Mailman 3 July 2012 - Twisted

[Twisted-Python] Logging observers and threads
by Tristan Seligmann 13 Jul '12

13 Jul '12

When an error occurs in a database connection thread, adbapi invokes log.err from that thread, which in turns causes log observers to be invoked in this thread. Mantissa's TracebackCollector has a log observer which logs items as Items in an Axiom store; this means that the log observer tries to run SQLite queries in the wrong thread, and explodes. However, I'm not sure whose fault this is; it seems there are three possibilities: 1) log.err and log.msg should not be called from a non-reactor thread, making this an adbapi bug. 2) twisted.python.log should not invoke log observers in a non-reactor thread, making this a twisted.python.log bug. 3) log observers should expect to be inovked in non-reactor threads, making this a Mantissa bug. Can anyone give a definitive answer on this? The "nothing except reactor.callFromThread is thread-safe" principle would suggest that 1) is the case, but logging seems like it might be a special case. -- mithrandi, i Ainil en-Balandor, a faer Ambar

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Re: [Twisted-Python] deferred graph?
by Terry Jones 10 Jul '12

10 Jul '12

Hi Glyph! There are a couple of tickets floating around: http://twistedmatrix.com/trac/ticket/3858 http://twistedmatrix.com/trac/ticket/1402 (closed as a dupe) T

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[Twisted-Python] Boston Twisted Sprint: MIT, July 14th
by Tenth 09 Jul '12

09 Jul '12

I'm pleased to finally announce another Boston area Twisted Sprint, on Saturday, July 14th, on the MIT Campus. Thanks to Jessica McKellar's tireless efforts, Building 8, Room 119 will be reserved for Twisted hacking from 12:00 PM to 11:00 PM. If you're interested, and haven't received a formal invitation, I'd be happy to add you to the list; This includes more specific information about how to find the site and contact the organizers. Thanks, - Dave

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[Twisted-Python] Send messages in an Infinite loop
by kangta123 08 Jul '12

08 Jul '12

Hello all: I am newbie to use twisted. I want to send message in an Infinite loop in server, such as send a timestamp each 5s to all clients. i have tried to use like "deferToThread" and "callFromThread", but i am failed.if have any suggestions please tell me. thanks.

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[Twisted-Python] Buildbot for PyCrypto 2.6?
by Paul Swartz 08 Jul '12

08 Jul '12

Per http://tm.tl/5700, newer versions of PyCrypto fail the current test cases. At the moment, all the buildbots are running PyCrypto 2.5. Can we upgrade one of them, or start a new buildbox, to test against the newer version? thanks, -p -- Paul Swartz paulswartz at gmail dot com http://paulswartz.net/

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[Twisted-Python] EuroPython 2012 Twisted tutorial postmortem
by Laurens Van Houtven 08 Jul '12

08 Jul '12

Hey :) As some of you probably know Stephen and I did the Twisted Tutorial at EuroPython. Let me start off by saying that there was a lot of interest. A picture says a thousand words: (We got upgraded to the bigger room because it was booked entirely and people were apparently still trying to get in -- that makes the Twisted tutorial the only one to be sold out before the conference even began, let alone doing that two years in a row!) Overall it went pretty well, but given that we had Orestis' slides to build on that was a pretty safe bet :) For next year, I think Stephen and I agree that a TDD approach to the exercises would be superior, because you'd acquaint people with trial and good software development practice at the same time. Plus, it's a lot clearer than human-langage specification of what an exercise solution should do ;) cheers lvh

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 07 Jul '12

07 Jul '12

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[Twisted-Python] Deserializing AMP callRemoteString without knowing the Command's signature
by Laurens Van Houtven 07 Jul '12

07 Jul '12

Hi, As some of you may know I am working on a JSON-RPC <-> AMP bridge to consume AMP services from browsers. WIP: http://lvh.github.com/amphibian/ I've hit a failing integration test. I know what the issue is -- I don't know how to resolve it. I attempted to write the proxy without any knowledge of the remote commands. It assumes that the JSON provided satisfies the remote signature. If it doesn't -- that's okay, we'll get a failure back from the AMP server. So, I use callRemoteString and manually serialize by typechecking. Although that works for sending, the result I get back from callRemoteString is also in wire format. Because I don't know the signature, I have no idea if the sender meant 4, "4", u"4"... On IRC: dreid pointed out that I really shouldn't need a language-specific implementation of a class for this to work teratorn pointed out that there is a JSON schema ticket for AMP. Perhaps there should also be a "DiscoverSchema" command? Alternatively I could just cop out and require commands to be importable. Would make the code simpler but the entire design would become significantly more coupled. -- cheers lvh

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[Twisted-Python] Doing HTTP file uploads (multipart forms)
by Laurens Van Houtven 07 Jul '12

07 Jul '12

Hi, I have some code that takes file uploads from browsers. I'm trying to write a test for it, so now I need to get Twisted to do file uploads like browsers do. I think my code (not test code) essentially works, by manually trying it with a browser. I can't get the functional test part to work. I have reduced the problem to what I think is a SSCCE. render_POST drops into a debugger to easily inspect the received request. Here's the code: https://gist.github.com/3058974 When debugging this with wireshark I found an obvious culprit: there's some random junk in front of it (3 ASCII hex digits and a CRLF) and some junk at the end (CRLF and an ASCII "0", although I'm not sure if that CRLF is junk). Wireshark reports some broken TCP packets (PCAP attached). I have no idea why that happens. Packets were captured with: tcpdump -i lo0 -nn -s0 -w sample.pcap port 8080 and analyzed with a recent version of Wireshark (1.6.2, SVN rev 38931). The analyzed TCP stream is also attached. If I look at the request in the debugger (request_POST *DOES* get called…): - it has an empty request.args, instead of having the expected keys "a", "b", "f" - request.content.getvalue() has the data you see in tcpdata.txt: it starts with "'1e7\r\n------------" even though I obviously would like it to start with just the dashes cheers lvh

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[Twisted-Python] twisted.web.static.File and MIME types
by Tobias Oberstein 07 Jul '12

07 Jul '12

Hi, I need to add MIME types to twisted.web.static.File. The following works, but seems to use internal stuff .. whats the "correct" way to do? from twisted.web.static import File webdir = File(".") webdir.contentTypes['.crt'] = 'application/x-x509-ca-cert' http://twistedmatrix.com/documents/12.1.0/api/twisted.web.static.File.html Cheers, Tobias

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