packfile: refactor kept-pack cache to work with packfile stores

The kept pack cache is a cache of packfiles that are marked as kept
either via an accompanying ".kept" file or via an in-memory flag. The
cache can be retrieved via `kept_pack_cache()`, where one needs to pass
in a repository.

Ultimately though the kept-pack cache is a property of the packfile
store, and this causes problems in a subsequent commit where we want to
move down the packfile store to be a per-object-source entity.

Prepare for this and refactor the kept-pack cache to work on top of a
packfile store instead. While at it, rename both the function and flags
specific to the kept-pack cache so that they can be properly attributed
to the respective subsystems.

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

1 files changed, 17 insertions, 8 deletions

diff --git a/packfile.h b/packfile.h
index 33cc1c1654..410f85f03d 100644
--- a/packfile.h
+++ b/packfile.h
@@ -90,9 +90,10 @@ struct packfile_store {
 	 * is an on-disk ".keep" file or because they are marked as "kept" in
 	 * memory.
 	 *
-	 * Should not be accessed directly, but via `kept_pack_cache()`. The
-	 * list of packs gets invalidated when the stored flags and the flags
-	 * passed to `kept_pack_cache()` mismatch.
+	 * Should not be accessed directly, but via
+	 * `packfile_store_get_kept_pack_cache()`. The list of packs gets
+	 * invalidated when the stored flags and the flags passed to
+	 * `packfile_store_get_kept_pack_cache()` mismatch.
 	 */
 	struct {
 		struct packed_git **packs;
@@ -210,6 +211,19 @@ struct packed_git *packfile_store_load_pack(struct packfile_store *store,
 int packfile_store_freshen_object(struct packfile_store *store,
 				  const struct object_id *oid);
 
+enum kept_pack_type {
+	KEPT_PACK_ON_DISK = (1 << 0),
+	KEPT_PACK_IN_CORE = (1 << 1),
+};
+
+/*
+ * Retrieve the cache of kept packs from the given packfile store. Accepts a
+ * combination of `kept_pack_type` flags. The cache is computed on demand and
+ * will be recomputed whenever the flags change.
+ */
+struct packed_git **packfile_store_get_kept_pack_cache(struct packfile_store *store,
+						       unsigned flags);
+
 struct pack_window {
 	struct pack_window *next;
 	unsigned char *base;
@@ -385,9 +399,6 @@ int packed_object_info(struct repository *r,
 void mark_bad_packed_object(struct packed_git *, const struct object_id *);
 const struct packed_git *has_packed_and_bad(struct repository *, const struct object_id *);
 
-#define ON_DISK_KEEP_PACKS 1
-#define IN_CORE_KEEP_PACKS 2
-
 /*
  * Iff a pack file in the given repository contains the object named by sha1,
  * return true and store its location to e.
@@ -398,8 +409,6 @@ int has_object_pack(struct repository *r, const struct object_id *oid);
 int has_object_kept_pack(struct repository *r, const struct object_id *oid,
 			 unsigned flags);
 
-struct packed_git **kept_pack_cache(struct repository *r, unsigned flags);
-
 /*
  * Return 1 if an object in a promisor packfile is or refers to the given
  * object, 0 otherwise.