pack-bitmap: simplify `reuse_partial_packfile_from_bitmap()` signature

The signature of `reuse_partial_packfile_from_bitmap()` currently takes
in a bitmap, as well as three output parameters (filled through
pointers, and passed as arguments), and also returns an integer result.

The output parameters are filled out with: (a) the packfile used for
pack-reuse, (b) the number of objects from that pack that we can reuse,
and (c) a bitmap indicating which objects we can reuse. The return value
is either -1 (when there are no objects to reuse), or 0 (when there is
at least one object to reuse).

Some of these parameters are redundant. Notably, we can infer from the
bitmap how many objects are reused by calling bitmap_popcount(). And we
can similar compute the return value based on that number as well.

As such, clean up the signature of this function to drop the "*entries"
parameter, as well as the int return value, since the single caller of
this function can infer these values themself.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 19 insertions, 20 deletions

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 321d7ef..c3df6d9 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -3943,13 +3943,15 @@ static int get_object_list_from_bitmap(struct rev_info *revs)
 	if (!(bitmap_git = prepare_bitmap_walk(revs, 0)))
 		return -1;
 
-	if (pack_options_allow_reuse() &&
-	    !reuse_partial_packfile_from_bitmap(
-			bitmap_git,
-			&reuse_packfile,
-			&reuse_packfile_objects,
-			&reuse_packfile_bitmap)) {
-		assert(reuse_packfile_objects);
+	if (pack_options_allow_reuse())
+		reuse_partial_packfile_from_bitmap(bitmap_git, &reuse_packfile,
+						   &reuse_packfile_bitmap);
+
+	if (reuse_packfile) {
+		reuse_packfile_objects = bitmap_popcount(reuse_packfile_bitmap);
+		if (!reuse_packfile_objects)
+			BUG("expected non-empty reuse bitmap");
+
 		nr_result += reuse_packfile_objects;
 		nr_seen += reuse_packfile_objects;
 		display_progress(progress_state, nr_seen);
diff --git a/pack-bitmap.c b/pack-bitmap.c
index d64a80c..c75a83e 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -2000,10 +2000,9 @@ static int bitmapped_pack_cmp(const void *va, const void *vb)
 	return 0;
 }
 
-int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
-				       struct packed_git **packfile_out,
-				       uint32_t *entries,
-				       struct bitmap **reuse_out)
+void reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
+					struct packed_git **packfile_out,
+					struct bitmap **reuse_out)
 {
 	struct repository *r = the_repository;
 	struct bitmapped_pack *packs = NULL;
@@ -2025,7 +2024,7 @@ int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
 				warning(_("unable to load pack: '%s', disabling pack-reuse"),
 					bitmap_git->midx->pack_names[i]);
 				free(packs);
-				return -1;
+				return;
 			}
 			if (!pack.bitmap_nr)
 				continue; /* no objects from this pack */
@@ -2059,10 +2058,10 @@ int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
 
 	reuse_partial_packfile_from_bitmap_1(bitmap_git, packs, reuse);
 
-	*entries = bitmap_popcount(reuse);
-	if (!*entries) {
+	if (bitmap_is_empty(reuse)) {
+		free(packs);
 		bitmap_free(reuse);
-		return -1;
+		return;
 	}
 
 	/*
@@ -2072,7 +2071,6 @@ int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
 	bitmap_and_not(result, reuse);
 	*packfile_out = packs[0].p;
 	*reuse_out = reuse;
-	return 0;
 }
 
 int bitmap_walk_contains(struct bitmap_index *bitmap_git,
diff --git a/pack-bitmap.h b/pack-bitmap.h
index b68b213..ab3fdcd 100644
--- a/pack-bitmap.h
+++ b/pack-bitmap.h
@@ -78,10 +78,9 @@ int test_bitmap_hashes(struct repository *r);
 struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs,
 					 int filter_provided_objects);
 uint32_t midx_preferred_pack(struct bitmap_index *bitmap_git);
-int reuse_partial_packfile_from_bitmap(struct bitmap_index *,
-				       struct packed_git **packfile,
-				       uint32_t *entries,
-				       struct bitmap **reuse_out);
+void reuse_partial_packfile_from_bitmap(struct bitmap_index *,
+					struct packed_git **packfile,
+					struct bitmap **reuse_out);
 int rebuild_existing_bitmaps(struct bitmap_index *, struct packing_data *mapping,
 			     kh_oid_map_t *reused_bitmaps, int show_progress);
 void free_bitmap_index(struct bitmap_index *);