Mailman 3 August 2003 - Twisted

[Twisted-Python] Forms-handling in Twisted
by Thomas Weholt Aug. 26, 2003

Aug. 26, 2003

Can anybody provide a simple example on how to use the form-widget in Twisted? I need something that sets datatype and some form of validation on post, server-side. Somethinglike the Guard-example in the latest alpha would be great. Best regards, Thomas Weholt

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[Twisted-Python] Progressbar via curses for cmdline, LivePage for web
by Justin Johnson Aug. 26, 2003

Aug. 26, 2003

I have some questions about displaying console output using curses for unix and Console or some other module for windows. I did see posts earlier about curses and have read the example cursesclient.py file in cvs, but I still have some questions. I have several methods in a PB server that do things with DeferredLists. I want progress on the overall task to be reported as each of the callbacks get called. The way I have been doing this is having my client subclass pb.Referenceable, defining remote_print on the client, and then passing the client as an argument to the server's remote calls. Then each callback prints a "." when they complete and an "F" upon failure, thus sort of simulating a progress bar. This doesn't work when I have multiple tasks going at once whose progress I want to report separately. So it seems to me that I need to start using curses or some other such module. I would have to define tasks (something that has its own progress bar) and pass the task or the id to the task to the callbacks so they would update the appropriate progress bar. Additionally, I would like to provide similar functionality for a web interface to the server, using woven, and probably LivePage so that progress could be communicated back appropriately. So... I'm going to start digging into this, but I am wondering, has anyone done this before? Do you have any pointers for me? Thanks. -Justin

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[Twisted-Python] twisted installation (new to list)
by Max Khesin Aug. 26, 2003

Aug. 26, 2003

Hi all, I am trying to get twisted working on an RH7.1 box (in order to run buildbot). As 7.1 comes with (and relies on) python 1.5 I had to install parallel version 2.2 as python2. How do I configure twisted to run with this setup? thanks, max.

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[Twisted-Python] Question about multiple XML-RPC handlers
by Thomas Weholt Aug. 25, 2003

Aug. 25, 2003

>From the docs I see this example on how to implement a XML-RPC service : from twisted.web import xmlrpc, server class Example(xmlrpc.XMLRPC): """An example object to be published.""" def xmlrpc_echo(self, x): """Return all passed args.""" return x def xmlrpc_add(self, a, b): """Return sum of arguments.""" return a + b def main(): from twisted.internet.app import Application app = Application("xmlrpc") r = Example() app.listenTCP(7080, server.Site(r)) return app application = main() if __name__ == '__main__': application.run(save=0) Test it with : >>> import xmlrpclib >>> s = xmlrpclib.Server('http://localhost:7080/') >>> s.echo("lala") 'lala' All is well and fine. But I need to differentiate abit, more like : >>> import xmlrpclib >>> s = xmlrpclib.Server('http://localhost:7080/') >>> s.Example.echo("lala") 'lala' For instance, if I create another XML-RPC-handler: class Dummy(xmlrpc.XMLRPC): def xmlrpc_subtract(self, x, y): return x - y I want someway to register it with the server and be able to call : >>> import xmlrpclib >>> s = xmlrpclib.Server('http://localhost:7080/') >>> s.Example.echo("lala") 'lala' >>> s.Example.add(1,2) 3 >>> s.Dummy.subtract(1,2) -1 I've hacked the current XML-RPC code in Twisted abit to fit my needs, but I'd like to be able to use the standard Twisted framework for this, not some ad-hoc/mediocre/experimental thingy. Can I create a root-request which somehow redirects the call to the correct instance/method if found or give a proper failure-result if nothing is found? Any clue or hint would be highly appreciated. Best regards, Thomas Weholt

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[Twisted-Python] bug in conch tutorial
by Paul Boehm Aug. 25, 2003

