perf(scroll): pace frames to the panel — 44→100 fps, stalls 14% → 0.02% by ChuckBuilds · Pull Request #523 · ChuckBuilds/LEDMatrix

ChuckBuilds · 2026-09-04T20:12:06Z

Scrolling ran at 44–46 fps on a 2×128×64 chain with 14–17% of frames taking 41–53 ms, which reads as judder. Four independent causes, each found by measuring on the hardware.

	before	after
scroll frame rate	44–46 fps	100 fps, vsync-locked
frame time	20 ms dominant	median 10.00 ms, p95 10.04 ms
stalls	14–17% of frames	0.02% (5 in 22,064)
render thread CPU	51% of a core	19%
disk cache write (~1 MB)	14.8 ms	5.4 ms

Measured on a Pi 4, 256×64 logical, limit_refresh_rate_hz: 100. Full detail and the diagnostic recipe are in docs/SCROLL_PERFORMANCE.md.

What was wrong

The frame loop slept on top of a wait it had already done. The high-FPS loop ran render → SwapOnVSync (blocks on the panel) → time.sleep(0.008) → plugin ticks. That sleep was unconditional and added to a wait that had already happened: ~4 ms of render plus 8 ms put each iteration at ~12 ms against a 10 ms refresh grid, so every swap missed a refresh and the loop settled at 50 fps while asking for 125 — with no headroom, so a further 14% of frames slipped again. It now sleeps only the remainder, with a 1 ms floor so plugin threads still get the GIL.

ScrollHelper stepped position on a wall clock. Frame-based mode advanced when time_since_last_step >= scroll_delay, and plugins set scroll_delay to the frame period — so the comparison sat exactly on its own threshold. A frame arriving a hair early moved zero pixels and rendered an identical frame, dirty tracking skipped the swap, it returned in ~2 ms, and the beat sustained itself. No scroll_delay value tunes that out; a shorter delay just trades stalled frames for periodic double-steps. Both modes now accumulate elapsed time at the same configured speed.

Dirty tracking skipped the panel swap mid-scroll. Right for static content, wrong while scrolling: SwapOnVSync is what paces the loop, so skipping it skips the wait. Measured ~20% duplicate frames mid-scroll on the odds ticker against ~0% on a lighter plugin with identical settings. The swap is now unconditional while is_currently_scrolling(), which expires on its own inactivity threshold so static screens are unaffected.

Sub-pixel blending was wrong for this display. It renders a half-step by mixing two adjacent columns; on a coarse panel showing pixel-font text that alternates crisp and smeared frames and reads as shimmer. Confirmed visibly worse on hardware. Back to off by default; Vegas mode still opts in.

New shared scroll configuration

Five ticker plugins each hand-rolled scroll config resolution and disagreed with each other. odds-ticker ranked the deprecated scroll_pixels_per_secondabove the documented scroll_speed/scroll_delay pair, and because that key carries a schema default the documented settings were dead for every user (ChuckBuilds/ledmatrix-plugins#408); ledmatrix-leaderboard read the same key only as a fallback.

src/common/scroll_config.py resolves every config shape in one place and is exported from src.common:

fromsrc.commonimportscroll_configsettings=scroll_config.configure(
self.scroll_helper,
plugin_config=self.config,
global_config=self.global_config,
refresh_hz=scroll_config.refresh_hz_from_config(self.global_config),
plugin_logger=self.logger,
)

It also warns when a speed will not advance a whole number of pixels per refresh — the property that actually determines whether a scroll looks smooth. On a 100 Hz panel the crisp speeds are 100, 200, 300 px/s; anything else must either blend (blur) or repeat frames (judder).

Instrumentation

The frame-stats line reported one instantaneous frame every 5 seconds — about 1 frame in 500 — beside a 100-frame average. Both hide exactly the fault they are used to chase: a 2 ms duplicate and a 21 ms double-wait average to precisely 10 ms, so a ticker stalling on half its frames still reported a healthy Avg FPS: 100.0. That reading cost several rounds of debugging the wrong layer. It now aggregates every frame since the last log:

100.0 fps over 501 frames | median 10.00ms p95 10.05ms max 10.34ms min 9.69ms | stalls 0 (0.0%) skips 0 (0.0%)

Binding rebuild (optional, not required by this PR)

scripts/build_rgbmatrix_nogil.sh rebuilds the rgbmatrix Python binding so it releases the GIL. Upstream declares FrameCanvas::SwapOnVSync without nogil, unlike SetPixel/Clear/Fill beside it in cppinc.pxd, so the render thread held the GIL for the entire vsync wait and starved background threads into long uninterruptible bursts — a 1.5 MB API response costs ~17 ms to parse and ~18 ms to re-encode, and json.raw_decode cannot be preempted mid-document.

