/// <summary>
/// Publishes the given packet to the broker.
/// </summary>
/// <param name="packet">Packet.</param>
private ushort Publish(PublishPacket packet)
{
packet.Validate();
if (packet.QosLevel != MqttQos.AtMostOnce)
{
if (packet.PacketId == 0)
{
packet.PacketId = this.GetNextPacketId();
}
// persistence needed only on qos levels 1 and 2
Persistence.RegisterOutgoingFlow(new OutgoingFlow()
{
PacketId = packet.PacketId,
Retain = packet.Retain,
Topic = packet.Topic,
Qos = packet.QosLevel,
Payload = packet.Message
});
}
try
{
IsPublishing = true;
Send(packet);
return(packet.PacketId);
}
catch
{
IsPublishing = false;
throw;
}
}
// -- incoming publish events --
void OnPublishReceived(PublishPacket packet)
{
if (packet.QosLevel == MqttQos.ExactlyOnce)
{
OnQos2PublishReceived(packet);
}
else
{
if (PublishReceived != null)
{
PublishReceived(this, new PublishReceivedEventArgs(packet));
}
if (packet.QosLevel == MqttQos.AtLeastOnce)
{
Send(new PubackPacket()
{
PacketId = packet.PacketId
});
}
}
}
void OnQos2PublishReceived(PublishPacket packet)
{
if (!Persistence.IsIncomingFlowRegistered(packet.PacketId))
{
if (PublishReceived != null)
{
PublishReceived(this, new PublishReceivedEventArgs(packet));
}
// Register the incoming packetId, so duplicate messages can be filtered.
// This is done after "ProcessIncomingPublish" because we can't assume the
// mesage was received in the case that method throws an exception.
Persistence.RegisterIncomingFlow(packet.PacketId);
// the ideal would be to run `PubishReceived` and `Persistence.RegisterIncomingFlow`
// in a single transaction (either both or neither succeeds).
}
Send(new PubrecPacket()
{
PacketId = packet.PacketId
});
}
// sends a publish with dup flag in the case of a publish redelivery
// or a pubrel in the case of qos2 message that we know was received by the broker
private void Resume(OutgoingFlow flow)
{
if (flow.Qos == MqttQos.AtLeastOnce ||
(flow.Qos == MqttQos.ExactlyOnce && !flow.Received))
{
var publish = new PublishPacket()
{
PacketId = flow.PacketId,
QosLevel = flow.Qos,
Topic = flow.Topic,
Message = flow.Payload,
DupFlag = true
};
Publish(publish);
}
else if (flow.Qos == MqttQos.ExactlyOnce && flow.Received)
{
Pubrel(flow.PacketId);
}
Persistence.LastOutgoingPacketId = flow.PacketId;
}
internal PublishReceivedEventArgs(PublishPacket packet) : base()
{
this.Packet = packet;
}