Revert "Extend the mDNS package with a native extension used on Mac OS"

pkg/mdns/lib/src/native_protocol_client.dart

-// Copyright (c) 2015, the Fletch project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE.md file.
-
-library mdns.src.native_protocol_client;
-
-import 'dart:async';
-import 'dart:collection';
-import 'dart:io';
-
-import 'package:mdns/mdns.dart';
-import 'package:mdns/src/constants.dart';
-import 'package:mdns/src/lookup_resolver.dart';
-import 'package:mdns/src/packet.dart';
-
-// Implementation of mDNS client using the native protocol.
-class NativeProtocolMDnsClient implements MDnsClient {
-  bool _starting = false;
-  bool _started = false;
-  RawDatagramSocket _incoming;
-  final List<RawDatagramSocket> _sockets = <RawDatagramSocket>[];
-  final LookupResolver _resolver = new LookupResolver();
-
-  /// Start the mDNS client.
-  Future start() async {
-    if (_started && _starting) {
-      throw new StateError('mDNS client already started');
-    }
-    _starting = true;
-
-    // Listen on all addresses.
-    _incoming = await RawDatagramSocket.bind(
-        InternetAddress.ANY_IP_V4, mDnsPort, reuseAddress: true);
-
-    // Find all network interfaces with an IPv4 address.
-    var interfaces =
-        await NetworkInterface.list(type: InternetAddressType.IP_V4);
-    for (NetworkInterface interface in interfaces) {
-      // Create a socket for sending on each adapter.
-      var socket = await RawDatagramSocket.bind(
-          interface.addresses[0], mDnsPort, reuseAddress: true);
-      _sockets.add(socket);
-
-      // Join multicast on this interface.
-      _incoming.joinMulticast(mDnsAddress, interface);
-    }
-    _incoming.listen(_handleIncoming);
-
-    _starting = false;
-    _started = true;
-  }
-
-  void stop() {
-    if (!_started) return;
-    if (_starting) {
-      throw new StateError('Cannot stop mDNS client wile it is starting');
-    }
-
-    _sockets.forEach((socket) => socket.close());
-    _incoming.close();
-
-    _started = false;
-  }
-
-  Future<InternetAddress> lookup(
-      String hostname, {Duration timeout: const Duration(seconds: 5)}) {
-    if (!_started) {
-      throw new StateError('mDNS client is not started');
-    }
-
-    // Add the pending request before sending the query.
-    var future = _resolver.addPendingRequest(hostname, timeout);
-
-    // Send the request on all interfaces.
-    List<int> packet = encodeMDnsQuery(hostname);
-    for (int i = 0; i < _sockets.length; i++) {
-      _sockets[i].send(packet, mDnsAddress, mDnsPort);
-    }
-
-    return future;
-  }
-
-  // Process incoming datagrams.
-  _handleIncoming(event) {
-    if (event == RawSocketEvent.READ) {
-      var data = _incoming.receive();
-      var response = decodeMDnsResponse(data.data);
-      if (response != null) {
-        _resolver.handleResponse(response);
-      }
-    }
-  }
-}