odb: move MRU list of packfiles into struct packfile_store

The object database tracks the list of packfiles in most-recently-used
order, which is mostly used to favor reading from packfiles that contain
most of the objects that we're currently accessing. With the
introduction of the `struct packfile_store` we have a better place to
host this list though.

Move the list accordingly.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

midx.c

@@ -468,7 +468,7 @@ int prepare_midx_pack(struct multi_pack_index *m,
 				   m->source->local);
 		if (p) {
 			install_packed_git(r, p);
-			list_add_tail(&p->mru, &r->objects->packed_git_mru);
+			list_add_tail(&p->mru, &r->objects->packfiles->mru);
 		}
 	}
 

odb.c

@@ -997,7 +997,6 @@ struct object_database *odb_new(struct repository *repo)
 	memset(o, 0, sizeof(*o));
 	o->repo = repo;
 	o->packfiles = packfile_store_new(o);
-	INIT_LIST_HEAD(&o->packed_git_mru);
 	pthread_mutex_init(&o->replace_mutex, NULL);
 	string_list_init_dup(&o->submodule_source_paths);
 	return o;
@@ -1035,7 +1034,6 @@ void odb_clear(struct object_database *o)
 		free((char *) o->cached_objects[i].value.buf);
 	FREE_AND_NULL(o->cached_objects);
 
-	INIT_LIST_HEAD(&o->packed_git_mru);
 	close_object_store(o);
 	packfile_store_free(o->packfiles);
 	o->packfiles = NULL;

odb.h

@@ -3,7 +3,6 @@
 
 #include "hashmap.h"
 #include "object.h"
-#include "list.h"
 #include "oidset.h"
 #include "oidmap.h"
 #include "string-list.h"
@@ -138,9 +137,6 @@ struct object_database {
 	 * Should only be accessed directly by packfile.c and midx.c.
 	 */
 	struct packfile_store *packfiles;
-	/* A most-recently-used ordered version of the packed_git list. */
-	struct list_head packed_git_mru;
-
 	struct {
 		struct packed_git **packs;
 		unsigned flags;

packfile.c

@@ -1017,10 +1017,10 @@ static void prepare_packed_git_mru(struct repository *r)
 {
 	struct packed_git *p;
 
-	INIT_LIST_HEAD(&r->objects->packed_git_mru);
+	INIT_LIST_HEAD(&r->objects->packfiles->mru);
 
 	for (p = r->objects->packfiles->packs; p; p = p->next)
-		list_add_tail(&p->mru, &r->objects->packed_git_mru);
+		list_add_tail(&p->mru, &r->objects->packfiles->mru);
 }
 
 static void prepare_packed_git(struct repository *r)
@@ -1095,7 +1095,7 @@ struct packed_git *get_all_packs(struct repository *r)
 struct list_head *get_packed_git_mru(struct repository *r)
 {
 	prepare_packed_git(r);
-	return &r->objects->packed_git_mru;
+	return &r->objects->packfiles->mru;
 }
 
 unsigned long unpack_object_header_buffer(const unsigned char *buf,
@@ -2078,10 +2078,10 @@ int find_pack_entry(struct repository *r, const struct object_id *oid, struct pa
 	if (!r->objects->packfiles->packs)
 		return 0;
 
-	list_for_each(pos, &r->objects->packed_git_mru) {
+	list_for_each(pos, &r->objects->packfiles->mru) {
 		struct packed_git *p = list_entry(pos, struct packed_git, mru);
 		if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) {
-			list_move(&p->mru, &r->objects->packed_git_mru);
+			list_move(&p->mru, &r->objects->packfiles->mru);
 			return 1;
 		}
 	}
@@ -2347,6 +2347,7 @@ struct packfile_store *packfile_store_new(struct object_database *odb)
 	struct packfile_store *store;
 	CALLOC_ARRAY(store, 1);
 	store->odb = odb;
+	INIT_LIST_HEAD(&store->mru);
 	hashmap_init(&store->map, pack_map_entry_cmp, NULL, 0);
 	return store;
 }

packfile.h

@@ -64,6 +64,9 @@ struct packfile_store {
 	 */
 	struct packed_git *packs;
 
+	/* A most-recently-used ordered version of the packs list. */
+	struct list_head mru;
+
 	/*
 	 * A map of packfile names to packed_git structs for tracking which
 	 * packs have been loaded already.