bug#68006: 30.0.50; Image-mode speed

[Eli Zaretskii]

> From: Manuel Giraud <manuel@ledu-giraud.fr>
> Cc: stefankangas@gmail.com,  68006@debbugs.gnu.org
> Date: Fri, 05 Jan 2024 11:50:24 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> Ok.  Maybe we should re-use the current C cache code with a "nice"
> >> interface for this too.
> >
> > Yes, that can be done.
> 
> Ok.  More thinking: my idea is to have an interface to create/destroy
> image caches and feed/query them.  And why not have a Lisp interface to
> it so something like image-mode could use this to manage its own cache.

Yes, of course.  We have a Lisp API for the existing cache as well,
but this new one will need it much more, since we basically rely on
the Lisp programs to manage this new cache.

> > But we might need to store additional information there, like the
> > buffer of the image, for example.
> 
> I don't understand.  Where do you think that the buffer of the image
> should be stored?

In the cache, together with the image, I think.  How else would the
Lisp programs know which images "belong" to them, and when to uncache
them?  I guess some other information relevant to the cache-removal
decision will also need to be stored there.