[Python-Dev] Locked-in defect? 32-bit hash values on 64-bit builds

Raymond Hettinger raymond.hettinger at gmail.com
Fri Oct 15 22:10:37 CEST 2010


On Oct 15, 2010, at 10:40 AM, Benjamin Peterson wrote:

> I think the panic is a bit of an overreaction. PEP 384 has still not
> been accepted, and I haven't seen a final decision about freezing the
> ABI in 3.2.

Not sure where the "panic" seems to be.
I just want to make sure the ABI doesn't get frozen
before hash functions are converted to Py_ssize_t.

Even if the ABI is nor frozen at 3.2 as Martin has proposed,
it would still be great to get this in for 3.2

Fortunately, this doesn't affect everyday users, it only
arises for very large datasets.  When it does kick-in though
(around 2**32 entries), the degradation is not small, it
is close to catastrophic, making dicts/set unusable
where O(1) lookups become O(n) with a *very* large n.


Raymond




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