GNU bug report logs - #68006
30.0.50; Image-mode speed

Previous Next

Full log

View this message in rfc822 format

From: Eli Zaretskii <eliz <at> gnu.org>
To: Manuel Giraud <manuel <at> ledu-giraud.fr>
Cc: stefankangas <at> gmail.com, 68006 <at> debbugs.gnu.org
Subject: bug#68006: 30.0.50; Image-mode speed
Date: Sat, 02 Nov 2024 13:08:35 +0200

> From: Manuel Giraud <manuel <at> ledu-giraud.fr>
> Cc: stefankangas <at> gmail.com,  68006 <at> debbugs.gnu.org
> Date: Mon, 28 Oct 2024 15:31:22 +0100
> 
> Here is a new version for my patch to add some user control on the image
> cache.  This time, I have done some tests and benchmarks.
> 
> Instead of trying to have a completely different cache, I'm using the
> current one but I had a condition to flush (or not) an image based on a
> user defined time to live (TTL) for an image.  This TTL is a number of
> seconds since the image was last displayed.
> 
> I have also tested it in image-mode with the second patch.  I tested by
> browsing a directory with some rather large pictures in it (4000x3000
> pixels, ≈6MB for each file).  I opened the first image in a 1640x1000
> window (so each image is scaled) and did the following:
> 
>   - M-: (dotimes (i 10) (image-next-file 1))  ;; for cache warming
>   - M-: (dotimes (i 10) (image-next-file -1)) ;; return to first image
>   - M-: (benchmark-run 10 (dotimes (i 10) (image-next-file 1))
>                           (dotimes (i 10) (image-next-file -1)))
> 
> Here is the timings I get:
> 
>      - with master (ea685170063): (109.208767158 15 1.0938777159999997)
>      - with this patch: (6.934307561 15 1.095243891)

The C part looks OK, but I don't understand how will this be used by
Lisp programs.  We don't intend to use the new TTL member by default
each time we display an image, do we?  So I think we need to analyze
the various uses of images and decide which ones will use TTL (and
what values to use in that case) and which won't.

I also envision a need to have a Lisp API which takes an existing
image and sets its TTL to a given value.  And maybe other APIs as
well, I don't know.  But without such APIs and without sensible
defaults about them, this features sounds incomplete.

Previous Next

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