[06/11] pack-bitmap: drop `from_midx` field from `bitmapped_pack`

Commit Message

Taylor Blau Oct. 9, 2024, 8:31 p.m. UTC

This field was added in 41cd4b478f7 (pack-bitmap: tag bitmapped packs
with their corresponding MIDX, 2024-08-27) in order to expose the
bitmap's MIDX in order to translate bit positions correctly from
within 'pack-objects' during pack-reuse (c.f., 125c32605ab
(builtin/pack-objects.c: translate bit positions during pack-reuse,
2024-08-27) for more details).

But another approach would have been to use the `->midx` field of the
`struct bitmap_index *` directly, which feels clearer and avoids
duplicating information.

Unfortunately, we can't access that field directly since it is part of
the `bitmap_index` structure which is static within the pack-bitmap.c
compilation unit.

So let's instead introduce a new function which returns that pointer
to us, and replace the `from_midx` field with uses of that new
function (which we call `bitmap_midx()` here).

Signed-off-by: Taylor Blau <[e-mail]>
---
 builtin/pack-objects.c | 4 ++--
 midx.c                 | 1 -
 pack-bitmap.c          | 6 +++++-
 pack-bitmap.h          | 2 +-
 4 files changed, 8 insertions(+), 5 deletions(-)

Patch

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 0fc0680b402..097bb5ac2ca 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1201,7 +1201,7 @@  static void write_reused_pack(struct bitmapped_pack *reuse_packfile,
 			if (pos + offset >= reuse_packfile->bitmap_pos + reuse_packfile->bitmap_nr)
 				goto done;
 
-			if (reuse_packfile->bitmap_pos) {
+			if (bitmap_is_midx(bitmap_git)) {
 				/*
 				 * When doing multi-pack reuse on a
 				 * non-preferred pack, translate bit positions
@@ -1209,7 +1209,7 @@  static void write_reused_pack(struct bitmapped_pack *reuse_packfile,
 				 * pack-relative positions before attempting
 				 * reuse.
 				 */
-				struct multi_pack_index *m = reuse_packfile->from_midx;
+				struct multi_pack_index *m = bitmap_midx(bitmap_git);
 				uint32_t midx_pos;
 				off_t pack_ofs;
 
diff --git a/midx.c b/midx.c
index 67e0d640046..ca98bfd7c64 100644
--- a/midx.c
+++ b/midx.c
@@ -496,7 +496,6 @@  int nth_bitmapped_pack(struct repository *r, struct multi_pack_index *m,
 				 MIDX_CHUNK_BITMAPPED_PACKS_WIDTH * local_pack_int_id +
 				 sizeof(uint32_t));
 	bp->pack_int_id = pack_int_id;
-	bp->from_midx = m;
 
 	return 0;
 }
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 6dbe6a2c5bc..b9ea1fab397 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -2326,7 +2326,6 @@  void reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
 		packs[packs_nr].pack_int_id = pack_int_id;
 		packs[packs_nr].bitmap_nr = pack->num_objects;
 		packs[packs_nr].bitmap_pos = 0;
-		packs[packs_nr].from_midx = bitmap_git->midx;
 
 		objects_nr = packs[packs_nr++].bitmap_nr;
 	}
@@ -2981,6 +2980,11 @@  int bitmap_is_midx(struct bitmap_index *bitmap_git)
 	return !!bitmap_git->midx;
 }
 
+struct multi_pack_index *bitmap_midx(struct bitmap_index *bitmap_git)
+{
+	return bitmap_git->midx;
+}
+
 const struct string_list *bitmap_preferred_tips(struct repository *r)
 {
 	const struct string_list *dest;
diff --git a/pack-bitmap.h b/pack-bitmap.h
index d7f4b8b8e95..a1e8c8936c9 100644
--- a/pack-bitmap.h
+++ b/pack-bitmap.h
@@ -60,7 +60,6 @@  struct bitmapped_pack {
 	uint32_t bitmap_pos;
 	uint32_t bitmap_nr;
 
-	struct multi_pack_index *from_midx; /* MIDX only */
 	uint32_t pack_int_id; /* MIDX only */
 };
 
@@ -157,6 +156,7 @@  char *midx_bitmap_filename(struct multi_pack_index *midx);
 char *pack_bitmap_filename(struct packed_git *p);
 
 int bitmap_is_midx(struct bitmap_index *bitmap_git);
+struct multi_pack_index *bitmap_midx(struct bitmap_index *bitmap_git);
 
 const struct string_list *bitmap_preferred_tips(struct repository *r);
 int bitmap_is_preferred_refname(struct repository *r, const char *refname);