[Twisted-Python] AMP message length limit

[Oon-Ee Ng]

On Tue, Nov 24, 2015 at 10:58 AM, Oon-Ee Ng <ngoonee.talk at gmail.com> wrote:
> On Tue, Nov 24, 2015 at 9:16 AM, Oon-Ee Ng <ngoonee.talk at gmail.com> wrote:
>>
>> Thanks, right now I just have plenty of return {} everywhere. Does
>> requiresAnswer=False mean less bandwidth usage (no need to transmit an
>> empty dict)?
>
> Having read the documentation a bit, it appears requiresAnswer=False
> is a hint and I'd still have to return the correct response (in this
> case an empty dict)
>
> http://twistedmatrix.com/trac/ticket/1985 and in particular the
> following comment by yourself:-
>
> Responders for Commands defined not to require a response should
> return a valid response nonetheless, because requiresAnswer is an
> optimization hint that the client can specify, on any request whose
> response it will not process, to optimize network traffic.
>
> Looks like I'll update my clients to specify it then. Was thinking it
> should be specified when defining message classes.

And it looks like I do have to specify it in defining message classes.

And furthermore that when I do that, callRemote no longer returns a
deferred (which makes sense, really) and instead gets a None. One more
check before I add my default errBacks then. Optimised network traffic
sounds positive, at the least (I assume this means one less
transmission since it effectively makes the AMP one-way for the
messages which have this set to False).