Mailman 3 May 2005 - Twisted

[Twisted-Python] Twisted Python 0.7.0 Prerelease Testing
by Glyph Lefkowitz Aug. 5, 2021

Aug. 5, 2021

hi there, folks: I'd really like to release 0.7.0 but I would like it to be at least a little bit tested before I do so. Could those of you with CVS trees check everything out and see if it performs as advertised? Deeper bugs than that will have to wait for the next release, but I'd at least like to know if it works for someone other than me. Thanks. ______ __ __ _____ _ _ | ____ | \_/ |_____] |_____| |… [View More]

4 5

[Twisted-Python] Get IP of connecting client in XMLRPC server
by Remy C. Cool April 28, 2013

April 28, 2013

Hello, On 18 May 2004, the following message was posted to this mailinglist: Jp Calderone exarkun at divmod.com wrote: >Daniel Newton wrote: > > I have a simple XML-PRC server similar to the example below: > > from twisted.web import xmlrpc, server > > class Example(xmlrpc.XMLRPC): > """An example object to be published.""" > > def xmlrpc_add(self, a, b): > """Return sum of arguments.""" > return a + b def … [View More]

3 3

[Twisted-Python] epoll reactor
by James Bunton June 3, 2005

June 3, 2005

Hi all I've implemented an epoll reactor using the level triggered mechanism. Please check it out and let me know if there's anything I've done wrong. This is the first time I've played with twisted reactor internals before. :) http://msn-transport.jabberstudio.org/tarballs/epoll-0.1.tar.gz There's a README file in the tarball with instructions on setting it up. Enjoy! :) --- James

3 9

[Twisted-Python] twisted.mail.imap4.MessageSet object & imap4 server example
by Sebastjan Trepca June 2, 2005

June 2, 2005

Hi! 1. I don't understand how to use this object. When the fetch method is called, this object is passed containing the requested messages which you then return, right? But is there any easy way to just iterate through it and get the requested UIDis, even if LAST is not set. 2. Where could I find some IMAP4 server examples? Thank you. Regards, Sebastjan

2 1

[Twisted-Python] Using twisted.conch.recvline
by Abe Fettig June 2, 2005

June 2, 2005

Hello all, I'm trying to figure out how to hook up the necessary classes in twisted.conch.recvline to add line-editing and history to a simple ssh app. It was easy to modify http://twistedmatrix.com/projects/conch/documentation/examples/sshsimpleser… to use a custom protocol (a simple command-line interface that sends web services requests to a JotSpot wiki), but I can't figure out how recvline is meant to be used. Could someone (Jp?) show me how you'd go about bolting recvline onto sshsimpleserver? Thanks! Abe

4 6

[Twisted-Python] wxpython, threadselectreactor and thread
by Michele Petrazzo May 31, 2005

May 31, 2005

I have a wxpython application that work with twsited 2.0 on win and linux. In these days I'm "porting" it from twisted 1.3 to 2.0 + threadselectreactor, but not all work well. Into my application I use: callLater threads.deferToThread with some addCallBack Three problems: 1) Sometime then I open and close my application I receive this error: Unhandled exception in thread started by <bound method Thread.__bootstrap of <Thread(Thread-1, stopped daemon)>> Traceback (most recent call … [View More]

5 8

[Twisted-Python] clustering or process group replication
by Laran Evans May 31, 2005

May 31, 2005

Has any work been done to enable process group communication similar to what Spread (spread.org), Ensemble, Horus, Isis, Eternal etc. offer? - Laran

5 15

[Twisted-Python] ftp server cannot access below directory
by seba.tutu May 31, 2005

May 31, 2005

Hi, I was trying to implement a very basic ftp server using the twisted framework (version 2). The server is running under WinXP. I launch the programm under the twisted shell using twistd -y name_program.py The client is linux partly because for the test it appears that I need a passice connection. I manage to login and to type basic command (like help, bin)... As soon as I ask for a ls, there is a message 550 : Cannot accsees below / directoey : Permission denied. The directory exists. … [View More]

