GNU bug report logs -
#57447
28.1.90; Can font-lock stop requesting fontification of invisible text?
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Reported by: Ihor Radchenko <yantar92 <at> gmail.com>
Date: Sat, 27 Aug 2022 05:35:02 UTC
Severity: normal
Found in version 28.1.90
Done: Stefan Monnier <monnier <at> iro.umontreal.ca>
Bug is archived. No further changes may be made.
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Message #14 received at 57447 <at> debbugs.gnu.org (full text, mbox):
> From: Ihor Radchenko <yantar92 <at> gmail.com>
> Cc: 57447 <at> debbugs.gnu.org
> Date: Sat, 27 Aug 2022 15:45:19 +0800
>
> I did expect some invisible text to be fontified, but did not expect 10x
> increase in the requested text size.
The increase depends on how much text is hidden in each chunk,
relative to jit-lock-chunk-size. If you have a lot of small shunks of
hidden text interspersed with visible text, you could have all of the
invisible text fontified.
> > One way this could be improved is by making jit-lock-chunk-size
> > smaller. This will make the probability of such "over-fontification"
> > lower.
>
> I tried to reduce the chunk size and at appears to help. However, I am
> not sure if there are other side effects of reducing
> jit-lock-chunk-size.
If the size is smaller than the visible portion of the buffer, it will
cause repeated calls to fontification-functions, instead of just one
call. If fontification-functions do their job in approximately linear
time, you shouldn't see any adverse effects, I think. But if each
call to fontification-functions incurs some one-time overhead that is
relatively expensive, the result could be slower redisplay when the
window is scrolled a lot.
> The code producing the messages is in
> https://github.com/yantar92/org/blob/feature/org-font-lock-element/lisp/org-font-lock-core.el
> Search for org-font-lock-verbose in the code.
>
> If you want to test it yourself, clone https://github.com/yantar92/org
> and use feature/org-font-lock-element branch with the file I provided,
> unfold the "Home" headline, and then unfold the "Ideas ..." headline.
I only want to test that if you see something that is inconsistent
with my description of how this stuff works, including the value of
jit-lock-chunk-size.
This bug report was last modified 2 years and 315 days ago.
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