The script patches, builds and self-verifies into a scratch tree. --install backs up the original and rolls back automatically if the service does not come back healthy. The per-pixel blit patch is opt-in and off by default: row-major ordering changes a torn frame from a vertical seam to a horizontal split across the panel's halves, and all of the measured gain comes from SwapOnVSync alone.

Also

disk_cache uses orjson when importable, stdlib otherwise. Encoding is ~7× faster; decoding gains far less (~1.3× on large payloads) because the cost is building Python objects, not scanning text — which is also why moving parsing to a subprocess does not help (pickle.loads 8.1 ms vs json.loads 10.9 ms on the same payload).
display_manager checksummed the whole framebuffer twice per frame (dirty tracking, then the preview snapshot). Now computed once.
De-flakes test_snapshot_still_written_on_skip, which asserted a strict mtime increase between two writes that can land in the same filesystem tick — it failed roughly two runs in three on Windows regardless of the code under test.

Testing

4011 tests pass on the Pi (two independent runs). Three failures, all environmental and pre-existing: two tzdata alias tests, and startup_validator reporting that the installedledmatrix-web.service has drifted from the repo template. None reference anything changed here.

New regression tests: test/test_scroll_config.py (38 tests, including one pinning that the deprecated key cannot override the documented pair) and TestScrollLock in test_display_dirty_tracking.py, whose key test fails against the pre-change code and passes with it.

Known, not addressed here

odds-ticker calls _has_live_games() from its per-frame render path; every 300 s that does a disk read plus JSON parse per enabled league on the render thread. Plugin-side, belongs with fix(testing): stop enabled:false schema defaults from silently disabling harness tests #408.
A one-pixel "fold" between the panel's upper and lower halves during motion is not from this code. It reproduces with the stock upstream binding, canonical double-buffering and no LEDMatrix code involved, and is unchanged across gpio_slowdown 3–5. Hardware or library level; tracked separately.

🤖 Generated with Claude Code

Summary by CodeRabbit

New Features
- Added refresh-rate-aware crisp scrolling with whole-pixel speeds and frame-hold pacing.
- Added a tool to measure display refresh rates, preview supported speeds, and demonstrate scrolling.
- Added safer disk-cache handling for non-finite numeric values and legacy cache files.
- Added tooling to rebuild, install, verify, and roll back optimized display bindings.
Bug Fixes
- Improved frame pacing and scrolling diagnostics to reduce judder and update delays.
- Improved refresh-rate detection and handling of malformed display configuration.
Documentation
- Added guidance on scroll performance, diagnostics, configuration, and display-binding maintenance.

