[PATCH 13/16] packfile: move `get_multi_pack_index()` into "midx.c"

[Patrick Steinhardt <ps@xxxxxx>]

The `get_multi_pack_index()` function is declared and implemented in the
packfile subsystem, even though it really belongs into the multi-pack
index subsystem. The reason for this is likely that it needs to call
`packfile_store_prepare()`, which is not exposed by the packfile system.
In a subsequent commit we're about to add another caller outside of the
packfile system though, so we'll have to expose the function anyway.

Do so now already and move `get_multi_pack_index()` into the MIDX
subsystem.

Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
---
 midx.c     |  6 ++++++
 midx.h     |  2 ++
 packfile.c |  8 +-------
 packfile.h | 10 +++++++++-
 4 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/midx.c b/midx.c
index d30feda019..c1b2f141fa 100644
--- a/midx.c
+++ b/midx.c
@@ -95,6 +95,12 @@ static int midx_read_object_offsets(const unsigned char *chunk_start,
 	return 0;
 }
 
+struct multi_pack_index *get_multi_pack_index(struct odb_source *source)
+{
+	packfile_store_prepare(source->odb->packfiles);
+	return source->midx;
+}
+
 static struct multi_pack_index *load_multi_pack_index_one(struct repository *r,
 							  const char *object_dir,
 							  const char *midx_name,
diff --git a/midx.h b/midx.h
index 076382de8a..8d6ea28682 100644
--- a/midx.h
+++ b/midx.h
@@ -100,6 +100,8 @@ void get_split_midx_filename_ext(const struct git_hash_algo *hash_algo,
 				 struct strbuf *buf, const char *object_dir,
 				 const unsigned char *hash, const char *ext);
 
+struct multi_pack_index *get_multi_pack_index(struct odb_source *source);
+
 struct multi_pack_index *load_multi_pack_index(struct repository *r,
 					       const char *object_dir,
 					       int local);
diff --git a/packfile.c b/packfile.c
index f7916543a6..bc32c45fe6 100644
--- a/packfile.c
+++ b/packfile.c
@@ -1004,7 +1004,7 @@ static void packfile_store_prepare_mru(struct packfile_store *store)
 		list_add_tail(&p->mru, &store->mru);
 }
 
-static void packfile_store_prepare(struct packfile_store *store)
+void packfile_store_prepare(struct packfile_store *store)
 {
 	struct odb_source *source;
 
@@ -1035,12 +1035,6 @@ struct packed_git *get_packed_git(struct repository *r)
 	return r->objects->packfiles->packs;
 }
 
-struct multi_pack_index *get_multi_pack_index(struct odb_source *source)
-{
-	packfile_store_prepare(source->odb->packfiles);
-	return source->midx;
-}
-
 struct packed_git *get_all_packs(struct repository *r)
 {
 	packfile_store_prepare(r->objects->packfiles);
diff --git a/packfile.h b/packfile.h
index 4971f18f51..1522da96f8 100644
--- a/packfile.h
+++ b/packfile.h
@@ -104,6 +104,15 @@ void packfile_store_free(struct packfile_store *store);
  */
 void packfile_store_close(struct packfile_store *store);
 
+/*
+ * Prepare the packfile store by loading packfiles and multi-pack indices for
+ * all alternates. This becomes a no-op if the store is already prepared.
+ *
+ * It shouldn't typically be necessary to call this function directly, as
+ * functions that access the store know to prepare it.
+ */
+void packfile_store_prepare(struct packfile_store *store);
+
 /*
  * Clear the packfile caches and try to look up any new packfiles that have
  * appeared since last preparing the packfiles store.
@@ -205,7 +214,6 @@ extern void (*report_garbage)(unsigned seen_bits, const char *path);
 
 struct packed_git *get_packed_git(struct repository *r);
 struct list_head *get_packed_git_mru(struct repository *r);
-struct multi_pack_index *get_multi_pack_index(struct odb_source *source);
 struct packed_git *get_all_packs(struct repository *r);
 
 /*

-- 
2.51.0.261.g7ce5a0a67e.dirty