Mailman 3 September 2003 - Twisted

[Twisted-Python] Re : executing .rpy in a thread
by Jerome Jushima 18 Sep '03

18 Sep '03

With the help of your hint I have come up with the following code. For simplicity's sake I don't use .rpys here since it shouldn't change the approach. What happens when I run this code and open the servers root in a webbrowser is that I get a page saying "NOT_DONE_YET." Also when I get rid of the quotation marks in the return statement it does not seem to work. Python just tells me that it does not know NOT_DONE_YET. I am also not coherent in my head of how to pass the request variable to my doLongPageGeneration function. Is it correct how I registered the callbacks? Thanks to all the twisted gurus, _stephan ---------------------------------------------------start from twisted.web import server, resource, static, script from twisted.internet import reactor from twisted.internet import threads def doLongPageGeneration(): return "<html><b>H</b>ello, <b>W</b>orld!</html>" class Simple(resource.Resource): isLeaf = True def render(self, request): d = threads.deferToThread(doLongPageGeneration) d.addCallback(request.write) d.addCallback(request.finish) return "NOT_DONE_YET" site = server.Site(Simple()) reactor.listenTCP(8080, site) reactor.run() ------------------------------------------------------end > The easiest way to run code in a thread and get the result back is with > twisted.internet.threads.deferToThread. Your Resource's render method > would need to return NOT_DONE_YET, and you'd need to add callbacks to > the Deferred from deferToThread that call request.write(...) and > request.finish(). >> Say I want to execute blocking code in a .rpy file. Can't I just >> execute all the code in a separate thread? I've found the following >> code to execute a function in a thread. How could I add a callback to >> that thread so I could get back the whole html page back from that >> "notthreadSafe" function and return it to the client >> (web browser)? -- +++ GMX - die erste Adresse für Mail, Message, More! +++ Getestet von Stiftung Warentest: GMX FreeMail (GUT), GMX ProMail (GUT) (Heft 9/03 - 23 e-mail-Tarife: 6 gut, 12 befriedigend, 5 ausreichend) Jetzt selbst kostenlos testen: http://www.gmx.net

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[Twisted-Python] Quotient Problems
by Justin Johnson 17 Sep '03

17 Sep '03

I'm not sure if Quotient questions should go to this list...? I installed the latest Quotient from CVS, including all its dependencies and Twisted itself from CVS. I got it installed on my RH9 Linux box and am running an instance of Quotient. I added an IMAP grabber, successfully I think, and now when I go to the Home page it says... Recent Items Nothing is new under the sun. Current Status myaddress@my.domain@myimap.host.com Initializing... (Note, I changed the address and host names above for this email.) It always says initializing whenever I return to this page. What does this mean? How do I get to my inbox? Thanks. -Justin

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[Twisted-Python] Perspective Broker in 1.0.7
by Itamar Shtull-Trauring 16 Sep '03

16 Sep '03

If you are using PB code, you will start getting deprecation warnings when you upgrade to 1.0.7. This is due to switching to: 1. A new connection API that doesn't suck. 2. New cred support. #1 is documented in the 1.0.7 Howtos. #2 isn't. You can however see examples of how to do #2 in CVS, specifically these two files: http://cvs.twistedmatrix.com/cvs/doc/examples/pbecho.py?rev=1.9&content-typ… http://cvs.twistedmatrix.com/cvs/doc/examples/pbechoclient.py?rev=1.10&cont… and compare them to doc/examples/pbecho(client).py in 1.0.7 or older CVS versions. Some of Twisted's internal code doesn't use this new API either. By 1.1 all docs, examples and code in Twisted will have switched to the new API. The old API will of course continue to be supported for some time, but it is recommended you switch as the new API is much cleaner and better designed. -- Itamar Shtull-Trauring http://itamarst.org/ Available for Python & Twisted consulting

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[Twisted-Python] Anti-Verisign DNS Filter.
by Andrew Bennetts 16 Sep '03

