findSecondaryUrl method

Future<String?> findSecondaryUrl(String atSign)

Implementation

Future<String?> findSecondaryUrl(String atSign) async {
  if (_rootDomain.startsWith("proxy:")) {
    // In order to make it easy for clients to connect to a reverse proxy
    // instead of doing a root lookup,  we adopt the convention that:
    // if the rootDomain starts with 'proxy:'
    // then the secondary domain name will be deemed to be the portion of rootDomain after 'proxy:'
    // and the secondary port will be deemed to be the rootPort
    return '${_rootDomain.substring("proxy:".length)}:$_rootPort';
  }
  String? address;
  for (int i = 0; i <= retryDelaysMillis.length; i++) {
    try {
      address = await _findSecondary(atSign);
      return address;
    } catch (e) {
      if (i < retryDelaysMillis.length) {
        _logger.info('AtLookup.findSecondary for $atSign failed with $e'
            ' : will retry in ${retryDelaysMillis[i]} milliseconds');
        await Future.delayed(Duration(milliseconds: retryDelaysMillis[i]));
        continue;
      }
      _logger.severe('AtLookup.findSecondary for $atSign failed with $e'
          ' : ${retryDelaysMillis.length + 1} failures, giving up');
      if (e is RootServerConnectivityException) {
        throw RootServerConnectivityException(
            'Unable to establish connection with root server.'
            ' Please check your internet connection and try again');
      }
    }
  }
  throw AtConnectException('Could not fetch secondary address for $atSign :'
      ' ${retryDelaysMillis.length + 1} failures, giving up');
}