Re: Another attempt at SpeedingUpStrings

[David Manura <dm.lua@...>]

> On 12/18/07, Asko Kauppi <askok <at> dnainternet.net> wrote:
> > You can push all the strings in startup on the registry, with light
> > userdata pointers (of the C side string constant) serving as keys.
> > This will turn string pushing into a table lookup instead; maybe no

Even better, make the string constants upvalues of the C closure.  Retrieve them
with lua_upvalueindex/lua_pushvalue.  Similar approaches are based on moving
more code from C to Lua.

I don't see this as a major performance problem.  If you have a bottleneck due
to the following function being executed a billion times:

  static const char * s = "hello.......";
  static bool b = true;
  int get_value(lua_State * L) {
    if (b) lua_pushstring(L, s);
    else   lua_pushnil(L);
    return 1;
  }

then rewrite it so that lua_pushstring is done only once at initialization time.
 It does involve duplicate memory usage (in C and Lua), but that isn't usually a
concern unless one has huge strings.