16 Sep '03

Robert Thomson, a workmate of mine, wrote this hack to filter DNS responses to thwart Verisign's stupid wildcard on root-level domains. It's simple but does the job. Enjoy. --- snip --- #!/usr/bin/python # # Run this as root with the command # twistd -y anti-verisign-dns.py from twisted.internet import app, defer from twisted.protocols import dns from twisted.names import client, server roots = [ ('198.41.0.4',53), ('128.9.0.107',53), ('192.33.4.12',53), ('128.8.10.90',53), ('192.203.230.10',53), ('192.5.5.241',53), ('192.112.36.4',53), ('128.63.2.53',53), ('192.36.148.17',53), ('192.58.128.30',53), ('193.0.14.129',53), ('198.32.64.12',53), ('202.12.27.33',53), ] #roots = [('202.129.64.42',53)] # just use my ISP's DNS VERISIGN='@^n\x0b' # 64.94.110.11 class AntiVerisignResolver(client.Resolver): def filterAnswers(self, message): if message.trunc: return self.queryTCP(message.queries).addCallback(self.filterAnswers) else: for i in range(len(message.answers)): x = message.answers[i] if x.type==1 and x.payload and x.payload.address==VERISIGN: message.answers[i] = None return (filter(lambda x:x,message.answers), message.authority, message.additional) verbosity = 0 resolver = AntiVerisignResolver(servers=roots) f = server.DNSServerFactory(clients=[resolver], verbose=verbosity) p = dns.DNSDatagramProtocol(f) f.noisy = p.noisy = verbosity application = app.Application('Non caching anti-verisign domain name resolver') application.listenUDP(53, p) application.listenTCP(53, f) --- snip --- -Andrew.

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[Twisted-Python] Release notes for 1.0.7
by Itamar Shtull-Trauring 16 Sep '03

16 Sep '03

Please email me anything I missed so I can fix before I email c.l.p and c.l.p.a What's New in 1.0.7 =================== - Client Jabber support. - twisted.xish, an XML package supporting a DOM-like API and a XPATH-like API. - Woven web templating toolkit is now much faster, and no longer supports the interim APIs it had during development. - Security tightening in the web server, especially on Windows. - XML-RPC server is now easier to extend, and can publish the XML-RPC introspection API as an option. - Working minimum and maximum sizes for database connection pools. - New connection API for Perspective Broker, allowing easy SSL support, reconnection, etc.. - Better lenient HTML parsing in microdom. - Many improvements to mail protocols (SMTP, POP3, IMAP). - Continued switch to updated cred unified authentication backend in the various protocols supported by Twisted. - SOAP support now requires SOAPpy 0.10.1 or later. - mailmail, a replacement for the common usage of command-line /usr/sbin/sendmail. - Bug fixes, documentation improvements, more tests.

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[Twisted-Python] How to save the content(string) of a DOM node into a file?
by suneetha velicheti 16 Sep '03

16 Sep '03

Hi, I wanted to save the content of a DOM node into a file and want my browser to prompt me with "save as" window. I already set the browser preferences. Right now the content of the node is just displaying in the browser window. Instead of that I want to promt the user to save that content into a file with "save as" option window. Are there any DOM helper methods to do this? Thanks for the help, Suneetha. _________________________________________________________________ Try MSN Messenger 6.0 with integrated webcam functionality! http://www.msnmessenger-download.com/tracking/reach_webcam

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[Twisted-Python] Small woven application example
by Stephen Thorne. 16 Sep '03

16 Sep '03

Hi. I did some hacking with twisted.web and woven, just to try and teach myself how to go about writing a web application using twisted, bearing in mind I write php in my day job, this was a little hard. http://thorne.ath.cx:3000/~stephen/wikiexample.xhtml is the result of my efforts, and you can see it running at http://thorne.ath.cx:8081/MainPage/ I've got there the original code I started with (using Resource and a fairly phpish methodology) and what I finished with. In my little venture back into the realm of twisted, I see the following lacking in the documentation: * The varied Views and Widgets are poorly documented, I found myself inventing what was needed, then going into Twisted/twisted/web/woven/ and reading widgets.py and view.py - and discovering that they already existed. * There is very little mapping between "This is how you would do it in a silly framework" -> "This is how twisted makes it cleaner and easier" * The pitfalls. * e.g. For submitting forms and the implicit header "Location:" redirects which obliterate your post values. (When you have <form action="/Foo/bar">, but you'll get redirected to "/Foo/bar/") * the interface to the factories should be written down on a piece of card and stuck to the monitor. Swapping 'request' and 'model' doesn't help things. As such, I intend to go through all the views and widgets, and write a small example piece of code, showing what each of them does, and what inputs/outputs they take. I also intend to take some php idioms and show a mapping from them to twisted. Fortuantely, I've got loads of experience with lore (I recently used it to typeset a 90+ page tutorial for a camp I'm leading on in 2 weeks, http://thorne.ath.cx:3000/lwdoc/index.xhtml if you're interested) Please send replies CC: stephen(a)thorne.id.au as I'm not currently subscribed to the list. Regards, Stephen Thorne

