void reliablyTransfer(char* hostname, unsigned short int hostUDPport, char* filename, unsigned long long int bytesToTransfer)
{
//printf("%s %hu %s %llu\n",hostname ,hostUDPport,filename,bytesToTransfer);
/*
make a udp socket. reach the host and the destination port. waiting for receive ack. if ok, send part 2. otherwise nack send last part again.
*/
int socket_fd;
//data
struct addrinfo * dest;
log_init(&data_to_send);
if( (socket_fd = socket_init(hostname, hostUDPport, &dest)) < 0){
return;
}
if( (Convert_File_To_List(&data_to_send , filename, bytesToTransfer)) < 0){
return;
}
a = data_to_send.head;///////
int rv = 1;
//rv = slow_start(socket_fd, dest, &data_to_send);
ack_r = calloc(total,sizeof(int));///
while(data_to_send.head != NULL){
//printf("timeout or dup or other?\n");
switch(rv){
case -1:{
free(ack_r);
freeaddrinfo(servinfo);
return;
}
case 1:{
rv = slow_start(socket_fd, dest, &data_to_send);
break;
}
//rv = slow_start(socket_fd, dest, &data_to_send);
//case 2:
// rv = slow_start(socket_fd, dest, &data_to_send);
// break;
case 2:{
//rv = slow_start(socket_fd, dest, &data_to_send);
rv = congestion_avoidance(socket_fd, dest, &data_to_send);
break;
}
//default:
// break;//rv = slow_start(socket_fd, dest, &data_to_send);
}
}
free(ack_r);
freeaddrinfo(servinfo);
/*
after part 1, add the function of trafic control which includes increase window size and decrease window size.
*/
}
int slow_start(){
printf("\nStarting slow start!");
int minWindow;
int number_of_packets;
//calculating number of packets
//getting the minimum of advertised window and congestion window
if( intial_start ){
printf("\nInitial Start!");
cwnd = 200;
minWindow = minimum(cwnd,advertised_window);
printf("\nWindow size calculated:%d",minWindow);
number_of_packets = minWindow/MSS;
exponentVal =2;
intial_start = false;
read_file(number_of_packets);
}
//when u get an ACK you do exponentially increase cwnd
else{
printf("\nIncreasing CWND exponentially!");
//checking cwnd
if(cwnd >= SSTHRESH ){
congestion_avoidance();
}
cwnd = exponentVal*cwnd;
exponentVal = exponentVal*2;
minWindow = minimum(cwnd,advertised_window);
number_of_packets = minWindow/MSS;
printf("Window size calculated:%d",minWindow);
read_file(number_of_packets);
}
}
