def handle_fin_pack(self, address):
self.wf.close()
self.message_box.insert_message("FIN pack has been received.")
ack_pack = Package()
ack_pack.set_flag(1)
ack_pack.set_num(self.pack_cnt)
self.sock.sendto(ack_pack.get_data(), address)
self.message_box.insert_message("FIN pack has been sent.")
self.message_box.insert_message("File " + self.file_name +
" has been received successfully.")
self.sock.close()
def listen(self):
data = None
address = None
while True:
try:
data, address = self.sock.recvfrom(self.pack_size)
except BlockingIOError:
# buffer-ul este gol
pass
# a fost receptionat un pachet
if data:
# este creat pachetul pe baza datelor receptionate
pack = Package()
pack.set_data(data)
# verificam ca pachetul are dimensiunea specificata, altfel ii facem 'drop'
if pack.get_dim() == len(pack.get_data()[8:]):
# se verifica daca a fost receptionat pachetul SYN
if self.pack_cnt == 0 and pack.get_flag(0):
self.handle_syn_pack(pack, address)
# se verifica daca a fost receptionat pachetul FIN
elif pack.get_flag(1):
# se verifica daca pachetul FIN este cel asteptat
if pack.get_num() == self.pack_cnt:
# daca pachetul FIN este cel asteptat atunci trimitem ack-ul si incheiem conexiunea.
self.handle_fin_pack(address)
break
# s-a receptionat un pachet normal(cu flag-urile SYN si FIN inactive).
else:
rand_val = random.random()
# facem 'drop' pachetelor conform procentului indicat
if rand_val > self.lost_percentage:
# am primit pachetul cu numarul asteptat, adica care urmeaza a fi scris in fisier
if pack.get_num() == self.pack_cnt:
self.handle_normal_pack(pack, address)
# a fost receptionat un pachet care a fost deja scris in fisier
elif pack.get_num() < self.pack_cnt:
self.handle_old_package(pack, address)
# a fost receptionat un pachet ulterior celui asteptat
else:
self.handle_following_package(pack, address)
else:
self.message_box.insert_message(
"Package no. " + str(pack.get_num()) +
" has been dropped.")
data = None