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[Twisted-Python] Server errors using Twisted with Python 2.3
by Richard.Townsend＠edl.uk.eds.com 15 Sep '03

15 Sep '03

Since installing Python 2.3 on HP-UX11i, I keep getting 'Resource temporarily unavailable' errors in server applications. E.g. using ../doc/examples/simpleserv.py & ../doc/examples/simpleclient.py: "richardt" capulet:doc/examples > python simpleserv.py Traceback (most recent call last): File "/opt/python/lib/python2.3/site-packages/twisted/python/log.py", line 65, in callWithLogger callWithContext({"system": lp}, func, *args, **kw) File "/opt/python/lib/python2.3/site-packages/twisted/python/log.py", line 52, in callWithContext return context.call({ILogContext: newCtx}, func, *args, **kw) File "/opt/python/lib/python2.3/site-packages/twisted/python/context.py", line 32, in callWithContext return func(*args,**kw) File "/opt/python/lib/python2.3/site-packages/twisted/internet/default.py", line 510, in _doReadOrWrite why = getattr(selectable, method)() --- <exception caught here> --- File "/opt/python/lib/python2.3/site-packages/twisted/internet/tcp.py", line 595, in doRead skt, addr = self.socket.accept() File "/opt/python/lib/python2.3/socket.py", line 167, in accept sock, addr = self._sock.accept() socket.error: (11, 'Resource temporarily unavailable') "richardt" capulet:doc/examples > python simpleclient.py Server said: hello, world! connection lost Connection lost - goodbye! The transaction appears to work, but the log file is filling up with these errors. This happens with Twisted 1.0.6 and 1.0.7. It doesn't happen when using Python 2.2 Can anyone advise how to fix this problem? regards, Richard Townsend

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[Twisted-Python] stack trace
by Kuzminski, Stefan R 15 Sep '03

15 Sep '03

Hi, I'm using twisted to build a process management tool. I have a TCP server that runs reactor.spawnProcess(), it runs the process, but then generates this stack trace. I'm at a bit of a loss as to how to resolve this.. Is there perhaps another approach I should try? I need to manage long running processes on remote boxes. Thanks, Stefan Traceback (most recent call last): File "/usr/lib/python2.3/site-packages/twisted/python/context.py", line 32, i\ n callWithContext return func(*args,**kw) File "/usr/lib/python2.3/site-packages/twisted/internet/pollreactor.py", line\ 173, in _doReadOrWrite selectable.connectionLost(f) File "/usr/lib/python2.3/site-packages/twisted/internet/process.py", line 431\ , in connectionLost self.maybeCallProcessEnded() File "/usr/lib/python2.3/site-packages/twisted/internet/process.py", line 394\ , in maybeCallProcessEnded self.reapProcess() --- <exception caught here> --- File "/usr/lib/python2.3/site-packages/twisted/internet/process.py", line 301\ , in reapProcess pid, status = os.waitpid(self.pid, os.WNOHANG) exceptions.OSError: [Errno 10] No child processes

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[Twisted-Python] Potential fix for vhost+distrib (issue125)
by Chris Armstrong 15 Sep '03

15 Sep '03

Can everyone who cares about vhosts with distrib (Alex Levy, Thomas Raschbacher) update to latest CVS and try putting a ResourceSubscription behind a vhost? I've tested twistedmatrix.com's setup with this fix, and it works (i.e., UserDirectories, static.Files, CGIs, etc). -- Twisted | Christopher Armstrong: International Man of Twistery Radix | Release Manager, Twisted Project ---------+ http://twistedmatrix.com/users/radix.twistd/

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