Instead of callbacks for key presses/releases convert our `ChartView`'s
kb input handling to async code using our event relaying-over-mem-chan
system. This is a first step toward a more async driven modal control
UX. Changed a bunch of "chart" component naming as part of this as well,
namely: `ChartSpace` -> `GodWidget` and `LinkedSplitCharts` ->
`LinkedSplits`. Engage the view boxe's async handler code as part of new
symbol data loading in `display_symbol_data()`. More re-orging to come!
Add an `open_handler()` ctx manager for wholesale handling event sets
with a passed in async func. Better document and implement the event
filtering core including adding support for key "auto repeat" filtering;
it turns out the events delivered when `trio` does its guest-most tick
are not the same (Qt has somehow consumed them or something) so we have
to do certain things (like getting the `.type()`, `.isAutoRepeat()`,
etc.) before shipping over the mem chan. The alt might be to copy the
event objects first but haven't tried it yet. For now just offer
auto-repeat filtering through a flag.
If a client attaches to a quotes data feed and requests a throttle rate,
be sure to unsub that side-band memchan + task when it detaches and
especially so on any transport connection error.
Also, use an explicit `tractor.Context.cancel()` on the client feed
block exit since we removed the implicit cancel option from the
`tractor` api.
There is no reason to have more then `brokerd` trades dialogue stream
open per `emsd`. Here we minimize to managing that lone stream and
multiplexing msgs from each client such that multiple clients can be
connected to the ems, conducting trading without requiring multiple
ems-client connections to the backend broker and without the broker
being aware there are even multiple flows going on.
This patch also sets up for being able to have ems clients which
register to receive and track trade flows from other piker clients thus
enabling so called "multi-player" trading where orders for both paper
and live trades can be shared between multiple participants in the form
of a pre-broker, local clearing service and trade signals dark book.
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.
An async exit stack around the new `@tractor.context` is problematic
since a pushed context can't bubble errors unless the exit stack has
been closed. But in that case why do you need the exit stack if you're
going to push it and wait it right away; it seems more correct to use
a nursery and spawn a task in `pikerd` that waits on the both the
target context completion first (thus being able to bubble up any errors
from the remote, and top level service task) and the sub-actor portal.
(Sub)service Daemons are spawned with `.start_actor()` and thus will
block forever until cancelled so, add a way to cancel them explicitly
which we'll need eventually for restarts and dynamic feed management.
The big lesson here is that async exit stacks are not conducive to
spawning and monitoring service tasks, and especially so if
a `@tractor.context` is used since if the `.open_context()` call isn't
exited (only possible by the stack being closed), then there will be no
way for `trio` to cancel the task that pushed that context (since it
can't run a checkpoint while yielded inside the stack) without also
cancelling all other contexts pushed on that stack. Presuming one
`pikerd` task is used to do the original pushing (which it was) then
any error would have to kill all service daemon tasks which obviously
won't work.
I see this mostly as the painz of tinkering out an SC service manager
with `tractor` / `trio` for the first time, so try to go easy on the
process ;P
Adding binance's "hft" ws feeds has resulted in a lot of context
switching in our Qt charts, so much so it's chewin CPU and definitely
worth it to throttle to the detected display rate as per discussion in
issue #192.
This is a first very very naive attempt at throttling L1 tick feeds on
the `brokerd` end (producer side) using a constant and uniform delivery
rate by way of a `trio` task + mem chan. The new func is
`data._sampling.uniform_rate_send()`. Basically if a client request
a feed and provides a throttle rate we just spawn a task and queue up
ticks until approximately the next display rate's worth period of time
has passed before forwarding. It's definitely nothing fancy but does
provide fodder and a start point for an up and coming queueing eng to
start digging into both #107 and #109 ;)
Avoids some cyclical and confusing import time stuff that we needed to get
DPI aware fonts configured from the active display. Move the main window
singleton into its own module and add a `main_window()` getter for it.
Make `current_screen()` a ``MainWindow` method to avoid so many module
variables.
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.