Aug. 25, 2003

class CatChannel(channel.SSHChannel): name = 'session' def channelOpen(self, data): d = self.conn.sendRequest(self, 'exec', common.NS('cat'), wantReply = 1) d.addCallback(self._cbSendRequest) self.catData = '' imho self.catData should be cleared before it's possible for the deferred to fire, and append to catData. def _cbSendRequest(self, ignored): self.write('This data will be echoed back to us by "cat."\r\n') self.conn.sendEOF(self) self.loseConnection() def dataReceived(self, data): self.catData += data def closed(self): print 'We got this from "cat":', self.catData

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[Twisted-Python] XML-RPC: Why encapsulate in a list?
by Steve Freitas Aug. 24, 2003

Aug. 24, 2003

Hi all, If I try this code: def xmlrpc_blah(self): return { 'x': "yadda" } What I get back through Python's xmlrpclib client is... [{'x':"yadda"}] Why does my dictionary (ergo struct) get encapsulated in a list (ergo array)? What should I do if I just want to return a struct? Thanks! Steve Freitas

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[Twisted-Python] twistedmatrix.com downtime!
by Christopher Armstrong Aug. 24, 2003

Aug. 24, 2003

Twistedmatrix.com is going to be down while glyph moves to Boston -- probably a couple of days. We have set up a secondary MX for email, so messages to people @ twistedmatrix.com will not be lost. Also, of course, the web site, CVS, and all other services will be down. Thank you for your patience in the matter! -- Twisted | Christopher Armstrong: International Man of Twistery Radix | Release Manager, Twisted Project ---------+ http://twistedmatrix.com/users/radix.twistd/

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[Twisted-Python] Benchmark/performance of Twisted vs. the Cheetah/Webware/Apache/mod_webkit combo? [newbie]
by Richard Johannesson Aug. 24, 2003

Aug. 24, 2003

Just curious about if there is some general feeling about how Twisted performs. Would be good to know for estimating the server hardware requirements. Is there some dicussion / paper that coves how best to configure Twisted/Woven for maxium performance? Not needed at the moment, but been reading the Apache load balancing features. Would be nice to know that this is available when required. What does the asynchronous implementation mean in terms of performance. How much does that give. Primarily looking at Twisted/Woven at the moment for creating web apps using postgresql DB backend. If there is some other group I should be posting these newbie questions to, please let me know. Thanks, Richard

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[Twisted-Python] Internet services for online gaming teams.
by Paul Rudin Aug. 23, 2003