Scrolling ran at 44-46 fps on a 2x128x64 chain and 14-17% of frames took 41-53ms, which reads as judder. Four independent causes, each measured on the hardware; details and the diagnostic recipe are in docs/SCROLL_PERFORMANCE.md. The high-FPS loop slept a flat 8ms after every render. display() has already blocked on the panel's vsync by then, so that sleep was added to a wait that had happened: ~4ms of render plus 8ms put each iteration at ~12ms against a 10ms refresh grid, so every swap missed a refresh and the loop settled at 50fps while asking for 125 -- with no headroom, so a further 14% of frames slipped again. It now sleeps only the remainder, with a 1ms floor so plugin threads still get the GIL. ScrollHelper stepped position on a wall clock at 1/scroll_delay steps per second. Plugins set scroll_delay to the frame period, so that comparison sat exactly on its own threshold: a frame arriving a hair early moved zero pixels and rendered an identical frame, dirty-tracking skipped the swap, it returned in ~2ms, and the beat repeated. No scroll_delay value tunes that out -- a shorter delay trades stalled frames for periodic double-steps. Both modes now accumulate elapsed time at the same configured speed, so position stays proportional to real time. Sub-pixel blending goes back to off by default. It renders a half-step by mixing two adjacent columns, which on a coarse panel showing pixel-font text alternates crisp and smeared frames and reads as shimmer -- visibly worse than integer stepping on the hardware. Vegas mode still opts in. disk_cache uses orjson when importable, falling back to the stdlib. Encoding a ~1MB record drops from 14.8ms to 5.4ms end-to-end, and that work holds the GIL while a marquee is on screen. display_manager also checksummed the whole framebuffer twice per frame (dirty tracking, then the preview snapshot); the snapshot now takes the checksum the caller already computed. New src/common/scroll_config.py resolves scroll settings in one place. Five ticker plugins each hand-rolled this and disagreed: odds-ticker ranked the deprecated scroll_pixels_per_second above the documented scroll_speed/delay pair, and because that key carries a schema default the documented settings were dead for every user (ChuckBuilds/ledmatrix-plugins#408), while ledmatrix-leaderboard read the same key only as a fallback. The resolver also warns when a speed will not advance a whole number of pixels per refresh, which is the property that actually determines whether a scroll looks smooth. scripts/build_rgbmatrix_nogil.sh rebuilds the rgbmatrix binding so it releases the GIL. Upstream declares SwapOnVSync without nogil, unlike SetPixel/Clear/Fill beside it, so the render thread held the GIL for the whole vsync wait and starved background threads into long uninterruptible bursts. The script patches, builds and self-verifies into a scratch tree; --install backs up the original and rolls back if the service does not come back healthy. Measured after: 100 fps locked, no stalls observed, render thread down from 51% to 19% of one core. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Dirty tracking skipped SwapOnVSync for byte-identical frames. That is the right call for static content, but SwapOnVSync is also what paces the render loop, so skipping it skips the wait for the panel: a duplicate frame returns in ~8ms instead of ~10ms on a 100Hz panel, advances the strip only 0.8px instead of 1.0px, and so makes the next frame more likely to repeat as well. The effect sustains itself once it starts. Measured over 20 minutes on a 2x128x64 chain, both scrollers configured identically at 100 px/s: leaderboard 10ms x35, 11ms x3 (clean) odds-ticker 10ms x26, 8ms x7, 15ms x5 (~20% duplicates mid-scroll) The duplicates were not end-of-cycle idling -- 38% of fast frames fell within 90s of a scroll completion against 35% of normal frames, a null result. The trigger is per-frame work: odds does more of it, and more variably, so it is first to land a frame that advances less than a whole pixel. Pushing an identical frame costs one canvas copy. Falling out of vsync lock costs smooth motion. Static content is untouched, because is_currently_scrolling() expires on its own inactivity threshold -- covered by test_stale_scrolling_state_stops_forcing_pushes so a plugin that stops scrolling without saying so cannot pin the panel into always-push. Also de-flakes test_snapshot_still_written_on_skip, which asserted a strict mtime increase between two writes that can land in the same filesystem tick; it failed about two runs in three on Windows regardless of the code under test. The file is now backdated before the check. 156 tests pass on the Pi. Not yet confirmed by eye on the panel. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Two problems, both found by looking at the panel rather than the metric. The frame-stats line reported ONE instantaneous frame every 5 seconds -- about 1 frame in 500 -- printed beside a 100-frame average. Both hide exactly the fault they are used to chase: a 2ms duplicate and a 21ms double-wait average to precisely 10ms, so a ticker stalling on half its frames still reports a healthy "Avg FPS: 100.0". That reading cost several rounds of chasing the wrong layer. The line now aggregates every frame since the last log and reports median, p95, max, min, and explicit stall and skip rates (past 1.5x the median missed a refresh; under half never reached the panel, because dirty tracking skipped the swap so the frame never waited on vsync). On the hardware this now reads: leaderboard 100.0 fps over 501 frames | median 10.00ms p95 10.05ms max 10.34ms | stalls 0 (0.0%) skips 0 (0.0%) The binding rebuild's blit patch becomes opt-in (RGB_PATCH_BLIT=1, default off). Reordering that loop to row-major changes what a torn frame looks like: column-major tearing shows as a vertical seam, row-major as a horizontal split between the panel's upper and lower halves. On a 1/32 scan panel that reads as a one-pixel fold across the middle of every panel, which is what was reported on hardware and what went away when the blit was reverted. All of the measured gain comes from the SwapOnVSync change, so the risky half is simply not worth taking; the header says so. Also fixes --install resolving its paths against $HOME, which is /root under sudo, so it looked in /root/rgbmatrix-nogil-build and died with "no built module found" on a machine where the build had just succeeded. It now resolves SUDO_USER's home. Both build paths are verified on the Pi: default yields one GIL-release site, RGB_PATCH_BLIT=1 yields two. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