Makes it so we can move toward separate provider results fills in an
async way, on demand.
Also,
- add depth 1 iteration helper method
- add section finder helper method
- fix last selection loading to be mostly consistent
This allows for more deterministically managing long running sub-daemon
services under `pikerd` using the new context api from `tractor`.
The contexts are allocated in an async exit stack and torn down at root
daemon termination. Spawn brokerds using this method by changing the
persistence entry point to be a `@tractor.context`.
Some providers do well with a "longer" debounce period (like ib) since
searching them too frequently causes latency and stalls. By supporting
both a min and max debounce period on keyboard input we can only send
patterns to the slower engines when that period is triggered via
`trio.move_on_after()` and continue to relay to faster engines when the
measured period permits. Allow search routines to register their "min
period" such that they can choose to ignore patterns that arrive before
their heuristically known ideal wait.
Obviously this only supports stocks to start, it looks like we might
actually have to hard code some of the futures/forex/cmdtys that don't
have a search.. so lame. Special throttling is added here since the api
will grog out at anything more then 1Hz.
Additionally, decouple the bar loading request error handling from the
shm pushing loop so that we can always recover from a historical bars
throttle-error even if it's on the first try for a new symbol.
This allows for more deterministically managing long running sub-daemon
services under `pikerd` using the new context api from `tractor`.
The contexts are allocated in an async exit stack and torn down at root
daemon termination. Spawn brokerds using this method by changing the
persistence entry point to be a `@tractor.context`.
This gets the binance provider meeting the data feed schema requirements
of both the OHLC sampling/charting machinery as well as proper
formatting of historical OHLC history.
Notably,
- spec a minimal ohlc dtype based on the kline endpoint
- use a dataclass to parse out OHLC bar datums and pack into np.ndarray/shm
- add the ``aggTrade`` endpoint to get last clearing (traded) prices,
validate with ``pydantic`` and then normalize these into our tick-quote
format for delivery over the feed stream api.
- a notable requirement is that the "first" quote from the feed must
contain a 'last` field so the clearing system can start up correctly.
This required a fsp task spawning logic rework which ended up being
cleaner just spawning tasks in a loop sequentially instead of trying
a 2-phase spawn-then-initialize approach.
This also includes changes from the symbol search branch hacked in.
Mostly it includes isolating the main chart startup-sequence to a
function that can be run in a new task every time a new symbol is
requested by the selector/searcher. The actual search functionality
obviously isn't in here yet but minor changes are included as part of
pulling out the `tractor` stream api patch from the symbol search dev
branch.
Avoid bothering with a trio event and expect the caller to do manual shm
registering with the write loop. Provide OHLC sample period indexing
through a re-branded pub-sub func ``iter_ohlc_periods()``.
Move all feed/stream agnostic logic and shared mem writing into a new
set of routines inside the ``data`` sub-package. This lets us move
toward a more standard API for broker and data backends to provide
cache-able persistent streams to client apps.
The data layer now takes care of
- starting a single background brokerd task to start a stream for as
symbol if none yet exists and register that stream for later lookups
- the existing broker backend actor is now always re-used if possible
if it can be found in a service tree
- synchronization with the brokerd stream's startup sequence is now
oriented around fast startup concurrency such that client code gets
a handle to historical data and quote schema as fast as possible
- historical data loading is delegated to the backend more formally by
starting a ``backfill_bars()`` task
- write shared mem in the brokerd task and only destruct it once requested
either from the parent actor or further clients
- fully de-duplicate stream data by using a dynamic pub-sub strategy
where new clients register for copies of the same quote set per symbol
This new API is entirely working with the IB backend; others will need
to be ported. That's to come shortly.
Add a `Services` nurseries container singleton for spawning sub-daemons
inside the long running `pikerd` tree. Bring in `brokerd` spawning util
funcs to start getting eyes on what can be factored into a service api.
The direct open is needed for running `pikerd` cmd and
the ems spawn point is the first step toward detaching UI based order
entry from the engine itself.
