On Fri, Oct 15, 2010 at 4:10 PM, Raymond Hettinger <raymond.hettin...@gmail.com> wrote: > > 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.
Just to be clear, hashing right now just uses the C long type. The only major platform where sizeof(long) < sizeof(Py_ssize_t) is 64-bit Windows, right? And the change being proposed is to make tp_hash return a Py_ssize_t instead of a long, and then make all the clients of tp_hash compute with Py_ssize_t instead of long? Reid _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
