buffer strategy for QOS>0 messages

[dakhnod]

In my application. I am publishing sensor data and need to buffer messages in case connection is temporarily lost.
Thus, I am sending my data with QOS 2.
I limited the number of queued message in case of disconnection via max_queued_messages_set().

Now, If I got it right, here is what happens when the buffer runs full: all newer messages get discarded.
So, with a limit of 5, if I publish 1 2 3 4 5 6 7 8 9 0, after reconnection these messages get delivered: 1 2 3 4 5.

For me, it would be more useful if the buffer would be circularly rewritten, so the newest 5 messages are queued.

Is there a way to set this up?

[MattBrittan]

Currently this is a fairly simple check

 if self._max_queued_messages > 0 and len(self._out_messages) >= self._max_queued_messages:
                    message.info.rc = MQTTErrorCode.MQTT_ERR_QUEUE_SIZE
                    return message.info

So the library does not offer the functionality you are looking for and I've tagged this as an enhancement request (feel free to submit a PR if it's something you wish to implement).