packfile: refactor get_packed_git_mru() to work on packfile store

The `get_packed_git_mru()` function prepares the packfile store and then
returns its packfiles in most-recently-used order. Refactor it to accept
a packfile store instead of a repository to clarify its scope.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

builtin/pack-objects.c

@@ -1748,12 +1748,12 @@ static int want_object_in_pack_mtime(const struct object_id *oid,
 		}
 	}
 
-	list_for_each(pos, get_packed_git_mru(the_repository)) {
+	list_for_each(pos, packfile_store_get_packs_mru(the_repository->objects->packfiles)) {
 		struct packed_git *p = list_entry(pos, struct packed_git, mru);
 		want = want_object_in_pack_one(p, oid, exclude, found_pack, found_offset, found_mtime);
 		if (!exclude && want > 0)
 			list_move(&p->mru,
-				  get_packed_git_mru(the_repository));
+				  packfile_store_get_packs_mru(the_repository->objects->packfiles));
 		if (want != -1)
 			return want;
 	}

packfile.c

@@ -1048,10 +1048,10 @@ struct packed_git *packfile_store_get_all_packs(struct packfile_store *store)
 	return store->packs;
 }
 
-struct list_head *get_packed_git_mru(struct repository *r)
+struct list_head *packfile_store_get_packs_mru(struct packfile_store *store)
 {
-	packfile_store_prepare(r->objects->packfiles);
-	return &r->objects->packfiles->mru;
+	packfile_store_prepare(store);
+	return &store->mru;
 }
 
 /*

packfile.h

@@ -148,6 +148,11 @@ struct packed_git *packfile_store_get_packs(struct packfile_store *store);
  */
 struct packed_git *packfile_store_get_all_packs(struct packfile_store *store);
 
+/*
+ * Get all packs in most-recently-used order.
+ */
+struct list_head *packfile_store_get_packs_mru(struct packfile_store *store);
+
 /*
  * Open the packfile and add it to the store if it isn't yet known. Returns
  * either the newly opened packfile or the preexisting packfile. Returns a
@@ -232,8 +237,6 @@ int for_each_packed_object(struct repository *repo, each_packed_object_fn cb,
 #define PACKDIR_FILE_GARBAGE 4
 extern void (*report_garbage)(unsigned seen_bits, const char *path);
 
-struct list_head *get_packed_git_mru(struct repository *r);
-
 /*
  * Give a rough count of objects in the repository. This sacrifices accuracy
  * for speed.