- break (custom) graphics item style marker drawing into separate func
but keep using it since it still seems oddly faster then the
QGraphicsPathItem thing..
- unfactor hover handler; it was uncessary
- make both the graphics path item and custom graphics items approaches
both work inside ``.paint()``
Add support for drawing ``QPathGraphicsItem`` markers but don't use them
since they seem to be shitting up when combined with the infinite line
(bounding rect?): weird artifacts and whatnot. The only way to avoid
said glitches seems to be to update inside the infinite line's
`.paint()` but that slows stuff down.. Instead stick with the manual
paint job use the same pin point: left of the L1 spread graphics - where
the lines now also extend to.
Further stuff:
- Pin the y-label to a line's value on hover.
- Disable x-dimension line moving
- Rework the labelling to be more minimal
Add a line which shows the current average price position with and arrow
marker denoting the direction (long or short). Required some further
rewriting of the infinite line from pyqtgraph including:
- adjusting marker (arrow) placement to be offset from axis + l1 labels
- fixing the hover event to not require the `.movable` attribute to be
set
It's a super naive implementation with no slippage model or network
latency besides some slight delays. Clearing only happens on bid/ask
sweep ticks at the moment - simple last volume based clearing coming
up next.
This turned into a larger endeavour then intended but now we're using our
own label system on level lines to be able to display things nicely
**pinned wherever we want in the UI**. Keep the old ``LevelLabel`` for
now for the L1 graphics but we'll likely replace this as well since i'm
pretty sure the new label type (which wraps `QGraphicsTextItem`) is more
performant anyway.
For labels that want it add nice arrow paths that point just over the
respective axis. Couple label text offset from the axis line based on
parent 'tickTextOffset' setting. Drop `YSticky` it was not enough
meat to bother with.
The min tick size is the smallest step an instrument can move in value
(think the number of decimals places of precision the value can have).
We start leveraging this in a few places:
- make our internal "symbol" type expose it as part of it's api
so that it can be passed around by UI components
- in y-axis view box scaling, use it to keep the bid/ask spread (L1 UI)
always on screen even in the case where the spread has moved further
out of view then the last clearing price
- allows the EMS to determine dark order live order submission offsets
Async spawn a deats getter task whenever we load a symbol data feed.
Pass these symbol details in the first message delivered by the feed at
open. Move stream loop into a new func.
Basically a stop limit mode where the dirty execution-condition deats
are entirely held client side away from the broker. For now, there's
a static order size setting and a 0.5% limit setting relative to the
trigger price. Swap to using 'd' for dump and 'f' for fill - they're
easier for use with ctrl (which is used now to submit orders directly to
broker - ala "live (order) mode"). Still more kinks to work out with too
fast cancelled orders and alerts but we're getting there.
Our first major UI "mode" (yes kinda like the modes in emacs) that has
handles to a client side order book api, line and arrow editors, and
interacts with a spawned `emsd` (the EMS daemon actor).
Buncha cleaning and fixes in here for various thingers as well.
Since the "crosshair" is growing more and more UX implementation details
it probably makes sense to call it what it is; a python level mouse
abstraction. Add 2 internal sets: `_hovered` for allowing mouse hovered
objects to register themselves to other cursor aware components, and
`_trackers` for allowing scene items to "track" cursor movements via
a `on_tracked_source()` callback.
Support tracking the mouse cursor using a new `on_tracked_sources()`
callback method. Make hovered highlight a bit thicker and highlight when
click-dragged. Add a delete method for removing from the scene along
with label.
Leverages `QGraphicsItem.cacheMode` to speed up interactivity via
less `.paint()` calls (on mouse interaction) and redraws of the
underlying path when there are no transformations (other then a shift).
In order to keep the "flat bar on new time period" UX, a couple special
methods have to be triggered to get a redraw of the pixel buffer when
appending new data.
Use `QPainterPath.controlPointRect()` over `.boundingRect()` since
supposedly it's a lot faster. Drop all use of `QPicture` (since it seems
to conflict with the pixel buffer stuff?) and it doesn't give any
measurable speedup when drawing the "last bar" lines.
