commit 16b41105215e3cad719ffb121caca0d065e05b6e
parent f14662fca63652dc112732b899e3d829bfecb1ae
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 16 Jul 2014 10:56:34 -0300
function 'type' keeps type names as upvalues to avoid creating strings
everytime it is called
Diffstat:
1 file changed, 21 insertions(+), 8 deletions(-)
diff --git a/lbaselib.c b/lbaselib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lbaselib.c,v 1.289 2014/06/10 17:41:38 roberto Exp roberto $
+** $Id: lbaselib.c,v 1.290 2014/06/30 19:48:08 roberto Exp roberto $
** Basic library
** See Copyright Notice in lua.h
*/
@@ -200,9 +200,12 @@ static int luaB_collectgarbage (lua_State *L) {
}
+/*
+** This function has all type names as upvalues, to maximize performance.
+*/
static int luaB_type (lua_State *L) {
luaL_checkany(L, 1);
- lua_pushstring(L, luaL_typename(L, 1));
+ lua_pushvalue(L, lua_upvalueindex(lua_type(L, 1) + 1));
return 1;
}
@@ -461,21 +464,31 @@ static const luaL_Reg base_funcs[] = {
{"setmetatable", luaB_setmetatable},
{"tonumber", luaB_tonumber},
{"tostring", luaB_tostring},
- {"type", luaB_type},
{"xpcall", luaB_xpcall},
+ /* placeholders */
+ {"type", NULL},
+ {"_G", NULL},
+ {"_VERSION", NULL},
{NULL, NULL}
};
LUAMOD_API int luaopen_base (lua_State *L) {
- /* set global _G */
- lua_pushglobaltable(L);
- lua_pushglobaltable(L);
- lua_setfield(L, -2, "_G");
+ int i;
/* open lib into global table */
+ lua_pushglobaltable(L);
luaL_setfuncs(L, base_funcs, 0);
+ /* set global _G */
+ lua_pushvalue(L, -1);
+ lua_setfield(L, -2, "_G");
+ /* set global _VERSION */
lua_pushliteral(L, LUA_VERSION);
- lua_setfield(L, -2, "_VERSION"); /* set global _VERSION */
+ lua_setfield(L, -2, "_VERSION");
+ /* set function 'type' with proper upvalues */
+ for (i = 0; i < LUA_NUMTAGS; i++) /* push all type names as upvalues */
+ lua_pushstring(L, lua_typename(L, i));
+ lua_pushcclosure(L, luaB_type, LUA_NUMTAGS);
+ lua_setfield(L, -2, "type");
return 1;
}