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LEDMatrix/test/test_vegas_live_gating.py
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ChuckandClaude Opus 5.5 56947298d6 a plugin API for content that changes while it scrolls (#696)
* perf(timing): say which render-thread work a late frame followed

The soak already says how often a moving frame reached the panel late, but
not what the render thread was doing just before it. Vegas does two kinds of
work there between frames -- building its strip (compose, extend) and, with
live elements, patching changed pixels into it -- and deciding whether either
is affordable needs their own numbers.

- FrameTimingRecorder.note_op(kind, nbytes) tags the next presented frame.
  Totals gain op_frames, late_op_frames, op_freezes and op_bytes per kind;
  aggregate() still takes frames without ops. The file schema is unchanged.
- Vegas tags compose and every strip extension (with the bytes it copied).
- frame_soak prints an "after work" table: frames, late %, freezes and MB
  moved per kind, only when something tagged its work.
- render_bench gains --strip-screens (Vegas-sized strips), --patch-bytes /
  --patch-every / --patch-where (in-place column writes, as a live element
  update does) and --extend-every-screens / --extend-width (append + trim on
  a fixed cadence that holds the strip's width).

No runtime behaviour changes: this is the measurement gate for live Vegas
elements.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* docs(changelog): note the frame-op attribution and bench modes

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* perf(scroll): build the strip's PIL image only when something reads it

Every Vegas strip extension rebuilt ScrollHelper.cached_image from
cached_array in full, twice (append, then trim), on the render thread:
Image.fromarray is 1.7ms for an 8,000px strip and 3.8ms for 20,000px on a
Pi 4 (measured on ledpi), about two thirds of an extension's render-thread
cost. Nothing on the frame path reads the image's pixels; every frame is cut
from the array.

cached_image is now a property. append_content and drop_scrolled_prefix
defer it; the first read builds it from the array it started with and keeps
it only if the strip has not changed meanwhile, so a sync push racing an
extension cannot leave a stale image cached. Assigning cached_image stores
exactly what was assigned, as before. has_strip() says whether there is a
strip without building its image; the helper's frame path, Vegas and the
adapter's scroll-cache invalidation use it. The strip is also no longer held
in memory twice.

In Vegas the image is now built only by a multi-display sync push.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(vegas): live elements -- a plugin API for content that changes while it scrolls

Vegas bakes each plugin's pictures into one strip, so a card already on its
way across the panel keeps what it showed when it was drawn. This adds the
API and bookkeeping for content that can be updated in place; the worker
that redraws and swaps it follows separately. No shipped plugin implements
the hook yet, so nothing changes for users.

Plugin API (core 3.8.0), all no-ops by default:
- BasePlugin.get_vegas_elements() -> [VegasElement(key, image, version,
  live, refresh_hz)]: named, fixed-width pieces of Vegas content.
- BasePlugin.redraw_vegas_element(key, width, height, at): a lock-free
  redraw for content that changes with time.
- BasePlugin.notify_vegas_data_changed(): data that lands outside update().
- src/plugin_system/vegas_elements.py (VegasElement, re-exported from
  base_plugin).

Core:
- PluginAdapter asks a plugin that implements the hook for elements on the
  background fetch only (under its lock, on its own canvas); every other
  path keeps get_vegas_content(). Live elements are pinned (padded with
  content_padding, never trimmed), tagged with their key, digest and data
  epoch in Image.info so the existing cache and group plumbing carry them
  unchanged, and untagged if a width budget crops them.
- RenderPipeline records where each live element lands (ElementRecord), in
  absolute strip columns a trim does not move; the block-start arithmetic
  is shared with the STATIC markers.
- PluginManager update listeners (add/remove_update_listener,
  notify_data_changed): told the moment update() completes, not at the
  next ~4s Vegas poll. The coordinator uses one to move each plugin's data
  epoch on.
- vegas_scroll.live_refresh (kill switch), live_max_hz, live_min_interval,
  live_lead_screens; per-plugin core-owned vegas_live. Live elements are
  off under multi-display sync, in swap mode and with offscreen_prefetch off.
- scripts/check_plugin.py checks the element contract
  (src/plugin_system/testing/vegas.py); test/fixtures/plugins/vegas-live-stub
  is a working example.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-30 20:59:16 -04:00

