Mailman 3 November 2011 - Twisted

[Twisted-Python] Prhaps 11.1rc2 should include #4669?
by Itamar Turner-Trauring 03 Nov '11

03 Nov '11

It seems like keeping IOCP from being broken on win64 is worth integrating.

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[Twisted-Python] Slow PB imports
by Marcel Gädigk 03 Nov '11

03 Nov '11

Hi, i using the Perspective Broker and i have problems with the speed of importing the modules. It takes 15 - 17 seconds for importing the Reactor and the PBServerFactory (or other pb imports). If i import the reactor or the pb imports alone it takes in avg. 2-3 seconds. def ImportIt(): from twisted.internet import reactor from twisted.spread.pb import PBServerFactory import timeit t = timeit.Timer(setup='from __main__ import ImportIt', stmt='ImportIt()') print t.timeit() How can i improve this? I running win7 32bit SP1 on a 2,93 Ghz Core 2 Duo with python 2.7.1 and twisted 11.0 cheers Marcel

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[Twisted-Python] t.i.task.Cooperator & inlineCallbacks mashup
by Phil Mayers 02 Nov '11

02 Nov '11

I only just noticed today that if a generator passed to a CooperativeTask does: result = yield some_deferred() ...it doesn't work, because CooperativeTask doesn't .send() the result of the deferred bacn into the generator. Is this intentional? If not, would that behaviour be desirable? It seems like it would be a useful pattern to me.

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[Twisted-Python] twistd/tac : when does logging start?
by Tobias Oberstein 02 Nov '11

02 Nov '11

I've got a Twisted application started via a tac file. Within the tac, I also initialize a database and create a db pool for use with adbapi. Now it seems that log messages from the network services are logged, but not from the initial DB setup stuff. When exactly does Twistd start the logging? How can I make it start logging from the very beginning? I've looked at the docs: "Before startLogging is called, log messages will be discarded and errors will be written to stderr." "If you are using twistd to run your daemon, it will take care of calling startLogging for you, ..." but that doesn't help me. Any hints are welcome

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[Twisted-Python] Interleaving long running loops
by Umit Oztosun 02 Nov '11

02 Nov '11

Hello, I have been developing a medium/large scale application using twisted and very happy about it. It is composed of two parts, an application server and a PyQt based client. Perspective broker is used for all communication between client and server. Server mainly talks with a database, formats results and sends to clients (roughly). Most formatting is done in simple for loops (there are many different kinds of operations which a client can choose): @defer.inlineCallbacks def operation(): dbQueryResult = yield runSomeSQL() for item in dbQueryResult: process(item) Again, most of the time these are light operations which complete in sub-seconds. However, rarely, results may be so large that it takes several seconds to process, and during this period all other server processing stops (i.e. accepting new client connections). I've written a utility function, deferredSleep(), which I call occasionally to avoid blocking: def deferredSleep(seconds=0.01): d = defer.Deferred() reactor.callLater(seconds, d.callback, None) return d And I use it like below to avoid blocking for very large result sets: @defer.inlineCallbacks def operation(): dbQueryResult = yield runSomeSQL() for i, item in enumerate(dbQueryResult): if i % 1000 == 0: # Breathe after a thousand iterations yield deferredSleep(0.01) process(item) So my question is, is this an acceptable solution? And is there a more generic way, i.e. for item in magicalIterator(dbQueryResult): process(item) I have lots of similar loops all over the place and a more generic solution would be great. I am also aware of deferToThread but I am trying to avoid using threads. Regards, -- Umit

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[Twisted-Python] Limitations & future extension of twisted
by nivedita datta 02 Nov '11

02 Nov '11

Hi all, I have to give a talk on twisted. Can anyone let me know about the limitations of twisted which can later be improved. Also let me know about the possible future extensions in twisted. Regards, Nivedita Datta Student, IISc Bangalore

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[Twisted-Python] Python 3 progress: Twisted Core, Twisted Names
by Antoine Pitrou 01 Nov '11

01 Nov '11

Hello, Just a heads up about the continuing experiment in porting Twisted to Python 3. The port has reached the point where most of Twisted Core and Twisted Names is now working. The exceptions are: twisted.cred, twisted.protocols.sip, twisted.python.hook. This is validated by running the corresponding test suites. Details about the successful tests are on the project page (*). I have also validated that merging upstream changes (from Twisted's trunk) is relatively painless. The merges produced few conflicts and few regressions (test failures), which were easy to fix. (*) Project page: https://bitbucket.org/pitrou/t3k/, as always. Regards Antoine.

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[Twisted-Python] Autobahn WebSockets 0.4.3
by Tobias Oberstein 01 Nov '11

01 Nov '11

New release 0.4.3 of Autobahn WebSockets including: + Hybi-17 support + TLS (secure WebSocket) + lots of new options + improved docs and tutorials + close behavior coverage for testsuite + many small things I forgot Special thanks to Peter Thorson for significant code contributions and fruitful discussions! Peter works on a C++/ASIO-based WebSocket client/server framework you may checkout here https://github.com/zaphoyd/websocketpp Updated Python package is here: http://pypi.python.org/pypi/autobahn Updated test suite reports are available under http://www.tavendo.de/autobahn/testsuite.html including mobile clients and servers. Cheers, Tobias

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