I have been working on a P2P chat application based on kivy and twisted frameworks, I was hoping to get a lay of the land but I have run into this problem where if a client needs to connect to another client (via its server) it needs to perform a kind of handshake,
now the initial step was to connect to the client ;
conn = reactor.connectTCP(host, port, CommCoreClientFactory(self))
and then write into the connection;
conn.transport.write("data..\r\n")
Here the connection succeeds but the line doesn't go through, I have condensed the above code as per my intent, please see the method add_peer_to_swarm(self, pid, host) in comm/twisscomm.py
my clientProtocol/Factory and serverProtocol/Factory code can be found below;
(they can be found in comm/commcoreclient.py and comm/commcoreserver.py resp.)
Client Protocol
class CommCoreClientProtocol(LineReceiver):
"""
Communications core client protocol code.
"""
def __init__(self, factory):
self._peer_host = None
self._peer_port = None
self._peer_repr = None
self.factory = factory
def connectionMade(self):
"Run when connection is established with server."
self._peer_host = self.transport.getPeer().host
self._peer_port = self.transport.getPeer().port
self._peer_repr = self._peer_host + " on " + str(self._peer_port)
Logger.debug(
"Connection success! Connected to {}".format(self._peer_repr))
def connectionLost(self, reason):
"Run when connection is lost with server."
Logger.warn("Lost connection with peer {}".format(self._peer_repr))
def lineReceived(self, line):
"Run when response is recieved from server."
response = self.factory.app.handle_response(line)
if response:
print response
Logger.debug("Recieved : {}".format(base64.b64encode(line)))
Client Factory
class CommCoreClientFactory(protocol.ReconnectingClientFactory):
protocol = CommCoreClientProtocol
def __init__(self, app):
self.app = app
def startedConnecting(self, connector):
"Run when initiaition of connection takes place."
Logger.debug("Attempting connection...")
def buildProtocol(self, addr):
"Build protocol on successful connection."
Logger.debug("Connected.")
Logger.debug("Resetting reconnection delay.")
# Reset the delay on connection success
self.resetDelay()
# Overridden build protocol
#client_protocol = self.protocol()
#client_protocol.factory = self
#return client_protocol
return CommCoreClientProtocol(self)
def clientConnectionLost(self, connector, reason):
"Run when connection with server is lost."
#self.app.print_message("connection lost")
Logger.debug("Lost connection: {}".format(reason.getErrorMessage()))
return protocol.ReconnectingClientFactory.clientConnectionLost(
self, connector, reason
)
def clientConnectionFailed(self, connector, reason):
"Run when attempt to connect with server fails."
#self.app.print_message("connection failed")
Logger.debug("Connection failed. {}".format(reason.getErrorMessage()))
return protocol.ReconnectingClientFactory.clientConnectionFailed(
self, connector, reason
)
Server Protocol
class CommCoreServerProtocol(LineReceiver):
"Server backend to pocess the commands"
def __init__(self):
self._peer_host = None
self._peer_port = None
self._peer_repr = None
def connectionMade(self):
"Run when connection is established with server."
self._peer_host = self.transport.getPeer().host
self._peer_port = self.transport.getPeer().port
self._peer_repr = self._peer_host + " on " + str(self._peer_port)
Logger.debug(
"Connection success! Connected to {}".format(self._peer_repr))
def connectionLost(self, reason):
"Run when connection is lost with server."
Logger.error("Lost connection with peer {}".format(self._peer_repr))
def lineReceived(self, line):
print "REVCD LINE!", line
response = self.factory.app.handle_recieved_data(line)
if response:
#self.transport.write(response)
self.sendLine(response)
Server Factory
class CommCoreServerFactory(protocol.Factory):
protocol = CommCoreServerProtocol
def __init__(self, app):
self.app = app
(Pardon the shoddy indent!)
I would like to know where I may be going wrong.
Also If you are interested I have filed this issue. If you go through my code (comm/twiscomm.py) you will see some things may not work completely on the server side especially with the handle_received_data() but this is never even called as the data is not received.