GNU bug report logs - #68244
hash-table improvements

Previous Next

Full log

Message #62 received at 68244 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Kangas <stefankangas <at> gmail.com>
To: Mattias Engdegård <mattias.engdegard <at> gmail.com>, 
 68244 <at> debbugs.gnu.org
Subject: Re: bug#68244: hash-table improvements
Date: Tue, 9 Jan 2024 13:51:24 -0800

Mattias Engdegård <mattias.engdegard <at> gmail.com> writes:

> It's the hash-table's turn to be subjected to some performance
> tuning. The implementation has changed very little over the years and
> it's not so much a matter of a single big thing to fix as many small
> ones, so the list of changes is fairly long but ever little helps.
>
> A working patch series can be found in the scratch/hash-table-perf
> branch. Although it should all be satisfactory and an improvement on
> what was before, there are a couple of details that I'd like to do
> better, which is why this hasn't been merged yet: the way shared
> hash_table_test structs are cached isn't very elegant, nor is the way
> we deal with Qunbound in pdumper.c.

Thanks, these changes make sense to me both in terms of the performance
gains and the cleaner implementation.

The improved usability (de-emphasizing `hash-table-size', etc.) and
printed representation are certainly appreciated too.

Maybe lift `hash-table-rehash-size' and `hash-table-rehash-threshold' to
Lisp and mark them obsolete.  The hash table implementation is complex
enough for it to be worth avoiding cruft lying around.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.