1 0

[Twisted-Python] using http server in twisted
by John Que May 31, 2005

May 31, 2005

Hello, I am trying the exmaple in the python docs - http://twistedmatrix.com/users/warner/doc-latest/web/howto/using-twistedweb… Configuring and Using the Twisted.Web Server - Twisted Web Development. it says there: "You can also create a Site instance by hand, passing it a Resource object which will serve as the root of the site: from twisted.web import server, resource from twisted.internet import reactor class Simple(resource.Resource): isLeaf = True def render_GET(self, … [View More]

2 4

[Twisted-Python] Alarm collection and display system?
by Brett Viren May 31, 2005

May 31, 2005

Hi, Our experiment has need for a pseudo real-time (prompt) networked alarm collection and display system. Before just diving in and writing something I thought I'd best try to see if anything is out there and Twisted certainly seems a fertile enough framework to have had at least one such system sprouted already. What we have is several, independent processes all of which can raise problems of varying degrees of severity. Most of the alarm producers are written in differing languages and … [View More]

8 10

[Twisted-Python] Weekly Bug Summary
by James Y Knight May 31, 2005

May 31, 2005

Bug summary ______________________ Since 2005-05-23 21:32:22.460000: Bugs opened: 20 Bugs closed: 12 Total open bugs: 377 (+8) Urgent: 6 (-1) Bug: 155 (+6) Feature: 141 (+2) Wish: 75 (+1) New / Reopened Bugs ______________________ ==== Urgent ==== Release 2.1 (4 days ago) http://twistedmatrix.com/bugs/issue1055 opened by jknight ==== Bug ==== [CORE, DOCUMENTATION] Deferred doc fix (3 days ago) http://twistedmatrix.com/… [View More]

1 0

RE: [Twisted-Python] Chat by html application
by Harald.Nyman＠astrazeneca.com May 29, 2005

May 29, 2005

Hi Tibi, Nevow is probably the best. But there are other ways too. I've been doing this for several years with a Tomcat servlet, and then there was no Nevow. After converting to Pythonism, I switched to a Twisted server. Haven't learned Nevow yet, despite good intentions..., but I think this may be similar. It's essentially doing all of "What I want to do:" below, only I'm not using it mainly for chat, but for distributing HTML or Javascript, for viewing things together during a phone meeting. … [View More] - the browser's background HTTPRequest sits in a threaded applet - someone switches on "collaboration" in his browser - the others see his name being added to the "virtual meeting" - one user drags a pointer (image) in his browser -> the pointer moves in the other browsers See also some A's to your Q's, below. Harald On 5/26/05, Tibi Dondera <incoming(a)pronet-romania.com> wrote: > Hello all, > > I'm trying to develop a chat application through a browser, using > twisted (if possible) > What I want to do: > - a user logs in the website > - he goes to the "chat page" > - he has the "classic" chat interface (sent messages, list of online > users, "send a message" field). All of these are simple "divs" > - when he sends a message, a post with the message is submitted to the > server, and registered in a temporary database table (or in memory, is > there some "temporary" memory that I can use in twisted for this purpose > ?) > - for refreshing the chat area, there is an open HTTPRequest in the > background. Twisted will do the following: > - accept the HTTPrequest connection > - keep it alive (i.e. do not send the answer, but maybe send some > empty chars to force the browser to keep the connection open) > - when a new message (from the other users) is available, send it > to the user and close the connection. > - in the user's browser, when the connection is closed (either with a > message, or after a certain timeout, that cannot be avoided anyway), a > new one will be opened, until the user quits the chat. > > Questions: > - Is this a plausible solution ? Yes, IMHO. > - Has this already been implemented (or at least partly) ? > - Can this actually be done with twisted ? Yes. > - Can I develop this on Windows ? (production will be on linux, but > still, I prefer developing local, and currently on windows) Hmm.. I develop "on Windows", but with a VMWare Linux server on the same laptop. Works great, but costs a bit. Should work with the server on Windows, too(?) > - Can you give me any pointers to some existing code, or where to start > ? (maybe jabber for twisted ?) Here's a few fragments from my server code - class Servlet(resource.Resource): ... # Send queued output to browser's background listener def render_GET(self, request): self.request = request session = request.getSession() ... anything = 0 while not session.outqueue.empty(): x = session.outqueue.get() request.transport.write(x) anything = 1 if anything: request.finish() return server.NOT_DONE_YET def render_POST(self, request): session = request.getSession() # Browser sends a dictionary as text msgDict = eval(request.args['message'][0]) request.finish() message = msgDict['message'] mSplit = message.split() ... # Do work here return server.NOT_DONE_YET > - How will a twisted http server coexist with my existing apache server > on the 80 port ? Not well, I guess. I use a different port for the Twisted server. > - Must I subscribe to the twisted-http mailing list instead and ask this > question there ? Twisted-web would be better, yes. I'm posting this one there too, with all due apologies... > > Thanks for any help. > > Tibi Dondera _______________________________________________ Twisted-Python mailing list Twisted-Python(a)twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python [View Less]

