Mailman 3 May 2003 - Twisted

[Twisted-Python] Need advice on changing blocking calls to be Twisted-aware...
by Stuart Hungerford 20 May '03

20 May '03

Hi all, I'm running a web application which makes use of the excellent Twisted.Web resource framework with customized .getChild() and .render() calls. In one of the resource .render() methods I've reached a point where the method needs some information on from the system via an os.popen2() call. This information is needed to be turned into HTML, and the HTML generation can't proceed without it. What I'm effectively doing in the render() call is: def render(...) ...generate some HTML do blocking system call ...generate some more HTML Which I understand is a no-no in the reactor and callback based Twisted framework. I believe that the Twisted way to do this is with a reactor.spawnProcess() call which in turn returns a Deferred object. Or maybe I should be using threads instead? Can someone point me to some example code where a blocking-system-call-and-it's-results-needed-here pattern is expressed in the spawnProcess/Deferred/callback world of Twisted? Cheers, Stu -- :: Stuart Hungerford (stuart.hungerford(a)anu.edu.au) :: ANU Internet Futures Group

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[Twisted-Python] Twisted and SQL-Ledger
by pobrien＠orbtech.com 19 May '03

19 May '03

I'm going to be creating a Twisted Woven/Enterprise interface for SQL-Ledger, an Open Source accounting package that uses PostgreSQL and a Perl web interface. Is anyone else interested in such a thing? SQL-Ledger: http://www.sql-ledger.org/ -- Patrick K. O'Brien Orbtech http://www.orbtech.com/web/pobrien ----------------------------------------------- "Your source for Python programming expertise." -----------------------------------------------

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[Twisted-Python] splitting log file
by Philippe Lafoucrière 19 May '03

19 May '03

Hello I've made a server using PB and woven (both are running in main server). When I do some very long calculations, the log file is splitted in several parts (977K). Moreover, web log is mixed with PB log, which hard to debug. Is there a way to correct these two problems ? thx Philippe

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[Twisted-Python] Interrupted system call in Twisted.Web...
by Stuart Hungerford 19 May '03

19 May '03

Hi all, My application is happily using Twisted.Web for a web interface to a set of resources. At one point I'm doing an os.popen2() call to find some details on a particular resource. For now at least using the popen2() call is the only way I can get this information. Occasionally I'm getting an "Interrupted system call" Python exception from this call. I'd guess that os.popen2() is not especially friendly to an asynchronous processing model like that used in Twisted? Could someone point me toward a more Twisted-aware approach than using os.popen2()? Cheers, Stu -- :: Stuart Hungerford (stuart.hungerford(a)anu.edu.au) :: ANU Internet Futures Group

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[Twisted-Python] protocols.smtp patch
by matiu 18 May '03

18 May '03

protocols.smtp client creates a temp file for every email it sends on my windows box. Apply this patch to stop that. Matthew Sherborne

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[Twisted-Python] web brokage
by Tommi Virtanen 18 May '03

18 May '03

<Tv> tm.com/documents/howto/ has "Form in Depth" and "Guard in Depth" repeated. <Tv> And the two lore docs have the same link text. <liiwi> |mail webmonkey(a)tm.com <Tv> Is that a real address? <liiwi> try :) I didn't. -- :(){ :|:&};:

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[Twisted-Python] [PATCH] remove and index for world's StorableList
by jml＠ids.org.au 17 May '03

17 May '03

Hi guys, I need these methods. They're untested but they look right-ish. cheers, jml Index: twisted/world/compound.py =================================================================== RCS file: /cvs/Twisted/twisted/world/compound.py,v retrieving revision 1.6 diff -u -r1.6 compound.py --- twisted/world/compound.py 16 May 2003 05:00:28 -0000 1.6 +++ twisted/world/compound.py 17 May 2003 09:47:44 -0000 @@ -227,6 +227,16 @@ l.sort() self[:] = l + def index(self, x): + for i in range(len(self)): + if x == self[i]: + return i + raise ValueError, "StorableList.index(x): x not in list" + + def remove(self, x): + del self[self.index(x)] + + class _Nothing: """ this can stop torg

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[Twisted-Python] Named Pipes
by Wari Wahab 17 May '03

17 May '03

Hi, is there a way to get twisted to listen to a named pipe like it's a TCP connection or something? How would I go about it? What I wanted goes like this, there's a named piped, and syslog or other programs can send one line alerts (or multiline as well), and my app is supposed to do something with this data while attending to other stuff as well. We have a perl program that does this using select(), and I bet this can be done with twisted. But I don't see a named pipe implementation in the twisted docs. I'm sure there's a way. -- Regards: Wari Wahab RoughingIT - http://roughingit.subtlehints.net PyBlosxom - http://roughingit.subtlehints.net/pyblosxom

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[Twisted-Python] twisted.web.woven.guard.SessionWrapper problems
by Matthias Urlichs 16 May '03

16 May '03

I was experimenting with twisted.web.woven.guard yesterday and ran into a problem. Some browsers, including wget, don't like _at_all_ when you have a cycle in your redirections, even though they should notice that they now have a cookie while formerly they didn't. Therefore I propose to rewrite the SessionWrapper to always change the user's path, like this (the string "sp" is self.cookieKey): /sessionized-url/foo Set cookie Redirect to /sessionized-url/sp__aef9c34aecc3d9148/foo /sessionized-url/sp__aef9c34aecc3d9148/foo Redirect to either of the next two URLs depending on whether I see a cookie /sessionized-url/sp/foo URL to use with cookies /sessionized-url/sp_aef9c34aecc3d9148/foo URL to use without cookies Finally, /sessionized-url/sp/foo, but no cookie, would do class SessionWrapper(...): def __init__(..., on_timeout=None): ... self.prefix=prefix self.timed_out = timed_out def getChild(...): if (path == self.prefix and not self.sessions.has_key(cookie): return self.on_timeout(path,request) so that access with no session can be distinguished from a plain link into /sessionized-url/foo; the latter means the user might want to log in, but the former should tell the user that their session has timed out before offering the login page. An additional advantage of this scheme would be that .../unsessionized-url/ can be reaced with a constant number of backpaths. Oh yes, and I'd like to make http://somewhere.example/sessionized-url and (i.e. no paths) work. At the moment that causes an ugly error because SessionWrapper doesn't override render(). Thoughts? Or is somebody else going to rewrite this module next week anyway and I therefore probably shouldn't bother? -- Matthias Urlichs | {M:U} IT Consulting @ m-u-it.de | smurf(a)smurf.noris.de Disclaimer: The quote was selected randomly. Really. | http://smurf.noris.de -- Van Roy's Law: An unbreakable toy is useful for breaking other toys.

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[Twisted-Python] Problem creating working .tap file
by Uwe C. Schroeder 16 May '03

16 May '03

Hi, something strange shows up here. I try to create a TAP from a pb application. The tap is created nicely, but I get an error when starting it: Failed to load application: <twisted.persisted.styles.Ephemeral instance at 0x82450a4> is not safe for unpickling So I tried a simple application and took the echoer from the manual. from twisted.spread import pb from twisted.internet import app class Echoer(pb.Root): def remote_echo(self,st): print "echo: ",st return st appl=app.Application("echo") appl.listenTCP(8888,pb.BrokerFactory(Echoer())) appl.save("start") Funny thing is, this generates the same error when I try to start it. I'm using 1.0.5 on mandrake 9.1 Any hints would be appreciated. UC -- Open Source Solutions 4U, LLC 2570 Fleetwood Drive Phone: +1 650 872 2425 San Bruno, CA 94066 Cell: +1 650 302 2405 United States Fax: +1 650 872 2417

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