Oh, and add some profiling for now.
This is a bit hacky (what with array indexing semantics being relative
to the primary index's "start" value but it works. We'll likely want
to somehow wrap this index finagling into an API soon.
Failed at using either.
Quirks in numba's typing require specifying readonly arrays by
composing types manually.
The graphics item path thing, while it does take less time to write on
bar appends, seems to be slower in general in calculating the
``.boundingRect()`` value. Likely we'll just add manual max/min tracking
on array updates like ``pg.PlotCurveItem`` to squeeze some final juices
on this.
Pertains further to #109.
Instead of redrawing the entire `QPainterPath` every time there's
a historical bars update just use `.addPath()` to slap in latest
history. It seems to work and is fast. This also seems like it will be
a great strategy for filling in earlier data, woot!
This gives a massive speedup when viewing large bar sets (think a day's
worth of 5s bars) by using the `pg.functions.arrayToQPath()` "magic"
binary array writing that is also used in `PlotCurveItem`. We're using
this same (lower level) function directly to draw bars as part of one
large path and it seems to be painting 15k (ish) bars with around 3ms
`.paint()` latency. The only thing still a bit slow is the path array
generation despite doing it with `numba`. Likely, either having multiple
paths or, only regenerating the missing backing array elements should
speed this up further to avoid slight delays when incrementing the bar
step.
This is of course a first draft and more cleanups are coming.
This makes it so you don't have to ctrl-c kill apps.
Add in the experimental openGL support even though I'm pretty sure it's
not being used much for curve plotting (but could be wrong).
Break the chart update code for fsps into a new task (add a nursery) in
new `spawn_fsps` (was `chart_from_fsps`) that async requests actor
spawning and initial historical data (all CPU bound work). For multiple
fsp subcharts this allows processing initial output in parallel
(multi-core). We might want to wrap this in a "feed" like api
eventually. Basically the fsp startup sequence is now:
- start all requested fsp actors in an async loop and wait for
historical data to arrive
- loop through them all again to start update tasks which do chart
graphics rendering
Add separate x-axis objects for each new subchart (required by
pyqtgraph); still need to fix hiding unnecessary ones.
Add a `ChartPlotWidget._arrays: dict` for holding overlay data distinct
from ohlc. Drop the sizing yrange to label heights for now since it's
pretty much all gone to hell since adding L1 labels. Fix y-stickies to
look up correct overly arrays.
Requires decent modification of the built-in ``ViewBox``.
We do away with the zoom functionality for now and instead just add
a label full of some simple stats on the bounded data.
I think this gets us to the same output as TWS both on booktrader and
the quote details pane. In theory there might be logic needed to
decreases an L1 queue size on trades but can't seem to get it without
getting -ves displayed occasionally - thus leaving it for now.
Also, fix the max-min streaming logic to actually do its job, lel.
Start a simple API for L1 bid/ask labels.
Make `LevelLabel` draw a line above/below it's text (instead of the
rect fill we had before) since it looks much simpler/slicker.
Generalize the label text orientation through bounding rect
geometry positioning.
Until we get a better datum "cursor" figured out just draw the flat bar
despite the extra overhead. The reason to do this in 2 separate calls is
detailed in the comment but basic gist is that there's a race between
writer and reader of the last shm index.
Oh, and toss in some draft symbol search label code.
Not sure what fixed it exactly, and I guess we didn't need any relative
DPI scaling factor after all. Using the 3px margin on the level label
seems to make it look nice for any font size (i think) as well.
Gonna need some cleanup after this one.
Make our own ``Axis`` and have it call an impl specific ``.resize()``
such that different axes can size to their own spec. Allow passing in a
"typical maximum value string" which will be used by default for sizing
the axis' minor dimension; a common value should be passed to all axes
in a linked split charts widget. Add size hinting for axes labels such
that they can check their parent (axis) for desired dimensions if
needed.
Compute the size in pixels the label based on the label's contents.
