Re: unifying sequencer's options persisting, was Re: [PATCH v2] sequencer: fix edit handling for cherry-pick and revert messages

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi,

On Fri, 2 Apr 2021, Junio C Hamano wrote:

> Elijah Newren <newren@gmail.com> writes:
>
> > Even if others now disagree with the above, I know I can get a huge
> > speedup by changing sequencer to stop per-commit wasteful work (stop
> > forking processes like "git commit", don't write control structures if
> > the rebase hasn't ended or hit a conflict, don't update the working
> > copy or index or reflog).  It's enough of a speedup that if backward
> > compatibility won't allow such a method to be used by default, I'd
> > still make yet another backend that could be optionally used.  And I'd
> > have the default rebase and cherry-pick start printing annoying
> > deprecation notices so that users become aware of a faster option.
>
> A faster and less powerful interface is good; I doubt deprecation
> would work well. If a workflow depends on things like post-commit
> hook, the affected users deserve some way to migrate to --exec or
> whatever method to compensate the loss of functionality.

I could imagine that there is opportunity to "persist on disk only when
needed". For example, if no `pre-commit` hook is installed that needs to
be run, there is no need to update the worktree nor HEAD until the rebase
is done.

And this type of `only write to disk when needed` functionality could
probably be abstracted away so much as to make the rest of the code
look elegant again.

Ciao,
Dscho