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Proper slow chart auto y-range support 

The slow (history) chart requires it's own y-range checker logic which
needs to be run in 2 cases:
- the last datum is in view and goes outside the previous mx/mn in view
- the chart is incremented a step

Since we need this duplicate logic this patch also factors the incremental
graphics update info "reading" into a new `DisplayState.incr_info()`
method that can be configured to a chart and input state and returns all
relevant "graphics update measure" in a tuple (for now).

Use this method throughout the rest of the display loop for both fast
and slow chart checks and in the `increment_history_view()` slow chart
task.
history_view
Tyler Goodlet 2022-09-02 16:42:48 -04:00
parent 7958d8ad4f
commit 10c1944de5
1 changed files with 133 additions and 88 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

189
piker/ui/_display.py
View File

@ -21,7 +21,6 @@ this module ties together quote and computational (fsp) streams with
graphics update methods via our custom ``pyqtgraph`` charting api.
'''
from dataclasses import dataclass
from functools import partial
import time
from typing import Optional, Any, Callable
@ -35,6 +34,7 @@ from ..data.feed import (
open_feed,
Feed,
)
from ..data.types import Struct
from ._axes import YAxisLabel
from ._chart import (
ChartPlotWidget,
@ -124,8 +124,7 @@ def chart_maxmin(
)
@dataclass
class DisplayState:
class DisplayState(Struct):
'''
Chart-local real-time graphics state container.
@ -146,12 +145,77 @@ class DisplayState:
hist_last_price_sticky: YAxisLabel
# misc state tracking
vars: dict[str, Any]
vars: dict[str, Any] = {
'tick_margin': 0,
'i_last': 0,
'i_last_append': 0,
'last_mx_vlm': 0,
'last_mx': 0,
'last_mn': 0,
}
vlm_chart: Optional[ChartPlotWidget] = None
vlm_sticky: Optional[YAxisLabel] = None
wap_in_history: bool = False
def incr_info(
self,
chart: Optional[ChartPlotWidget] = None,
shm: Optional[ShmArray] = None,
state: Optional[dict] = None, # pass in a copy if you don't
update_state: bool = True,
update_uppx: float = 16,
) -> tuple:
shm = shm or self.ohlcv
chart = chart or self.chart
state = state or self.vars
if not update_state:
state = state.copy()
# compute the first available graphic's x-units-per-pixel
uppx = chart.view.x_uppx()
# NOTE: this used to be implemented in a dedicated
# "increment task": ``check_for_new_bars()`` but it doesn't
# make sense to do a whole task switch when we can just do
# this simple index-diff and all the fsp sub-curve graphics
# are diffed on each draw cycle anyway; so updates to the
# "curve" length is already automatic.
# increment the view position by the sample offset.
i_step = shm.index
i_diff = i_step - state['i_last']
state['i_last'] = i_step
append_diff = i_step - state['i_last_append']
# update the "last datum" (aka extending the flow graphic with
# new data) only if the number of unit steps is >= the number of
# such unit steps per pixel (aka uppx). Iow, if the zoom level
# is such that a datum(s) update to graphics wouldn't span
# to a new pixel, we don't update yet.
do_append = (append_diff >= uppx)
if do_append:
state['i_last_append'] = i_step
do_rt_update = uppx < update_uppx
_, _, _, r = chart.bars_range()
liv = r >= i_step
# TODO: pack this into a struct
return (
uppx,
liv,
do_append,
i_diff,
append_diff,
do_rt_update,
)
async def graphics_update_loop(
@ -271,7 +335,11 @@ async def graphics_update_loop(
# API that can be reused at least in terms of pulling view
# params (eg ``.bars_range()``).
async def increment_history_view():
i_last_append = i_last = hist_ohlcv.index
i_last = hist_ohlcv.index
state = ds.vars.copy() | {
'i_last_append': i_last,
'i_last': i_last,
}
_, hist_step_size_s, _ = feed.get_ds_info()
async with feed.index_stream(
