Server::Server(QObject* parent) :
QObject(parent)
{
connect(&server, SIGNAL(newConnection()), SLOT(newConnectionHandler()));
quint16 port = Protocol::ServerPort;
if (settings.contains(SettingsKey::PORT_KEY)){
port = quint16(settings.value(SettingsKey::PORT_KEY).toInt());
}
bool res = server.listen(QHostAddress::Any, port);
qDebug() << "is listening = " << res;
}
/*
* Function: eventHandler()
* Parameters: None
* Returns: None
* Description: This function creates a listening socket and accepts new incoming connections, apart from it it also reads from stdin such that server works as a unix shell and also handles incoming connections
*/
void Server::eventHandler() {
char buffer[1024];
startListenServer();
for(;;) {
// copy master set to read set
m_readSet = m_masterSet;
// start polling on read set, which is blocking indefinitely
if(select(m_nMaxFd+1, &m_readSet, NULL, NULL, NULL) == -1) {
perror("select");
exit(EXIT_FAILURE);
}
// check if there is data on any of the sockets
int bytesRead;
for(int i=0; i<=m_nMaxFd; i++) {
if(FD_ISSET(i, &m_readSet)) {
if(i == STDIN) {
// data from stdin, process approriate commands
fgets(buffer, sizeof(buffer), stdin);
buffer[strlen(buffer)-1] = '\0';
if(strlen(buffer) != 0)
commandShell(buffer);
}
else if(i == m_nListenSd) {
// new connection
newConnectionHandler();
}
else {
// handle data from existing client
// process SYNC message
char recvBuff[1024] = {0};
int bytesRead;
if( (bytesRead = recv(i, recvBuff, sizeof(recvBuff), 0)) > 0) {
recvBuff[strlen(recvBuff)] = 0;
if(strcmp(recvBuff, "SYNC") == 0) {
cout << "Received Message: " << recvBuff << " from client" << endl;
m_nQueIx = 0;
// update this message to all connected clients
for(int i=0; i<10; i++) {
if(m_nodeList[i].state == ACTIVE) {
sendall(m_nodeList[i].sockFd, recvBuff, &bytesRead);
}
}
}
if(strcmp(recvBuff, "QUIT") == 0) {
cout << "Received Message: " << recvBuff << " from client" << endl;
for(int j=0; j<10; j++) {
if(m_nodeList[j].sockFd == i) {
handle_terminate(j);
}
}
updateNodesinList();
}
if(strcmp(recvBuff, "SYNC WRITE") == 0) {
/*cout << "Received Message: " << recvBuff << " from client ";
int p;
for(p=0; p<10; p++) {
if(m_nodeList[p].state == ACTIVE && m_nodeList[p].sockFd == i)
cout << m_nodeList[p].hostName << endl;
}*/
// add this socket to sync que
m_syncQue[m_nQueIx] = i;
m_nQueIx++;
// if message has been recieved from all registered clients then start writing
if(m_nQueIx == m_nLatestIndex) {
// send Sync OK message to first client in Queue
char buff[1024] = {0};
sprintf(buff,"SYNC OK");
int len = sizeof buff;
sendall(m_syncQue[0], buff, &len);
// send SYNC READ message to rest of the clients
memset(buff, 0, sizeof buff);
sprintf(buff, "SYNC READ %s", m_nodeList[0].hostName);
for(int j=1; j<m_nQueIx; j++) {
len = sizeof buff;
sendall(m_syncQue[j], buff, &len);
}
}
}
if(strcmp(recvBuff, "SYNC FIN") == 0) {
/*cout << "Received Message: " << recvBuff << " from client ";
int p;
for(p=0; p<10; p++) {
if(m_nodeList[p].state == ACTIVE && m_nodeList[p].sockFd == i)
cout << m_nodeList[p].listenPort << endl;
}*/
// get the index of client which sent fin
int j;
for(j=0; j<m_nQueIx; j++)
if(i == m_syncQue[j]) break;
if(j == m_nQueIx-1) {
m_nQueIx = 0;
}
else {
// send SYNC OK message to the next client in the queue
char buff[1024] = {0};
sprintf(buff,"SYNC OK");
int len = sizeof buff;
sendall(m_syncQue[j+1], buff, &len);
// send SYNC READ message to rest of the clients
memset(buff, 0, sizeof buff);
sprintf(buff, "SYNC READ %s", m_nodeList[j+1].hostName);
for(int k=0; k<m_nQueIx; k++) {
if(k != j+1) {
len = sizeof buff;
sendall(m_syncQue[k], buff, &len);
}
}
}
}
cout << endl;
}
// if bytesRead=0 then terminate connection
else {
cout << "Client disconnected: " << m_nodeList[i].hostName << endl;
for(int j=0; j<10; j++) {
if(m_nodeList[j].sockFd == i)
handle_terminate(j);
}
updateNodesinList();
}
}
}
}
}
}
