Mailman 3 March 2010 - Twisted

[Twisted-Python] Twisted Sprint this Sunday
by exarkun＠twistedmatrix.com 19 Mar '10

19 Mar '10

Hi all, Flumotion is going to be hosting a sprint this Sunday (Mid-morning to evening, Spanish time). I'll be introducing a lot of developers to the Twisted development process and trying to find them good first-time- contributor tickets to work on. Even if you're not on the Iberian peninsula this weekend, you can still participate virtually. :) If anyone wants to help out with reviews or suggest tickets that might be productive to work on, meet up with us in #twisted on Freenode. Jean-Paul

2 1

[Twisted-Python] FTP Client - questions
by Renan Mathias Fernandes 18 Mar '10

18 Mar '10

Hello, I am trying to learn/implement a FTP Client, but I am facing a problem: How can I check if the retrieveFile method has finished downloading a file? As far as I can see, there is no easy way to do this, am I incorrect? Below is an example of what I am doing to retrieve a file: class FileReceiver(Protocol): """ Protocol subclass that writes received data to a local file. """ def __init__(self, filename): self.file = open(filename, 'wb') def dataReceived(self, data): self.file.write(data) def connectionMade(ftpClient): test = FileReceiver('./testRetrieve.txt') try: ftpClient.retrieveFile('testFile.txt',test) except: print "Exception -", sys.exc_value reactor.stop() Can anyone shed a light? Thanks in advance, Renan Mathias Fernandes

2 1

[Twisted-Python] Is it possible to turn off transactions for adbapi?
by markscottwright＠gmail.com 18 Mar '10

18 Mar '10

I'm trying to get SQL Server 2005 to CREATE DATABASE using twisted. However, SQL Server won't allow you to run CREATE DATABASE within a transaction (apparently, it's not something sql server can roll back, which seems sensible). Which means that the following code results in an error. Is there a way to turn transactions off for a query? @defer.inlineCallbacks def test_simple_create(): try: password = "xxx" connection_string = "Driver={SQL Native Client}; Server=(local); UID=sa; PWD=%s;" % password db = adbapi.ConnectionPool("pyodbc", connection_string, cp_noisy=True) cmd = """CREATE DATABASE atest ON (NAME=atest, FILENAME='c:\temp\atest', SIZE=64MB) LOG ON (NAME=atestlog, FILENAME='c:\temp\atestlog', SIZE=64MB)""" yield db.runOperation(cmd) except Exception, e: print e finally: db.close() reactor.stop() if __name__ == "__main__": from twisted.python import log import sys test_simple_create() log.startLogging(sys.stdout) reactor.run() === 2010-03-18 09:28:45-0500 [-] Log opened. 2010-03-18 09:28:45-0500 [-] adbapi connecting: pyodbc ('Driver={SQL Native Client}; Server=(local); UID=sa; PWD=xxx;',) 2010-03-18 09:28:45-0500 [-] ('42000', '[42000] [Microsoft][SQL Native Client][SQL Server]CREATE DATABASE statement not allowed within multi-statement transaction. (226) (SQLExecDirectW)') 2010-03-18 09:28:45-0500 [-] adbapi closing: pyodbc 2010-03-18 09:28:45-0500 [-] Main loop terminated. 2010-03-18 09:28:45-0500 [-]

3 2

[Twisted-Python] Twisted and python threading
by (*)·´`·.¸.»ÐëÄdMäñ·´`·.¸.»(*) 18 Mar '10

18 Mar '10

Hi, I'm trying to spawn a threading.Thread from a Twisted application, but the thread won't start unless I schedule the the code with reactor.callLater(), any Ideas ?

3 3

[Twisted-Python] Log Rotation Blocks w/ Large Number of Log Files
by Jason J. W. Williams 17 Mar '10

17 Mar '10

Hello, Twistd blocks for a long period of time when the number of log files built up is large, thereby causing connections to freeze and (depending on the length of the rotation) time out. Given I've only used Twisted in the past and not contributed to it, I was curious if someone could take a look at my changes to twisted.python.logfile.LogFile's rotate() method and see if there's any reason the changes would be a bad idea. What I've attempted to do is defer the rotation of the old log files to a thread, and only rotate the current log file in the foreground. Original twisted.python.logfile.LogFile.rotate(): http://gist.github.com/334538 My version with deferral of old log rotation: http://gist.github.com/334545 (Changes are against Twisted 10.0). Thank you in advance. -J

3 4

[Twisted-Python] Twisted easy bugs, and other thoughts about getting people involved in Twisted
by Asheesh Laroia 17 Mar '10

