numbers.js cache excessive memory usage about mqtt-packet

[David-Parker]

Thanks Matteo, the comment on endianess makes sense.

Yes, the interface is a little bit different, but wondering if these buffers can be combined somehow into a single buffer object with different views. I have some ideas on how to improve the stream writing, will see if I get some time to hack on it and run some benchmarks.

[mcollina]

Part of the reason we are allocating all those buffers is to avoid creating them at runtime when this information is sent on to the wire. The question is how much writing a slice of this new massive UInt16Array will cost.

I always welcome perf improvemements, so why don't you prepare a PR and we can benchmark? I don't think the logic of what you propose would be identical to what we have here.

(Note that the endianess is required by the MQTT protocol)