2 1

[Twisted-Python] threadedselectreactor
by Michele Petrazzo May 28, 2005

May 28, 2005

I found some messages that explain the new threadedselectreactor function, but on the last package 2.0.1 I don't found that file. Where can I download this new function/file? And after, is this a stable or only an unstable version? Thanks, Michele

4 6

[Twisted-Python] xmlrpc deferred
by Catalin Constantin May 28, 2005

May 28, 2005

Hi there, I have the following xmlrpc method: class FeederResource(xmlrpc.XMLRPC): def __init__(self): xmlrpc.XMLRPC.__init__(self) self.feeder=Feeder() def xmlrpc_getList(self, id): return self.feeder.get_urls(id) The thing is that the self.feeder.get_urls takes too long to execute and while the request is running all the others are blocked. I want that while it computes the result the other XML RPC methods to … [View More]

4 8

[Twisted-Python] adbapi and pymssql
by Mike Pelletier May 27, 2005

May 27, 2005

I am attempting to use pymssql in an new Twisted app I am developing for a client (so please don't ask for a lot of detail). pymssql claims to implement "most" of ADBAPI 2.0 and it's not on the list of known supported back ends, so I realize I'm pressing my luck a bit here. Bare pymssql seemed to work well, so I pressed on and attempted to use it with adbapi. Here is what I am using for testing: from twisted.internet import reactor from twisted.enterprise import adbapi from agent.db … [View More]import makeDbpool def printResultAndDie(*result): print "result:", result reactor.stop() def printErrorAndDie(error): error.printTraceback() reactor.stop() import sys dbpool = makeDbpool() query = " ".join(sys.argv[1:]) print query d = dbpool.runQuery(query) d.addCallbacks(printResultAndDie, printErrorAndDie) reactor.run() This reports an error, though it appears on the server that the transaction was completely successful. The exception is thrown by adbapi.py:310, "self._rollback(trans)". This line is itself in an exception handler, and it is handling an exception thrown by line 306, "trans._connection.commit()". A little further testing suggested to me that there is nothing obviously wrong with pymssql's commit or rollback features. The problem seems to be line 305: "trans.close()". I guess pymssql doesn't support commits and rollbacks after that, which seems almost reasonable. (Mind, I am in much deeper than I have any actual understanding.) I have locally modified _runinteraction. I would *really* appreciate it if someone took a look at my changes. I don't understand why close() is supposed to be called before commit() or rollback(), so maybe this is a completely wrongheaded move on my part. Here is my version: def _runInteraction(self, interaction, *args, **kw): trans = Transaction(self) try: try: result = interaction(trans, *args, **kw) trans._connection.commit() except: self._rollback(trans) raise finally: trans.close() return result And for comparison, the original: def _runInteraction(self, interaction, *args, **kw): trans = Transaction(self) try: result = interaction(trans, *args, **kw) trans.close() trans._connection.commit() return result except: self._rollback(trans) raise Thanks in advance! Mike. [View Less]

