void FingerTable::initfingers()
{
ChordId EmptyId ;
for (int pos = 1; pos <= getTableLength(); pos++)
{
/*generater start*/
ChordId start = ChordId(localnode->getChordId().GetId(),constants,"","");
start.add(ChordId(int(pow(2,pos-1)),constants,"",""));
/*generater end*/
ChordId end = ChordId(localnode->getChordId().GetId(),constants,"","");
if(pos != NBITS)
end.add(ChordId(int(pow(2,pos)),constants,"",""));
fingers[pos-1].start = start ;
fingers[pos-1].interval[0] = start ;
fingers[pos-1].interval[1] = end ;
//init the all nodes
fingers[pos-1].node = EmptyId ;
}
setPredecessor(EmptyId) ;
clearSuccList() ;
}
/* Notifies the current node that its predecessor may have changed. */
void Node::notify(int predecessor_candidate_id)
{
if (pred_id_ == -1 || is_in_interval(predecessor_candidate_id, pred_id_ + 1, id_ - 1)) {
setPredecessor(predecessor_candidate_id);
printFingerTable();
} else {
XBT_DEBUG("I don't have to change my predecessor to %d", predecessor_candidate_id);
}
}
void Node::join(int known_id)
{
XBT_INFO("Joining the ring with id %d, knowing node %d", id_, known_id);
setPredecessor(-1); // no predecessor (yet)
int successor_id = remoteFindSuccessor(known_id, id_);
if (successor_id == -1) {
XBT_INFO("Cannot join the ring.");
} else {
setFinger(0, successor_id);
printFingerTable();
joined = true;
}
}
/* This function is called when a node receives a message.
*
* \param message the message to handle (don't touch it afterward: it will be destroyed, reused or forwarded)
*/
void Node::handleMessage(ChordMessage* message)
{
switch (message->type) {
case FIND_SUCCESSOR:
XBT_DEBUG("Received a 'Find Successor' request from %s for id %d", message->issuer_host_name.c_str(),
message->request_id);
// is my successor the successor?
if (is_in_interval(message->request_id, id_ + 1, fingers_[0])) {
message->type = FIND_SUCCESSOR_ANSWER;
message->answer_id = fingers_[0];
XBT_DEBUG("Sending back a 'Find Successor Answer' to %s (mailbox %s): the successor of %d is %d",
message->issuer_host_name.c_str(), message->answer_to->get_cname(), message->request_id,
message->answer_id);
message->answer_to->put_init(message, 10)->detach(ChordMessage::destroy);
} else {
// otherwise, forward the request to the closest preceding finger in my table
int closest = closestPrecedingFinger(message->request_id);
XBT_DEBUG("Forwarding the 'Find Successor' request for id %d to my closest preceding finger %d",
message->request_id, closest);
simgrid::s4u::MailboxPtr mailbox = simgrid::s4u::Mailbox::by_name(std::to_string(closest));
mailbox->put_init(message, 10)->detach(ChordMessage::destroy);
}
break;
case GET_PREDECESSOR:
XBT_DEBUG("Receiving a 'Get Predecessor' request from %s", message->issuer_host_name.c_str());
message->type = GET_PREDECESSOR_ANSWER;
message->answer_id = pred_id_;
XBT_DEBUG("Sending back a 'Get Predecessor Answer' to %s via mailbox '%s': my predecessor is %d",
message->issuer_host_name.c_str(), message->answer_to->get_cname(), message->answer_id);
message->answer_to->put_init(message, 10)->detach(ChordMessage::destroy);
break;
case NOTIFY:
// someone is telling me that he may be my new predecessor
XBT_DEBUG("Receiving a 'Notify' request from %s", message->issuer_host_name.c_str());
notify(message->request_id);
delete message;
break;
case PREDECESSOR_LEAVING:
// my predecessor is about to quit
XBT_DEBUG("Receiving a 'Predecessor Leaving' message from %s", message->issuer_host_name.c_str());
// modify my predecessor
setPredecessor(message->request_id);
delete message;
/*TODO :
>> notify my new predecessor
>> send a notify_predecessors !!
*/
break;
case SUCCESSOR_LEAVING:
// my successor is about to quit
XBT_DEBUG("Receiving a 'Successor Leaving' message from %s", message->issuer_host_name.c_str());
// modify my successor FIXME : this should be implicit ?
setFinger(0, message->request_id);
delete message;
/* TODO
>> notify my new successor
>> update my table & predecessors table */
break;
case PREDECESSOR_ALIVE:
XBT_DEBUG("Receiving a 'Predecessor Alive' request from %s", message->issuer_host_name.c_str());
message->type = PREDECESSOR_ALIVE_ANSWER;
XBT_DEBUG("Sending back a 'Predecessor Alive Answer' to %s (mailbox %s)", message->issuer_host_name.c_str(),
message->answer_to->get_cname());
message->answer_to->put_init(message, 10)->detach(ChordMessage::destroy);
break;
default:
XBT_DEBUG("Ignoring unexpected message: %d from %s", message->type, message->issuer_host_name.c_str());
delete message;
}
}
