Problem with Twisted python - sending binary data

Question

What I'm trying to do is pretty simple: send the file from the client to the server. Firstly, the client sends information about the file - its size. Then it sends the actual file.

This is what I have done so far:

Server.py

from twisted.internet import reactor, protocol
from twisted.protocols.basic import LineReceiver

import pickle
import sys

class Echo(LineReceiver):

    def connectionMade(self):
        self.factory.clients.append(self)
        self.setRawMode()

    def connectionLost(self, reason):
        self.factory.clients.remove(self)

    def lineReceived(self, data):
        print "line", data

    def rawDataReceived(self, data):
            try:
                obj = pickle.loads(data)
                print obj
            except:
                print data

        #self.transport.write("wa2")

def main():
    """This runs the protocol on port 8000"""
    factory = protocol.ServerFactory()
    factory.protocol = Echo
    factory.clients = []
    reactor.listenTCP(8000,factory)
    reactor.run()

# this only runs if the module was *not* imported
if __name__ == '__main__':
    main()

Client.py

import pickle

from twisted.internet import reactor, protocol
import time
import os.path
from twisted.protocols.basic import LineReceiver

class EchoClient(LineReceiver):

    def connectionMade(self):
        file = "some file that is a couple of megs"
        filesize = os.path.getsize(file)
        self.sendLine(pickle.dumps({"size":filesize}))

        f = open(file, "rb")
        contents = f.read()
        print contents[:20]
        self.sendLine(contents[:20])
        f.close()

#        self.sendLine("hej")
#        self.sendLine("wa")

    def connectionLost(self, reason):
        print "connection lost"

class EchoFactory(protocol.ClientFactory):
    protocol = EchoClient

    def clientConnectionFailed(self, connector, reason):
        print "Connection failed - goodbye!"
        reactor.stop()

    def clientConnectionLost(self, connector, reason):
        print "Connection lost - goodbye!"
        reactor.stop()


# this connects the protocol to a server runing on port 8000
def main():
    f = EchoFactory()
    reactor.connectTCP("localhost", 8000, f)
    reactor.run()

# this only runs if the module was *not* imported
if __name__ == '__main__':
    main()

The server will only output the deserialized object:

{'size': 183574528L}

How did it happen? What happened to 20 characters from the file I wanted to send?

If hej and wa are used instead, I will get both of them (in the same message, not twice).

Is anyone

Answer 1

setRawMode(), rawDataReceived (not lineReceived). , rawDataReceived, , , pickle , .

( netstring), pickle, .

self.sendLine(pickle.dumps({"size":filesize, 'content': contents[:20]}))