if (symphony.getId().compareTo(longHandle.getId()) < 0) {
// do'nt require a CLOSE_CONNECT message
incommingSet.remove(longHandle);
if (!alreadyInOutcommingSet) outcommingSet.add(longHandle);
} else {
getNewLongDistance();
return;
}
} else {
if (!alreadyInOutcommingSet) outcommingSet.add(longHandle);
}
}
/*
* If enough long link's aspirants, the new outcommingSet is the new long distances set
* and the old outcomming's Set is now stale. Therefore, the peers must close the stale
* long connections. Otherwise, we call getNewLongDistance() method.
*
*/
if (outcommingSet.size() > SymphonyNode.getLongDistanceNumber()) {
// the stalest node is the first in the outcomming set (the vector adds at the end)
stale = (NodeHandle) outcommingSet.remove(0);
close =
symphony.buildMessage(
symphony.getLocalHandle(),
stale,
SymphonyNode.CLOSE_LONG_CONNECT,
SymphonyNode.REFRESH,
null);
symphony.sendMessage(close);
} else if (outcommingSet.size() < SymphonyNode.getLongDistanceNumber()) getNewLongDistance();
}