Mailman 3 August 2007 - Twisted

[Twisted-Python] Twisted Python 0.7.0 Prerelease Testing
by Glyph Lefkowitz 05 Aug '21

05 Aug '21

hi there, folks: I'd really like to release 0.7.0 but I would like it to be at least a little bit tested before I do so. Could those of you with CVS trees check everything out and see if it performs as advertised? Deeper bugs than that will have to wait for the next release, but I'd at least like to know if it works for someone other than me. Thanks. ______ __ __ _____ _ _ | ____ | \_/ |_____] |_____| |_____| |_____ | | | | @ t w i s t e d m a t r i x . c o m http://www.twistedmatrix.com/~glyph/

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[Twisted-Python] Get IP of connecting client in XMLRPC server
by Remy C. Cool 28 Apr '13

28 Apr '13

Hello, On 18 May 2004, the following message was posted to this mailinglist: Jp Calderone exarkun at divmod.com wrote: >Daniel Newton wrote: > > I have a simple XML-PRC server similar to the example below: > > from twisted.web import xmlrpc, server > > class Example(xmlrpc.XMLRPC): > """An example object to be published.""" > > def xmlrpc_add(self, a, b): > """Return sum of arguments.""" > return a + b def xmlrpc_whatIsMyAddress(self): return self.transport.getPeer().host > > if __name__ == '__main__': > from twisted.internet import reactor > r = Example() > reactor.listenTCP(7080, server.Site(r)) > reactor.run() > > I want to be able to get the address of the client that calls the xmlrpc > method can anyone help me with this? This solution didn't work because 'transport' isn't a property of the Example class. I'm currently in the process of changing from a customized SimpleXMLRPCServer to a twisted XMLRPC server solution and I need to insert the client IP into the attributes passed to the called xmlrpc method. Anyone who knows the answer and is willing to share the info? Regards, Remy

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[Twisted-Python] Reconnecting PB Client
by Don Smith 12 Sep '07

12 Sep '07

Does anyone have some example code for building a reconnecting PB client? This is what I have now: from twisted.spread import pb from twisted.internet import reactor from twisted.python import util events = pb.PBClientFactory() reactor.connectTCP("localhost", 8789, events) queue = events.getRootObject()

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[Twisted-Python] Win32 IOCPReactor?
by Trent Nelson 04 Sep '07

04 Sep '07

I'm new to Twisted. Perusing the documentation, I came across IOCPReactor. It's marked as 'extremely experimental', and it appears it only provides support for TCP events. It seems the last check in to anything IOCPReactor-related was back in 2005. Is it dead? Is anyone using it? Is anyone planning to pick development back up? Were there specific issues with IOCP that impeded development, or just a general lack of people with time, inclination, or Win32-fu? Assuming the IOCPReactor's not feasible for high load production deployment, can anyone comment on how the default select()-based reactor for Win32 fares under high load? Trent.

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[Twisted-Python] Media Resource Control Protocol (MRCP)
by Ivan Uemlianin 04 Sep '07

04 Sep '07

Dear All I am interested in writing an MRCP (Media Resource Control Protocol [1]) server. In particular I want to write an MRCP speech recognition resource server as part of my trefnydd [2] project. I am posting here to ask for advice about the network programming part. I shall also be writing an MRCP client (if only to test the server). All the code will be GPL'd. As far as I understand it, an overview of the networking would go like this: An MRCP session between client and server is initiated using the Session Initiation Protocol (SIP). Client and server negotiate using SIP messages containing SDP message bodies to define the participants and the resources required in the session. After session initiation, two channels are launched: a media channel using RTP to carry binary audio (i.e., speech) data, and a control channel using TCP (control channel messages are text-based and in MRCP format). It seems to me that both client and server software would have to cope with SIP, SDP, RTP, MRCP (message format) and plain old TCP (for the SIP/SDP and MRCP control channel messages). Here are my questions: - Does anyone know of a FOSS project to write an MRCP server? preferably in python. I know of mrcp4j [3]. - My first plan would be to make the MRCP client/server a subclass of an SIP client/server, as SIP is used to set up (and tear down) the session. Does that sound sensible? - Can twisted.protocols.sip be used to write a SIP server? Would it give me everything I need, or would I also need something like pjsip [4] or jain-sip [5] for the low-level stuff? - Have I missed anything? Any advice would be gratefully received. I'll report back with progress. Best wishes Ivan [1] MRCP: http://www.llaisdy.com/static/tech/mrcp/ [2] trefnydd: http://www.llaisdy.com/static/trefnydd/ [3] mrcp4j: "MRCP4J provides a Java API that encapsulates the MRCPv2 protocol and can be used to implement MRCPv2 clients and/or servers." http://mrcp4j.sourceforge.net/ [4] pjsip: http://www.pjsip.org/ [5] jain-sip: https://jain-sip.dev.java.net/