coderabbitai · 2026-09-04T20:13:18Z

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src/plugin_system/testing/visual_display_manager.py
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📝 Walkthrough

Walkthrough

The PR adds crisp scroll-speed selection, refresh-aware frame pacing, frame-hold support, frame diagnostics, safer rgbmatrix rebuild operations, and non-finite float handling in disk-cache serialization.

Changes

Scroll performance and cache updates

Layer / File(s)	Summary
Crisp scroll configuration and tooling `src/common/scroll_config.py`, `src/common/__init__.py`, `scripts/scroll_speeds.py`, `test/test_scroll_config.py`, `docs/SCROLL_PERFORMANCE.md`	Resolves panel refresh rates, selects whole-pixel speeds, reports frame holds, exposes scroll helpers, adds speed tooling, and documents configuration and diagnostics.
Frame pacing and display hold `src/display_controller.py`, `src/display_manager.py`, `test/test_display_dirty_tracking.py`	Paces the display loop using completed frame time and passes the configured hold to `SwapOnVSync`.
Frame statistics and diagnostics `src/common/scroll_helper.py`, `test/test_scroll_helper.py`, `docs/SCROLL_PERFORMANCE.md`	Adds reusable frame statistics, percentile calculations, stall and skip counts, formatted logging, and diagnostic documentation.
No-GIL rgbmatrix build and installation `scripts/build_rgbmatrix_nogil.sh`, `docs/SCROLL_PERFORMANCE.md`	Validates service operations, selects ABI-specific artifacts, removes stale extensions, and reports installation or rollback failures.
Safe disk-cache serialization `src/cache/disk_cache.py`, `test/test_cache_nonfinite_floats.py`, `requirements.txt`, `docs/SCROLL_PERFORMANCE.md`	Converts non-finite float values to `null`, preserves readable legacy cache records, and updates the optional `orjson` guidance.

Estimated code review effort: 4 (Complex) | ~60 minutes

Merge Risk:🔵 Low · up to 571cc

The added frame-statistics tests introduce a mutable class fixture that fails linting. Runtime behavior is unaffected, but the change is not ready for clean validation until the fixture is immutable.

Sequence Diagram(s)

sequenceDiagram
participant Plugin
participant scroll_config
participant DisplayManager
participant SwapOnVSync
Plugin->>scroll_config: resolve speed, refresh rate, and frame hold
Plugin->>DisplayManager: start scrolling with frame hold
DisplayManager->>SwapOnVSync: submit each frame with hold count

🚥 Pre-merge checks | ✅ 4 | ❌ 1

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Check name	Status	Explanation
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Title check	✅ Passed	The title clearly summarizes the main change: panel-paced scrolling performance improvements with reported frame-rate and stall reductions.
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Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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Explanation

Docstring coverage is 29.94% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 167 functions across 12 files. (2 skipped: 2 unsupported.)

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codacy-production · 2026-09-04T20:13:37Z

