Mailman 3 August 2002 - Twisted

[Twisted-Python] Patch for dbauth.tac in examples
by Steve Waterbury Aug. 6, 2002

Aug. 6, 2002

Since I want to implement a PB-based app with db authorization, I was tinkering with the dbauth.tac example in an effort to educate myself. Changed "passport" to "cred" and set the database explicitly (created the dbcred tables in the "twisted" database that bugs uses). "Create an Identity", "remove", and "[change] password" work; there seems to be a problem with gotPerspectives' call to dbgadgets.py, but I haven't messed with gadgets (don't need them yet), so I won't be looking at … [View More]

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[Twisted-Python] ClientFactory.connectionLost(connector, reason)
by Tommi Virtanen Aug. 6, 2002

Aug. 6, 2002

Hi. I've been groaning about how Twisted loses the actual errors, and does not allow programs to accurately report them to the user. Here is some progress on fixing that.. ClientFactory's connectionLost() method will get a new parameter "reason", which will be a failure.Failure(SomeException()). There will be no backwards compatibility; I will fix atleast the code in the main tree that has tests (that succeeded before the patch!). If you want to ensure compatibility, start using "… [View More]

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[Twisted-Python] spread.sturdy reconnect delay
by Paul Boehm Aug. 4, 2002

Aug. 4, 2002

currently, when spread.sturdy is unable to (re)connect (e.g. because the connection was refused/server not running), it retries at full speed.. without any delay.. implementing some kind of rate limiting is trivial, but i'm not sure about the right approach. the issue is current for me, as i'm using sturdy in my application and wouldn't want it to flood the network too much. i've come up with the following approaches: *) try n times, then wait i seconds, rinse, repeat *) try, sleep i, … [View More]

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[Twisted-Python] debian/control bug: only python-twisted depends on python-gtk
by Tommi Virtanen Aug. 4, 2002

Aug. 4, 2002

I think there's a bug in debian/control: currently, only python-twisted depends on python-gtk. But python-twisted is only a dummy package, and it's presence is not guaranteed in anyway (e.g. an app that needs python2.2 will depend on python2.2-twisted). Shouldn't python-gtk be split into python2.1-gtk, python2.2-gtk, and pythonX.Y-twisted depend on pythonX.Y-gtk? And while python-gtk is not split, python2.1-twisted should depend on python-gtk (>= 2.1), python-gtk (<< 2.2), … [View More]

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[Twisted-Python] dbapi and pb question
by Fredrik Aug. 3, 2002

Aug. 3, 2002

I am a newbie to this and i try to connect a database to pb, when trying this code i dont get any response from the server (running pbgtk.py)but the server outputs the print statement, how do I send bacdk a callback to the client ?? from twisted.enterprise import adbapi from twisted.spread import pb from twisted.internet import app class AgeDatabase(adbapi.Augmentation): """A simple example that can retrieve an age from the database""" def getAAge(self): sql = """… [View More]

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[Twisted-Python] Dynamic web application using twisted.web.resource
by Mukhsein Johari Aug. 3, 2002

Aug. 3, 2002

Hello fellow twisters, This is a question (albeit a long one) directed at twisted.web and resource. The project: I would like to serve a dynamic website using the twisted web server. I understand that the webserver's 'root' directory can be set at a file? I may have a misunderstanding of the code and docs but if so, feel free to set me straight. The website (not real): http://www.mywebsite.com/ This is the root of the site, which is in reality a erm..rpy? program? Which means that there … [View More]

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[Twisted-Python] FilePager
by Paul Boehm Aug. 1, 2002

Aug. 1, 2002

intended for twisted.spread.util: class FilePager(Pager): """A pager for files. """ def __init__(self, collector, file, chunkSize=8192): self.file = file self.chunkSize = chunkSize Pager.__init__(self, collector) def nextPage(self): data = self.file.read(self.chunkSize) if len(data) < self.chunkSize: self.stopPaging() return data

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[Twisted-Python] The stopConsuming method
by Matt Campbell Aug. 1, 2002

Aug. 1, 2002

I noticed a method in twisted.internet.abstract.FileDescriptor called stopConsuming, which can be called by the producer to indicate that there is nothing more to produce. The method calls self.unregisterProducer, then self.loseConnection. I also noticed that this method isn't part of the IConsumer interface and isn't implemented by twisted.protocols.http.Request. I think this method should be added to IConsumer and implemented by all classes that implement that interface, because it enables … [View More]

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[Twisted-Python] WebConduit
by Donovan Preston Aug. 1, 2002

Aug. 1, 2002

I developed this as a proof of concept and several people have expressed interest in seeing the implementation, so I thought I'd clean it up a little and send it to the list. The WebConduit is a project that I have been thinking about doing for several years now. Basically, it allows users to interact with a MUD server from a web page without any silly Java applets or frames that reload every 5 seconds. It does rely heavily on JavaScript to work, specifically it relies on the later browser's … [View More]

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[Twisted-Python] Updated defer patch
by Christopher Armstrong Aug. 1, 2002

