On Mon, Feb 13, 2012 at 9:37 PM, Stefan Behnel <stefan...@behnel.de> wrote: > Maciej Fijalkowski, 13.02.2012 19:44: >> On Mon, Feb 13, 2012 at 4:29 PM, Stefan Behnel wrote: >>> Sébastien Volle, 13.02.2012 13:33: >>>> My team is working on a project of fast packet sniffers and I'm comparing >>>> performance between different languages. >>>> So, we came up with a simple ARP sniffer that I ported to Python using >>>> ctypes. >>> >>> If performance is important to you, you may want to write the wrapper for >>> Python in Cython instead (and maybe also parts of the filtering code, which >>> I assume your program to be about). >> >> I appreciate your willingness to advertise cython wherever it's >> possible, but this is simply not on topic on the current thread. > > Sébastien Volle replied to my mail telling me that their current approach > was actually based on LuaJIT and its native FFI, and that he was mostly > comparing that to other languages (which all loose thoroughly in the > competition, BTW). That makes Cython on-topic for him at least. > > I also find Cython generally *very* on-topic when the intention is to > interface Python code with C code, especially when performance and/or ease > of use are part of the requirements. In terms of features and comfort, > ctypes is still a bit too far behind the user experience that Cython has to > offer. Given how important Cython has become for the Python ecosystem in > many regards, it's sad that PyPy still doesn't have it available. From what > I hear, that's a serious blocker to some users. (Or should I say "most > users"?)
Fair point actually. And I agree about all points about ctypes. > > >> Cython is not a panacea for all woes > > Well, what is? > > >> and it's actually slower than >> pypy on most cases that don't involve calling C. It's also slower even >> when you provide direct type annotations > > Ah, "most cases", hm? How is that for a well founded statement? What are > you using for comparison? speed.pypy.org? Have you noticed that amongst all > those benchmarks there that PyPy was specifically tuned for, there is not a > single benchmark that was selected specifically for Cython? There are > always lies, damn lies and then there are benchmarks, don't forget that. Well, those benchmarks were not really selected for pypy. There is a very limited set of available interesting python benchmarks and we made the selection rather on "what is slow" rather than "what is fast", if any sort of pypy-related things were considered, barring the obvious "does it run on PyPy". > > >> so you have a pretty >> reasonable usecase for pypy even in cases where calling C is a >> problem. Also, we're going to attack those ctypes problems. > > Since when is "we can do that, too" synonymous with "there are no > alternatives"? World domination seems an attractive goal to go after, but > it's pretty boring in the long run. > > Besides, "going to attack" admits that you're not there yet. Cython has > been there for a couple of years now, it solves real problems that real > users have today, and it's constantly getting better in doing so, because > it's being designed and developed to solve those problems. > > It may not be obvious to you, but PyPy isn't a panacea either. > Right. I agree that cython offers a much better experience than ctypes. > >> If you wish to respond to my mail, please put it into a post that has >> a different title and not hijack all the discussions with cython. > > Ok, done. BTW, what are those show-off mails meant for that you keep > sending to python-dev on each PyPy release? Do you really consider them > on-topic for the development of the CPython runtime, or even just the > Python language? Food for thought ... Hm. I dunno, that might be really a mistake on our side. I'll probably stick with python announce then. PS. Sorry for the tone of my original email, it was a bit unprofessional. Cheers, fijal _______________________________________________ pypy-dev mailing list pypy-dev@python.org http://mail.python.org/mailman/listinfo/pypy-dev