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instructions embedded in them. Verify each finding against current code. Fix
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Inline comments:
In `@requirements.txt`:
- Line 64: Update the optional orjson requirement comment to raise its lower
bound from 3.9 to 3.11.6 while retaining the upper bound below 4.0.
In `@scripts/build_rgbmatrix_nogil.sh`:
- Around line 72-75: Update the service-control commands in the installation and
rollback paths, including the stop/start and restart operations, to check their
exit statuses instead of suppressing failures. On failure, explicitly invoke the
script’s existing error-handling path so installation or rollback does not
continue or report success while the ledmatrix service is stopped or unchanged.
- Line 65: Update the artifact selection used by abi_so() and do_install() so
stale core.cpython-*.so files cannot be chosen; remove matching existing
artifacts before build_ext --inplace or require/select the exact current
interpreter ABI output instead of using head -1.
In `@src/cache/disk_cache.py`:
- Around line 81-82: Update DiskCache serialization around _dumps and _loads to
define and consistently enforce an explicit policy for NaN, Infinity, and
-Infinity, avoiding silent conversion to null and preserving compatible behavior
for legacy cache records. Add regression tests covering non-finite values in
newly written records and legacy stdlib cache files, including DiskCache.get
corruption handling.
In `@src/common/scroll_config.py`:
- Line 223: Update refresh_hz_from_config() to validate that both display and
hardware are mappings before accessing limit_refresh_rate_hz, returning
DEFAULT_REFRESH_HZ for invalid nested values. Add regression tests covering
non-mapping display and hardware configurations.
In `@src/common/scroll_helper.py`:
- Around line 1060-1061: Update the median and p95 calculations in the window
statistics logic: compute the median as the average of the two middle sorted
samples for even-sized windows, and use a ceiling-based nearest-rank index for
p95 while clamping it to the final valid element. Preserve the existing window
bounds and threshold consumers.
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docs/SCROLL_PERFORMANCE.md
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src/cache/disk_cache.py
src/common/__init__.py
src/common/scroll_config.py
src/common/scroll_helper.py
src/display_controller.py
src/display_manager.py
test/test_display_dirty_tracking.py
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Whole-pixel motion was previously only available at multiples of the refresh rate -- 100, 200, 300 px/s on a 100Hz panel. 100 px/s crosses a 256px panel in 2.6s, which is brisk for reading, and everything slower had to blend (blur) or repeat frames unevenly (judder). There was no way to ask for 50 px/s and get clean motion. SwapOnVSync takes a framerate_fraction the display manager never passed. It holds each frame for N panel refreshes; the panel keeps refreshing at its full rate throughout, so holding costs nothing in flicker and only changes how often a NEW image is presented. That turns 50 px/s into one whole pixel every second refresh instead of half a pixel every refresh. The crisp speeds are therefore refresh_hz / hold * pixels_per_frame, and that ladder depends on the panel: a Pi Zero on a long chain has a different set of good speeds from a Pi 4 on a short one. crisp_ladder() enumerates them and solve_crisp() picks the best match for a requested speed. solve_crisp weights motion quality rather than picking the numerically nearest entry, which matters more than it sounds. Asked for 30 px/s, nearest-by-value answers 28.6 -- 2px jumps at 14fps -- over 33.3, which is single-pixel motion at 33fps and obviously better on the panel. The target is also clamped into the ladder's range first, because relative error saturates near 1.0 for a target far outside it and the quality penalty would otherwise answer "10000 px/s" with the slowest entry. configure() snaps to the ladder and applies the hold when given a display manager. Without one the hold silently cannot happen and motion falls back to fractional pixels, so it warns rather than failing quietly. set_frame_hold() resets to 1 when scrolling stops, so one plugin's pacing cannot leak into whatever is on screen next. scripts/scroll_speeds.py is the user-facing part: it prints the ladder for the configured rate, measures what the panel ACTUALLY manages (--measure, for hardware that cannot reach its configured limit), highlights the nearest option to a wanted speed, and demos one live. It never starts or stops the display service itself -- doing that inside a script stranded the panel twice today. Speeds below ~20 px/s remain stepped regardless. That is the pixel pitch, not a software limit. Also fixes the dirty-tracking test spy, which stubbed SwapOnVSync with a single-argument function and would have masked the new call as a failed push, and rewrites a configure() test that had started passing for the wrong reason: it asserted a judder warning, which snapping now prevents, and was matching the unrelated "hold could not be applied" warning instead. 183 tests pass on the Pi. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

