raw_object_store: drop extra pointer to replace_map

We store the replacement data in an oidmap, which is itself a pointer in
the raw_object_store struct. But there's no need for an extra pointer
indirection here. It is always allocated and initialized along with the
containing struct, and we never check it for NULL-ness.

Let's embed the map directly in the struct, which is simpler and avoids
extra pointer chasing.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: peff

commit-graph.c

@@ -222,7 +222,7 @@ static int commit_graph_compatible(struct repository *r)
 
 	if (replace_refs_enabled(r)) {
 		prepare_replace_object(r);
-		if (oidmap_get_size(r->objects->replace_map))
+		if (oidmap_get_size(&r->objects->replace_map))
 			return 0;
 	}
 

object-store.c

@@ -1017,8 +1017,7 @@ void raw_object_store_clear(struct raw_object_store *o)
 {
 	FREE_AND_NULL(o->alternate_db);
 
-	oidmap_clear(o->replace_map, 1);
-	FREE_AND_NULL(o->replace_map);
+	oidmap_clear(&o->replace_map, 1);
 	pthread_mutex_destroy(&o->replace_mutex);
 
 	free_commit_graph(o->commit_graph);

object-store.h

@@ -5,6 +5,7 @@
 #include "object.h"
 #include "list.h"
 #include "oidset.h"
+#include "oidmap.h"
 #include "thread-utils.h"
 
 struct oidmap;
@@ -176,7 +177,7 @@ struct raw_object_store {
 	 * Objects that should be substituted by other objects
 	 * (see git-replace(1)).
 	 */
-	struct oidmap *replace_map;
+	struct oidmap replace_map;
 	unsigned replace_map_initialized : 1;
 	pthread_mutex_t replace_mutex; /* protect object replace functions */
 

replace-object.c

@@ -31,7 +31,7 @@ static int register_replace_ref(const char *refname,
 	oidcpy(&repl_obj->replacement, oid);
 
 	/* Register new object */
-	if (oidmap_put(r->objects->replace_map, repl_obj))
+	if (oidmap_put(&r->objects->replace_map, repl_obj))
 		die(_("duplicate replace ref: %s"), refname);
 
 	return 0;
@@ -48,9 +48,7 @@ void prepare_replace_object(struct repository *r)
 		return;
 	}
 
-	r->objects->replace_map =
-		xmalloc(sizeof(*r->objects->replace_map));
-	oidmap_init(r->objects->replace_map, 0);
+	oidmap_init(&r->objects->replace_map, 0);
 
 	refs_for_each_replace_ref(get_main_ref_store(r),
 				  register_replace_ref, r);
@@ -80,7 +78,7 @@ const struct object_id *do_lookup_replace_object(struct repository *r,
 	/* Try to recursively replace the object */
 	while (depth-- > 0) {
 		struct replace_object *repl_obj =
-			oidmap_get(r->objects->replace_map, cur);
+			oidmap_get(&r->objects->replace_map, cur);
 		if (!repl_obj)
 			return cur;
 		cur = &repl_obj->replacement;

replace-object.h

@@ -47,7 +47,7 @@ static inline const struct object_id *lookup_replace_object(struct repository *r
 {
 	if (!replace_refs_enabled(r) ||
 	    (r->objects->replace_map_initialized &&
-	     oidmap_get_size(r->objects->replace_map) == 0))
+	     oidmap_get_size(&r->objects->replace_map) == 0))
 		return oid;
 	return do_lookup_replace_object(r, oid);
 }