Function RedisGenericCommand

src/storage/scripting.cc:771–903

TODO: we do not want to repeat same logic as Connection::ExecuteCommands, so the function need to be refactored

// TODO: we do not want to repeat same logic as Connection::ExecuteCommands,
// so the function need to be refactored
int RedisGenericCommand(lua_State *lua, int raise_error) {
  auto *script_run_ctx = GetFromRegistry<ScriptRunCtx>(lua, REGISTRY_SCRIPT_RUN_CTX_NAME);
  CHECK(script_run_ctx != nullptr);

  int argc = lua_gettop(lua);
  if (argc == 0) {
    PushError(lua, "Please specify at least one argument for redis.call()");
    return raise_error ? RaiseError(lua) : 1;
  }

  std::vector<std::string> args;
  for (int j = 1; j <= argc; j++) {
    if (lua_type(lua, j) == LUA_TNUMBER) {
      lua_Number num = lua_tonumber(lua, j);
      args.emplace_back(fmt::format("{:.17g}", static_cast<double>(num)));
    } else {
      size_t obj_len = 0;
      const char *obj_s = lua_tolstring(lua, j, &obj_len);
      if (obj_s == nullptr) {
        PushError(lua, "Lua redis.call() command arguments must be strings or integers");
        return raise_error ? RaiseError(lua) : 1;
      }
      args.emplace_back(obj_s, obj_len);
    }
  }

  auto cmd_s = Server::LookupAndCreateCommand(args[0]);
  if (!cmd_s) {
    PushError(lua, "Unknown Redis command called from Lua script");
    return raise_error ? RaiseError(lua) : 1;
  }
  auto cmd = *std::move(cmd_s);

  auto attributes = cmd->GetAttributes();
  if (!attributes->CheckArity(argc)) {
    PushError(lua, "Wrong number of args while calling Redis command from Lua script");
    return raise_error ? RaiseError(lua) : 1;
  }

  auto *conn = script_run_ctx->conn;
  auto *srv = conn->GetServer();
  Config *config = srv->GetConfig();

  auto cmd_flags = attributes->GenerateFlags(args, *config);

  if ((script_run_ctx->flags & ScriptFlagType::kScriptNoWrites) && !(cmd_flags & redis::kCmdReadOnly)) {
    PushError(lua, "Write commands are not allowed from read-only scripts");
    return raise_error ? RaiseError(lua) : 1;
  }

  if ((cmd_flags & redis::kCmdNoScript) || (cmd_flags & redis::kCmdExclusive)) {
    PushError(lua, "This Redis command is not allowed from scripts");
    return raise_error ? RaiseError(lua) : 1;
  }

  std::string cmd_name = attributes->name;
  cmd->SetArgs(args);
  auto s = cmd->Parse();