cocos2d-x载入lua的过程

//类CCLuaEngine 实现了 cocos2d-x的脚本引擎接口 
CCScriptEngineProtocol* pEngine = CCLuaEngine::engine();
//manager中设置脚本引擎
CCScriptEngineManager::sharedManager()->setScriptEngine(pEngine);
//通过相对路径获取绝对路径
string path = CCFileUtils::sharedFileUtils()->fullPathFromRelativePath("script/Main.lua");
//把文件所在目录添加至lua文件搜索路径
pEngine->addSearchPath(path.substr(0, path.find_last_of("/")).c_str());
//运行指定的文件
pEngine->executeScriptFile(path.c_str());

int CCLuaEngine::executeScriptFile(const char* filename)
{
    //  读入文件
    int nRet = luaL_dofile(m_state, filename);
    //    lua_gc(m_state, LUA_GCCOLLECT, 0);

    if (nRet != 0)
    {
        CCLOG("[LUA ERROR] %s", lua_tostring(m_state, -1));
        lua_pop(m_state, 1);
        return nRet;
    }
    return 0;
}

#define luaL_dofile(L, fn) \
    (luaL_loadfile(L, fn) || lua_pcall(L, 0, LUA_MULTRET, 0))

LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
  ...
  status = lua_load(L, getF, &lf, lua_tostring(L, -1));
  ...
}

static const char *getF (lua_State *L, void *ud, size_t *size) {
  LoadF *lf = (LoadF *)ud;
  (void)L;
  if (lf->extraline) {
    lf->extraline = 0;
    *size = 1;
    return "\n";
  }
  if (feof(lf->f)) return NULL;
  memset(lf->buff, 0, sizeof(lf->buff));
  
  //将文件读入LoadF结构体的buff内存, 并将实际读到的长度赋予size, 
  *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f);
  return (*size > 0) ? lf->buff : NULL;
}

typedef struct LoadF {
  int extraline;
  FILE *f;
  unsigned char buff[LUAL_BUFFERSIZE];
} LoadF;

static const char *getF (lua_State *L, void *ud, size_t *size) {
  ...
  //将文件读入LoadF结构体的buff内存, 并将实际读到的长度赋予size, 
  *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f);
  //将buff内容解密
  *size = aes256_decrypt(key, lf->buff,*size);
  return (*size > 0) ? lf->buff : NULL;
}