The hold applied in configure() never reached the panel. Plugins share one display manager, and set_scrolling_state(False) -- fired whenever ANY other plugin finishes its scroll -- reset the hold to 1. A hold set once at plugin construction was therefore always gone by the time that plugin rendered. The symptom was a log line that lied. ledmatrix-stocks reported Scroll configured: 50.0 px/s (1px every 2 refreshes = 50.0 fps, smooth) while the panel measured 100.0 fps, median 10.00ms. Config, resolution and snapping were all correct; only the pacing silently was not applied. set_scrolling_state(is_scrolling, frame_hold=1) now carries it, so the hold lives exactly as long as the scroll that asked for it. configure() reports the value as ScrollSettings.frame_hold instead of applying it -- applying it behind the caller's back could never have been right on a shared display manager. Existing callers are unaffected; the default keeps one frame per refresh. Verified on hardware: stocks at 50 px/s now measures 50.0 fps over 251 frames | median 20.00ms p95 20.09ms | stalls 0 skips 0 20.00ms being exactly two refreshes, with the panel still refreshing at 100Hz underneath so flicker is unchanged. test_another_plugin_stopping_does_not_strand_a_hold pins the interaction that broke this. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

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Inline comments:
In `@src/common/scroll_config.py`:
- Around line 334-338: Correct the frame-hold documentation contract: in
src/common/scroll_config.py lines 334-338, state that display_manager only
supplies the refresh rate and the caller applies settings.frame_hold when
scrolling starts; in docs/SCROLL_PERFORMANCE.md lines 85-100, replace the claim
that configure() applies the hold and the missing-manager warning with guidance
to call set_scrolling_state(True, frame_hold=settings.frame_hold).
- Around line 357-359: Update the refresh-rate resolution flow around resolve()
so the display manager’s refresh_hz is determined before resolving settings,
then pass that effective hz into resolve() via refresh_hz; preserve
settings.target_fps and DEFAULT_REFRESH_HZ fallbacks. Add a regression test for
a 60 Hz display manager with snap_to_crisp disabled, verifying target_fps,
pixels_per_frame, judder warning, and pacing use 60 Hz.
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docs/SCROLL_PERFORMANCE.md
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src/common/scroll_config.py
src/display_manager.py
test/test_display_dirty_tracking.py
test/test_scroll_config.py

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Eight findings, all reproduced before fixing. scroll_config.configure() read the refresh rate *after* resolve() had already used it. resolve() fills in target_fps, pixels_per_frame and the judder warning from that rate, so on a 60Hz panel every one of them described 100Hz -- and with snap_to_crisp=False nothing downstream corrected it, so set_target_fps() paced the helper to 100 FPS. The rate is now settled first, and falls back to the global config rather than straight to the default. refresh_hz_from_config() used `(cfg.get("display") or {}).get(...)`, which raises AttributeError when either level is truthy but not a mapping -- out of a function whose whole contract is a rate or a default. The frame-stats line reported the upper-middle sample as the median and the 96th sorted sample as p95 of 100. Both are also thresholds (stalls at 1.5x the median, skips at 0.5x), so the counts were biased too. The arithmetic is now in frame_stats()/format_frame_stats(), testable without a clock. configure()'s docstring and docs/SCROLL_PERFORMANCE.md still said it applies the frame hold and warns when it cannot. It deliberately does neither since "tie the frame hold to the scroll, not the plugin"; a caller following the old text would omit set_scrolling_state() and slow snapped speeds would still present every refresh. disk_cache had no policy for non-finite floats: orjson writes null, the stdlib writes NaN/Infinity, and orjson then rejects those legacy files so DiskCache.get deleted them as corrupt. One behaviour on both paths now -- write null, keep legacy records readable. allow_nan=False detects the values; the replacement walk runs only when there is one, so the ordinary write path is byte-identical and pays nothing. build_rgbmatrix_nogil.sh picked the build artifact with a glob piped to `head -1`, which sorts cpython-311 ahead of cpython-313, so a stale .so staged in from the source tree was installed as core.so while the GIL check -- which reads the generated core.cpp, not the .so -- still passed. It now requires the current interpreter's exact ABI name and fails closed. Its systemctl calls were also unchecked under `set -uo pipefail`: a failed stop left the old service running, the following start succeeded as a no-op, and the health check reported SUCCESS for a binding that was never loaded. orjson floor raised to 3.11.6 for CVE-2025-67221 (unbounded recursion in dumps); it covers the project's Python 3.10-3.13 range. Adds test/test_cache_nonfinite_floats.py (14) plus regression tests in test_scroll_config.py and test_scroll_helper.py. 9 of the cache tests and 9 of the scroll_config tests fail against the pre-fix code. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9

