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function 'type' keeps type names as upvalues to avoid creating strings

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everytime it is called
This commit is contained in:
Roberto Ierusalimschy
2014-07-16 10:56:59 -03:00
parent f14662fca6
commit 16b4110521
1 changed files with 21 additions and 8 deletions
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29
lbaselib.c
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@@ -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 ** Basic library
** See Copyright Notice in lua.h ** 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) { static int luaB_type (lua_State *L) {
luaL_checkany(L, 1); luaL_checkany(L, 1);
lua_pushstring(L, luaL_typename(L, 1)); lua_pushvalue(L, lua_upvalueindex(lua_type(L, 1) + 1));
return 1; return 1;
} }
@@ -461,21 +464,31 @@ static const luaL_Reg base_funcs[] = {
{"setmetatable", luaB_setmetatable}, {"setmetatable", luaB_setmetatable},
{"tonumber", luaB_tonumber}, {"tonumber", luaB_tonumber},
{"tostring", luaB_tostring}, {"tostring", luaB_tostring},
{"type", luaB_type},
{"xpcall", luaB_xpcall}, {"xpcall", luaB_xpcall},
/* placeholders */
{"type", NULL},
{"_G", NULL},
{"_VERSION", NULL},
{NULL, NULL} {NULL, NULL}
}; };
LUAMOD_API int luaopen_base (lua_State *L) { LUAMOD_API int luaopen_base (lua_State *L) {
/* set global _G */ int i;
lua_pushglobaltable(L);
lua_pushglobaltable(L);
lua_setfield(L, -2, "_G");
/* open lib into global table */ /* open lib into global table */
lua_pushglobaltable(L);
luaL_setfuncs(L, base_funcs, 0); 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_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; return 1;
} }