def _timertransmit(self, now):
"""A periodic handler that iterates through the nodes and sends
any packets that are queued for delivery.
Args:
now (float): Current time.
"""
srcnode = self.LocalNode
dstnodes = self.peer_list(True)
while len(dstnodes) > 0:
newnodes = []
for dstnode in dstnodes:
msg = dstnode.get_next_message(now)
if msg:
if dstnode.Enabled or msg.IsSystemMessage:
# basically we are looping through the nodes & as long
# as there are messages pending then come back around &
# try again
newnodes.append(dstnode)
packet = message.Packet()
packet.add_message(msg, srcnode, dstnode,
self.next_sequence_number())
packet.TransmitTime = now
if packet.IsReliable:
self.PendingAckMap[packet.SequenceNumber] = packet
self._dowrite(packet.pack(), dstnode)
dstnodes = newnodes
def datagramReceived(self, data, address):
"""Handles a received datagram.
Find a handler for the message if one exists, and call it if
the message has not already been handled. Also forward to peers
as appropriate.
Args:
data (str): the text of the message
address (str): host:port network address of the peer
"""
if not self.ProcessIncomingMessages:
return
self.PacketStats.BytesReceived.add_value(len(data))
# unpack the header
try:
packet = message.Packet()
packet.unpack(data)
except:
logger.exception('failed to unpack message')
return
# Grab peer information if it is available, unless this is a system
# message we don't process any further without a known peer
srcpeer = self.NodeMap.get(packet.SenderID)
if srcpeer:
srcpeer.reset_ticks()
# Handle incoming acknowledgements first, there is no data associated
# with an ack
if packet.IsAcknowledgement:
if srcpeer:
self._handleack(packet)
return
# first thing to do with the message is to send an ACK, all
# retransmissions will be handled by the sending node, if the
# IsReliable flag is set then this is not a system message & we know
# that the peer exists
if packet.IsReliable:
if srcpeer:
self._sendack(packet, srcpeer)
# now unpack the rest of the message
try:
minfo = message.unpack_message_data(packet.Data)
except:
logger.exception('unable to decode message with length %d',
len(data))
return
# if we don't have a handler, thats ok we just dont do anything
# with the message, note the missing handler in the logs however
typename = minfo['__TYPE__']
self.MessageStats.MessageType.increment(typename)
if typename not in self.MessageHandlerMap:
logger.info('no handler found for message type %s from %s',
minfo['__TYPE__'], srcpeer or packet.SenderID[:8])
return
try:
msg = self.unpack_message(typename, minfo)
msg.TimeToLive = packet.TimeToLive - 1
msg.SenderID = packet.SenderID
except:
logger.exception(
'unable to deserialize message of type %s from %s', typename,
packet.SenderID[:8])
return
# if we have seen this message before then just ignore it
if msg.Identifier in self.MessageHandledMap:
logger.debug('duplicate message %s received from %s', msg,
packet.SenderID[:8])
self.PacketStats.DuplicatePackets.increment()
# if we have received a particular message from a node then we dont
# need to send another copy back to the node, just remove it from
# the queue
try:
if srcpeer:
srcpeer.dequeue_message(msg)
except:
pass
return
# verify the signature, this is a no-op for the gossiper, but
# subclasses might override the function, system messages need not have
# verified signatures
if not msg.IsSystemMessage and not msg.verify_signature():
logger.warn('unable to verify message %s received from %s',
msg.Identifier[:8], msg.OriginatorID[:8])
return
# Handle system messages,these do not require the existence of
# a peer. If the packet is marked as a system message but the message
# type does not, then something bad is happening.
self.PacketStats.MessagesHandled.increment()
if srcpeer or msg.IsSystemMessage:
self.handle_message(msg)
return
logger.warn('received message %s from an unknown peer %s', msg,
packet.SenderID[:8])