Eventually we want to have an update system that can iterate through
axes and labels to do this whenever needed (eg. after widget is moved
to a new screen with a different DPI).
Avoid drawing a new new sticky position if the mouse hasn't moved to the
next (rounded) index in terms of the scene's coordinates. This completes
the "discrete-ization" of the mouse/cursor UX.
Finalizing this feature helped discover and solve
pyqtgraph/pyqtgraph#1418 which masssively improves interaction
performance throughout the whole lib!
Hide stickys on startup until cursor shows up on plot.
This is likely a marginal improvement but is slightly less execution and
adds a coolio black border around the label. Drop all the legacy code
from quantdom which was quite a convoluted mess for "coloring".
Had to tweak sticky offsets to get the crosshair to line up right; not
sure what that's all about yet.
With the improved update logic on `BarsItems` it doesn't seem to be
necessary. Remove y sticky for overlays for now to avoid clutter that
looks like double draws when the last overlay value is close to the last
price.
It seems a plethora of problems (including drawing performance) are due
to trying to hack around the strange rendering bug in Qt with `QLineF`
with y1 == y2. There was all sorts of weirdness that would show up with
trying (a hack) to just set all 4 points to the same value including
strange infinite diagonal ghost lines randomly on charts. Instead, just
place hold these flat bar's 'body' line with a `None` and filter the
null values out before calling `QPainter.drawLines()`. This results
in simply no body lines drawn for these datums. We can probably `numba`
the filtering too if it turns out to be a bottleneck.
Add a new graphic `LineDot` which is a `pg.CurvePoint` that draws
a simple filled dot over a curve at the specified index.
Add support for adding these cursor-dots to the crosshair/mouse through
a new `CrossHair.add_curve_cursor()`. Discretized the vertical line
updates on the crosshair such that it's only drawn in the middle of
the current bar in the main chart.
Makes the chart act like tws where each new time step increment the
chart shifts to the right so that the last bar stays in place. This
gets things looking like a proper auto-trading UX.
Added a couple methods to ``ChartPlotWidget`` to make this work:
- ``.default_view()`` to set the preferred view based on user settings
- ``.increment_view()`` to shift the view one time frame right
Also, split up the `.update_from_array()` method to be curve/ohlc
specific allowing for passing in a struct array with a named field
containing curve data more straightforwardly. This also simplifies the
contest label update functions.
Lookup overlay contents from the OHLC struct array (for now / to make
things work) and fix anchoring logic with better offsets to keep
contents labels super tight to the edge of the view box. Unfortunately,
had to hack the label-height-calc thing for avoiding overlap of graphics
with the label; haven't found a better solution yet and pyqtgraph seems
to require more rabbit holing to figure out something better. Slap in
some inf lines for over[sold/bought] rsi conditions thresholding.
If you have a common broker feed daemon then likely you don't want to
create superfluous shared mem buffers for the same symbol. This adds an
ad hoc little context manger which keeps a bool state of whether
a buffer writer task currently is running in this process. Before we
were checking the shared array token cache and **not** clearing it when
the writer task exited, resulting in incorrect writer/loader logic on
the next entry..
Really, we need a better set of SC semantics around the shared mem stuff
presuming there's only ever one writer per shared buffer at given time.
Hopefully that will come soon!
If we know the max and min in view then on datum updates we can avoid
resizing the y-range when a new max/min has not yet arrived.
This adds a very naive numpy calc in the drawing thread which we can
likely improve with a more efficient streaming alternative which can
also likely be run in a fsp subactor. Also, since this same calc is
essentially done inside `._set_yrange()` we will likely want to allow
passing the result into the method to avoid duplicate work.
This kicks off what will be the beginning of hopefully a very nice
(soft) real-time financial signal processing system. We're keeping the
hack to "time align" curves (for now) with the bars for now by slapping
in an extra datum at index 0.
Just like for the source OHLC, we now have the chart parent actor create
an fsp shm array and use it to read back signal data for plotting.
Some tweaks to get the price chart (and sub-charts) to load historical
datums immediately instead of waiting on an initial quote.
