ServiceData::SetOptionResult ServiceData::setOptionWithResult()

in fb303/ServiceData.cpp [596:648]
40 lines of code
10 McCabe index (conditional complexity)

ServiceData::SetOptionResult ServiceData::setOptionWithResult(
    string_view key,
    string_view value) {
  // Check to see if a dynamic option is registered for this key
  {
    auto dynamicOptionsRLock = dynamicOptions_.rlock();
    if (auto ptr = folly::get_ptr(*dynamicOptionsRLock, key)) {
      if (ptr->setter) {
        as_mutable(ptr->setter)(string{value});
      }
      return SetOptionResult::Dynamic;
    }
  }

  // This is not a dynamic option.
  // Set it in the static option map.
  (*options_.wlock())[key] = string{value};

  // Next check to see if we should update command line flags based
  // on this static option name.

  // By default allow modifying glog verbosity (options 'v' or 'vmodule')
  auto useOptionsAsFlags = useOptionsAsFlags_.load(std::memory_order_relaxed);
  static constexpr StringPiece blacklistedOptions[] = {
      StringPiece{"logmailer"}, StringPiece{"whitelist_flags"}};
  if (std::count(
          std::begin(blacklistedOptions), std::end(blacklistedOptions), key) >
      0) {
    return SetOptionResult::CmdlineBlacklisted;
  }

  if (!(useOptionsAsFlags || key == "v" || key == "vmodule")) {
    return SetOptionResult::CmdlineDisabled;
  }

  string res =
      gflags::SetCommandLineOption(string{key}.c_str(), string{value}.c_str());
  if (res.empty()) {
    LOG(ERROR) << "Couldn't set flag 'FLAGS_" << key << "' to val '" << value
               << "'";
    return SetOptionResult::CmdlineNoUpdate;
  }
  // special handling for vmodule changes as SetCommandLineOption()
  // is not sufficient. Need to call SetVLOGLevel() as well.
  if (key == "vmodule") {
    setVModuleOption(key, value);
  } else if (key == "v") {
    gflags::SetCommandLineOption("minloglevel", "0");
  }
  LOG(WARNING) << "FLAG CHANGE: overrode 'FLAGS_" << key << "' to val '"
               << value << "', res '" << res << "'";
  return SetOptionResult::CmdlineUpdated;
}