Hi Armin, That sounds like a good simplification to me.
Cheers, Carl Friedrich On January 28, 2017 1:28:18 PM GMT+01:00, Armin Rigo <armin.r...@gmail.com> wrote: >Hi all, > >I would like to merge the branch "rpython-hash". That branch drops >the RPython requirement that hashes (notably of prebuilt instances) >don't change across translation. By dropping it, I could remove some >cruft at various places, and it makes the life a bit easier for other >systems like STM, too. > >The motivation is that in py3.5 we're considering the hash >randomization feature again, for strings. This feature is not >compatible at all with the idea that hashes should not change. So >with "rpython-hash" it should be possible, at translation-time, to >choose the algorithm used by CPython 3.5 (siphash-2-4), and moreover >with an optional seed at runtime. > >The main place that relied on the hashes not changing is prebuilt >dictionaries. That branch fixes them by not including the "indexes" >part at all during translation, and rebuilding the index on the first >usage. > >There were only three places I found in PyPy that relied on this >feature: weakrefs caching the hash of their referent; frozensets >caching their own hash; and a detail inside _cffi_backend. All places >needed fixing, but that was easy. > >I think it's a good move and a small simplification of RPython >internals. Of course it might break other RPython-based interpreters >out there. Any feedback about that would be appreciated. > > >A bientôt, > >Armin. >_______________________________________________ >pypy-dev mailing list >pypy-dev@python.org >https://mail.python.org/mailman/listinfo/pypy-dev
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