On Tuesday, 4 February 2020 07:39:11 GMT Colin Dunklau wrote: > On Tue, Feb 4, 2020 at 1:18 AM Go Luhng <golu...@gmail.com> wrote: > > > Colin Dunklau wrote: > > > > > > Assuming the header has a fixed length, > > > > It does. The header is just a serialized C struct, so it's > > fully-specified for length and offset of each field. > > > > > OTOH, that's for stream protocols, so if you want to eventually handle > > > UDP, it's probably nicer to do the full sans-io thing > > > (https://sans-io.readthedocs.io/) and wire it up with a more-basic > > > Twisted protocol. > > > > Could you elaborate on this? I'm new to Twisted, and also unfamiliar > > with sans-io. > > > > Specifically, I'm wondering what type of "more-basic" Twisted protocol you > > mean. > The sans-io pattern is described well at that site, including a link > to Cory Benfield's great talk > (https://www.youtube.com/watch?v=7cC3_jGwl_U). The idea is to keep > your protocol logic strictly separate from anything that does IO (like > a Twisted Protocol's `dataReceived` and its transport's `write` > method, or an asyncio thing, or blocking socket operations, etc), to > make it easier to test and reuse. > > By "more-basic" I mean twisted.internet.protocol.Protocol and > twisted.internet.protocol.DatagramProtocol. > > If you don't go full sans-io, I'd still strongly recommend splitting > up you protocol implementation into distinct pieces. Twisted protocols > can become hard to reason about when they become implicit state > machines... avoid it by making a separate, explicit state machine and > use that in the Protocol, instead of dumping the bits on the protocol > instance itself. This way you at least still get the testability.
The sans-io is a worth considering. The advice to use explicit state machines I fully endorse. I'm maintaining some code that uses an implicit state machine and its a pain to reason about and avoid bugs with. Barry > > _______________________________________________ > Twisted-Python mailing list > Twisted-Python@twistedmatrix.com > https://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com https://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
