Mailman 3 November 2009 - Twisted

[Twisted-Python] twisted.web.server sessions
by vitaly＠synapticvision.com 21 Nov '09

21 Nov '09

hi, is the re any convenient way to get from twisted.web.server all non expired sessions in one single call? Regards, Vitaly.

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[Twisted-Python] TwistedGateway instead of TwistedChannelSet
by vitaly＠synapticvision.com 20 Nov '09

20 Nov '09

hi guys, how the following example could be re-created using TwistedGateway, reactor.listenSSL and reactor.run instead of TwistedChannel? Appreciate the help. # ------------------------------------------ import logging import sys from twisted.application import service, strports from twisted.web import static, server, resource, vhost import amfast from amfast.remoting.twisted_channel import TwistedChannelSet, TwistedChannel amfast.log_debug = True handler = logging.StreamHandler(sys.stdout) handler.setLevel(logging.DEBUG) amfast.logger.addHandler(handler) # Setup domain root = vhost.NameVirtualHost() root.default = static.File("../flex/deploy") domain = "localhost" root.addHost(domain, static.File("../flex/deploy")) # If the code is completely asynchronous, # you can use the dummy_threading module # to avoid RLock overhead. import dummy_threading amfast.mutex_cls = dummy_threading.RLock # Setup ChannelSet channel_set = TwistedChannelSet(notify_connections=True) # Clients connect every x seconds # to polling channels to check for messages. # If messages are available, they are # returned to the client. polling_channel = TwistedChannel('amf-polling-channel') channel_set.mapChannel(polling_channel) # Long-poll channels do not return # a response to the client until # a message is available, or channel.max_interval # is reached. long_poll_channel = TwistedChannel('long-poll-channel', wait_interval=90) channel_set.mapChannel(long_poll_channel) # Setup channels root.putChild('amf', polling_channel) root.putChild('longPoll', long_poll_channel) # Setup server port = 8000 application = service.Application('AmFast Example') server = strports.service('tcp:%s' % port, server.Site(root)) server.setServiceParent(application) print "serving on %s:%s" % (domain, port) print "Press ctrl-c to halt."

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[Twisted-Python] Grabbing HTTP Headers with twisted.web.soap.SOAPPublisher
by Cole Tuininga 19 Nov '09

19 Nov '09

Hopefully quick question. Is there an existing way to easily get at the HTTP headers in an incoming SOAP request being handled by twisted.web.soap.SOAPPublisher? Or do I need to override the render method to keep/return it? Thanks in advance... -- Cole Tuininga http://www.tuininga.org/

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[Twisted-Python] long-polling channels with Twisted
by vitaly＠synapticvision.com 19 Nov '09

19 Nov '09

hi, is there any example how to implement long-polling channel with Twisted while using reactor()? Thank you.

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[Twisted-Python] Passing messages from HTTP Request to another factory or protocol
by Don Schoeman 18 Nov '09

18 Nov '09

Hi guys, I am busy developing a gateway of some sort and have the following running so far on the reactor: - HTTP Server listening for incoming connections and HTTP requests. - LineReceiver client permanently connected to another server. (Connection is established at startup) What I need to do is to first translate and then pass messages received at the HTTP listening end - over to the LineReceiver client. The client in turn will pass it on to a server using a custom protocol called SSMI, for example: Web Browser Requests -> HTTPServer -> SSMIClient -> ServerXYZ For the HTTPServer I'm using the classic design where you inherit from twisted.web.http.Request for the Protocol, while having twisted.web.http.HTTPChannel and twisted.web.http.HTTPFactory inherited classes to support it. Also, there will only ever be one SSMIClient protocol instance whereas the HTTPServer needs to process multiple requests at a time, so it will be a many-to-one design. What I need to know is how to pass the "packets" received by the HTTPServer onto the SSMIClient protocol..? I am assuming one would use deferreds, but the twisted.web.http.Request derived class seemingly does not have "access" to the Reactor or it's Factory object. But to be honest, I'm a little in over my head on this and don't even know how to approach this. I don't know whether I should use a FIFO queue to store the messages and I don't even know where to keep such a queue. If anyone have done something even remotely like this I'd love to get some input from you. It will be greatly appreciated! Kind Regards, Don Schoeman

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[Twisted-Python] Farming off work to other web services
by Ted Pederson 18 Nov '09

18 Nov '09

How can my server utilize other web services? Is there part of the framework to do this, or should I just write a mini-client? Basically, I want to use a very simple web service, a url with a couple of params, and I get back xml or json data. Sorry for fundamental nature of this question. Perhaps I should be redirected to a book or docs, but the docs are pretty large and I am just getting my feet wet.

