(Replying on list - assuming Justin went off list my mistake) On Fri, Mar 16, 2012 at 4:54 AM, Justin Peel <pee...@gmail.com> wrote: > Two things to mention. First, if you are going to use valgrind, you > will need to build your own pypy because, as far as I know, the > buildbot ones do not have the debug info so you won't have any helpful > function names in your profile. If I remember correctly, most of the > time used is in _operate in rzlib.py. > > Also, in my opinion, the next thing to try in speeding up this code is > to do a faster copy than a char by char copy for copying to the input > buffer that is sent to the external C function. I'm not sure if the > copying from the output buffer to the string builder is char by char > or not.
Looking at the code for rzlib.py, _operate does seem to be the core function, and so likely the hot spot. https://bitbucket.org/pypy/pypy/src/default/pypy/rlib/rzlib.py It uses the StringBuilder class from rstring via the append_charpsize method, defined as follows: https://bitbucket.org/pypy/pypy/src/default/pypy/rlib/rstring.py def append_charpsize(self, s, size): l = [] for i in xrange(size): l.append(s[i]) self.l.append(self.tp("").join(l)) self._grow(size) So it is indeed doing a char by char copy of the string from Python to zlib (in my case to decompress a long chunk of data). I don't know enough about PyPy's internals to say if something naive like this would work faster (guessing looking at the append_slice method): def append_charpsize(self, s, size): assert 0 <= size self.l.append(s[0:size]) self._grow(size) Presumably to try this idea out I'm going to first need to get PyPy to build locally? Thanks, Peter _______________________________________________ pypy-dev mailing list pypy-dev@python.org http://mail.python.org/mailman/listinfo/pypy-dev
