Now spawned under the `pikerd` tree as a singleton-daemon-actor we offer
a slew of new routines in support of this micro-service:
- `maybe_open_samplerd()` and `spawn_samplerd()` which provide the
`._daemon.Services` integration to conduct service spawning.
- `open_sample_stream()` which is a client-side endpoint which does all
the work of (lazily) starting the `samplerd` service (if dne) and
registers shm buffers for update as well as connect a sample-index
stream for iterator by the caller.
- `register_with_sampler()` which is the `samplerd`-side service task
endpoint implementing all the shm buffer and index-stream registry
details as well as logic to ensure a lone service task runs
`Services.increment_ohlc_buffer()`; it increments at the shortest period
registered which, for now, is the default 1s duration.
Further impl notes:
- fixes to `Services.broadcast()` to ensure broken streams get discarded
gracefully.
- we use a `pikerd` side singleton mutex `trio.Lock()` to ensure
one-and-only-one `samplerd` is ever spawned per `pikerd` actor tree.
Drop the `_services` module level ref and adjust all client code to
match. Drop struct inheritance and convert all methods to class level.
Move `Brokerd.locks` -> `Services.locks` and add sampling mod to pikerd
enabled set.
We're moving toward a single actor managing sampler work and distributed
independently of `brokerd` services such that a user can run samplers on
different hosts then real-time data feed infra. Most of the
implementation details include aggregating `.data._sampling` routines
into a new `Sampler` singleton type.
Move the following methods to class methods:
- `.increment_ohlc_buffer()` to allow a single task to increment all
registered shm buffers.
- `.broadcast()` for IPC relay to all registered clients/shms.
Further add a new `maybe_open_global_sampler()` which allocates
a service nursery and assigns it to the `Sampler.service_nursery`; this
is prep for putting the step incrementer in a singleton service task
higher up the data-layer actor tree.
Goes back to always adjusting the y-axis range to include the L1 spread
and clearing label in view whenever the last datum is also in view,
previously this was broken after reworking the display loop for
multi-feeds.
Drops a bunch of old commented tick looping cruft from before we started
using tick-type framing. Also adds more stringent guards for ignoring
but error logging quote values that are more then 25% out of range; it
seems particularly our `ib` feed has some issues with strange `price`
values that are way off here and there?
- adjust zoom focal to be min of the view-right coord or the right-most
point on the flow graphic in view and drop all the legacy l1-in-view
focal point cruft.
- flip to not auto-scaling overlays by default.
- change the `._set_yrange()` margin to `0.09`.
- drop `use_vr: bool` usage.
Use proper uppx scaling when either of scaling the data to the x-domain
index-range or when the uppx is < 1 (now that we support it) such that
both the fast and slow chart always appropriately scale and offset to
the y-axis with the last datum graphic just adjacent to the order line
arrow markers.
Further this fixes the `.index_step()` calc to use the "earliest" 16
values to compute the expected sample step diff since the last set often
contained gaps due to start up race conditions and generated
unexpected/incorrect output.
Further this drops the `.curve_width_pxs()` method and replaces it with
`.px_width()`, taken from the graphics object API and instead returns
the pixel account for the whole view width instead of the
x-domain-data-range within the view.
In the case where the last-datum-graphic hasn't been created yet, simply
return a `None` from this method so the caller can choose to ignore the
output. Further, drop `.px_width()` since it makes more sense defined on
`Viz` as well as the previously commented `BarItems.x_uppx()` method.
Also, don't round the `.x_uppx()` output since it can then be used when
< 1 to do x-domain scaling during high zoom usage.
Doesn't seem like we really need to handle the situation where the start
or stop input time stamps are outside the index range of the data since
the new binary search handling via `numpy.searchsorted()` covers this
case at minimal runtime cost and with an equally correct output. Allows
us to drop some other indexing endpoint internal variables as well.
Factor some common methods into the parent type:
- `.x_uppx()` for reading the horizontal units-per-pixel.
