/// <summary>
/// Searches asynchronously.
/// </summary>
/// <param name="destinations">The destinations.</param>
public void SearchAsync(params IPEndPoint[] destinations)
{
lock (this.SearchLock)
{
// If we're already searching then this is not allowed so throw an error
if (this.IsSearching)
{
throw new InvalidOperationException("Search is already in progress.");
}
this.IsSearching = true;
this.Server.DataReceived += OnServerDataReceived;
// TODO: Come up with a good calculation for this
// Just double our mx value for the timeout for now
this.CreateSearchTimeout(TimeSpan.FromSeconds(this.Mx * 2));
}
// If no destinations were specified then default to the IPv4 discovery
if (destinations == null || destinations.Length == 0)
{
destinations = new IPEndPoint[] { Protocol.DiscoveryEndpoints.IPv4 }
}
;
// Start the server
this.Server.StartListening();
// Do we really need to join the multicast group to send out multicast messages? Seems that way...
foreach (IPEndPoint dest in destinations.Where(ep => IPAddressHelpers.IsMulticast(ep.Address)))
{
this.Server.JoinMulticastGroupAllInterfaces(dest);
}
// If we're sending out any searches to the broadcast address then be sure to enable broadcasts
if (!this.Server.EnableBroadcast)
{
this.Server.EnableBroadcast = destinations.Any(ep => ep.Address.Equals(IPAddress.Broadcast));
}
// Now send out our search data
foreach (IPEndPoint dest in destinations)
{
// Make sure we respect our option as to whether we use the destination as the host value
IPEndPoint host = (this.UseRemoteEndpointAsHost ? dest : this.HostEndpoint);
string req = Protocol.CreateDiscoveryRequest(host, this.SearchType, this.Mx);
byte[] bytes = Encoding.ASCII.GetBytes(req);
// TODO: Should we make this configurable?
// NOTE: It's recommended to send two searches
this.Server.Send(bytes, bytes.Length, dest);
this.Server.Send(bytes, bytes.Length, dest);
}
}
