Data message: Send to channel

Messages sent from the client to a channel on the server. If the channel doesn’t exist on the server then a channel will be created.

If the channel is full and ack is True then the server will send an exception back to the client. If ack is False then the message will be dropped silently.

The client can specify two properties:

• ttl (float): Time in seconds after the server receives the message that it will be deleted. If the message is forwarded to a client from the server then the time that the message is due to expire it must be passed to the client as a property (expiry) with the message.

• ack (bool): True if the server should acknowledge the message. The client must wait until the server has acknowledged the message. If ack is False then the server must process the message silently without reporting any exceptions to the client.

If ack is true then the send function will block the thread until a response is received from the server. If ack is false then execution will continue without waiting for a response.

Action	Client -> Server	Server -> Client
Initial action	Message: b"SENDCHAN" Properties: ttl (float): Time to live in seconds. ack (bool): Acknowledge task complete.	Add message to queue. If no queue, create queue. If ack = False: -> No response. If ack = True: -> Respond complete. -> Respond exception.
Respond complete		Message: b"COMPLETE"
Respond exception		Message: b"EXCEPTON" Properties: exception (str): Error message