Subject: bug#76230: [PATCH] New command 'project-forget-all-projects'

From: Ship Mints <[email-masked]>
Date: Wed, 5 Mar 2025 13:51:53 -0500

On Sun, Mar 2, 2025 at 10:01 PM Dmitry Gutov <[email-masked]> wrote:

> Hi, sorry about the late response.
>
> On 12/02/2025 19:07, Ship Mints wrote:
> > This command prompts to clear all projects. It also calls the new, but
> > unadvertised, 'project-clear-cache' command after clearing 'project-
> > list'. The lack of a supported project cache clearing function is
> > something that has been discussed in the past.
>
> > +(defun project-clear-cache ()
> > + "Clear the project directory cache."
>  > + (interactive)
>  > + (vc-clear-context))
>
> The new command is okay, but the cache clearing lacks an indirection -
> we shouldn't go straight to the project-vc's cache here because that's
> not the only backend that can be used here.
>
> The PoC previously posted in here https://debbugs.gnu.org/72300#26 could
> use some testing (I haven't come up with anything fundamentally better),
> and an improved cache structure will only affect the internal
> implementation.
>

Right.  We did discuss this a bit back then.  Which of these two less
heavy-handed approaches do you prefer?  Setting the property to nil or
removing it?

(defun project-clear-cache ()
  "Clear the project directory cache."
  (interactive)
  (obarray-map (lambda (ent)
                 (setq ent (symbol-name ent))
                 (when (vc-file-getprop ent 'project-vc)
                   (vc-file-setprop ent 'project-vc nil)))
               vc-file-prop-obarray))

(defun project-clear-cache ()
  "Clear the project directory cache."
  (interactive)
  (let ((ents-to-remove))
    (obarray-map (lambda (ent)
                   (when (vc-file-getprop (symbol-name ent) 'project-vc)
                     (push ent ents-to-remove)))
                 vc-file-prop-obarray)
    (mapc (lambda (ent)
            (obarray-remove vc-file-prop-obarray ent))
          ents-to-remove)))