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datagram.py
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datagram.py
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from datetime import datetime
from gevent.server import DatagramServer
from peerlist import Peer, peerlist, findpeer, find_peer_by_address
from peerlist import PeerNotFoundException
from message import create_message, HiMessage, YoMessage, ByeMessage
from message import FileMessage
import settings
datagram_servers = []
def send_hi_message_to_multicast_group():
hi = HiMessage(username=settings.ALIAS, port=settings.TCP_PORT)
for s in datagram_servers:
s.send_message_to_multicast_group(hi)
def send_bye_message_to_multicast_group():
for s in datagram_servers:
s.send_message_to_multicast_group(ByeMessage())
def send_file_announcement_message_to_multicast_group(f):
for s in datagram_servers:
s.send_message_to_multicast_group(FileMessage(
f.sha_hash, f.ttl, f.length, f.name, f.meta))
class TrummaDatagramServer(DatagramServer):
def __init__(self, multicast_group, *args, **kwargs):
self.multicast_group = multicast_group
super(TrummaDatagramServer, self).__init__(*args, **kwargs)
def handle(self, data, address):
message = create_message(data)
if (address[0] in settings.OWN_IP_ADDRESSES):
return
elif message is None:
# discard message
print "Datagram with unknown message received"
elif isinstance(message, HiMessage):
self.handle_hi_message(message, address[0])
elif isinstance(message, YoMessage):
self.handle_yo_message(message, address[0])
elif isinstance(message, ByeMessage):
self.handle_bye_message(message, address[0])
elif isinstance(message, FileMessage):
self.handle_file_message(message, address[0])
def handle_hi_message(self, message, address):
# insert the new peer into our peerlist
try:
peer = find_peer_by_address(address)
except PeerNotFoundException:
new_peer = Peer(address)
new_peer.tcp_port = message.port
new_peer.alias = message.username
peerlist.append(new_peer)
else:
peer.last_seen = datetime.now()
# prepare a yo, but only if the hi did not come from myself
if address not in settings.OWN_IP_ADDRESSES:
yo = YoMessage(peerlist.self_peer.tcp_port,
peerlist.self_peer.alias)
self.send_message_to_multicast_group(yo)
def handle_yo_message(self, message, address):
# insert the new peer into our peerlist
try:
peer = find_peer_by_address(address)
except PeerNotFoundException:
new_peer = Peer(address)
new_peer.tcp_port = message.port
new_peer.alias = message.username
peerlist.append(new_peer)
else:
peer.last_seen = datetime.now()
def handle_bye_message(self, message, address):
try:
peer = find_peer_by_address(address)
peerlist.remove(peer)
except PeerNotFoundException:
return
def handle_file_message(self, message, address):
try:
peer = find_peer_by_address(address)
peerlist.update_with_file_announcement_message(message, peer)
except PeerNotFoundException:
return
def send_message_to_multicast_group(self, message):
data = message.data
self.sendto(data, (self.multicast_group, settings.UDP_PORT))