6 8

[Twisted-Python] Some questions from a newby
by Stefano Canepa May 27, 2005

May 27, 2005

Dear all, I am new to twisted and have some questions I cannot find answer in the twisted documentation or using google. 1) in writing a server, what is better to write a twisted application to be run using twistd -y or a python app using a reactor? 2) how do I use configuration without using a tac? TIA Stefano -- Stefano Canepa - email: sc(a)linux.it - www: http://www.stefanocanepa.it Three great virtues of a programmer: laziness, impatience and hubris. Le tre grandi virtù di un … [View More]

2 2

[Twisted-Python] xmlBlaster/twisted experience?
by Ross Jekel May 27, 2005

May 27, 2005

Has anyone out there used xmlBlaster with Twisted? They seem like a good match. I'm considering taking the pyBlaster interface which basically implements a standalone async threading xmlrpc client/server to handle interfacing with xmlBlaster and rewriting it in twisted. Before I do so, has anyone done this already? If not, I'll write what I need and either try to get it in the xmlBlaster distribution and/or distribute it here. Any hints on the best way to do this would be appreciated. Thanks, Ross

1 0

[Twisted-Python] How to create a new service and listen on a new port?
by Eric Hsu May 27, 2005

May 27, 2005

Hi all, This is my first post here, and I'm not a native English speaker, so please bear with me :) I'm trying to implement something like this: * A UDP server listening on port1 for incoming request * A client sends the requset to port1 * The server confirms the request and creates another (different) UDP service on a new port (port2) * The client then would be able to connect to port2 and do some other things... By reading this "Writing a New Plug-In for mktap" - http://twistedmatrix.… [View More]

3 5

Re: [Twisted-Python] cleanup in twisted
by Joachim Boomberschloss May 26, 2005

May 26, 2005

--- Jp Calderone <exarkun(a)divmod.com> wrote: > On Wed, 25 May 2005 06:12:16 -0700 (PDT), Joachim > Boomberschloss <boomberschloss(a)yahoo.com> wrote: > > > >--- Jp Calderone <exarkun(a)divmod.com> wrote: > > > >> [snip] > >> > >> Rescuing an object from garbage collection is > easier > >> than you may expect: > >> > >> exarkun@boson:~$ python > >> Python 2.4.1 (#2, Mar 30 2005, 21:… [View More]51:10) > >> [GCC 3.3.5 (Debian 1:3.3.5-8ubuntu2)] on linux2 > >> Type "help", "copyright", "credits" or > "license" > >> for more information. > >> >>> L = [] > >> >>> class Foo: > >> ... def __del__(self): > >> ... L.append(self) > >> ... > >> >>> f = Foo() > >> >>> del f > >> >>> L > >> [<__main__.Foo instance at 0xb7dff34c>] > >> >>> > >> > >> Of course, for it to ever be collected, you'll > need > >> to take it out of that list. > >> > > > >Hmmm. Good to know. I thought this sort of thing > was > >considered illegal in Python. This resolves > deferring > >the destruction, but not the problem with reference > >cycles. Is there any way to do it without __del__? > > The garbage collector goes to great lengths to make > sure it works :) > > Well, here's an example of how you'd use weakrefs. > It may or may not apply to your case: > > exarkun@boson:~$ python > Python 2.4.1 (#2, Mar 30 2005, 21:51:10) > [GCC 3.3.5 (Debian 1:3.3.5-8ubuntu2)] on linux2 > Type "help", "copyright", "credits" or "license" > for more information. > >>> import weakref > >>> def cleanup(handle): > ... print 'Cleaned up', handle > ... > >>> class Foo: > ... def __init__(self, x, y, z): > ... self.x, self.y, self.z = x, y, z > ... self._cleanup = weakref.ref( > ... self, lambda deadref: cleanup(x)) > ... > >>> f = Foo('hello', 'world', 42) > >>> del f > Cleaned up hello > >>> > > The main point here is the isolation of the objects > needed for actual cleanup from the object which may > participate in a cycle. In this way, it is similar > to moving the __del__ implementation onto a separate > class. > > Since the cleanup callback does not have access to > the instance, it is somewhat more limited. For > example, if the `x' attribute of a Foo instance is > ever changed, the callback will still be invoked > with the original value. > Got it. Well, indeed, this is not exactly what I need because of the limitation you mentioned, but I think I found a solution: to have a global object that points to all instances of Cleanuppable, and a LoopingCall that checks every minute or so whether this global object is the only referrer to each Cleanuppable instance, in which case it activates the __cleanup__ method of the Cleanuppable, and waits for the procedure to complete, then deletes the instance. This is somewhat unelegant (because of the arbitrariness of the LoopingCall as opposed to being dependent on the garbage collection process), but I think it should be completely satisfactory functionality-wise. This brings me back to the question of attractiveness, which makes me suspect that I am missing some point. What I thought was that it would be very convenient to be able to specify once, using a simple Twisted-style idiom, what should happen with an object when it is no longer needed, which, because of the way Twisted works, should be given a chance to execute before the reactor shuts down, but similarly when the object simply dies out normally (i.e. the point here is being able to use deferred to specify a non-instantaneous cleanup procedure). An example of this would be an object that interacts with a remote server that should notify the server before retiring from the interaction. I think the method I proposed including the missing element I described above handles this nicely. I'm not sure what you meant by explicit cleanup. Joe. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com [View Less]