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[Twisted-Python] A non-blocking socket operation could not be completed immediately
by Tommaso Mazzafico 18 Nov '09

18 Nov '09

I tried this code: ----------------------------------------- from twisted.spread import pb from twisted.internet import reactor class Echoer(pb.Root): def remote_echo(self, s): return s if __name__ == "__main__": reactor.listenTCP(8001, pb.PBServerFactory(Echoer())) reactor.run() ----------------------------------------- On Windows XP all is ok. On Windows 7 64 I receive this error message: ----------------------------------------- C:\Program Files (x86)\Python\lib\site-packages\twisted\spread\pb.py:30: DeprecationWarning: the md5 module is deprecated; use hashlib instead import md5 Traceback (most recent call last): File "C:\Users\bob\Documents\Twisted\pbs.py", line 11, in <module> reactor.listenTCP(8001, pb.PBServerFactory(Echoer())) File "C:\Program Files (x86)\Python\lib\site-packages\twisted\internet\posixbase.py", line 356, in listenTCP p.startListening() File "C:\Program Files (x86)\Python\lib\site-packages\twisted\internet\tcp.py", line 862, in startListening self._realPortNumber = skt.getsockname()[1] File "<string>", line 1, in getsockname socket.error: [Errno 10035] A non-blocking socket operation could not be completed immediately ----------------------------------------- What can I do?

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[Twisted-Python] server push data to client
by vitaly＠synapticvision.com 18 Nov '09

18 Nov '09

hi, what could be the way(Producer/Consumer?) and simple,basic example to push data(~10Kb) from Twisted based server(that listening for incoming requests) into client side(for example FLEX) not as a response to the incoming request, but occasionally, triggered by server side??? In traditional client/server arch, the server is listening, accepting and responding to the client's requests, but here I'm looking for something that initiated from server itself and pushing data to client. Appreciate the help.

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[Twisted-Python] Proposal (almost) to switch from Lore to Sphinx
by Kevin Horn 18 Nov '09

18 Nov '09

Back in July, there was a long discussion thread regarding Twisted Documentation, and the idea of switching to Sphinx came up. Here's probably the culmination of that thread: http://twistedmatrix.com/pipermail/twisted-python/2009-July/020114.html To summarize, Glyph laid out the following items that would need to happen in order for Twisted to move from Lore to another documentation system: 1. Someone would have to volunteer to maintain the documentation infrastructure and teach others to use it. 2. Submit a complete proposal outlining benefits for the move so that it could be discussed rationally without having to chase down lots of little bits in email, irc, etc. 3. Address the transition process. So I went away and did some thinking, and some research and some experimenting, and I decided that I really want this to happen. So I am hereby volunteering to manage a Sphinx-based documentation infrastructure (should there eventually be one) for the Twisted project as well as the transition to said system. I have written up a proposal here: http://twistedsphinx.funsize.net/proposal.html that I think addresses at least the main points of what should need to happen in order to move from Lore to Sphinx. It's not quite finished, but I think it's close enough for people to start discussing it. In particular, there are a few claims I've made about Lore and it's capabilities that I'm not quite sure of (just search for the question marks). I would very much like to get some feedback from the community (especially the core developers) on this proposal. I'd especially like to hear about: - things which are not addressed and should be. - anything that is addressed in the proposal, but you think should be done in a different way. - Lore's capabilities. Please let me know what you think. Thanks, Kevin Horn

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[Twisted-Python] pb, viewable, avatars: The example chatserver is buggy
by Wolfgang Rohdewald 18 Nov '09

18 Nov '09

I tried this example: http://twistedmatrix.com/projects/core/documentation/howto/pb-cred.html#aut… (scripts chatserver.py and chatclient.py) but they do not work with python 2.6.4 (twisted 8.2.0). Before the client can do much, the server function User.detached is called resulting in an exception later when User.send is called but self.remote is None. I can fix this by changing chatclient.py: def connected(self, perspective): self.perspective = perspective ... and continue as in the original script it seems that otherwise the perspective is destroyed too early. also the documentation should perhaps mention that the client can only connect to the server once because the server code does not remove a user from her group when she detaches. Is there any more complete example anywhere with better error handling? -- Wolfgang

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Twisted November 2009