//function used to communicate with the sequencer so as to join the chat group.
int chatClient::dojoin(string rs_ip, int rs_port){
string outmsg;
int outlen, saddr_len;
s_ip = rs_ip;
s_port = rs_port;
//setupt the UDP socket
UDP joinUDP;
joinUDP.setRemoteAddr(s_ip.c_str(),s_port);
//args: sequencer's ip, port, myIP, myPort,myName;
myMsg message = mmaker.makeJoin(name);
msgMaker::serialize(outmsg, outlen, message);
if(joinUDP.sendToNACK(outmsg.c_str(),outlen)==-2){
cerr<<"Error! Not able to join to the group... App is about to exit..."
<<endl;
exit(-1);
}
return 1;
}
int chatClient::dojoin(string &rs_ip, int &rs_port, UDP &listener){
string outmsg;
int outlen, saddr_len, recvlen, MAX_MSG_LEN=2048;
char recvMsg[2048];
const string myName,myIP;
int myPort,myID;
s_ip = rs_ip;
s_port = rs_port;
//setupt the UDP socket
UDP joinUDP;
joinUDP.setRemoteAddr(s_ip.c_str(),s_port);
//args: sequencer's ip, port, myIP, myPort,myName;
myMsg message = mmaker.makeJoin(name);
msgMaker::serialize(outmsg, outlen, message);
if(joinUDP.sendToNACK(outmsg.c_str(),outlen)==-2){
cerr<<"Error! Not able to join to the group... App is about to exit..."
<<endl;
exit(-1);
}
while(1){
recvlen = listener.recvFromNACK(recvMsg, MAX_MSG_LEN, myName, myIP,
myPort, myID);
string reMsg(recvMsg,recvlen);
msgParser tempParser(reMsg.c_str(),recvlen);
processMSG(reMsg.c_str(),recvlen);
if(tempParser.msgTypeIs()==join_ack){
rs_ip = s_ip;
rs_port = s_port;
break;
}
}
return 1;
}
//fuction actually used to process the message.
//it will analyze the header of the message and take actions accordingly.
int chatClient::processMSG(const char* msg, int mlen)
{
peer newUser;
string newName, newIP, textmsg, outmsg;
int newPort, newID;
int outlen,i;
int seqNum =0;
myMsg tempMsg;
vector<peer>::iterator aIter;
msgParser parser(msg, mlen);
if(parser.isACK()){
//return 0;
//since all the UDP_ACKs are handled in the underlaying UDP-wrapper layer, we simply
//ignore the this message.
}
else{
switch (parser.msgTypeIs()) {
case join:
if(status!=ELEC){
status=NORMAL;
//setup and send a Navi message
mmaker.setInfo(sname,s_ip, s_port,s_id);
tempMsg = mmaker.makeNavi();
msgMaker::serialize(outmsg,outlen,tempMsg);
parser.senderInfo(newIP,newName,newPort,newID);
UDP joinUDP;
joinUDP.setRemoteAddr(newIP.c_str(),newPort);
joinUDP.sendToNACK(outmsg.c_str(),outlen);
mmaker.setInfo(name,IP, port,C_ID);
return 1;
}
else{
//receive a Join request message during the election,
//push it into message queue and
//handle it later on.
inMsgQ.push(msg);
return 1;
}
break;
case navi:
//the chatClient get a navi message, which means the one
//he asked is not the sequencer, and the info of the
//sequencer is returned via this message.
//get the info of the sequencer and send another join
//message to it.
parser.senderInfo(newIP, newName, newPort,newID);
dojoin(newIP, newPort);
return 1;
break;
case join_ack:
//get the peerlist and client_id decided by the sequencer
//and store them locally for future use.
parser.joinFeedback(msgMaxCnt, C_ID, clientList);
parser.senderInfo(newIP,newName,newPort,newID);
s_id = newID;
s_ip = newIP;
s_port = newPort;
sname = newName;
clntUDP.setRemoteAddr(s_ip.c_str(), s_port);
//call the setInfo again so as to set the C_ID field
mmaker.setInfo(name,IP, port,C_ID);
displayClients();
status = NORMAL;
return 1;
break;
case join_broadcast:
//get the ip ,port name and client ID of the new user
//and store them locally.
