[PATCH 34/49] repack: keep track of MIDX pack names using existing_packs

Taylor Blau
2025-09-28T22:09:25Z

Instead of storing the list of MIDX pack names separately, let's inline
it into the existing_packs struct, further reducing the number of
parameters we have to pass around.

This amounts to adding a new string_list to the existing_packs struct,
and populating it via `existing_packs_collect()`. This is fairly
straightforward to do, since we are already looping over all packs, all
we need to do is:

if (p->multi_pack_index)
string_list_append(&existing->midx_packs, pack_basename(p));

Note, however, that this check *must* come before other conditions where
we discard and do not keep track of a pack, including the condition "if
(!p->pack_local)" immediately below. This is because the existing
routine which collects MIDX pack names does so blindly, and does not
discard, for example, non-local packs.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
builtin/repack.c | 26 ++++----------------------
repack.c | 5 +++++
repack.h | 1 +
3 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/builtin/repack.c b/builtin/repack.c
index 8ae56b05e9..251dd08b0a 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -118,8 +118,7 @@ struct repack_write_midx_opts {
int midx_must_contain_cruft;
};

-static int midx_has_unknown_packs(struct string_list *midx_pack_names,
- struct string_list *include,
+static int midx_has_unknown_packs(struct string_list *include,
struct pack_geometry *geometry,
struct existing_packs *existing)
{
@@ -127,7 +126,7 @@ static int midx_has_unknown_packs(struct string_list *midx_pack_names,

string_list_sort(include);

- for_each_string_list_item(item, midx_pack_names) {
+ for_each_string_list_item(item, &existing->midx_packs) {
const char *pack_name = item->string;

/*
@@ -190,7 +189,6 @@ static int midx_has_unknown_packs(struct string_list *midx_pack_names,

static void midx_included_packs(struct string_list *include,
struct existing_packs *existing,
- struct string_list *midx_pack_names,
struct string_list *names,
struct pack_geometry *geometry)
{
@@ -245,8 +243,7 @@ static void midx_included_packs(struct string_list *include,
}

if (midx_must_contain_cruft ||
- midx_has_unknown_packs(midx_pack_names, include, geometry,
- existing)) {
+ midx_has_unknown_packs(include, geometry, existing)) {
/*
* If there are one or more unknown pack(s) present (see
* midx_has_unknown_packs() for what makes a pack
@@ -604,7 +601,6 @@ int cmd_repack(int argc,
struct child_process cmd = CHILD_PROCESS_INIT;
struct string_list_item *item;
struct string_list names = STRING_LIST_INIT_DUP;
- struct string_list midx_pack_names = STRING_LIST_INIT_DUP;
struct existing_packs existing = EXISTING_PACKS_INIT;
struct pack_geometry geometry = { 0 };
struct tempfile *refs_snapshot = NULL;
@@ -978,18 +974,6 @@ int cmd_repack(int argc,

string_list_sort(&names);

- if (get_multi_pack_index(repo->objects->sources)) {
- struct multi_pack_index *m =
- get_multi_pack_index(repo->objects->sources);
-
- for (; m; m = m->base_midx) {
- for (uint32_t i = 0; i < m->num_packs; i++) {
- string_list_append(&midx_pack_names,
- m->pack_names[i]);
- }
- }
- }
-
close_object_store(repo->objects);

/*
@@ -1015,8 +999,7 @@ int cmd_repack(int argc,
.write_bitmaps = write_bitmaps > 0,
.midx_must_contain_cruft = midx_must_contain_cruft
};
- midx_included_packs(&include, &existing, &midx_pack_names,
- &names, &geometry);
+ midx_included_packs(&include, &existing, &names, &geometry);

ret = write_midx_included_packs(&opts);

@@ -1063,7 +1046,6 @@ int cmd_repack(int argc,
cleanup:
string_list_clear(&keep_pack_list, 0);
string_list_clear(&names, 1);
- string_list_clear(&midx_pack_names, 0);
existing_packs_release(&existing);
pack_geometry_release(&geometry);
pack_objects_args_release(&po_args);
diff --git a/repack.c b/repack.c
index d8afdd352d..1d485e0112 100644
--- a/repack.c
+++ b/repack.c
@@ -80,6 +80,9 @@ void existing_packs_collect(struct existing_packs *existing,
size_t i;
const char *base;

+ if (p->multi_pack_index)
+ string_list_append(&existing->midx_packs,
+ pack_basename(p));
if (!p->pack_local)
continue;

@@ -104,6 +107,7 @@ void existing_packs_collect(struct existing_packs *existing,
string_list_sort(&existing->kept_packs);
string_list_sort(&existing->non_kept_packs);
string_list_sort(&existing->cruft_packs);
+ string_list_sort(&existing->midx_packs);
strbuf_release(&buf);
}

@@ -220,6 +224,7 @@ void existing_packs_release(struct existing_packs *existing)
string_list_clear(&existing->kept_packs, 0);
string_list_clear(&existing->non_kept_packs, 0);
string_list_clear(&existing->cruft_packs, 0);
+ string_list_clear(&existing->midx_packs, 0);
}

static struct {
diff --git a/repack.h b/repack.h
index 803e129224..6aa5b4e0f0 100644
--- a/repack.h
+++ b/repack.h
@@ -40,6 +40,7 @@ struct existing_packs {
struct string_list kept_packs;
struct string_list non_kept_packs;
struct string_list cruft_packs;
+ struct string_list midx_packs;
};

#define EXISTING_PACKS_INIT { \
--
2.51.0.243.g16eca91f2c0