On 2 April 2011 23:12, C++ RTMP Server
<crtmpserver@gmail.com> wrote:
Hi,
I have a special situation in which I have to create an association between my app-specific state and the lua_State. For this I have 3 solutions:
1. create pair of maps: map <MyStateStruct*, lua_State *> and the other way around map <lua_State *, MyStateStruct*>
2. create an unique ID for each MyStateStruct and store that ID into GLOBALINDEX inside lua_State
3. Same as 2, but store MyStateStruct directly into lua_State GLOBALINDEX as user-data
Honestly, I don't like any of them:
1st one introduces a lot of management code and is prone to errors
2nd and 3rd introduces few calls for extracting my MyStateStruct structure
I hope that there is a way to associate a void * pointer with a lua_State so when lua calls C/C++ code I can get my hands on the MyStateStruct without calling additional stuff (get the global index) or indexing through those 2 maps. I was thinking more like simple dereferencing a void * inside lua_State
int luaapi_application_getConfig(lua_State *L) {
MyStateStruct *pMyState=(MyStateStruct *)L->pMagicUserDataField;
//do stuff with pMyState
....
}
Thank you
------
Eugen-Andrei Gavriloaie
Web: http://www.rtmpd.com
If there is a one to one mapping of application state to lua_State, you can register the luaCfunctions with the upvalue stored as a void pointer. See the section [1] in Programming in Lua which talks about this situation using the registry or upvalues.
Liam
