private Task SerializeAsync(MqttPublishPacket packet, IMqttCommunicationChannel destination)
{
ValidatePublishPacket(packet);
using (var output = new MqttPacketWriter())
{
output.WriteWithLengthPrefix(packet.Topic);
if (packet.QualityOfServiceLevel > MqttQualityOfServiceLevel.AtMostOnce)
{
output.Write(packet.PacketIdentifier);
}
else
{
if (packet.PacketIdentifier > 0)
{
throw new MqttProtocolViolationException("Packet identifier must be empty if QoS == 0 [MQTT-2.3.1-5].");
}
}
if (packet.Payload?.Length > 0)
{
output.Write(packet.Payload);
}
var fixedHeader = new ByteWriter();
fixedHeader.Write(packet.Retain);
fixedHeader.Write((byte)packet.QualityOfServiceLevel, 2);
fixedHeader.Write(packet.Dup);
output.InjectFixedHeader(MqttControlPacketType.Publish, fixedHeader.Value);
return(output.WriteToAsync(destination));
}
}
private Task SerializeEmptyPacketAsync(MqttControlPacketType type, IMqttCommunicationChannel destination)
{
using (var output = new MqttPacketWriter())
{
output.InjectFixedHeader(type);
return(output.WriteToAsync(destination));
}
}
private Task SerializeAsync(MqttUnsubAckPacket packet, IMqttCommunicationChannel destination)
{
using (var output = new MqttPacketWriter())
{
output.Write(packet.PacketIdentifier);
output.InjectFixedHeader(MqttControlPacketType.UnsubAck);
return(output.WriteToAsync(destination));
}
}
private async Task SerializeAsync(MqttPubRelPacket packet, IMqttCommunicationChannel destination)
{
using (var output = new MqttPacketWriter())
{
output.Write(packet.PacketIdentifier);
output.InjectFixedHeader(MqttControlPacketType.PubRel, 0x02);
await output.WriteToAsync(destination);
}
}
private Task SerializeAsync(MqttConnectPacket packet, IMqttCommunicationChannel destination)
{
ValidateConnectPacket(packet);
using (var output = new MqttPacketWriter())
{
// Write variable header
output.Write(0x00, 0x04); // 3.1.2.1 Protocol Name
output.Write(MqttPrefix);
output.Write(0x04); // 3.1.2.2 Protocol Level
var connectFlags = new ByteWriter(); // 3.1.2.3 Connect Flags
connectFlags.Write(false); // Reserved
connectFlags.Write(packet.CleanSession);
connectFlags.Write(packet.WillMessage != null);
if (packet.WillMessage != null)
{
connectFlags.Write((int)packet.WillMessage.QualityOfServiceLevel, 2);
connectFlags.Write(packet.WillMessage.Retain);
}
else
{
connectFlags.Write(0, 2);
connectFlags.Write(false);
}
connectFlags.Write(packet.Password != null);
connectFlags.Write(packet.Username != null);
output.Write(connectFlags);
output.Write(packet.KeepAlivePeriod);
output.WriteWithLengthPrefix(packet.ClientId);
if (packet.WillMessage != null)
{
output.WriteWithLengthPrefix(packet.WillMessage.Topic);
output.WriteWithLengthPrefix(packet.WillMessage.Payload);
}
if (packet.Username != null)
{
output.WriteWithLengthPrefix(packet.Username);
}
if (packet.Password != null)
{
output.WriteWithLengthPrefix(packet.Password);
}
output.InjectFixedHeader(MqttControlPacketType.Connect);
return(output.WriteToAsync(destination));
}
}
private Task SerializeAsync(MqttConnAckPacket packet, IMqttCommunicationChannel destination)
{
using (var output = new MqttPacketWriter())
{
var connectAcknowledgeFlags = new ByteWriter();
connectAcknowledgeFlags.Write(packet.IsSessionPresent);
output.Write(connectAcknowledgeFlags);
output.Write((byte)packet.ConnectReturnCode);
output.InjectFixedHeader(MqttControlPacketType.ConnAck);
return(output.WriteToAsync(destination));
}
}
private Task SerializeAsync(MqttUnsubscribePacket packet, IMqttCommunicationChannel destination)
{
using (var output = new MqttPacketWriter())
{
output.Write(packet.PacketIdentifier);
if (packet.TopicFilters?.Any() == true)
{
foreach (var topicFilter in packet.TopicFilters)
{
output.WriteWithLengthPrefix(topicFilter);
}
}
output.InjectFixedHeader(MqttControlPacketType.Unsubscibe, 0x02);
return(output.WriteToAsync(destination));
}
}
private Task SerializeAsync(MqttSubAckPacket packet, IMqttCommunicationChannel destination)
{
using (var output = new MqttPacketWriter())
{
output.Write(packet.PacketIdentifier);
if (packet.SubscribeReturnCodes?.Any() == true)
{
foreach (var packetSubscribeReturnCode in packet.SubscribeReturnCodes)
{
output.Write((byte)packetSubscribeReturnCode);
}
}
output.InjectFixedHeader(MqttControlPacketType.SubAck);
return(output.WriteToAsync(destination));
}
}
private Task SerializeAsync(MqttSubscribePacket packet, IMqttCommunicationChannel destination)
{
using (var output = new MqttPacketWriter())
{
output.Write(packet.PacketIdentifier);
if (packet.TopicFilters?.Count > 0)
{
foreach (var topicFilter in packet.TopicFilters)
{
output.WriteWithLengthPrefix(topicFilter.Topic);
output.Write((byte)topicFilter.QualityOfServiceLevel);
}
}
output.InjectFixedHeader(MqttControlPacketType.Subscribe, 0x02);
return(output.WriteToAsync(destination));
}
}