[Python-Dev] CFFI released (original) (raw)

Terry Reedy tjreedy at udel.edu
Tue Jun 19 04:35:35 CEST 2012

On 6/18/2012 5:29 PM, Armin Rigo wrote:

On Mon, Jun 18, 2012 at 9:10 PM, Maciej Fijalkowski <fijall at gmail.com> wrote:

Me

Make cffi less buggy (check the tracker for new test cases ;-), faster (closer to swig type wrappers), and easier to use than ctypes, and I am sure there will be interest.

I would say it's already fulfilling those three, but I suppose you should try for yourself.

I don't think the first is fulfilled so far, as we found various issues on various Linux and non-Linux platforms (and fixed them, so I suppose that release 0.1.1 is coming soon). But I agree with Fijal about speed and ease of use. Like SWIG it generates wrappers in the form of a CPython C extension with built-in functions, so I suppose the performance is similar to SWIG and not ctypes. Well, SWIG wrappers typically have custom logic written in C, whereas in cffi this logic is typically written as Python code, so I suppose it ends up being slower (on CPython; on PyPy small wrapping functions are inlined and have little cost). But the same argument can be pushed further to "why did you use a slow language like Python to write your app in the first place", which I hope we agree is bogus :-)

Yes, because languages have no speed, only implementations do; and yes, because when CPython really is too slow for a particular task, it can be pushed onto C. But some people (pygame, others on python-list) have reported that for their project, ctypes negates too much of the C speedup, relative to swig or similar. So it has not been quite the C wrapper generator killer that some people hoped for. (This is not to say that is not great for uses it does succeed at.)

-- Terry Jan Reedy

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