Mailman 3 March 2008 - Twisted

[Twisted-Python] Twisted Python 0.7.0 Prerelease Testing
by Glyph Lefkowitz 06 Aug '21

06 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] regarding xml elements
by Raj kumar 02 Oct '13

02 Oct '13

Hi, I have an xml file in my application, I have created an element using Example goes like this......... document.createElement("abc") and i appeneded it by using append() method. But how i can reflect this change to my xml file? and one more thing is i want to create element with some other parameters.... like............. <abc m=" " n=" "> </abc> and i have m and n values as strings with me. can anybody help me to create this element and write it to the existing xml file as a child of an existing element? Thanks in advance.. Raj.. Forgot the famous last words? Access your message archive online at http://in.messenger.yahoo.com/webmessengerpromo.php

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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] Is psycopg or pygresql better with twisted.enterprise?
by Nathan 14 Apr '08

14 Apr '08

Is there any noticeable difference between psycopg (version 2) or pygresql (version 3.8.1) when used with twisted.enterprise to connect to postgresql? Pygresql hasn't been updated since June 2006, but maybe that's just because it's stable (?) -- I haven't used it at all, ever. Psycopg2 has had more recent releases, but I've experience some bugs with it in (non-twisted) threaded code and the web site has been down for weeks (months?), so I thought it wise to explore alternatives... Or is there a better third alternative??? Also, we're considering turning on SSL client-certificate verification on our postgresql installation -- does anyone know whether either of the above support SSL client certificates? Opinions? ~ Nathan

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[Twisted-Python] win32 reactors
by James Mansion 07 Apr '08

07 Apr '08

I'm just starting to evaluate Twisted, so apologies if these questions seem naive. It seems to me that the Twisted model for 'reactor' is actually not what you'd expect from the name (at least, if you have a background in other reactor implementations including ACE, basic select etc and Java NIO) since it a) handles queueing outgoing data for you and b) presents incoming data after completion of the IO So its a model that maps well to an AIO implementation so long as inputs from non-blocking sources complete as soon as "some" data is ready, rather than buffer full. This high level approachh should work well on Windows - which is really pleasing. (Albeit there may be buffer starvation issues on all platforms I guess, but that's probably scaled beyond Python ambitions) A quick look at the open bug list shows a lot of noise on the Win32 side though. Is there any reason to have any framework that calls the Win32 select function? And why is the event reactor broken at 64 handles? From what I can see, that's not how to use WaitForMultipleEvents - rather one should regard it as a way to hash completion events from standard overlapped IO requests against 61 of the handles and keep a list of the IOs in progress against each handle. Scales admirably, unlike any attempt to treat the handle array like a select fd_set. Shouldn't broken Win32 implementations be 'retired'? Also - is there any way to determine how much data is queued for write against an ITransport? It appears not, though I would have thought it useful (and, a way to get an event callback when the queued amount falls below a specified threshold) - then in cases where data can be generated on demand we can limit the outgoing buffer usage. James

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[Twisted-Python] Other ways to integrate foreign event loops?
by Nathan 04 Apr '08

04 Apr '08

Is there a way to do the opposite of task.coiterate? I'm using pyglet for my UI, which was working great until I upgraded from pyglet 1.0 to 1.1. Now for some reason, the pyglet performance tanked. Since I'm only using twisted to send AMP messages very rarely (on the order of one every few seconds), it seems like I could try to work around the problem by giving pyglet back control of the main loop and occasionally giving twisted some time to breath (occasionally like every 50ms or something). Can that be done? Here's what I'm doing _now_ that technically works, but pyglet 1.1 is really choking on: > class MyWindow(pyglet.window.Window): > def run(self): > while not self.has_exit: > do_some_stuff_like_dispatching_updating_and_drawing() > yield 1 > > my_window = MyWindow() > task.coiterate(my_window.run()) > reactor.run() By the way, the preferred method for the runloop on pyglet 1.1 is to use a builtin one like so: > window = pyglet.window.Window() > > @window.event > def on_draw(): > window.clear() > do_drawing_stuff() > > pyglet.app.run() So if twisted can stand giving up it's run loop, I could periodically call it from that "on_draw()" method. ~ Nathan