1 0

[Twisted-Python] Sending arguments to application
by Roland Hedberg May 25, 2005

May 25, 2005

Hi! I using the variant "twistd -y foo.py" and I would like to be able to send arguments to foo.py in the same command. The preferable way would be something like "twistd -y foo.py arg1 arg2" But that doesn't work, twistd complains. If it can be done some other way, how ? -- Roland

3 2

Re: [Twisted-Python] cleanup in twisted
by Joachim Boomberschloss May 25, 2005

May 25, 2005

--- Jp Calderone <exarkun(a)divmod.com> wrote: > On Mon, 23 May 2005 05:12:49 -0700 (PDT), Joachim > Boomberschloss <boomberschloss(a)yahoo.com> wrote: > > > >--- Jp Calderone <exarkun(a)divmod.com> wrote: > >> On Mon, 23 May 2005 02:40:53 -0700 (PDT), Joachim > >> Boomberschloss <boomberschloss(a)yahoo.com> wrote: > >> > > >> >--- Bob Ippolito <bob(a)redivi.com> wrote: > >> >> > >> … [View More]>> On May 22, 2005, at 8:46 AM, Joachim > >> Boomberschloss > >> >> wrote: > >> >> > >> >> > I just jotted down a little mechanism for > >> >> cleaning-up > >> >> > in Twisted, and I wanted to see if: > >> >> > 1. other people think it's needed > >> >> > 2. other people manage to use it > >> >> > > >> >> > What this does is enable one to define a > >> >> __cleanup__ > >> >> > method which gets call either when the > instance > >> is > >> >> > deleted, or when the reactor shuts down. It > can > >> >> return > >> >> > a dereffed that delays the shutdown. The > >> benefit > >> >> is > >> >> > being able to define communication-related > >> stuff > >> >> in > >> >> > the cleanup method, which is not so useful > to > >> do > >> >> in > >> >> > __del__. > >> >> > >> >> This is just begging for object leaks, because > >> >> __del__ disables > >> >> aspects of cyclic GC. > >> > > >> >Hmmpf. What does this mean, and is there a > simple > >> way > >> >of resolving it? > >> > > >> > >> If you construct a reference cycle which > contains > >> an object which has a __del__ method, the entire > >> cycle becomes "garbage" - Python cannot free any > of > >> the objects or call any of their __del__ methods. > >> Instead, it puts them into the gc module's > `garbage' > >> list and leaves them there forever. > >> > >> There's no simple way to resolve this (except > to > >> not implement __del__, of course ;). > >> > >> A non-simple way to resolve it is to use > weakref > >> callbacks instead of __del__. Weakref callbacks > >> have some nasty bugs in versions of Python older > >> than 2.3.5 (more, the further back you go), and > >> they're trickier to use than __del__. They don't > >> create garbage cycles, though. > >> > > > >Can you point me to an example of this (preferably > in > >Twisted)? Is this whole cleanup thing worth my time > >fixing it in your opinion? > > > > Twisted doesn't make use of it, due to the > instabilities in previous Python versions (which > Twisted still supports). > > Another technique I didn't mention is to move the > __del__ implementation off of the object which might > participate in a cycle and onto a subsidiary object. > Deferreds do this in Twisted 2.0. As a general > technique, this doesn't make much sense, since it > depends on knowledge of the structure of specific > object graphs (ie, you need to know where cycles > will form and where they will not). > > I'm not sure if it's worth the effort. I don't > exactly see the attraction of the functionality > being provided. I tend to find that explicit > cleanup is not overly burdensome. Perhaps you can > share some examples of how you see it being used? Well, the attraction is this: I ran into situations in which it is desirable for an object to do some communication-related cleanup when deleted, either when the program shuts down or when it is no longer referenced. For example, I have objects responsible for maintaining communication with some servers, and I want them to inform the server when they cease to maintain communication with it. This should be done either when the service is no longer necessary and the object (the maintainer) is deleted, or when the program shuts down, so basically, the functionality required is to be able to define communication-related stuff (i.e. things that aren't instantaneous and involve deferreds) to be done either when the object is deleted or when twisted shuts down. The latter is easy to do, but the former isn't, and come to think of it, my solution isn't good regardless of reference cycles, because, since the cleanup method is spawned from __del__, it has to do the cleanup instantaneously or the cleanup process won't be able to refer to the object at a later stage. Basically what is needed is to be able to defer the destruction of the object both at program shutdown, which is easy, and before object deletion, which I don't know how to do. Any thoughts (either about the attractiveness of the functionality or about how to achieve it)? Joe. __________________________________ Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html [View Less]