Aug. 23, 2003

Greetings Twisted people (Twisters? :-)), I recently stumbled over twisted and I thought it might be an appropriate base for an idea I had. This message outlines what I have in mind, and I'm hoping that people will provide some insight into whether Twisted would be likely to be of significant assistance in implementing such an idea. This message is possibly only marginally on topic for this list - please forgive me if you feel it's inappropriate content. If I proceed with this idea rest assured I will be back with many specific technical queries :-) Background ---------- Competitive gaming over the internet has been around for about a decade, and today is a hobby for millions (and a living for a few). Teams - in this context traditionally called "clans" compete against in other in online leagues and ladders, as well as sending teams to compete in LAN tournaments. Popular games are Quake3, Unreal Tournament, CounterStrike... (there are hundreds if not thousands). Clans are notable in that they exist almost exclusively in the internet. The vast majority of clan members will never meet their teammates in real life - although as noted above some teams will attend LAN events. Hence nearly all the organisation and social interaction happens over the net. Clans typically will have a number of online services to facilitate this. Examples: - irc channels - usually a private one and a public one, normally on quakenet (in Europe at least) - One or more web servers. Often incorporating some kind of "web forum" - phpbb or similar. Clan web servers often have similar functionality - access to rosters, game strategies, upcoming events, team lists for particular events... result history - standing in various leagues and ladders and so forth. - One or more ftp servers. For hosting recording of prior games; and miscellaneous useful files for members. - A nntp server. - A voice comms server. E.g. teamspeak or similar. - One or more game servers. - A mail server. These servers may interact with each other in an ad hoc way. For example web severs may use scripts to query or control game servers. Bots in irc channels might provide access to some information on game servers. However in general these services will not be well integrated - it is necessary for members to have accounts on each different server these accounts need to be managed as people join or leave the clan or change their roles with the clan. These servers are often hosted in fairly unreliable environments. Many clan members will have broadband connections at home and some of the services will be hosted on these. Some services might be hosted using machines and bandwidth provided by people's employers or place of study. Those administering the services will often not be experienced system administrators and will be using platforms not necessarily ideal for such operations. Often there maybe be external factors controlling when machines will be up; the availability of bandwith; and firewalls limiting the types of packets the machines can send and receive. Game servers tend to be the exception where the clan will pay a hosting company to provide a server on fast hardware with a high bandwith, low latency net connection. The idea. --------- I am aware of a number of projects attempting to provide an off the shelf web server for clans; but it strikes me that it would be a fun and potentially useful project to have an integrated system across web, ftp, irc, game servers, voice comms servers etc. Such a system would have a number of features. - A repository of all information relating to the clan. This repository of information should be stored redundantly and it should be easy to propagate across the internet. - Authentication and sophisticated authorisation mechanism the work across all the services - Access to information information using a variety of standard net protocols using familiar software. - The ability to host services on a variety of different platforms and to share the hosting among different servers which may not be very reliable. - Some "off the shelf" utilities to provide the kinds of thing likely to be common to most clans. - Customisable and extensible. - Very easy to install, so that people without technical expertise can contribute CPU cycles and bandwidth to providing services. A prototype ----------- As a starting point a web server and an irc bot providing access to the same distributed persistent information would be a good starting point for a kind of proof of concept. Twisted. -------- I hope the above gives you the flavour of the kind of thing I have in mind. It's not a detailed or well thought out plan - just something that occurred to me the other day. I don't know much about Twisted - but on looking through the web site it seems like it would be a good tool kit for building such a system. Is this impression accurate? Part of my motivation for contemplating this is simply to gain some experience of network programming. I have considerable programming experience, but mostly large desktop applications.

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[Twisted-Python] Re: [Pyobjc-dev] Re: pdb in PyObjC apps?
by Bob Ippolito Aug. 22, 2003

Aug. 22, 2003

On Tuesday, Aug 19, 2003, at 05:45 America/New_York, Michael Hudson wrote: > Zachery Bir <zbir(a)urbanape.com> writes: > >> Note to self: Don't use pdb and try to catch it through >> double-clicking the app :) > > :-) > > It shouldn't be *too* outrageously hard to teach my pyrepl interactive > tool how to cooperate with the Cocoa run loop (you need a way to give > an fd to Cocoa and say "give me control when there's something to read > on this" and I'm sure I saw one of them somewhere) in which case you > could have an interactive session running alongside your > application... Hmm, where's that can of tuits? I've developed a CoreFoundation reactor for Twisted that would facilitate this sort of thing. It's not mainline yet because I haven't had time to fully test and write enough examples -- it does work, but I'm not currently comfortable putting it in the rest of Twisted yet (especially due to the Pyrex build dependency). Here's what you would do (this obviously needs Developer Tools installed): Download Pyrex 0.8.2 Modify Pyrex/Compiler/Nodes.py .. change the block starting on line 160 to this (small fix to allow system includes): for filename in env.include_files: if not (filename.startswith('<') and filename.endswith('>')): filename = '"%s"' % filename code.putln('#include %s' % filename) Install Pyrex Checkout CVS HEAD of Twisted Build and install Twisted (or put twisted into your PYTHONPATH, I have a symlink of ~/src/Twisted/twisted at ~/Library/Python/2.3/site-packages/twisted) Go into Twisted/sandbox/etrepum/cfsupport python setup.py build_ext -i cd TWISTEDPACKAGE/internet ln -s TWISTEDCVS/sandbox/etrepum/cfreactor.py . ln -s TWISTEDCVS/sandbox/etrepum/cfsupport/cfsupport.so . That should work, to test it check out the examples in TWISTEDCVS/sandbox/etrepum/examples/PyObjC (which obviously require PyObjC, you can get that from PackageManager) Also note that the cfsupport module is enough to just get notifications on the fd, but I recommend using Twisted for anything that talks sockets anyway. -bob

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