degesch: optimize Lua weak refs

1 files changed, 11 insertions, 30 deletions

diff --git a/degesch.c b/degesch.c
index c604e83..132ebab 100644
--- a/degesch.c
+++ b/degesch.c
@@ -9860,19 +9860,6 @@ static luaL_Reg lua_plugin_library[] =
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-static struct lua_ispect_mapping
-{
-	struct ispect_field *ispect;        ///< Type info
-	struct lua_weak_info *info;         ///< Lua-specific additions
-}
-lua_types[] =
-{
-	{ g_user_ispect,    &lua_user_info    },
-	{ g_channel_ispect, &lua_channel_info },
-	{ g_buffer_ispect,  &lua_buffer_info  },
-	{ g_server_ispect,  &lua_server_info  },
-};
-
 static void *
 lua_plugin_alloc (void *ud, void *ptr, size_t o_size, size_t n_size)
 {
@@ -9896,27 +9883,14 @@ lua_plugin_panic (lua_State *L)
 	return 0;
 }
 
-// As a rule in this codebase, these fields are right at the top of structs
-struct list_header
-{
-	void *next;                         ///< Next item
-	void *prev;                         ///< Previous item
-};
-
 static void
 lua_plugin_push_ref (struct lua_plugin *self, void *object,
 	struct ispect_field *field)
 {
-	// TODO: we can definitely make a resolution table right in Lua,
-	//   lua_plugin_reg_weak() can fill it automatically (lightud->lightud)
-	struct lua_weak_info *info = NULL;
-	for (size_t i = 0; i < N_ELEMENTS (lua_types); i++)
-		if (lua_types[i].ispect == field->fields)
-		{
-			info = lua_types[i].info;
-			break;
-		}
-	hard_assert (info != NULL);
+	// We create a mapping on object type registration
+	hard_assert (lua_rawgetp (self->L, LUA_REGISTRYINDEX, field->fields));
+	struct lua_weak_info *info = lua_touserdata (self->L, -1);
+	lua_pop (self->L, 1);
 
 	if (!field->is_list)
 	{
@@ -9924,6 +9898,9 @@ lua_plugin_push_ref (struct lua_plugin *self, void *object,
 		return;
 	}
 
+	// As a rule in this codebase, these fields are right at the top of structs
+	struct list_header { LIST_HEADER (void) };
+
 	int i = 1;
 	lua_newtable (self->L);
 	LIST_FOR_EACH (struct list_header, iter, object)
@@ -10097,6 +10074,10 @@ lua_plugin_reg_meta (lua_State *L, const char *name, luaL_Reg *fns)
 static void
 lua_plugin_reg_weak (lua_State *L, struct lua_weak_info *info, luaL_Reg *fns)
 {
+	// Create a mapping from the object type back to our metadata
+	lua_pushlightuserdata (L, info);
+	lua_rawsetp (L, LUA_REGISTRYINDEX, info->ispect);
+
 	luaL_newmetatable (L, info->name);
 	luaL_setfuncs (L, fns, 0);
 	lua_plugin_reg_finish (L, info);