Questrade is the default broker backend (for now) so the CI
can run using a practice account token handed down through an
env variable. If we add a cached directory to the build then the token
should remain persistent in the brokers config and will only need to be
updated if something goes wrong.
Also, add a `--confdir` flag for pytest much in the same way as for
the `piker` cli.
Fixes to `tractor` that resolve issues with async generators being
non-task safe make the need for the mutex lock in
`DataFeed.open_stream()` unnecessary. Also, don't bother pushing empty
quotes from the publisher; avoids hitting the network when possible.
Questrade's API is half baked and can't handle concurrency.
It allows multiple concurrent requests to most endpoints *except*
for the auth endpoint used to refresh tokens:
https://www.questrade.com/api/documentation/security
I've gone through extensive dialogue with their API team and despite
making what I think are very good arguments for doing the request
serialization on the server side, they decided that I should instead
do the "locking" on the client side. Frankly it doesn't seem like they
have that competent an engineering department as it took me a long time
to explain the issue even though it's rather trivial and probably not
that hard to fix; maybe it's better this way.
This adds a few things to ensure more reliable token refreshes on
expiry:
- add a `@refresh_token_on_err` decorator which can be used on `_API`
methods that should refresh tokens on failure
- decorate most endpoints with this *except* for the auth ep
- add locking logic for the troublesome scenario as follows:
* every time a request is sent out set a "request in progress" event
variable that can be used to determine when no requests are currently
outstanding
* every time the auth end point is hit in order to refresh tokens set
an event that locks out other tasks from making requests
* only allow hitting the auth endpoint when there are no "requests in
progress" using the first event
* mutex all auth endpoint requests; there can only be one outstanding
- don't hit the accounts endpoint at client startup; we want to
eventually support keys from multiple accounts and you can disable
account info per key and just share the market data function
Adjust feed locking around internal manager `yields` to make this work.
Also, change quote publisher to deliver a list of quotes for each
retrieved batch. This was actually broken for option streaming since
each quote was being overwritten due to a common `key` value for all
expiries. Asjust the `packetizer` function accordingly to work for
both options and stocks.
The pub-sub data feed system was factored into `tractor` as an
experimental api / subsystem. Move to using that which greatly
simplifies the data feed architecture.
Start working toward a more general (on-demand) pub-sub system which
can be brought into ``tractor``. Right now this just means making
the code in the `fan_out_to_ctxs()` less specific but, eventually
I think this function should be coupled with a decorator and shipped
as a standard "message pattern".
Additionally,
- try out making `BrokerFeed` a `@dataclass`
- strip out all the `trio.Event` / uneeded nursery / extra task crap
from `start_quote_stream()`
Tyler Goodlet
goodboy