/// <summary>
/// Handle incoming ping request responses and saves them in the current working data dictionary
/// If a PingOK packet is received, the suspected peer is considered alive.
/// If a PingFailed packet is received and that's the only kind of messages that
/// have been received concerning this peer, the peer is concidered dead.
/// </summary>
/// <param name="message">The message to handle</param>
/// <returns>AcceptAndFinish if all suspected peers is concluded dead or alive.
/// Accept if the packet is of type PingOK or PingFailed. Decline otherwise</returns>
public PacketResponse HandlePacket(Message message)
{
if (message.MessageType != MessageType.PingOk && message.MessageType != MessageType.PingFailed)
{
return(PacketResponse.Decline);
}
IPAddress pingedIp;
var validIp = IPAddress.TryParse(message.DataAsString, out pingedIp);
if (!validIp)
{
message.DeemInvalid();
return(PacketResponse.Decline);
}
if (nonRespondingPeers.ContainsKey(pingedIp))
{
UpdateResponses(pingedIp, message.Sender, message.MessageType);
}
if (nonRespondingPeers.Count == 0)
{
var vrl = new VoteReponseListener(networkListener, vote);
networkListener.RegisterHandler(vrl, VoteReponseListener.Timeout);
vote.SendToAll();
return(PacketResponse.AcceptAndFinish);
}
return(PacketResponse.Accept);
}
/// <summary>
/// Handles a PingRequest packet by creating a <see cref="PongListener">PongListener</see> and sending a ping to the suspect
/// </summary>
/// <param name="pingRequest">The received PingRequest object</param>
/// <returns>Accept or Decline depending on what type of packet was received</returns>
public PacketResponse HandlePacket(Message pingRequest)
{
if (pingRequest.MessageType != MessageType.PingRequest)
{
return(PacketResponse.Decline);
}
IPAddress peerToPing;
var valid = IPAddress.TryParse(pingRequest.DataAsString, out peerToPing);
if (!valid)
{
pingRequest.DeemInvalid();
return(PacketResponse.Decline);
}
var pongListener = new PongListener(pingRequest.Sender, peerToPing);
networkListener.RegisterHandler(pongListener, PongListener.Timeout);
var ping = new Message(MessageType.Ping, peerToPing);
Outbox.SendMessage(ping);
return(PacketResponse.Accept);
}
/// <summary>
/// Creates a new PingRequestResponseListener and sends out a new PingRequest
/// message to each of the peers that has not yet replied in the VoteReplyList.
/// </summary>
public void TimedOut()
{
var prrl = new PingRequestResponseListener(networkListener, vote);
networkListener.RegisterHandler(prrl, PingRequestResponseListener.Timeout);
foreach (var peer in vote.VoteReplyList)
{
if (!peer.Value)
{
var pingRequest = new Message(MessageType.PingRequest)
{
DataAsString = peer.Key.ToString()
};
Outbox.SendMessage(pingRequest);
}
}
}
