Rethink UI + messaging abstraction

[anonimal]

Brought in up today's meeting (#47), Monero's use of ZeroMQ and Qt.

In #49 I proposed an ncurses GUI. With ZMQ, I believe we could still do that while maintaining a method to interface with Monero's GUI (please correct me if I'm wrong). @majestrate also points out that ZMQ over I2CP is doable (and I think it's interesting).

For all of these issues, I think that a solid abstraction layer to interface with for messaging could be a great solution and we should look into ZMQ (or alternative).

If we ZMQ, how could we integrate #33?

[anonimal]

@anonimal       I'm kind of running into dead-ends re: #53. zmq has those 4 message types (req-rep, pub-sub, push-pull, ex-pair) so I'm not seeing much use-case, *but*,
@anonimal       1. I'm wondering if MoroccanMalinois would want to do something with IPC and reporting and,
@anonimal       2. I'm really liking the idea of curvezmq as a replacement for tls/ssl with reseed and address book 
@anonimal       basically throwing out ssl all-together. That be amazing but we would have to implement a curvezmq server option for both those components (afaict).
@anonimal       And of course we'd have to get the monero community to host those reseed servers, etc.
@anonimal       SSL is that annoying skin tag that just won't go away.
@anonimal       AFAICT zmq is great for what it provides but our parallel tasks and data aren't uniform in the sense that *I think* zmq works best with; e.g., our data is determined on a per-host basis (alice has multiple bobs to chose from, each bob is different, each bob ephemeral).
@anonimal       I can't seem to find a way to cram that into a fan-in message pattern or any other zmq pattern; at least in a way that we can use.
@anonimal       fwiw, The zmq features seem superb though (I like the queuing), and azmq has boost asio bindings (not sure how useful that would be though).
@anonimal       If/when we move to tweetnacl after sarang gets more kovri time, curvezmq would integrate nicely.

Note: UDP transport can only be used with the 'ZMQ_RADIO' and 'ZMQ_DISH' socket types. https://github.com/zeromq/libzmq/blob/3683a96fcbf25c4bc04ac4b002a1b1550db99767/doc/zmq_udp.txt#L18-L19 so this may be a good reason to NACK this issue for an SSU use-case.

More research needed. Pinging @MoroccanMalinois.

[anonimal]

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