Re: [PATCH 5/7] shortlog: implement `--group=author` in terms of `--group=<format>`

From: Taylor Blau <me@ttaylorr.com>
Date: Oct 11, 2022, 01:48 UTC
Message-ID: <Y0TLf/J22ioQ5UCt@nand.local>
In-Reply-To: <Y0TIMlrrifYKuBnR@coredump.intra.peff.net>

On Mon, Oct 10, 2022 at 09:34:42PM -0400, Jeff King wrote:

Show 11 quoted lines

> On Mon, Oct 10, 2022 at 08:34:15PM -0400, Taylor Blau wrote:
>
> I think the name of the helper function puzzled me a bit. It is really
> "finish up any setup for the shortlog struct". We could lazily do it in
> shortlog_add_commit(), but that's pretty subtle. But could we maybe call
> it:
>
>   shortlog_finish_setup();
>
> or something? I dunno. I might be nit-picking, but I actually had to
> scratch my head quite a bit to understand what was going on here.

I think that shortlog_finish_setup() is probably the most reasonable choice (and I changed it to that locally). I spent a day or so thinking on and off about this while writing the series, and didn't come up with any satisfying names.

I think it points to something deeper about the API that doesn't quite sit right with me. But shortlog_finish_setup() is the least-unsatisfying name so far, so let's go with that ;-).

Show 28 quoted lines

> > diff --git a/builtin/shortlog.c b/builtin/shortlog.c
> > index f708d96558..aac8c7afa4 100644
> > --- a/builtin/shortlog.c
> > +++ b/builtin/shortlog.c
> > @@ -245,15 +245,6 @@ void shortlog_add_commit(struct shortlog *log, struct commit *commit)
> >  	}
> >  	oneline_str = oneline.len ? oneline.buf : "<none>";
> >
> > -	if (log->groups & SHORTLOG_GROUP_AUTHOR) {
> > -		strbuf_reset(&ident);
> > -		format_commit_message(commit,
> > -				      log->email ? "%aN <%aE>" : "%aN",
> > -				      &ident, &ctx);
> > -		if (!HAS_MULTI_BITS(log->groups) ||
> > -		    strset_add(&dups, ident.buf))
> > -			insert_one_record(log, ident.buf, oneline_str);
> > -	}
>
> This loses the HAS_MULTI_BITS() optimization. The idea there is that if
> you have a single group-by that can't produce multiple outputs, then
> there's no need to do duplicate detection.
>
> The equivalent in an all-formats world is something like:
>
>   log.format.nr > 1 && !log.trailers.nr
>
> (because trailers are special in that one trailer key can produce
> multiple idents for a single commit).

Hmm. I suspect that this is going to become more complicated by the time that you read the final patch ;-). Let's wait until then and see what you think.

Show 13 quoted lines

> > +void shortlog_init_group(struct shortlog *log)
> > +{
> > +	if (!log->groups)
> > +		log->groups = SHORTLOG_GROUP_AUTHOR;
> > +
> > +	if (log->groups & SHORTLOG_GROUP_AUTHOR)
> > +		string_list_append(&log->format,
> > +				   log->email ? "%aN <%aE>" : "%aN");
> > +}
>
> Regardless of the naming suggestion I made, I think things would be more
> obvious if this top conditional remained in cmd_shortlog(). And then the
> explicit assignment of "log.group" in make_cover_letter() would remain.

Yep, works for me.

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> > @@ -439,8 +440,8 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
> >  	log.file = rev.diffopt.file;
> >  	log.date_mode = rev.date_mode;
> >
> > -	if (!log.groups)
> > -		log.groups = SHORTLOG_GROUP_AUTHOR;
> > +	shortlog_init_group(&log);
> > +
> >  	string_list_sort(&log.trailers);
>
> Now that we have a "finish the shortlog init" function, probably this
> trailer sort should go into it, too. The current caller doesn't need it,
> but it removes on more gotcha from using the shortlog API.

We'll drop this list by the end of the series, too, so it probably isn't worth moving it into shortlog_finish_setup() in the interim.

> -Peff

Thanks, Taylor