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[Twisted-Python] Possible to delay connectTCP?
by Beau Hargis 31 Aug '07

31 Aug '07

I have an application which connects to a machine which has 50-60 ports open on it to receive data (each for a different region). It acts like a switch. Problem is that when I make all those connection requests at the same time the server falls over trying to handle all the connections requests from my application. I cannot control or change the behaviour of the server I am connecting to, however, I am also unable to find a way to easily to add a delay between connection requests in twisted (without blocking the reactor), so that only 2 or 3 start up at a time. Is there an elegant and clean way to do such a thing? Twisted has worked beautifully for everything else, but I can't replace this one server for a while until I can duplicate the rest of its functionality, so I am dependant on it providing the data.

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[Twisted-Python] SSL: Getting the client certificate
by Dirk Loss 30 Aug '07

30 Aug '07

Hi, following Eli Criffields nice example [1] I implemented a small SSL server with Twisted. My server should not only verify the client certificate, but also check the Common Name (CN) against a whitelist. All this should happen before any user data is exchanged. Verifying the client certificate worked nicely, but I couldn't access its contents: transport.getPeerCertificate() always returned 'None'. Apparently Eli had the same problem [2]. After some testing with PyOpenSSL now I think I have found a solution: Before we can get the client certificate, we have to make sure that the SSL handshake has taken place. (If it hasn't, there simply is no client certificate to deal with yet.) This can be done by calling the do_handshake() method of the underlying socket. The SSL handshake takes some time so we will have to try several times. Here's an (incomplete) example showing the interesting part: - - cut --- import OpenSSL class MyProtocol(Protocol): def connectionMade(self): # Make sure that SSL handshake has taken place while True: try: self.transport.socket.do_handshake() break except OpenSSL.SSL.WantReadError: pass clientCert = self.transport.getPeerCertificate() if clientCert is None: log.msg("No client cert available.") else: subject = clientCert.get_subject() log.msg("Subject: %s" % subject) log.msg("Common Name: %s" % subject.CN) - - cut --- If you see a nicer way to wait for the SSL handshake please let me know. Using time.sleep() didn't work for me. Side note: Getting the certificate in a dataReceived() instead of connectionMade() works without manually doing the handshake. I think this is because the underlying PyOpenSSL recv() method handles the handshake for us. But at least for my purpose it makes more sense to verify the client cert right upon connection, before any user data is exchanged. Regards, Dirk [1] http://archives.free.net.ph/message/20070511.203607.36001e38.en.html [2] http://archives.free.net.ph/message/20070607.211438.9354342f.en.html

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[Twisted-Python] deferToThread crashing on Windows, stable on Linux
by Allen Bierbaum 30 Aug '07

30 Aug '07

I have run into an interesting little bug and before I try to hunt it down further I wanted to check and see if anyone else has seen anything similar. I have a fairly complex twisted 2.5 application that uses deferToThread to spawn off worker threads that need to call some blocking non-twisted code (query webserver, query database, etc). The application uses these workers quite a bit but there are normally never more then 2 or 3 outstanding requests running. The application runs rock-solid on Linux, but it crashes in less then a minute on Windows. Has anyone else seen anything like this? Are there any known issues of deferToThread being less stable on Windows then Linux or are their any differences between how twisted works on the platforms that I should be looking into? -Allen

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[Twisted-Python] AsynQueue
by Vitaliyi 30 Aug '07

30 Aug '07

Good Day Does someone have an idea how to use AQ remotely with PB ? I was unable to find any documentation and stuck in trying to make it work as expected. Thanks

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[Twisted-Python] matching ip ranges
by Alec Matusis 29 Aug '07

29 Aug '07

We need to match IP ranges of connections, were ranges are specified in the "/" notation (e.g. 10.10.2.0/24) What is the best way to do this without consuming too much CPU resources when the connection rate is very high?

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Twisted August 2007