dial function

Implementation

Future<ClientChannelBase> dial(String address, DialOptions? options, String Function() sessionCallback) async {
  final dialSW = Stopwatch()..start();
  _logger.i('Connecting to address $address');
  final opts = options ?? DialOptions();

  if (opts.attemptMdns) {
    final mdnsSW = Stopwatch()..start();
    try {
      final mdnsUri = await _searchMdns(address);
      // Let downstream calls know when mdns was used. This is helpful to inform
      // when determining if we want to use the external auth credentials for the signaling
      // in cases where the external signaling is the same as the external auth. For mdns
      // this isn't the case.
      final dialOptsCopy = opts.._usingMdns = true;
      dialOptsCopy.webRtcOptions ??= DialWebRtcOptions();
      dialOptsCopy.webRtcOptions?.signalingServerAddress = mdnsUri;
      return await _dialWebRtc(address, dialOptsCopy, sessionCallback);
    } on NotLocalAddressException catch (e) {
      _logger.d(e.toString());
    } catch (e) {
      _logger.d('Error dialing with mDNS; falling back to other methods', error: e);
    }
    mdnsSW.stop();
    _logger.d('STATS: mDNS discovery took ${mdnsSW.elapsed}');
  }

  bool disableWebRtc = opts.webRtcOptions?.disable ?? false;
  if (address.contains('.local.') || address.contains('localhost')) {
    disableWebRtc = true;
  }
  final Future<ClientChannelBase> chan;
  if (disableWebRtc) {
    chan = _dialDirectGrpc(address, opts, sessionCallback);
  } else {
    chan = _dialWebRtc(address, opts, sessionCallback);
  }
  dialSW.stop();
  _logger.d('STATS: dial function took ${dialSW.elapsed}');
  return chan.timeout(opts.timeout);
}