Subject: bug#56682: Fix the long lines font locking related slowdowns

From: "[email-masked]" <[email-masked]>
Date: Sat, 13 Aug 2022 11:00:22 +0300

09:13, August 13, 2022, Eli Zaretskii <[email-masked]>:

From: Stefan Monnier <[email-masked]>
Cc: Dmitry Gutov <[email-masked]>, Eli Zaretskii <[email-masked]>,
[email-masked]
Date: Fri, 12 Aug 2022 22:01:54 -0400

> I can only repeat that the only ways to improve font locking in a non-local
> way (or at least, the only ways that were identified in the discussions so
> far) are either to improve the speed of syntax-ppss by an order of
> magnitude, in which case it would perhaps become feasible to allow
> syntax-ppss to have access to the whole buffer, or to equip syntax-ppss with
> heuristics to make it work "as well as possible" even when it only has
> access to a portion of the buffer.

But the locked narrowing is applied based on the presence of long-lines
rather than based on the total size of the buffer.

That's true, but the two are closely related: a buffer with very long
lines tends also to be a large buffer.

Like I mentioned prevously (a few times), the thresholds are very different.

And now you have a branch where you can experiment with setting them separately.