- `.x_last()` for reading the "closest to y-axis" last datum coordinate
for zooming "around" during mouse interaction.
- `.px_width()` for computing the max width of any curve in view in
pixels.
Adjust all previous derived `pg.GraphicsObject` child types to now
inherit from this new parent and in particular enable proper `.x_uppx()`
support to `BarItems`.
We want the fast and slow chart to behave the same on calls to
`Viz.default_view()` so adjust the offset calc to make both work:
- just offset by the line len regardless of step / uppx
- add back the `should_line: bool` output from `render_bar_items()` (and
use it to set a new `ds_allowed: bool` guard variable) so that we can
bypass calling the m4 downsampler unless the bars have been switched
to the interpolation line graphic (which we normally required before
any downsampling of OHLC graphics data).
Further, this drops use of the `use_vr: bool` flag from all rendering
since we pretty much always use it by default.
Instead of having the l1 lines be inside the view space, move them to be
inside their respective axis (with only a 16 unit portion inside the
view) such that the clear price label can overlay with them nicely
without obscuring; this is much better suited to multiple adjacent
y-axes and in general is simpler and less noisy.
Further `L1Labels` + `LevelLabel` style tweaks:
- adjust `.rect` positioning to be "right" (i.e. inside the parent
y-axis) with a slight 16 unit shift toward the viewbox (using the new
`._x_br_offset`) to allow seeing each level label's line even when the
clearing price label is positioned at that same level.
- add a newline's worth of vertical space to each of the bid/ask labels
so that L1 labels' text content isn't ever obscured by the clear price
label.
- set a low (10) z-value to ensure l1 labels are always placed
underneath the clear price label.
- always fill the label rect with the chosen background color.
- make labels fully opaque so as to always make them hide the parent
axes' `.tickStrings()` contents.
- make default color the "default" from the global scheme.
- drop the "price" part from the l1 label text contents, just show the
book-queue's amount (in dst asset's units, aka the potential clearing vlm).
Previously with array-int indexing we had to map the input x-domain
"indexes" passed to `DynamicDateAxis._indexes_to_timestr()`. In the
epoch-time indexing case we obviously don't need to lookup time stamps
from the underlying shm array and can instead just cast to `int` and
relay the values verbatim.
Further, this patch includes some style adjustments to `AxisLabel` to
better enable multi-feed chart overlays by avoiding L1 label clutter
when multiple y-axes are stacked adjacent:
- adjust the `Axis` typical max string to include a couple spaces suffix
providing for a bit more margin between side-by-side y-axes.
- make the default label (fill) color the "default" from the global
color scheme and drop it's opacity to .9
- add some new label placement options and use them in the
`.boundingRect()` method:
* `._x/y_br_offset` for relatively shifting the overall label relative
to it's parent axis.
* `._y_txt_h_scaling` for increasing the bounding rect's height
without including more whitespace in the label's text content.
- ensure labels have a high z-value such that by default they are always
placed "on top" such that when we adjust the l1 labels they can be set
to a lower value and thus never obscure the last-price label.
When we see multiple history frames that are duplicate to the request
set, bail re-trying after a number of tries (6 just cuz) and return
early from the tsdb backfill loop; presume that this many duplicates
means we've hit the beginning of history. Use a `collections.Counter`
for the duplicate counts. Make sure and warn log in such cases.
Turns out we were updating the wrong ``Viz``/``DisplayState`` inside the
closure style `increment_history_view()`` (probably due to looping
through the flumes and dynamically closing in that task-func).. Instead
define the history incrementer at module level and pass in the
`DisplayState` explicitly. Further rework the `DisplayState` attrs to be
more focused around the `Viz` associated with the fast and slow chart
and be sure to adjust output from each `Viz.incr_info()` call to latest
update. Oh, and just tweaked the line palette for the moment.
FYI "treading" here is referring to the x-shifting of the curve when
the last datum is in view such that on new sampled appends the "last"
datum is kept in the same x-location in UI terms.
Tyler Goodlet