@ -279,27 +347,26 @@ async def graphics_update_loop(
) as istream:
async for msg in istream:
# increment the view position by the sample offset.
uppx = hist_chart.view.x_uppx()
l, lbar, rbar, r = hist_chart.bars_range()
i_step = hist_ohlcv.index
i_diff = i_step - i_last
i_last = i_step
liv = r >= i_step
append_diff = i_step - i_last_append
do_append = (append_diff >= uppx)
if do_append:
i_last_append = i_step
# check if slow chart needs a resize
(
uppx,
liv,
do_append,
i_diff,
append_diff,
do_rt_update,
) = ds.incr_info(
chart=hist_chart,
shm=ds.hist_ohlcv,
state=state,
# update_state=False,
)
if (
# i_diff > 0 # no new sample step
do_append
# and uppx < 4 # chart is zoomed out very far
and liv
):
hist_chart.increment_view(steps=i_diff)
hist_chart.view._set_yrange(yrange=hist_chart.maxmin())
nurse.start_soon(increment_history_view)
@ -374,47 +441,15 @@ def graphics_update_cycle(
vars = ds.vars
tick_margin = vars['tick_margin']
update_uppx = 16
for sym, quote in ds.quotes.items():
# compute the first available graphic's x-units-per-pixel
uppx = chart.view.x_uppx()
# NOTE: vlm may be written by the ``brokerd`` backend
# event though a tick sample is not emitted.
# TODO: show dark trades differently
# https://github.com/pikers/piker/issues/116
# NOTE: this used to be implemented in a dedicated
# "increment task": ``check_for_new_bars()`` but it doesn't
# make sense to do a whole task switch when we can just do
# this simple index-diff and all the fsp sub-curve graphics
# are diffed on each draw cycle anyway; so updates to the
# "curve" length is already automatic.
# increment the view position by the sample offset.
i_step = ohlcv.index
i_diff = i_step - vars['i_last']
vars['i_last'] = i_step
append_diff = i_step - vars['i_last_append']
# update the "last datum" (aka extending the flow graphic with
# new data) only if the number of unit steps is >= the number of
# such unit steps per pixel (aka uppx). Iow, if the zoom level
# is such that a datum(s) update to graphics wouldn't span
# to a new pixel, we don't update yet.
do_append = (append_diff >= uppx)
if do_append:
vars['i_last_append'] = i_step
do_rt_update = uppx < update_uppx
# print(
# f'append_diff:{append_diff}\n'
# f'uppx:{uppx}\n'
# f'do_append: {do_append}'
# )
(
uppx,
liv,
do_append,
i_diff,
append_diff,
do_rt_update,
) = ds.incr_info()
# TODO: we should only run mxmn when we know
# an update is due via ``do_append`` above.
@ -430,8 +465,6 @@ def graphics_update_cycle(
profiler('`ds.maxmin()` call')
liv = r >= i_step # the last datum is in view
if (
prepend_update_index is not None
and lbar > prepend_update_index
@ -446,16 +479,10 @@ def graphics_update_cycle(
# don't real-time "shift" the curve to the
# left unless we get one of the following:
if (
(
# i_diff > 0 # no new sample step
do_append
# and uppx < 4 # chart is zoomed out very far
and liv
)
(do_append and liv)
or trigger_all
):
chart.increment_view(steps=i_diff)
# chart.increment_view(steps=i_diff + round(append_diff - uppx))
if vlm_chart:
vlm_chart.increment_view(steps=i_diff)
@ -606,10 +633,12 @@ def graphics_update_cycle(
l1.bid_label.update_fields({'level': price, 'size': size})
# check for y-range re-size
if (mx > vars['last_mx']) or (mn < vars['last_mn']):
# fast chart resize case
if (
(mx > vars['last_mx']) or (mn < vars['last_mn'])
liv
and not chart._static_yrange == 'axis'
and liv
):
main_vb = chart.view
if (
@ -627,6 +656,22 @@ def graphics_update_cycle(
yrange=(mn, mx),
)
# check if slow chart needs a resize
(
_,
hist_liv,
_,
_,
_,
_,
) = ds.incr_info(
chart=hist_chart,
shm=ds.hist_ohlcv,
update_state=False,
)
if hist_liv:
hist_chart.view._set_yrange(yrange=hist_chart.maxmin())
# XXX: update this every draw cycle to make L1-always-in-view work.
vars['last_mx'], vars['last_mn'] = mx, mn