odb: move packfile map into `struct packfile_store`

The object database tracks a map of packfiles by their respective paths,
which is used to figure out whether a given packfile has already been
loaded. With the introduction of the `struct packfile_store` we have a
better place to host this list though.

Move the map accordingly.

`pack_map_entry_cmp()` isn't used anywhere but in "packfile.c" anymore
after this change, so we convert it to a static function, as well. Note
that we also drop the `inline` hint: the function is used as a callback
function exclusively, and callbacks cannot be inlined.

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

midx.c

@@ -460,7 +460,7 @@ int prepare_midx_pack(struct multi_pack_index *m,
 	strbuf_addbuf(&key, &pack_name);
 	strbuf_strip_suffix(&key, ".idx");
 	strbuf_addstr(&key, ".pack");
-	p = hashmap_get_entry_from_hash(&r->objects->pack_map,
+	p = hashmap_get_entry_from_hash(&r->objects->packfiles->map,
 					strhash(key.buf), key.buf,
 					struct packed_git, packmap_ent);
 	if (!p) {

odb.c

@@ -998,7 +998,6 @@ struct object_database *odb_new(struct repository *repo)
 	o->repo = repo;
 	o->packfiles = packfile_store_new(o);
 	INIT_LIST_HEAD(&o->packed_git_mru);
-	hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 	pthread_mutex_init(&o->replace_mutex, NULL);
 	string_list_init_dup(&o->submodule_source_paths);
 	return o;
@@ -1041,6 +1040,5 @@ void odb_clear(struct object_database *o)
 	packfile_store_free(o->packfiles);
 	o->packfiles = NULL;
 
-	hashmap_clear(&o->pack_map);
 	string_list_clear(&o->submodule_source_paths, 0);
 }

odb.h

@@ -135,7 +135,7 @@ struct object_database {
 	/*
 	 * private data
 	 *
-	 * should only be accessed directly by packfile.c
+	 * 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. */
@@ -155,12 +155,6 @@ struct object_database {
 	struct cached_object_entry *cached_objects;
 	size_t cached_object_nr, cached_object_alloc;
 
-	/*
-	 * A map of packfiles to packed_git structs for tracking which
-	 * packs have been loaded already.
-	 */
-	struct hashmap pack_map;
-
 	/*
 	 * A fast, rough count of the number of objects in the repository.
 	 * These two fields are not meant for direct access. Use

packfile.c

@@ -788,7 +788,7 @@ void install_packed_git(struct repository *r, struct packed_git *pack)
 	r->objects->packfiles->packs = pack;
 
 	hashmap_entry_init(&pack->packmap_ent, strhash(pack->pack_name));
-	hashmap_add(&r->objects->pack_map, &pack->packmap_ent);
+	hashmap_add(&r->objects->packfiles->map, &pack->packmap_ent);
 }
 
 void (*report_garbage)(unsigned seen_bits, const char *path);
@@ -901,7 +901,7 @@ static void prepare_pack(const char *full_name, size_t full_name_len,
 		hashmap_entry_init(&hent, hash);
 
 		/* Don't reopen a pack we already have. */
-		if (!hashmap_get(&data->r->objects->pack_map, &hent, pack_name)) {
+		if (!hashmap_get(&data->r->objects->packfiles->map, &hent, pack_name)) {
 			p = add_packed_git(data->r, full_name, full_name_len, data->local);
 			if (p)
 				install_packed_git(data->r, p);
@@ -2328,11 +2328,26 @@ int parse_pack_header_option(const char *in, unsigned char *out, unsigned int *l
 	return 0;
 }
 
+static int pack_map_entry_cmp(const void *cmp_data UNUSED,
+			      const struct hashmap_entry *entry,
+			      const struct hashmap_entry *entry2,
+			      const void *keydata)
+{
+	const char *key = keydata;
+	const struct packed_git *pg1, *pg2;
+
+	pg1 = container_of(entry, const struct packed_git, packmap_ent);
+	pg2 = container_of(entry2, const struct packed_git, packmap_ent);
+
+	return strcmp(pg1->pack_name, key ? key : pg2->pack_name);
+}
+
 struct packfile_store *packfile_store_new(struct object_database *odb)
 {
 	struct packfile_store *store;
 	CALLOC_ARRAY(store, 1);
 	store->odb = odb;
+	hashmap_init(&store->map, pack_map_entry_cmp, NULL, 0);
 	return store;
 }
 
@@ -2342,6 +2357,7 @@ void packfile_store_free(struct packfile_store *store)
 		next = p->next;
 		free(p);
 	}
+	hashmap_clear(&store->map);
 	free(store);
 }
 

packfile.h

@@ -64,6 +64,12 @@ struct packfile_store {
 	 */
 	struct packed_git *packs;
 
+	/*
+	 * A map of packfile names to packed_git structs for tracking which
+	 * packs have been loaded already.
+	 */
+	struct hashmap map;
+
 	/*
 	 * Whether packfiles have already been populated with this store's
 	 * packs.
@@ -89,20 +95,6 @@ void packfile_store_free(struct packfile_store *store);
  */
 void packfile_store_close(struct packfile_store *store);
 
-static inline int pack_map_entry_cmp(const void *cmp_data UNUSED,
-				     const struct hashmap_entry *entry,
-				     const struct hashmap_entry *entry2,
-				     const void *keydata)
-{
-	const char *key = keydata;
-	const struct packed_git *pg1, *pg2;
-
-	pg1 = container_of(entry, const struct packed_git, packmap_ent);
-	pg2 = container_of(entry2, const struct packed_git, packmap_ent);
-
-	return strcmp(pg1->pack_name, key ? key : pg2->pack_name);
-}
-
 struct pack_window {
 	struct pack_window *next;
 	unsigned char *base;