Aug. 1, 2002

Ok, so I've added some code that wraps plain strings passed to .errback with a "DefaultException" and then issues a DeprecationWarning. Unfortunately, this patch causes tests to fail, since they pass a string to .errback and try to ensure that what gets passed to their error-callback is the same thing. So, following itamar's lead, this is backwards-compatibility-code-that's-only-half-backwards-compatible ;-) I've also updated the docstrings for callback and errback, they were out-of-date. (… [View More]Note, this is an updated version of my last patch, so those modifications are duplicated here) Index: twisted/internet/defer.py =================================================================== RCS file: /cvs/Twisted/twisted/internet/defer.py,v retrieving revision 1.12 diff -u -r1.12 defer.py --- twisted/internet/defer.py 24 Jul 2002 19:04:56 -0000 1.12 +++ twisted/internet/defer.py 1 Aug 2002 01:36:17 -0000 @@ -32,6 +32,9 @@ class TimeoutError(Exception): pass +class DefaultException(Exception): + pass + def logError(err): log.err(err) return err @@ -103,7 +106,7 @@ These will be executed when the 'master' callback is run. """ cbs = ((callback, callbackArgs, callbackKeywords), - (errback or logError, errbackArgs, errbackKeywords)) + (errback or (lambda x: x), errbackArgs, errbackKeywords)) if self.default: self.callbacks[-1] = cbs else: @@ -152,10 +155,9 @@ Each callback will have its result passed as the first argument to the next; this way, the callbacks act as a - 'processing chain'. - - If this deferred has not been armed yet, nothing will happen until it - is armed. + 'processing chain'. Also, if the success-callback returns a Failure + or raises an Exception, processing will continue on the *error*- + callback chain. """ self._startRunCallbacks(result, 0) @@ -165,13 +167,24 @@ Each callback will have its result passed as the first argument to the next; this way, the callbacks act as a - 'processing chain'. - - If this deferred has not been armed yet, nothing will happen until it - is armed. - """ - if not fail: + 'processing chain'. Also, if the error-callback returns a non-Failure + or doesn't raise an Exception, processing will continue on the + *success*-callback chain. + + The argument must be a Failure instance or None, and strings are + accepted for backward-compatibility, but are deprecated. + """ + if isinstance(fail, types.StringType) or isinstance(fail, types.UnicodeType): + import warnings + warnings.warn( + "Don't pass strings (like %r) to Deferred.errback (replacing with a DefaultException)." % + fail, DeprecationWarning, stacklevel=2) + fail = failure.Failure(DefaultException(fail)) + elif fail is None: fail = failure.Failure() + elif not isinstance(fail, failure.Failure): + raise TypeError("Deferred.errback accepts failure.Failure instances, strings, or None. %r is none of these." % fail) + self._startRunCallbacks(fail, 1) @@ -228,14 +241,8 @@ callbackArgs=(0,), errbackArgs=(1,)) break - if type(self.result) != types.StringType: - # TODO: make this hack go away; it has something to do - # with PB returning strings from errbacks that are - # actually tracebacks that we still want to handle as - # errors sometimes... can't find exactly where right - # now - if not isinstance(self.result, failure.Failure): - self.isError = 0 + if not isinstance(self.result, failure.Failure): + self.isError = 0 except: self.result = failure.Failure() self.isError = 1 -- Chris Armstrong << radix(a)twistedmatrix.com >> http://twistedmatrix.com/users/carmstro.twistd/ [View Less]

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[Twisted-Python] Defer changes
by Christopher Armstrong Aug. 1, 2002

Aug. 1, 2002

Two changes to defer.py 1) get rid of 'logError' as default errback. Tv complained about this, and I agree that it's silly -- logging should happen at the end of the chain, not at random points during the execution. instead of using 'logError', it now just uses (lambda x: x). 2) Get rid of old PB compatibility thing. We had a check for StringType in the result of a call/errback, because PB errors used to be strings. They're not any more. I committed the Failure patch months ago ;-) And one … [View More]more thing that I propose, but that's not in this patch: Enforcing the arguments to errbacks to be Failures. Very confusing things may happen if you pass something other than a Failure to an errback, and besides, passing something other than a Failure is like using 'raise "string"' rather than 'raise MyError("string")'. Here's the patch: Index: twisted/internet/defer.py =================================================================== RCS file: /cvs/Twisted/twisted/internet/defer.py,v retrieving revision 1.12 diff -u -r1.12 defer.py --- twisted/internet/defer.py 24 Jul 2002 19:04:56 -0000 1.12 +++ twisted/internet/defer.py 1 Aug 2002 00:42:15 -0000 @@ -103,7 +103,7 @@ These will be executed when the 'master' callback is run. """ cbs = ((callback, callbackArgs, callbackKeywords), - (errback or logError, errbackArgs, errbackKeywords)) + (errback or (lambda x: x), errbackArgs, errbackKeywords)) if self.default: self.callbacks[-1] = cbs else: @@ -228,14 +228,8 @@ callbackArgs=(0,), errbackArgs=(1,)) break - if type(self.result) != types.StringType: - # TODO: make this hack go away; it has something to do - # with PB returning strings from errbacks that are - # actually tracebacks that we still want to handle as - # errors sometimes... can't find exactly where right - # now - if not isinstance(self.result, failure.Failure): - self.isError = 0 + if not isinstance(self.result, failure.Failure): + self.isError = 0 except: self.result = failure.Failure() self.isError = 1 -- Chris Armstrong << radix(a)twistedmatrix.com >> http://twistedmatrix.com/users/carmstro.twistd/ [View Less]

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