- Move to new shared mem system only writing on the first (by process)
entry to `stream_quotes()`.
- Deliver bars before first quote arrives so that chart can populate and
then wait for initial arrival.
- Allow caching clients per actor.
- Load bars using the same (cached) client that starts the quote stream
thus speeding up initialization.
Wraps the growing tuple of items being delivered by `open_feed()`.
Add lazy loading of the broker's signal step stream with
a `Feed.index_stream()` method.
Add an internal `_Token` to do interchange (un)packing for passing
"references" to shm blocks between actors. Part of the token involves
providing the `numpy.dtype` in a cross-actor format. Add a module
variable for caching "known tokens" per actor. Drop use of context
managers since they tear down shm blocks too soon in debug mode and
there seems to be no reason to unlink/close shm before the process has
terminated; if code needs it torn down explicitly, it can.
Adjust the `data.open_feed()` api to take a shm token so the
broker-daemon can attach a previously created (by the parent actor) mem
buf and push real-time tick data. There's still some sloppiness here in
terms of ensuring only one mem buf per symbol (can be seen in
`stream_quotes()`) which should really managed at the data api level.
Add a bar incrementing stream-task which delivers increment msgs to any
consumers.
Logic in `SharedArray.push()` was totally wrong.
Remove all the `multiprocessing.resource_tracker` crap such that we
aren't loading an extra process at every layer and we don't get tons of
errors when cleaning on in an SC way.
This adds a shared memory "incrementing array" sub-sys interface
for single writer, multi-reader style data passing. The main motivation
is to avoid multiple copies of the same `numpy` array across actors
(plus now we can start being fancy like ray).
There still seems to be some odd issues with the "resource tracker"
complaining at teardown (likely partially to do with SIGINT stuff) so
some further digging in the stdlib code is likely coming.
Pertains to #107 and #98
Added a comment to clarify, ish.
Add `ChartPlotWidget._overlays` as registry of curves added on top of
main graphics. Hackishly (ad-hoc-ishly?) update the curve assuming the
data resides in the same `._array` for now (which it does for historical
vwap).
Allow passing a fixed ylow, yhigh tuple to `._set_yrange()` which avoids
recomputing the range from data if desired (eg. rsi-like bounded
signals). Add support for overlay curves to the OHLC chart and add basic
support to brokers which provide a historical 'vwap`. The data array
increment logic had to be tweaked to copy the vwap from the last bar.
Oh, and hack the subchart curves with two extra prepended datums to make
them align "better" with the ohlc main chart; need to talk to
`pyqtgraph` core about how to do this more correctly.
By mapping any in view "contents labels" to the range of the
``ViewBox``'s data we can avoid having graphics overlap with labels.
Take this approach instead of specifying a min y-range using the std
and activate the range compute on resize and mouser scrolling.
Also, add y-sticky update for signal plots.
Use two separate `QPicture` instances:
- one for the 3 lines for the last bar
- one for all the historical bars lines
On price changes update the last bar and only update historical bars
when the current bar's period expires (when a new bar is "added").
Add a flag `just_history` for this `BarItems.draw_lines()`.
Also, switch the internal lines array/buffer to a 2D numpy array to avoid
the type-cast step and instead just flatten using `numpy.ravel()`.
Overall this should avoid the problem of draws getting slower over time
as new bars are added to the history since price updates only redraw
a single bar to the "last" `QPicture` instance. Ideally in the future we
can make the `history` `QPicture` a `QPixmap` but it looks like this
will require some internal work in `pyqtgraph` to support it.
Use a ``rec2array`` struct array converter to generate lines sequence
faster. Start looking into using a `QPixmap` to avoid redrawing all
bars every update.
Add a default "contents label" (eg. OHLC values for bar charts) to each
chart and update on crosshair interaction.
Few technical changes to make this happen:
- adjust bar graphics to have the HL line be in the "middle" of the
underlying arrays' "index range" in the containing view.
