bug#68006: 30.0.50; Image-mode speed

[Manuel Giraud]

Eli Zaretskii <eliz@gnu.org> writes:

[...]

>> For image-dired, there is 'image-dired-contents-sha1'.  Maybe this the
>> one you thought about?
>
> Probably.

Hi Eli,

I was comtemplating the idea of using 'image-dired-contents-sha1' to
ensure that the image contents has not changed on disk.  But then I
asked myself if a function "give me a unique id of this file based on
its content" does not already exist in Emacs.  I could not found one but
maybe we could create one (eg. file-unique-identifier)?

Or do you prefer to keep this into the image library?  In which case,
i'll move this function to "image.el" or "image-mode.el".
-- 
Manuel Giraud