Author benjamin.peterson
Recipients Arfrever, Bob.Ziuchkovski, Giovanni.Bajo, PaulMcMillan, ReneSac, Vlado.Boza, alex, arigo, benjamin.peterson, camara, christian.heimes, cvrebert, dmalcolm, gregory.p.smith, haypo, iElectric, koniiiik, lemburg, mark.dickinson, ncoghlan, sbermeister, serhiy.storchaka, Łukasz.Rekucki
Date 2013-01-02.14:49:29
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Content
2013/1/2 Giovanni Bajo <report@bugs.python.org>:
>
> Giovanni Bajo added the comment:
>
> Il giorno 02/gen/2013, alle ore 06:52, Christian Heimes <report@bugs.python.org> ha scritto:
>
>>
>> Christian Heimes added the comment:
>>
>> Thanks for the information! I'm working on a PEP for the issue at hand.
>
> Since you're collecting ideas on this, I would like to stress that, in the Python 3 transition, it was deemed acceptable to switch all objects to use unicode strings for attribute names, making the hash computation of such attributes (in the context of the instance dictionary) at least twice as slow than it used to be (the 'at least' refers to the fact that longer strings might have even worse effects because of a higher number of cache misses). SipHash isn't twice as slow as the current hash function, not even for short strings.
>
> So there is a precedent in slowing down the hash computation time in a very important use case, and it doesn't look like hell froze over.

It's probably not to bad for attribute names because a) they're short
b) they're interned c) the hash is cached.
History
Date User Action Args
2013-01-02 14:49:30benjamin.petersonsetrecipients: + benjamin.peterson, lemburg, arigo, gregory.p.smith, mark.dickinson, ncoghlan, haypo, christian.heimes, iElectric, Arfrever, alex, cvrebert, dmalcolm, Giovanni.Bajo, PaulMcMillan, serhiy.storchaka, Vlado.Boza, koniiiik, sbermeister, camara, Łukasz.Rekucki, ReneSac, Bob.Ziuchkovski
2013-01-02 14:49:30benjamin.petersonlinkissue14621 messages
2013-01-02 14:49:29benjamin.petersoncreate