def send_packet(self, packet, client):
seq_num = packet.__get__('seq_num')
client_timeout_count = CLIENT_TIMEOUT_TRIALS
while client_timeout_count:
if randint(1, 100) > LOSS_PROBABILITY:
client.send(packet.__dumb__())
else:
print(colored('Simulating Packet Loss: ' + seq_num, 'red'))
try: # Wait for response or timeout
res = client.recv(PACKET_SIZE)
if not res:
print('Client Disconnected')
return 0
pkt = Packet(pickled=res)
pkt.__print__()
if pkt.__get__('ack') == '+':
return 1
else:
print(colored('Negative ack, resending : ' + seq_num,
color='red'))
except timeout:
print(colored('Timeout, resending packet: ' + seq_num,
color='red'))
client_timeout_count -= 1
return 0
def wait_for_request(self, client, address):
client_timeout_count = CLIENT_TIMEOUT_TRIALS
while client_timeout_count:
try:
request = client.recv(PACKET_SIZE)
if request:
pkt = Packet(pickled=request)
pkt.__print__()
return pkt
else:
print('Client disconnected, address:', address)
break
except timeout:
client_timeout_count -= 1
return 0
def begin_transimission(self, packets, client, address):
base = 0
self.send_window(packets, base, client, address)
client_timeout_count = CLIENT_TIMEOUT_TRIALS
while client_timeout_count:
if base >= len(packets):
break
end = base + WINDOW_SIZE
end = end if end < len(packets) else len(packets)
client.settimeout(TIME_OUT_SEC)
try: # Wait for response or timeout
res = client.recv(PACKET_SIZE)
if not res:
break
pkt = Packet(res=res)
pkt.__print__(from_address=address)
seq_num = int(pkt.__get__('seq_num'))
if base <= seq_num <= base + WINDOW_SIZE:
if pkt.__get__('ack') == '+':
client.settimeout(None)
free_slots = int(pkt.__get__('seq_num')) - base + 1
nEnd = end + free_slots
nEnd = nEnd if nEnd < len(packets) else len(packets)
new_pkts = packets[end:nEnd]
for pkt in new_pkts:
if randint(1, 100) > LOSS_PROBABILITY:
pkt.__print__(to_address=address)
client.send(pkt.__dump__())
else:
print(colored('Simulating Packet Loss: ' +
pkt.__get__('seq_num'), 'red'))
base += free_slots
else:
print(colored('Ack out of window, discard ' +
str(seq_num) + ' => from: ' + str(address),
color='blue'))
except timeout:
print(colored('Timeout, resending window. => to: ' +
str(address), color='red'))
self.send_window(packets, base, client, address)
client_timeout_count -= 1
# Retrun number of timeouts
return CLIENT_TIMEOUT_TRIALS - client_timeout_count