17 Mar '10

I ran into David Reid at PyCon a few weeks ago, and I showed him an index of "easy" and "bitesize" bugs I'm putting on the web at https://openhatch.org/search/. He told me that the Twisted team tags bugs as "easy" in Trac. So all you might like to see https://openhatch.org/search/?q=Twisted&toughness=bitesize -- it's the result of search for bugs whose full text or project matches "Twisted", constrained to only include the bugs that are "easy". This is the same query as http://twistedmatrix.com/trac/query?status=new&status=assigned&status=reope… -- the same 18 tickets -- but cached in our index. The OpenHatch website aims to show helpful, friendly things to potential new contributors. A list of bugs isn't always adequate, so I'm really happy jesstess wrote some tips on the OpenHatch project page regarding getting involved in Twisted: https://openhatch.org/+projects/Twisted The "Relatedly" sidebox on that project page has other helpful links: potential mentors, namely people who have signed into OpenHatch and said they can mentor in Python or Twisted. So that's a quick tour of some of relevant things to you guys. I have a few questions for you guys, if you're game: * Of these things, what are the most interesting or useful? the least? * Are there other tickets from the Twisted Trac that would be good to pull in? * Would you like me to ping the list if we come up with anything else I think you might find interesting? * Do any of you want to re-use some of this data -- can we make that easier? We're pretty interested in helping projects convert users to contributors (in code, testing, documentation, whatever!) across free software. I wonder if there is a website widget that we could make for you to put on twistedmatrix.com -- a big box talking about how "You TOO can contribute to Twisted -- there are mentors, easy bugs, and everything!" This email has gotten fairly long, so I'll stop here for now. I don't mean to barge in; let me know if I'm unwelcome, and I'll wander off. I find myself in a maze of Twisted developers, none of whom are alike. Thanks! I'll be hanging out on #twisted as myself, paulproteus. -- Asheesh. P.S. If you think this is interesting, stay in touch with us: IRC (freenode): #openhatch Twitter/Identi.ca: @openhatchery blog: https://openhatch.org/blog/ email and more: https://openhatch.org/contact/ P.S. The OpenHatch website has its source in git and shared under a free license -- https://openhatch.org/source-code-etc/ -- "World conquerors sometimes become fools, but fools never become world conquerors." -- "The Outer Limits: The Invisibles"

4 5

[Twisted-Python] http://twistedmatrix.com/ trac installation updated
by exarkun＠twistedmatrix.com 16 Mar '10

16 Mar '10

Hi all, Thomas and I have finished upgrading the trac installation on http://twistedmatrix.com/ to 0.11.6. We expect that this will resolve a number of the issues the site has had. If you notice anything broken about the website now, please point it out. Jean-Paul

10 18

[Twisted-Python] My twisted application could not start after reboot be cause of "twistd.pid"
by Peter Cai 16 Mar '10

16 Mar '10

Someone turn off the server by cutting power of the server. When the machine is power on, I found my twisted application could not start and emit the following error. Another twistd server is running, PID 3398 This could either be a previously started instance of your application or a different application entirely. To start a new one, either run it in some other directory, or use the --pidfile and --logfile parameters to avoid clashes. After I deleted twistd.pid, it could start normally. I checked if there is process with PID 3398, but there wasn't. What might cause this problem? How to avoid it? -- look to the things around you,the immediate world around you, if you are alive,it will mean something to you ——Paul Strand

6 7

[Twisted-Python] Application mode: Killing a peer connection from the server in a thread. Is this correct?
by Jonathan Sawyer 14 Mar '10

14 Mar '10

Hi everyone, I am running a server in application context via: # code: server.tac factory = Factory() factory.protocol = MyProtocol application = service.Application("MyServer") service = internet.TCPServer(5555, factory) service.setServiceParent(application) # end code ran with $ twistd -ny server.tac Here is some of my Protocol code: # code: myprotocol.py def checkIdle(transport): while 1: now = time.time() if now - transport.activityFlag > 30.0: transport.loseConnection() time.sleep(1) break return time.sleep(8) return class MyProtocol(Protocol): def connectionMade(self): self.transport.activityFlag = time.time() thread.start_new_thread(checkIdle, (self.transport,)) # ... the rest of the methods... not important for this question # end code Now here's my problem: I want to kill connections from the server that have been idle for, say, 30 seconds. An idle connection is one in which is a _valid_ connection (i.e., it hasn't disconnected from the server) but hasn't sent any data for 30 seconds. The way I have initially set it up was in a thread. I simply check the last time it had activity from that particular transport. The really real problem I am having is when the connection is closed, the client doesn't know about it. It is simply closed on the server and the client is left hanging. If I test this in telnet with: $ telnet localhost 5555 telnet never quits with a message: Connection closed by foreign host. (which is indeed exactly what I want) The only way I get this response is if I try to send data to the server while the connection has been "lost". Can anyone direct me on the proper way to kill a connection from the server end in a clean manner? (By the way, I'm very new to twisted, not so new to Python). Thanks for any help! -- Jonathan Sawyer Geographic Information Network of Alaska (GINA) University of Alaska Fairbanks (907) 474-5689

2 1

Re: [Twisted-Python] [Twisted] #4331: SIGCHLD causes "Interrupted system call" errors on Python 2.4, in a fresh SVN checkout (was: SIGCHILD causes "Interrupted system call" errors on Python 2.4, in a fresh SVN checkout)
by Glyph Lefkowitz 14 Mar '10

14 Mar '10

Also regarding Trac issues; I'm not sure if this one is new, but I received this message from the ticket notifier and I noticed that since the only thing that changed is the ticket subject, there appears to be no indication of who changed it or what changed, unless you look at the 'subject' line of the email. On Mar 14, 2010, at 3:29 AM, Twisted wrote: > #4331: SIGCHLD causes "Interrupted system call" errors on Python 2.4, in a fresh > SVN checkout > --------------------------+------------------------------------------------- > Reporter: TimAllen | Owner: glyph > Type: defect | Status: new > Priority: normal | Milestone: > Component: core | Keywords: > Branch: | Branch_author: > Launchpad_bug: | > --------------------------+------------------------------------------------- > > -- > Ticket URL: <http://twistedmatrix.com/trac/ticket/4331#comment:4> > Twisted <http://twistedmatrix.com/trac/> > Engine of your Internet

1 0