Re: [PATCH 4/4] pack-bitmap: pass object filter to fill-in traversal

From: Taylor Blau <me@ttaylorr.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Taylor Blau <me@ttaylorr.com>,
	git@vger.kernel.org, peff@peff.net, chriscool@tuxfamily.org
Subject: Re: [PATCH 4/4] pack-bitmap: pass object filter to fill-in traversal
Date: Tue, 5 May 2020 10:00:14 -0600	[thread overview]
Message-ID: <20200505160014.GB69300@syl.local> (raw)
In-Reply-To: <xmqq1rnzc52c.fsf@gitster.c.googlers.com>

On Mon, May 04, 2020 at 10:40:43PM -0700, Junio C Hamano wrote:
> Taylor Blau <me@ttaylorr.com> writes:
>
> > But now that we support tree filters, there's opportunity for savings. A
> > tree:depth=0 filter means we can avoid accessing trees entirely, since
> > we know we won't them (or any of the subtrees or blobs they point to).
>
> "we know we won't _have_ them"?

Yep, fixed. Thanks for pointing it out.

> > @@ -506,7 +506,8 @@ static int should_include(struct commit *commit, void *_data)
> >  static struct bitmap *find_objects(struct bitmap_index *bitmap_git,
> >  				   struct rev_info *revs,
> >  				   struct object_list *roots,
> > -				   struct bitmap *seen)
> > +				   struct bitmap *seen,
> > +				   struct list_objects_filter_options *filter)
> >  {
> >  	struct bitmap *base = NULL;
> >  	int needs_walk = 0;
> > @@ -599,8 +600,9 @@ static struct bitmap *find_objects(struct bitmap_index *bitmap_git,
> >  		show_data.bitmap_git = bitmap_git;
> >  		show_data.base = base;
> >
> > -		traverse_commit_list(revs, show_commit, show_object,
> > -				     &show_data);
> > +		traverse_commit_list_filtered(filter, revs,
> > +					      show_commit, show_object,
> > +					      &show_data, NULL);
>
> And then finally the change in step 1/4 pays off.

Woohoo!

> >  	}
> >
> >  	return base;
> > @@ -999,7 +1001,8 @@ struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs,
> >
> >  	if (haves) {
> >  		revs->ignore_missing_links = 1;
> > -		haves_bitmap = find_objects(bitmap_git, revs, haves, NULL);
> > +		haves_bitmap = find_objects(bitmap_git, revs, haves, NULL,
> > +					    filter);
> >  		reset_revision_walk();
> >  		revs->ignore_missing_links = 0;
> >
> > @@ -1007,7 +1010,8 @@ struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs,
> >  			BUG("failed to perform bitmap walk");
> >  	}
> >
> > -	wants_bitmap = find_objects(bitmap_git, revs, wants, haves_bitmap);
> > +	wants_bitmap = find_objects(bitmap_git, revs, wants, haves_bitmap,
> > +				    filter);
> >
> >  	if (!wants_bitmap)
> >  		BUG("failed to perform bitmap walk");
> > diff --git a/t/perf/p5310-pack-bitmaps.sh b/t/perf/p5310-pack-bitmaps.sh
> > index 75ccf9f4e3..b3e725f031 100755
> > --- a/t/perf/p5310-pack-bitmaps.sh
> > +++ b/t/perf/p5310-pack-bitmaps.sh
> > @@ -91,4 +91,9 @@ test_perf 'pack to file (partial bitmap)' '
> >  	git pack-objects --use-bitmap-index --all pack2b </dev/null >/dev/null
> >  '
> >
> > +test_perf 'rev-list with tree filter (partial bitmap)' '
> > +	git rev-list --use-bitmap-index --count --objects --all \
> > +		--filter=tree:0 >/dev/null
> > +'
> > +
> >  test_done

Thanks,
Taylor