/// <summary>
/// Invoked when a publish packet is received.
/// </summary>
/// <param name="client">The client sending the packet.</param>
/// <param name="packet">The packet received from the client.</param>
public static ProcessingState OnPublish(IClient client, MqttPublishPacket packet)
{
// Publish through emitter
HandlePublish.Process(client, packet.Channel, packet.Message);
// Send the ack and stop the processing
if (client.Context.QoS > QoS.AtMostOnce)
{
client.SendMqttPuback(packet.MessageId);
}
return(ProcessingState.Stop);
}
/// <summary>
/// Sends a response to the client.
/// </summary>
/// <param name="client">The client to reply to.</param>
/// <param name="response">The emitte response to send.</param>
private static void SendResponse(IClient client, string channel, EmitterResponse response)
{
// Serialize the response
var serialized = JsonConvert.SerializeObject(response, Formatting.Indented);
if (serialized == null)
{
return;
}
// Send the message out
var msg = MqttPublishPacket.Acquire();
msg.Channel = channel;
msg.Message = serialized.AsUTF8().AsSegment();
client.Send(msg);
}
private static MqttPacket Acquire(MqttPacketType type, IClient client)
{
switch (type)
{
case MqttPacketType.Connect: return(MqttConnectPacket.Acquire());
case MqttPacketType.Subscribe: return(MqttSubscribePacket.Acquire());
case MqttPacketType.Unsubscribe: return(MqttUnsubscribePacket.Acquire());
case MqttPacketType.PingReq: return(MqttPingReqPacket.Acquire());
case MqttPacketType.Disconnect: return(MqttDisconnectPacket.Acquire());
case MqttPacketType.Publish: return(MqttPublishPacket.Acquire());
case MqttPacketType.PubAck: return(MqttPubackPacket.Acquire());
default:
Service.Logger.Log("Unknown MQTT Type: " + type);
return(null);
}
}
/// <summary>
/// Occurs when the remote client attempts to subscribe to a hub.
/// </summary>
/// <param name="client">The remote client.</param>
/// <param name="channel">The full channel string.</param>
public static EmitterEventCode Process(IClient client, string channel)
{
try
{
// Parse the channel
EmitterChannel info;
if (!EmitterChannel.TryParse(channel, true, out info))
{
return(EmitterEventCode.BadRequest);
}
// Simple ACK for api subscribe. We don't really need to subscribe as
// this uses request/response topology and hence the response is sent
// through the same TCP connection.
if (info.Key == "emitter")
{
return(EmitterEventCode.Success);
}
// Attempt to parse the key
SecurityKey key;
if (!SecurityKey.TryParse(info.Key, out key))
{
return(EmitterEventCode.BadRequest);
}
// Has the key expired?
if (key.IsExpired)
{
return(EmitterEventCode.Unauthorized);
}
// Have we already subscribed?
//if (client[channel] != null)
// return EmitterEventCode.Success;
// Attempt to fetch the contract using the key. Underneath, it's cached.
var contract = Services.Contract.GetByKey(key.Contract) as EmitterContract;
if (contract == null)
{
return(EmitterEventCode.NotFound);
}
// Check if the payment state is valid
if (contract.Status == EmitterContractStatus.Refused)
{
return(EmitterEventCode.PaymentRequired);
}
// Validate the contract
if (!contract.Validate(ref key))
{
return(EmitterEventCode.Unauthorized);
}
// Check if the key has the permission to read here
if (!key.HasPermission(SecurityAccess.Read))
{
return(EmitterEventCode.Unauthorized);
}
// Check if the key has the permission for the required channel
if (key.Target != 0 && info.Target != key.Target)
{
return(EmitterEventCode.Unauthorized);
}
// Subscribe to the channel
var subs = Dispatcher.Subscribe(client, key.Contract, info.Channel, SubscriptionInterest.Messages);
// Check if the history was also requested and we have the permission to do so
var last = 0;
if (!info.RequestedLast(out last) || !key.HasPermission(SecurityAccess.Load))
{
return(EmitterEventCode.Success);
}
// Get the ssid
var ssid = EmitterChannel.Ssid(key.Contract, info.Channel);
// Stream the history
Services.Storage
.GetLastAsync(key.Contract, ssid, last)
.ContinueWith(async(t) =>
{
// Now send each message in order
var stream = t.Result;
while (stream.HasNext)
{
// Get the message asyncronously
var item = await stream.GetNext();
if (item.Count == 0)
{
continue;
}
// Increment the counter
Service.MessageSent?.Invoke(contract, channel, item.Count);
// Send the message out
var msg = MqttPublishPacket.Acquire();
msg.Channel = info.Channel;
msg.Message = item;
client.Send(msg);
}
});
// We have successfully subscribed
return(EmitterEventCode.Success);
}
catch (NotImplementedException)
{
// We've got a not implemented exception
return(EmitterEventCode.NotImplemented);
}
catch (Exception ex)
{
// We need to log it
Service.Logger.Log(ex);
// We've got a an internal error
return(EmitterEventCode.ServerError);
}
}
public static void SendMqttPublish(this IClient client, string channel, ArraySegment <byte> message)
{
client.Send(
MqttPublishPacket.Acquire(channel, message)
);
}