Mailman 3 August 2003 - Twisted

[Twisted-Python] Event Driven Programming 101 question
by Steve Freitas Aug. 2, 2003

Aug. 2, 2003

Hi all, I've got a few questions about Deferreds. I understand the concept better, but I need a little help at the moment. It's apparent to me that a lot's going on behind the scenes between Deferreds and the Reactor, and that twisted.enterprise orchestrates things in a way I don't yet understand. I'm looking at this from the perspective of my little XML-RPC server. A client hits a XML-RPC function, and by the time that function returns its value, it needs all its Deferreds to have … [View More]

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[Twisted-Python] StepReactor?
by Nicola Larosa Aug. 2, 2003

Aug. 2, 2003

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 What about a StepReactor? It would be great to be able to stop time, have a means to look at the event queue and to say "DispatchNextEvent" by hand. Or even better, "PushTimeForward(x)" and see what happens. In short, a simulator. This assuming, of course, that all other parts of the system are pausable, be they internal or external. - -- "It seems like Zope has done a dance with Twisted but still hasn't asked it out on a date." Paul Everitt … [View More]

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[Twisted-Python] Docs...
by Micah Yoder Aug. 1, 2003

Aug. 1, 2003

Hi, I know it has been mentioned before that more/better docs would be nice. Can I suggest a doc like "twisted.web for PHP developers" with lots of examples including stuff like sessions and database access? I would actually be willing to help with such a manual, but I'm still trying to understand much of this stuff myself. :) I am currently working on my first twisted.web app. I'm getting there, but the docs still leave some questions. If a few others would find this useful and have … [View More]

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Re: [Twisted-Python] twisted and wxPython 2.4.1.2
by Michael Porter Aug. 1, 2003

Aug. 1, 2003

From: "Itamar Shtull-Trauring" <itamar(a)itamarst.org> > On Fri, 1 Aug 2003 13:05:04 +0100 > "Michael Porter" <mporter(a)despammed.com> wrote: > > > If I change the demo to run with reactor.run(installSignalHandlers=0) > > it works fine, but I'd prefer to have this enabled. > > > > The problem occurs with Python 2.2 or 2.3 with this version of > > wxPython but it didn't occur with wxPython 2.3.2.1. > > As far as we can tell this is a … [View More]

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Re: [Twisted-Python] Win32 Service
by Justin Johnson Aug. 1, 2003

Aug. 1, 2003

I'm not using twistd, but I did get my xmlrpc service written in twisted to run as a service using the attached file. -Justin On Fri, 1 Aug 2003 18:20:14 +1000, screwtape(a)froup.com said: > On Thu, Jul 31, 2003 at 07:05:09AM -0700, Mike Owens wrote: > > I am currently running twisted on an XP machine. What is the > > recommended way of running twistd as a service? Or should I just > > create a custom web script and run that as a service? > > I don't believe … [View More]

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[Twisted-Python] kill a twisted server on Windows
by RITA Y/O RODRIGO DIAZ Y/O BENENSON Aug. 1, 2003

Aug. 1, 2003

Hi, How do I write at basch command on Window equivalent to the *nix shell command kill `cat twistd.pid` ? Thanks. RodrigoB.

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[Twisted-Python] Re: Re: PB - detecting loss of connection
by Richard.Townsend＠edl.uk.eds.com Aug. 1, 2003

Aug. 1, 2003

> aReferenceable.broker.notifyOnDisconnect(f) > f() will now be called on disconnect, aReferenceable the result of > getObjectAt() or any call that returns a RemoteReference. Thanks, Itamar - that's just what I wanted. -Richard

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[Twisted-Python] Callbacks, Looping, and Variable Binding
by Justin Johnson Aug. 1, 2003

Aug. 1, 2003

When I run the following code, everytime the callbacks to "onSuccess" get called, "item" is bound to the last element in "list". Obviously what I want is to have "item" bound to the value it had when I added the callback. How does one handle looping constructs like this in Twisted? def someFunc(): deferreds = [] def onSuccess(results): d = item.doSomethingElseThatReturnsDeferred() return d d = doSomethingThatReturnsDeferred() for item in list: d.… [View More]

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[Twisted-Python] Considering Twisted for OfflineIMAP
by John Goerzen Aug. 1, 2003

Aug. 1, 2003

Hello, I am the author of OfflineIMAP, a multi-threaded multi-account bi-directional synchronization tool (http://quux.org/devel/offlineimap) written in Python. I am running up against several limitations of the current way I'm doing things. They include: 1. Lack of thread groups in Python, meaning that if there was a network error synchronizing account A, I'd also have to kill off the entire application and the synchronizing threads for account B -- I couldn't just kill of account … [View More]A. 2. Various bugs in Python's threading implementation 3. imaplib.py being a stinking festering heap of crap leading to unmaintainable code in everything that touches it My first plan was to just rewrite imaplib, which wouldn't be too hard. But someone on the OfflineIMAP list pointed me to Twisted, which I observe already contains an IMAP library that looks nice, plus a different paradigm that may spare me from the whole thread groups question altogether. My questions, then, are these: 1. How does Twisted interact with things like threads and connection pooling? I currently let the user control the maximum number of connections that are open to a given server, and whenever the code needs to access an IMAP server, it grabs a connection from the appropriate pool and uses it (using threading primitives to block if no connection is available.) Can Twisted handle multiple connections to multiple servers doing multiple things at once? Can it do connection pools? If it needs threading to do these things, does it play nice with it? 3. I notice the "Deferred" object and the benefits it provides when a server response is expected to take some time. I assume that some sort of internal threading is taking place here? What if the server *request* takes some time -- say, uploading a 2MB e-mail over a dialup link. Are we still OK with handling that in a non-blocking fashion? 4. The howto "book" alludes to pending improvements on the mail infrastructure. Anything I should be aware of here? 5. Is there any sort of unified mail API in Twisted (like JavaMail) that would present me with a single API to both IMAP and Maildir repositories, or is that something I need to do on my own? (I've already done it, so it's no big deal to do that again) 6. OfflineIMAP supports several different user interfaces (two written with Tkinter, 1 using Curses, and three plain console ones.) I would like to reimplement the Tkinter ones with wxPython, and am glad to see that Twisted works well with this. One concern, though, is that the users can supply a list of UIs to try in the config file: for instance, Tk, Curses, Noninteractive. The system will try each one in turn until it reaches one that works. (For instance, Tk may not work if the user is not in X, and Curses may not work if stdout is not a tty). It looks like this may be problematic with Twisted since the UI selection always seems to be known in advance with the import commands related to the reactor. Any thoughts here? Thanks! -- John Goerzen [View Less]

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[Twisted-Python] Win32 Service
by Mike Owens Aug. 1, 2003

Aug. 1, 2003

I am currently running twisted on an XP machine. What is the recommended way of running twistd as a service? Or should I just create a custom web script and run that as a service?

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