Re: Redisplay slower in Emacs 28 than Emacs 27

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> I mean, it's between 0% to 50% faster, but the 50% test was somewhat
> unrealistic (many identical images in the same buffer).  In a more
> realistic, but very image-heavy eww-like buffer, it's about 15% faster
> scrolling through the buffer.

img_hash 32.1s
sxhash 42.0s

with this test:

(defun bench ()
  (switch-to-buffer "images")
  (erase-buffer)
    (dotimes (i 200)
      (let ((file (format "/tmp/P%d.JPG" (+ i 1320800))))
        (when (file-exists-p file)
          (insert-image
           (create-image
            (with-temp-buffer
              (set-buffer-multibyte nil)
              (insert-file-contents-literally file)
              (buffer-string))
            'jpeg t :scale 1)))
        (insert "\n\n")))
  (goto-char (point-min))
  (benchmark-progn
    (dotimes (i 5)
      (goto-char (point-min))
      (while (not (eobp))
        (sit-for 0.01)
        (forward-line 2)))))

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no