Method applyTransformLua

app/src/DataModel/FrameBuilder.cpp:2258–2342

* @brief Calls the cached Lua transform function for @p uniqueId under the per-call deadline. */

 * @brief Calls the cached Lua transform function for @p uniqueId under the per-call deadline.
 */
QVariant DataModel::FrameBuilder::applyTransformLua(TransformEngine& engine,
                                                    int uniqueId,
                                                    const QVariant& rawValue,
                                                    const TransformFrameInfo& info)
{
  auto refIt = engine.luaRefs.find(uniqueId);
  if (refIt == engine.luaRefs.end())
    return rawValue;

  lua_State* L           = engine.luaState;
  const auto& transform  = refIt->second;
  const bool acceptsInfo = transform.acceptsInfo;
  engine.luaDeadline.setRemainingTime(kTransformWatchdogMs);

  try {
    lua_rawgeti(L, LUA_REGISTRYINDEX, transform.ref);
    if (rawValue.typeId() == QMetaType::Double) {
      lua_pushnumber(L, SerialStudio::toDouble(rawValue));
    } else {
      const auto utf8 = rawValue.toString().toUtf8();
      lua_pushlstring(L, utf8.constData(), static_cast<size_t>(utf8.size()));
    }

    int argCount = 1;
    if (acceptsInfo) {
      lua_createtable(L, 0, 3);
      lua_pushinteger(L, static_cast<lua_Integer>(info.frameNumber));
      lua_setfield(L, -2, "frameNumber");
      lua_pushinteger(L, info.sourceId);
      lua_setfield(L, -2, "sourceId");
      lua_pushinteger(L, static_cast<lua_Integer>(info.timestampMs));
      lua_setfield(L, -2, "timestampMs");
      argCount = 2;
    }

    int pcallStatus = LUA_ERRRUN;
    try {
      pcallStatus = lua_pcall(L, argCount, 1, 0);
    } catch (...) {
      qWarning() << "[FrameBuilder] Uncaught exception escaped lua_pcall in transform for"
                 << uniqueId;
      try {
        lua_settop(L, 0);
        lua_pushstring(L, "uncaught Lua exception (escaped lua_pcall)");
      } catch (...) {
      }
      pcallStatus = LUA_ERRRUN;
    }
    engine.luaDeadline = QDeadlineTimer(QDeadlineTimer::Forever);

    if (pcallStatus != LUA_OK) [[unlikely]] {
      qWarning() << "[FrameBuilder] Lua transform call failed for dataset" << uniqueId << ":"
                 << lua_tostring(L, -1);
      lua_pop(L, 1);
      return rawValue;
    }

    if (lua_isnumber(L, -1)) {