bug#11757: Acknowledgement (24.1.50; vc-git calls `process-file' too many times)

[Dmitry Gutov]

On 06.07.2012 17:44, Michael Albinus wrote:
> Dmitry Gutov <dgutov@yandex.ru> writes:
>
> > > If we assume that there are no dangerous vc commands outside Emacs, we
> > > wouldn't have a problem.
> >
> > In this case, the behavior of the first patch I posted here should be
> > acceptable, right? It's simpler, has pretty much the same effect, and
> > should be a tiny bit faster.
>
> That I don't know. Both patches do almost what we expect, and having a
> cached value for `vc-registered' sounds more performant when applied
> often enough.

With the attached patch, `vc-git-registered' is usually called only once 
during the lifetime of a buffer.

For caching to be an improvement, 'git-registered value has to be 
invalidated separately from 'vc-backend, yet less often than 
`vc-git-state' is called.

> > > Yes. I don't know, whether we will be able to handle any surprise when
> > > using caches. There will always be a scenario which lets fail a given
> > > algorithm. I fear.
> >
> > Sure, but I'm just asking for one scenario that works better with
> > explicitly caching 'git-registered, instead of not calling it in
> > vc-git-state'.
> > If `vc-git-state' doesn't call `vc-git-registered' (just assumes it's
> > t), then `vc-registered' is the latter's only client, and so its
> > return value is implicitly cached in 'vc-backend property.
>
> Maybe. Could you show a patch? (Please with ChangeLog entry, I would
> commit if it looks good).

* vc-git.el (vc-git-state): Don't call `vc-git-registered', assume it's 
always t.
(vc-git-registered): Remove caching, the function is only called once.

Thank you,

--Dmitry

vc-git-registered.diff
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