138 lines
4.2 KiB
Python

"""When Vegas live elements are on, and that everywhere else nothing changes.
Live elements run only when the config allows them and nothing rules them
out: multi-display sync (the follower mirrors whole strips only), swap mode,
the offscreen kill switch, or a display manager with no off-screen canvas.
While they are on, the coordinator listens for plugin updates and moves each
plugin's data epoch on; while off, the adapter never asks for elements.
"""
import sys
from contextlib import contextmanager
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import MagicMock
import pytest
from PIL import Image
sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
from src.vegas_mode.coordinator import VegasModeCoordinator # noqa: E402
class _DM:
width, height = 128, 32
def __init__(self, offscreen=True):
self.image = Image.new("RGB", (128, 32))
if offscreen:
self.offscreen = self._offscreen
@contextmanager
def _offscreen(self, width=None, height=None):
yield SimpleNamespace(image=Image.new("RGB", (width or 128, 32)))
def set_scrolling_state(self, *a, **k):
pass
def update_display(self):
pass
class _PM:
def __init__(self):
self.plugins = {}
self.listeners = []
def add_update_listener(self, fn):
if fn not in self.listeners:
self.listeners.append(fn)
def remove_update_listener(self, fn):
self.listeners = [f for f in self.listeners if f != fn]
def _coordinator(dm=None, **vegas):
vegas.setdefault("enabled", True)
config = {"display": {"vegas_scroll": vegas}}
return VegasModeCoordinator(config, dm or _DM(), _PM())
def test_on_by_default():
c = _coordinator()
c._apply_live_state()
assert c.live_active
assert c.plugin_adapter.live_elements_enabled
assert c._on_plugin_data_changed in c.plugin_manager.listeners
@pytest.mark.parametrize("why,vegas,dm", [
("switched off", {"live_refresh": False}, None),
("swap mode", {"continuous_scroll": False}, None),
("offscreen kill switch", {"offscreen_prefetch": False}, None),
("no offscreen canvas", {}, _DM(offscreen=False)),
])
def test_off_when_ruled_out(why, vegas, dm):
c = _coordinator(dm, **vegas)
c._apply_live_state()
assert not c.live_active
assert not c.plugin_adapter.live_elements_enabled
assert c.plugin_manager.listeners == []
@pytest.mark.parametrize("role", ["leader", "follower"])
def test_off_whenever_sync_is_configured(role):
c = _coordinator()
c.set_sync_manager(SimpleNamespace(role=role))
c._apply_live_state()
assert not c.live_active
assert not c.plugin_adapter.live_elements_enabled
def test_a_standalone_sync_manager_does_not_count():
from src.common.sync_manager import SyncRole
c = _coordinator()
c.set_sync_manager(SimpleNamespace(role=SyncRole.STANDALONE))
c._apply_live_state()
assert c.live_active
def test_stopping_switches_it_off_and_stops_listening():
c = _coordinator()
c._apply_live_state()
c._is_active = True
c.stop()
assert not c.live_active and not c.plugin_adapter.live_elements_enabled
assert c.plugin_manager.listeners == []
def test_a_config_change_can_switch_it_off_mid_run():
c = _coordinator()
c._apply_live_state()
c._is_active = True
c.stream_manager.refresh = MagicMock()
c.update_config({"display": {"vegas_scroll": {"enabled": True,
"live_refresh": False}}})
c._apply_pending_config()
assert not c.live_active
assert c.plugin_manager.listeners == []
def test_an_update_moves_the_plugins_epoch_on():
c = _coordinator()
c._apply_live_state()
before = c.live_epochs.get("p")
for listener in c.plugin_manager.listeners:
listener("p")
assert c.live_epochs.get("p") > before
assert c.plugin_adapter.live_epochs is c.live_epochs
def test_the_state_change_is_logged_once(caplog):
c = _coordinator(live_refresh=False)
with caplog.at_level("INFO"):
c._apply_live_state()
c._apply_live_state()
lines = [r.message for r in caplog.records if "live elements" in r.message]
assert lines == ["Vegas live elements off: switched off (vegas_scroll.live_refresh)"]