def GBN(self):
window = Window(self.window_size)
# ack = None
# new_ack = False
current_seq = 0
with open('serverfiles\\' + self.file_requested, 'rb') as f:
size = len(f.read())
f.seek(0)
packet_num = math.ceil(size / 256)
sent = 0
line = f.read(256)
while sent != packet_num:
ready = select([self.sock], [self.sock], [])
if ready[1]:
if window.within_win():
if line:
pkt = Packet.create_udp_packet(
self.port, self.dest_addr[1],
window.next_seq(), line)
window.send_next_pkt(line)
if random.random() > self.loss_prob:
print("SERVER sending packet with seq",
window.next_seq() - 1)
self.sock.sendto(pkt, self.dest_addr)
# print("Server sending packet", window.next_seq()-1)
print(window.current_s())
line = f.read(256)
else:
window.update()
for s in window.current_s():
if s.sent and not s.acked and (time.time() -
s.timeout) >= TIMEOUT:
pkt = Packet.create_udp_packet(
self.port, self.dest_addr[1], s.seq_no, s.data)
window.update_timer(s.seq_no)
if random.random() > self.loss_prob:
print("TIMEOUT ", s.seq_no)
print("SERVER resending packet with seq",
s.seq_no)
self.sock.sendto(pkt, self.dest_addr)
if ready[0]:
ack = self.sock.recv(8)
ack_no = int.from_bytes(ack, 'big')
print("Receiving ack", ack_no)
if current_seq == ack_no:
window.acknowledge(ack_no)
sent += 1
current_seq += 1
# print("acknowledged", ack_no)
print(window.current_s())
self.sock.sendto(b'EOF', self.dest_addr)
def selective_repeat(self):
window = Window(self.window_size)
ack = None
new_ack = False
with open('serverfiles\\' + self.file_requested, 'rb') as f:
# Calculates the number of required packets to send the file in
# Advance.
size = len(f.read())
f.seek(0)
packet_num = math.ceil(size / 256)
# Number of sent packets
sent = 0
line = f.read(256)
while sent != packet_num:
# returns 3 lists one for ready sockets to read from, one for
# ready sockets to send on and one for exceptions.
ready = select([self.sock], [self.sock], [])
# Ready to send on sockets
if ready[1]:
# If the next_sequence value is still in the window frame
# if this is false, then it means we sent all of the packets
# currently in the window and we're waiting for ACKs
if window.within_win():
if line:
pkt = Packet.create_udp_packet(
self.port, self.dest_addr[1],
window.next_seq(), line)
print("SERVER sending packet with seq",
window.next_seq())
window.send_next_pkt(line)
if random.random() > self.loss_prob:
self.sock.sendto(pkt, self.dest_addr)
line = f.read(256)
# Update the window manually if we sent all of the window's
# Packets.
else:
window.update()
# If the packets are send but not acked after TIMEOUT time
# Send them again with probability of loss.
# RESETS TIMER.
for s in window.current_s():
if s.sent and not s.acked and (time.time() -
s.timeout) >= TIMEOUT:
pkt = Packet.create_udp_packet(
self.port, self.dest_addr[1], s.seq_no, s.data)
print("SERVER resending packet with seq", s.seq_no)
window.update_timer(s.seq_no)
if random.random() > self.loss_prob:
self.sock.sendto(pkt, self.dest_addr)
if ready[0]:
ack = self.sock.recv(8)
sent += 1
ack_no = int.from_bytes(ack, 'big')
window.acknowledge(ack_no)
self.sock.sendto(b'EOF', self.dest_addr)