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[Twisted-Python] win 32 reactor
by Gabriel Rossetti 01 Apr '08

01 Apr '08

Hello, I need to use PyHook, a win32 lib allowing global input monitoring (mouse, keyboard, etc). It uses the PyWin32 extentions, in particular win32com's PumpMessages() function. This is an event loop defined like so : // @pymethod |pythoncom|PumpMessages|Pumps all messages for the current thread until a WM_QUIT message. static PyObject *pythoncom_PumpMessages(PyObject *self, PyObject *args) { MSG msg; int rc; Py_BEGIN_ALLOW_THREADS while ((rc=GetMessage(&msg, 0, 0, 0))==1) { TranslateMessage(&msg); // needed? DispatchMessage(&msg); } Py_END_ALLOW_THREADS if (rc==-1) return PyWin_SetAPIError("GetMessage"); Py_INCREF(Py_None); return Py_None; } my question is ho can I make this work with twisted? Is there a way to use the supplied win32 reactors (there are three I think) or do I have to write one myself? Could someone please point me in the right direction? Thanks, Gabriel

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[Twisted-Python] Correct way to handle errors of connectTCP
by Simon Pickles 01 Apr '08

01 Apr '08

Hi, I expected reactor.connectTCP to return a deferred. That would have been nice, since callbacks would have handled the outcome. So how to I handle failure with it? I tried: from twisted.internet.error import ConnectionRefusedError print "Connecting..." try: reactor.connectTCP(self.server, self.port, self.f) except ConnectionRefusedError(reason): self.Connect_Failure() return self.Connect_Success() No good. What am I missing? Thank you! Simon -- Linux user #458601 - http://counter.li.org.

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[Twisted-Python] Deferred Network requests
by Simon Pickles 31 Mar '08

31 Mar '08

Hi, I've been using twisted in a low-level way for some time and am now interested in the higher level aspects. Particularly I hope to be able to make deferred requests across a network. I'd like to have a hub server, with many small apps (modules) which are all clients of the hub server. I'd like the modules to be able to request information from each other, via the hub, in a deferred way, so the callback will be triggered when the requested information arrives. So I need a chain like this: ModuleA.RequestName(id).addCallback(modACallback) -> Hub Hub.RequestName(id).addCallback(hubCallback)-> ModuleB ModuleB.SendNameToHub() -> Hub Hub.hubCallback triggered: SendNameToModA() -> ModuleA ModuleA.modACallback triggered - request is complete. Perhaps one issue is that I have a client->server->client sequence. Although it looks slow, I am designing my system to be as concurrent as possible. Also, the hub can make decisions about sharing requests with several modules on a round-robin, or sending requests (and events, particularly) to more than one module. I know I can do this through TCP or similar, but hoped someone might suggest which elements of twisted (a very large framework) I should look at more closely. Many thanks! Simon -- Linux user #458601 - http://counter.li.org.

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Re: [Twisted-Python] Perspective Broker vs AMP
by David Ripton 31 Mar '08

31 Mar '08

On 2008.03.31 09:00:40 +0100, Simon Pickles wrote: > As I understand PB, a client can get the root object of a > PBServerFactory, thru which it can call methods with the 'remote_' > prefix. I'm not clear how this can work in the other direction. The mind argument to Realm.requestAvatar holds a reference to the client object that the client passed to PBClientFactory.login You can stash that reference somewhere on the server side, and call callRemote on it later. http://twistedmatrix.com/projects/core/documentation/howto/cred.html > As for > AMP, this seems similar - the client uses callRemote() to execute remote > methods on the amp server. And the server can use callRemote on a client's protocol object. I have a simple AMP chat example that demonstrates this: http://ripton.net/hg/ampchat -- David Ripton dripton(a)ripton.net

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Twisted March 2008