- add a label dict each chart's graphics name to a label + update routine
- use symbol names instead of this "main" identifier crap for referring to
particular price curves/graphics
This is a first attempt at a financial signal processing subsystem which
utilizes async generators for streaming frames of numpy array data
between actors. In this initial attempt the focus is on processing price
data and relaying it to the chart app for real-time display. So far this
seems to work (with decent latency) but much more work is likely needed
around improving the data model for even better latency and less data
duplication.
Surprisingly (or not?) a lot of simplifications to the charting code
came out of this in terms of conducting graphics updates in streaming
tasks instead of hiding them inside the obfuscated mess that is the
Qt-style-inheritance-OO-90s-trash. The goal from here on wards will be
to enforce strict semantics around reading and writing of data such that
state is kept outside "object trees" as much as possible and streaming
function semantics guide our flow model. Unsurprisingly, this reduction
in "instance state" is happening wherever we use `trio` ;)
A little summary on the technical changes:
- not going to explain the fsp system yet; it's too nascent and
probably going to get some heavy editing.
- drop any "update" methods from the `LinkedCharts` type since each
sub-chart will have it's own update task and thus a separate update
loop; further individual graphics (per chart) may eventually require
this same design.
- delete `ChartView`; moved into separate mod.
- add "stream from fsp" task to start our foray into real-time actor
processed numpy streaming.
Wait for a first actual real-time quote before starting graphics update
tasks. Use the new normalized tick format brokers are expected to emit
as a `quotes['ticks']` list. Auto detect time frame from historical
bars.
Add `ChartPlotWidget.add_plot()` to add sub charts for indicators which
can be updated independently. Clean up rt bar update code and drop some
legacy ohlc loading cruft.
Stop with all this "main chart" special treatment.
Manage all lines in the same way across all referenced plots.
Add `CrossHair.add_plot()` for adding new plots dynamically.
Just, smh.
There's really nothing coupling it to the graphics class (which frankly
also seems like it doesn't need to be a class.. Qt).
Add support to `.update_from_array()` for diffing with the input array
and creating additional bar-lines where necessary. Note, there are still
issues with the "correctness" here in terms of bucketing open/close
values in the time frame / bar range. Also, this jamming of each bar's 3
lines into a homogeneous array seems like it could be better done with
struct arrays and avoid all this "index + 3" stuff.
Flat bars have a rendering issue we work around by hacking values in `QLineF`
but we have to revert those on any last bar that is being updated in
real-time. Comment out candle implementations for now; we can get back
to it if/when the tinas unite. Oh, and make bars have a little space
between them.
Don't allow zooming to less then a min number of data points. Allow
panning "outside" the data set (i.e. moving one of the sequence "ends"
to the middle of the view. Start adding logging.
For whatever reason if the `QLineF` high/low values are the same a weird
little rectangle is drawn (my guess is a `float` precision error of some
sort). Instead, if they're the same just use one of the values.
Also, store local vars to avoid so many lookups.
`pg.PlotCurveItem.setData()` is normally used for real-time updates to
curves and takes in a whole new array of data to graphics.
It makes sense to stick with this interface especially if
the current datum graphic will originally be drawn from tick quotes and
later filled in when bars data is available (eg. IB has this option in
TWS charts for volume). Additionally, having a data feed api where the push
process/task can write to shared memory and the UI task(s) can read from
that space is ideal. It allows for indicator and algo calculations to be
run in parallel (via actors) with initial price draw instructions
such that plotting of downstream metrics can be "pipelined" into the
chart UI's render loop. This essentially makes the chart UI async
programmable from multiple remote processes (or at least that's the
goal).
Some details:
- Only store a single ref to the source array data on the
`LinkedSplitCharts`. There should only be one reference since the main
relation is **that** x-time aligned sequence.
- Add `LinkedSplitCharts.update_from_quote()` which takes in a quote
dict and updates the OHLC array from it's contents.
- Add `ChartPlotWidget.update_from_array()` method to trigger graphics
updates per chart with consideration for overlay curves.