2 3

[Twisted-Python] Handle Control-C
by Johannes Beigel May 25, 2005

May 25, 2005

Is there a (preferred) way to handle breaks with Control-C? I'm aware of reactor.addSystemEventTrigger("before", "shutdown",...), but I'd like to do some stuff with a fully running reactor and then call reactor.stop() manually after some Deferreds come back. -jojo

2 1

[Twisted-Python] Twisted server connection loss with Mysql
by Raghul Jagan May 25, 2005

May 25, 2005

Dear Friends, I am using a twisted server to connect the mysql database using "adbapi".When I start my server the connection to the mysql established and the run as a separate thread. Suppose If the database is restarted or there is a response delay, then the twisted server losses the connection and when I tried by quering the database it reports the error giving "Loss in mysql connection". I also tried using the twisted 2.0 version,… [View More]

2 1

[Twisted-Python] Twisted as subprocess
by Nicola Larosa May 25, 2005

May 25, 2005

I need to turn reactor.spawnProcess on its head. That is, I need to run a Twisted-based program as a subprocess, getting requests on stdin and giving responses on stdout. How do I hook up the protocol and the rest? It's going to be spawned by the snmpd daemon of net-snmp, via the pass_persist directive in snmpd.conf . -- Nicola Larosa - nico(a)tekNico.net How can I in five minutes shift a lifetime's hidden pain? -- Julia Fordham, Girlfriend, Porcelain, 1989

2 3

[Twisted-Python] Zope interfaces
by Grant McDonald May 23, 2005

May 23, 2005

Hi All, I have just tried running my 1.3.0 application in 2.0.0 (rc2 I think?) and I received the following message: raise ImportError, "you need zope.interface installed (http://zope.org/Products/ZopeInterface/)" ImportError: you need zope.interface installed ( http://zope.org/Products/ZopeInterface/ <http://zope.org/Products/ZopeInterface/> ) >From this I understand that I need to install zope interfaces even if I don't use them, is that correct? (I imagine this is because … [View More]

6 5