In `try_partial_reuse()`, for any object which is either an OFS_DELTA
or REF_DELTA, we need to determine the bitmap position for its base.
We handle the case of single- and multi-pack bitmaps separately:
- For multi-pack bitmaps, we look to see if the MIDX selected the
base we're looking at to represent that object. If the base object
was selected from a different pack in the MIDX, we won't reuse the
delta.
- For single-pack bitmaps, we convert the base object's offset into
a pack-relative position (identified here as 'base_pos') by
calling `offset_to_pack_pos()`.
But we also call `offset_to_pack_pos()` before handling each case
above separately. For the MIDX case, this is unnecessary, since we
don't need to lookup the base object's pack-relative position;
instead, we just care whether the selected copy of that base is from
the same pack we're currently operating on.
For the non-MIDX case, we end up calling offset_to_pack_pos() again,
yielding the same result, making the earlier call wasteful. This
behavior dates back to 519e17ff75 (pack-bitmap: prepare to mark
objects from multiple packs for reuse, 2023-12-14).
Let's correct that by avoiding the unconditional call to
'offset_to_pack_pos()'.
Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx>
---
pack-bitmap.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 706ff26a7b1..5c5c26efe0d 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -2069,7 +2069,6 @@ static int try_partial_reuse(struct bitmap_index *bitmap_git,
if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA) {
off_t base_offset;
- uint32_t base_pos;
uint32_t base_bitmap_pos;
/*
@@ -2085,8 +2084,6 @@ static int try_partial_reuse(struct bitmap_index *bitmap_git,
if (!base_offset)
return 0;
- offset_to_pack_pos(pack->p, base_offset, &base_pos);
-
if (bitmap_is_midx(bitmap_git)) {
/*
* Cross-pack deltas are rejected for now, but could
@@ -2105,6 +2102,8 @@ static int try_partial_reuse(struct bitmap_index *bitmap_git,
return 0;
}
} else {
+ uint32_t base_pos;
+
if (offset_to_pack_pos(pack->p, base_offset,
&base_pos) < 0)
return 0;
--
2.47.0.11.g487258bca34