This makes a OHLC graphics "sequence" update very similar (actually API
compatible) with `pg.PlotCurveItem.setData()`. The difference here is
that only latest OHLC datum is used to update the charts last bar.
This was a mess before with a weird loop using the parent split charts
to update all "indicators". Instead just have each plot do its own
yrange updates since the signals are being handled just fine per plot.
Handle both the OHLC and plane line chart cases with a hacky `try:,
except IndexError:` for now.
Oh, and move the main entry point for the chart app to the relevant
module. I added some WIP bar update code for the moment.
Speed up the lines array creation using proper slice assignment.
This gives another 10% speedup to the historical price rendering.
Drop ``_tina_mode`` support for now since we're not testing it.
Previously graphics were loaded and rendered implicitly during the
import and creation of certain objects. Remove all this and instead
expect client code to pass in the OHLC sequence to plot. Speed up
the bars graphics rendering by simplifying to a single iteration of
the input array; gives about a 2x speedup.
Move chart resize code into our ``ViewBox`` subtype (a ``ChartView``)
in an effort to start organizing interaction behaviour closer to the
appropriate underlying objects. Add some docs for all this and do some
renaming.
Modify the default ``ViewBox`` scroll to zoom behaviour such that
whatever right-most point is visible is used as the "center" for
zooming. Add a "traditional" cross-hair cursor.
- Move out equity plotting to new module.
- Make axis margins and fonts look good on i3.
- Adjust axis labels colors to gray.
- Start commenting a lot of the code after figuring out what it all does
when cross referencing with ``pyqtgraph``.
- Add option to move date axis to middle.
Hand select necessary components to get real-time charting with
`pyqtgraph` from the `Quantdom` projects:
https://github.com/constverum/Quantdom
We've offered to collaborate with the author but have received no
response and the project has not been updated in over a year.
Given this, we are moving forward with taking the required components to
make further improvements upon especially since the `pyqtgraph` project
is now being actively maintained again.
If the author comes back we will be more then happy to contribute
modified components upstream:
https://github.com/constverum/Quantdom/issues/18
Relates to #80
Since the new FSP system will require time aligned data amongst actors,
it makes sense to share broker data feeds as much as possible on a local
system. There doesn't seem to be downside to this approach either since
if not fanning-out in our code, the broker (server) has to do it anyway
(and who knows how junk their implementation is) though with more
clients, sockets etc. in memory on our end. It also preps the code for
introducing a more "serious" pub-sub systems like zeromq/nanomessage.
Start a draft normalization format for (sampled) tick data.
Ideally we move toward the dense tick format (DFT) enforced by
techtonicDB, but for now let's just get a dict of something simple
going: `{'type': 'trade', 'price': <price}` kind of thing. This
gets us started being able to real-time chart from all data feed
back-ends. Oh, and hack in support for XAUUSD..and get subactor
logging workin.
Add a `Client.find_contract()` which internally takes
a <symbol>.<exchange> str as input and uses `IB.qualifyContractsAsync()`
internally to try and validate the most likely contract. Make the module
script call this using `asyncio.run()` for console testing.
Infected `asyncio` support is being added to `tractor` in
goodboy/tractor#121 so delegate to all that new machinery.
Start building out an "actor-aware" api which takes care of all the
`trio`-`asyncio` interaction for data streaming and request handling.
Add a little (shudder) method proxy system which can be used to invoke
client methods from another actor. Start on a streaming api in
preparation for real-time charting.
Start working towards meeting the backend client api.
Infect `asyncio` using `trio`'s new guest mode and demonstrate
real-time ticker streaming to console.
Since the new FSP system will require time aligned data amongst actors,
it makes sense to share broker data feeds as much as possible on a local
system. There doesn't seem to be downside to this approach either since
if not fanning-out in our code, the broker (server) has to do it anyway
(and who knows how junk their implementation is) though with more
clients, sockets etc. in memory on our end. It also preps the code for
introducing a more "serious" pub-sub systems like zeromq/nanomessage.
Tyler Goodlet
goodboy
Konstantine Tsafatinos
Guillermo Rodriguez
wattygetlood