/// <summary>
/// Handles the receipt of publish acknowledgement messages.
/// </summary>
/// <param name="msg">The publish acknowledgement</param>
/// <returns>True; always.</returns>
/// <remarks>
/// This callback simply removes it from the list of published messages.
/// </remarks>
private bool HandlePublishAcknowledgement(MqttMessage msg)
{
MqttPublishAckMessage ackMsg = (MqttPublishAckMessage)msg;
// if we're expecting an ack for the message, remove it from the list of pubs awaiting ack.
if (publishedMessages.Keys.Contains(ackMsg.VariableHeader.MessageIdentifier))
{
publishedMessages.Remove(ackMsg.VariableHeader.MessageIdentifier);
}
return(true);
}
/// <summary>
/// Handles the receipt of publish messages from a message broker.
/// </summary>
/// <param name="msg">The message that was published.</param>
/// <returns></returns>
private bool HandlePublish(MqttMessage msg)
{
var pubMsg = (MqttPublishMessage)msg;
var publishSuccess = true;
try {
var topic = new PublicationTopic(pubMsg.VariableHeader.TopicName);
if (pubMsg.Header.Qos == MqttQos.AtMostOnce)
{
// QOS AtMostOnce 0 require no response.
// send the message for processing to whoever is waiting.
OnMessageReceived(topic, pubMsg);
}
else if (pubMsg.Header.Qos == MqttQos.AtLeastOnce)
{
// QOS AtLeastOnce 1 require an acknowledgement
// send the message for processing to whoever is waiting.
OnMessageReceived(topic, pubMsg);
var ackMsg = new MqttPublishAckMessage()
.WithMessageIdentifier(pubMsg.VariableHeader.MessageIdentifier);
connectionHandler.SendMessage(ackMsg);
}
else if (pubMsg.Header.Qos == MqttQos.ExactlyOnce)
{
// QOS ExactlyOnce means we can't give it away yet, we gotta do a handshake
// to make sure the broker knows we got it, and we know he knows we got it.
// if we've already got it thats ok, it just means its being republished because
// of a handshake breakdown, overwrite our existing one for the sake of it
if (!receivedMessages.ContainsKey(pubMsg.VariableHeader.MessageIdentifier))
{
receivedMessages[pubMsg.VariableHeader.MessageIdentifier] = pubMsg;
}
var pubRecv = new MqttPublishReceivedMessage()
.WithMessageIdentifier(pubMsg.VariableHeader.MessageIdentifier);
connectionHandler.SendMessage(pubRecv);
}
} catch (ArgumentException ex) {
Log.Warn(m => m("Message recieved which contained topic ({0}) that was not valid according to MQTT Spec was suppressed.",
pubMsg.VariableHeader.TopicName), ex);
publishSuccess = false;
} catch (Exception ex) {
Log.Error(m => m("An error occurred while processing a message received from a broker ({0}).", msg), ex);
publishSuccess = false;
}
return(publishSuccess);
}
/// <summary>
/// Handles the receipt of publish messages from a message broker.
/// </summary>
/// <param name="msg">The message that was published.</param>
/// <returns></returns>
private bool HandlePublish(MqttMessage msg)
{
MqttPublishMessage pubMsg = (MqttPublishMessage)msg;
bool publishSuccess = false;
if (pubMsg.Header.Qos == MqttQos.AtMostOnce)
{
// QOS AtMostOnce 0 require no response.
// send the message for processing to whoever is waiting.
publishSuccess = publishMessageCallback(pubMsg);
}
else if (pubMsg.Header.Qos == MqttQos.AtLeastOnce)
{
// QOS AtLeastOnce 1 require an acknowledgement
// send the message for processing to whoever is waiting.
publishSuccess = publishMessageCallback(pubMsg);
MqttPublishAckMessage ackMsg = new MqttPublishAckMessage()
.WithMessageIdentifier(pubMsg.VariableHeader.MessageIdentifier);
connectionHandler.SendMessage(ackMsg);
}
else if (pubMsg.Header.Qos == MqttQos.ExactlyOnce)
{
// QOS ExactlyOnce means we can't give it away yet, we gotta do a handshake
// to make sure the broker knows we got it, and we know he knows we got it.
// if we've already got it thats ok, it just means its being republished because
// of a handshake breakdown, overwrite our existing one for the sake of it
if (!receivedMessages.ContainsKey(pubMsg.VariableHeader.MessageIdentifier))
{
receivedMessages[pubMsg.VariableHeader.MessageIdentifier] = pubMsg;
}
MqttPublishReceivedMessage pubRecv = new MqttPublishReceivedMessage()
.WithMessageIdentifier(pubMsg.VariableHeader.MessageIdentifier);
connectionHandler.SendMessage(pubRecv);
publishSuccess = true;
}
return(publishSuccess);
}
public void ValidPayload()
{
// publish ack msg with message identifier 4
var expected = new[]
{
(byte)0x40,
(byte)0x02,
(byte)0x0,
(byte)0x4,
};
MqttPublishAckMessage msg = new MqttPublishAckMessage().WithMessageIdentifier(4);
Console.WriteLine(msg.ToString());
byte[] actual = MessageSerializationHelper.GetMessageBytes(msg);
Assert.Equal<int>(expected.Length, actual.Length);
Assert.Equal<byte>(expected[0], actual[0]); // msg type of header
Assert.Equal<byte>(expected[1], actual[1]); // remaining length
Assert.Equal<byte>(expected[2], actual[2]); // connect ack - compression? always empty
Assert.Equal<byte>(expected[3], actual[3]); // return code.
}