static byte EncodeSubscribePacket(MqttSubscribePacket packet, IMqttPacketWriter packetWriter)
{
if (packet.TopicFilters?.Any() != true)
{
throw new MqttProtocolViolationException("At least one topic filter must be set [MQTT-3.8.3-3].");
}
ThrowIfPacketIdentifierIsInvalid(packet.PacketIdentifier, packet);
packetWriter.Write(packet.PacketIdentifier);
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
if (packet.Properties.SubscriptionIdentifier > 0)
{
propertiesWriter.WriteSubscriptionIdentifier(packet.Properties.SubscriptionIdentifier);
}
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
propertiesWriter.WriteTo(packetWriter);
if (packet.TopicFilters?.Count > 0)
{
foreach (var topicFilter in packet.TopicFilters)
{
packetWriter.WriteWithLengthPrefix(topicFilter.Topic);
var options = (byte)topicFilter.QualityOfServiceLevel;
if (topicFilter.NoLocal)
{
options |= 1 << 2;
}
if (topicFilter.RetainAsPublished)
{
options |= 1 << 3;
}
if (topicFilter.RetainHandling != MqttRetainHandling.SendAtSubscribe)
{
options |= (byte)((byte)topicFilter.RetainHandling << 4);
}
packetWriter.Write(options);
}
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Subscribe, 0x02));
}
private static byte EncodePublishPacket(MqttPublishPacket packet, IMqttPacketWriter packetWriter)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
if (packetWriter == null)
{
throw new ArgumentNullException(nameof(packetWriter));
}
if (packet.QualityOfServiceLevel == 0 && packet.Dup)
{
throw new MqttProtocolViolationException("Dup flag must be false for QoS 0 packets [MQTT-3.3.1-2].");
}
packetWriter.WriteWithLengthPrefix(packet.Topic);
if (packet.QualityOfServiceLevel > MqttQualityOfServiceLevel.AtMostOnce)
{
if (!packet.PacketIdentifier.HasValue)
{
throw new MqttProtocolViolationException("Publish packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier.Value);
}
else
{
if (packet.PacketIdentifier > 0)
{
throw new MqttProtocolViolationException("Packet identifier must be 0 if QoS == 0 [MQTT-2.3.1-5].");
}
}
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
propertiesWriter.WritePayloadFormatIndicator(packet.Properties.PayloadFormatIndicator);
propertiesWriter.WriteMessageExpiryInterval(packet.Properties.MessageExpiryInterval);
propertiesWriter.WriteTopicAlias(packet.Properties.TopicAlias);
propertiesWriter.WriteResponseTopic(packet.Properties.ResponseTopic);
propertiesWriter.WriteCorrelationData(packet.Properties.CorrelationData);
propertiesWriter.WriteSubscriptionIdentifier(packet.Properties.SubscriptionIdentifier);
propertiesWriter.WriteContentType(packet.Properties.ContentType);
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
propertiesWriter.WriteToPacket(packetWriter);
if (packet.Payload?.Length > 0)
{
packetWriter.Write(packet.Payload, 0, packet.Payload.Length);
}
byte fixedHeader = 0;
if (packet.Retain)
{
fixedHeader |= 0x01;
}
fixedHeader |= (byte)((byte)packet.QualityOfServiceLevel << 1);
if (packet.Dup)
{
fixedHeader |= 0x08;
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Publish, fixedHeader));
}