if(status!=ELEC){
status=NORMAL;
parser.senderInfo(newIP, newName, newPort, newID);
if(newID==C_ID){
return 1;
}
parser.joinName(newName);
memset(&newUser, 0, sizeof(peer));
memcpy(newUser.name,newName.c_str(),newName.size());
memcpy(newUser.ip, newIP.c_str(), newIP.size());
newUser.c_id = newID;
newUser.port = newPort;
clientList.push_back(newUser);
cout<<"NOTICE "<<newUser.name<<" joined on "
<<newUser.ip<<":"<<newUser.port<<endl;
return 1;
}
else{
//in wrong state, push the message into message queue
//and handle later on
cerr<<"Unexpected Join Broadcast message @"<<name
<<" !"<<endl;
string temps(msg,mlen);
inMsgQ.push(temps);
return -1;
}
break;
case leave_broadcast:{
//remove the specific user from the peer list
vector<peer> timeoutList;
if(status!=ELEC){
status=NORMAL;
parser.senderInfo(newIP, newName, newPort,newID);
for(aIter = clientList.begin();
aIter != clientList.end(); aIter++){
if((*aIter).c_id==newID){
cout<<"NOTICE "<<aIter->name
<<" left the chat or crashed"<<endl;
clientList.erase(aIter);
break;
}
}
//sequencer leaves
if (newID==s_id) {
for(aIter = clientList.begin();
aIter != clientList.end(); aIter++){
if((*aIter).c_id==newID){
clientList.erase(aIter);
cout<<"NOTICE "<<aIter->name
<<" left the chat or crashed"<<endl;
break;
}
}
if(doElection()==1){
return 10;
}
else return -10;
}
}
else{
cerr<<"Unexpected Leave Broadcast message @"<<name
<<" !"<<endl;
string temps(msg,mlen);
inMsgQ.push(temps);
return -1;
}
break;
}
case msg_broadcast:
//show the message to the standard output
if(status!=ELEC){
status =NORMAL;
if(parser.getMsg(seqNum,textmsg)<0){
cerr<<"failed to get the message content! @"
<<name<<endl;
exit(-1);
}
//normal case
if(seqNum==(msgMaxCnt+1)){
cout<<textmsg<<endl;
msgMaxCnt++;
}
//receive duplicated message, ignore.
else if(seqNum<(msgMaxCnt+1)){
//ignore;
}
//missed earlier messages, search & wait for retransimit.
else if(seqNum>(msgMaxCnt+1)){
dspMsg.insert(pair<int,string>(seqNum,textmsg));
it = dspMsg.find((msgMaxCnt+1));
while(it!=dspMsg.end()){
cout<<(*it).second<<endl;
dspMsg.erase(it);
msgMaxCnt++;
it = dspMsg.find((msgMaxCnt+1));
}
}
return 1;
}
else{
cerr<<"Unexpected msg Broadcast message @"<<name
<<" !"<<endl;
string temps(msg,mlen);
inMsgQ.push(temps);
return -1;
}
break;
case election_req:{
//do BULLY
if(status==NORMAL){
parser.senderInfo(newIP, newName, newPort,newID);
if(C_ID>=newID){
if(doElection()>0){
return 10;
}
else return -10;
}
}
else return -1;
break;
}
case election_ok:
//do BULLY
if(status!=ELEC){
cerr<<"Unexpected msg election ok message @"<<name
<<" !"<<endl;
exit(-1);
}
else{
electWin=false;
}
return 1;
break;
case leader_broadcast:
//get and setup the info of the new sequencer
//here we just ignore the state which this client is in.
//Cause it's safe
//to change the sequencer here.
if(status==ELEC_CLIENT||status==NORMAL){
status = NORMAL;
parser.senderInfo(newIP, newName, newPort,newID);
if(newID!=C_ID&&newID!=s_id){
s_ip = newIP;
s_port = newPort;
s_id = newID;
sname = newName;
pthread_mutex_lock(&udpMutex);
clntUDP.updateSocket(s_ip.c_str(),s_port);
pthread_mutex_unlock(&udpMutex);
return 9;
}
}return 1;
break;
default: //not used here.
break;
}
}
}