On Wed, Apr 17, 2024 at 08:53:25AM -0700, Junio C Hamano wrote:
> Patrick Steinhardt <ps@pks.im> writes:
> 
> > The `run_auto_maintenance()` function is responsible for spawning a new
> > `git maintenance run --auto` process. To do so, it sets up the `sturct
> > child_process` and then runs it by executing `run_command()` directly.
> > This is rather inflexible in case callers want to modify the child
> > process somewhat, e.g. to redirect stderr or stdout.
> >
> > Introduce a new `prepare_auto_maintenance()` function to plug this gap.
> 
> I guess the mention of "inflexible" and "redirection" above refers
> to some incompatibile behaviour we would introduce if we just
> replaced the manual spawning of "gc --auto" with a call to
> run_auto_maintenance(), but I would have expected that will be
> solved by making the interface to run_auto_maintenance() richer, not
> forcing the callers that would want to deviate from the norm to
> write the second half of the run_auto_maintenance() themselves.
> 
> > +int run_auto_maintenance(int quiet)
> > +{
> > +	struct child_process maint = CHILD_PROCESS_INIT;
> > +	if (!prepare_auto_maintenance(quiet, &maint))
> > +		return 0;
> >  	return run_command(&maint);
> >  }
> 
> But given that the "second half" is to just call run_command() on
> the prepared child control structure, it is probably not a huge
> deal.  It just felt somewhat an uneven API surface that 'quiet' can
> be controlled with just a single bit and doing anything more than
> that would require the caller to go into the structure to tweak.
> 
> Will queue.  Thanks.

git-receive-pack(1) needs to do some magic with file descriptors and
needs to copy output of the command to the sideband. I first thought
about extending `run_auto_maintenance()` to support this, but found it
to be messy as this really is quite a specific usecase. So I figured
that prepping the `struct child_process` like this is the nicer way to
approach it.

Thanks.

Patrick