This solves a bunch of issues to do with `brokerd` order status msgs
getting relayed for each order to **every** correspondingly connected
EMS client. Previously we weren't keeping track of which emsd orders
were associated with which clients so you had backend msgs getting
broadcast to all clients which not only resulted in duplicate (and
sometimes erroneous, due to state tracking) actions taking place in the
UI's order mode, but it's also just duplicate traffic (usually to the
same actor) over multiple logical streams. Instead, only keep up **one**
(cached) stream with the `trades_dialogue()` endpoint such that **all**
emsd orders route over that single connection to the particular
`brokerd` actor.
This moves the entire clearing system to use typed messages using
`pydantic.BaseModel` such that the streamed request-response order
submission protocols can be explicitly viewed in terms of message
schema, flow, and sequencing. Using the explicit message formats we can
now dig into simplifying and normalizing across broker provider apis to
get the best uniformity and simplicity.
The order submission sequence is now fully async: an order request is
expected to be explicitly acked with a new message and if cancellation
is requested by the client before the ack arrives, the cancel message is
stashed and then later sent immediately on receipt of the order
submission's ack from the backend broker. Backend brokers are now
controlled using a 2-way request-response streaming dialogue which is
fully api agnostic of the clearing system's core processing; This
leverages the new bi-directional streaming apis from `tractor`. The
clearing core (emsd) was also simplified by moving the paper engine to
it's own sub-actor and making it api-symmetric with expected `brokerd`
endpoints.
A couple of the ems status messages were changed/added:
'dark_executed' -> 'dark_triggered'
added 'alert_triggered'
More cleaning of old code to come!
This makes the paper engine look IPC-wise exactly like any
broker-provider backend module and uses the new ``trades_dialogue()``
2-way streaming endpoint for commanding order requests.
This serves as a first step toward truly distributed forward testing
since the paper engine can now be run out-of tree from `pikerd` if
needed thus demonstrating how real-time clearing signals can be shared
between fully distinct services.
This avoids somewhat convoluted "hackery" making 2 one-way streams
between the order client and the EMS and instead uses the new
bi-directional streaming and context API from `tractor`. Add a router
type to the EMS that gets setup by the initial service tree and which
we'll eventually use to work toward multi-provider executions and
order-trigger monitoring. Move to py3.9 style where possible throughout.
Tyler Goodlet