Am 03.10.2013 21:53, schrieb Serhiy Storchaka: >> the first time time with a bit shift of 7 > > Double "time".
thx, fixed >> with a 128bit seed and 64-bit output > > Inconsistancy with hyphen. There are same issues in other places. I have unified the use of hyphens, thx! >> bytes_hash provides the tp_hash slot function for unicode. > > Typo. Should be "unicode_hash". Fixed > x = _PyHash_Func->hashfunc(PyUnicode_BYTE_DATA(self), > PyUnicode_GET_LENGTH(self) * PyUnicode_KIND(self)); Oh nice, that's easier to read. It's PyUnicode_DATA(). > I doubt about this. If one collects bytes and strings in one dictionary, > this equality will only double the number of collisions (for DoS attack > we need increase it by thousands and millions times). So it doesn't > matter. On the other hand, I one deliberately uses bytes and str > subclasses with overridden equality, same hash for ASCII bytes and > strings can be needed. It's not a big problem. I merely wanted to point out that there is a simple possibility for a minor optimization. That's all. :) >> For very short strings the setup costs for SipHash dominates its speed > but it is still in the same order of magnitude as the current FNV code. > > We could use other algorithm for very short strings if it makes matter. I though of that, too. The threshold is rather small, though. As far as I remember an effective hash collision DoS works with 7 or 8 chars. >> The summarized total runtime of the benchmark is within 1% of the > runtime of an unmodified Python 3.4 binary. > > What about deviations of individual tests? Here you go. http://pastebin.com/dKdnBCgb http://pastebin.com/wtfUS5Zz Christian _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