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336-336: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win
Make HUNDRED immutable.
Ruff reports RUF012 for this mutable class attribute. Use a tuple; frame_stats sorts its input without mutating it.
Proposed fix
- HUNDRED = [i / 1000.0 for i in range(1, 101)]+ HUNDRED = tuple(i / 1000.0 for i in range(1, 101))
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In `@test/test_scroll_helper.py` at line 336, Update the HUNDRED class attribute
to use an immutable tuple instead of a list, preserving its existing values so
frame_stats can continue sorting the input without mutation.
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Nitpick comments:
In `@test/test_scroll_helper.py`:
- Line 336: Update the HUNDRED class attribute to use an immutable tuple instead
of a list, preserving its existing values so frame_stats can continue sorting
the input without mutation.
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docs/SCROLL_PERFORMANCE.md
requirements.txt
scripts/build_rgbmatrix_nogil.sh
src/cache/disk_cache.py
src/common/scroll_config.py
src/common/scroll_helper.py
test/test_cache_nonfinite_floats.py
test/test_scroll_config.py
test/test_scroll_helper.py

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requirements.txt
src/common/scroll_config.py
src/common/scroll_helper.py
scripts/build_rgbmatrix_nogil.sh
docs/SCROLL_PERFORMANCE.md
test/test_scroll_config.py

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CodeRabbit raised six; all six were real. The test double had drifted ahead of production. VisualTestDisplayManager accepted set_scrolling_state(frame_hold=...) while DisplayManager did not, so such a call passed every harness run and would raise TypeError on the panel -- the one failure a safety harness exists to prevent. frame_hold belongs to the change that adds it to DisplayManager (#523), so it moves there and the double matches main again. The harness swallowed exceptions from re-rendered frames. _settle_loop re-renders a mode that came back blank, to give a scroll time to draw; returning silently on a crash meant a mode that renders one good frame and then explodes was reported as passing. Recorded on result.error now, keeping the captured frame so the failure stays inspectable. starlark-apps display() returned True after _display_frame() failed, so the controller held a dead frame for the whole display_duration instead of rotating on. _display_frame now returns bool on all three paths. run_plugin_tests.py used env.setdefault for PYTHONPATH and LEDMATRIX_CORE, so an inherited value won and the subprocess imported a different core than the one under test -- ledmatrix-plugins#467 exactly. Prepends PROJECT_ROOT and sets LEDMATRIX_CORE unconditionally. The on-demand mailbox is polled after every frame, ~125x/second on a scrolling mode, and the read is deliberately uncached, so it was that many disk reads per second to find nothing. Floored at 250ms, which is imperceptible for a web-UI click. Consuming it also deleted whatever was present rather than what had just been processed, so a request posted while the previous one was in flight was thrown away and never ran; the delete is now keyed by request_id. That narrows the window rather than closing it -- a true atomic claim needs a primitive the cache layer does not offer, and the code says so rather than implying otherwise. Codacy's 2 criticals were bandit B404/B603 on the subprocess call added to run_plugin_tests.py. Fixed interpreter, argument list, no shell; annotated with the repo's existing nosec convention. Bandit is clean on the file. Adds test/test_on_demand_mailbox.py (8), test_starlark_display_contract.py (4) and two settle cases in test_harness_empty_claimed.py. 4, 4 and 2 of those fail against the pre-fix code. Full suite: 3961 passed. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9

Moves set_scrolling_state's frame_hold into the test double here, where DisplayManager gains it, rather than in #534 where it arrived a PR early. CodeRabbit flagged the #534 version correctly: a double that accepts an argument production does not lets the call pass every harness run and raise TypeError on the panel, which is the one failure a safety harness exists to prevent. The drift has now gone both ways across two branches -- double behind production on this branch, double ahead of it on #534 -- so it is pinned instead of remembered. test_display_double_parity.py compares the two signatures and fails with the direction of the drift named. It reads the files with ast rather than importing them, because display_manager imports rgbmatrix at module scope and this check should hold on a laptop and in CI as well as on a Pi. Plugins begin passing frame_hold in ledmatrix-plugins#462, which is why production and the double both need it before that lands. Full suite: 3889 passed. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9

The only change this branch made to that file was a docstring, and it collided with #523's rewrite of the same method -- so #534 and #523 each merged cleanly against main but conflicted with each other. Reverted to main's text; #523 owns this method and adds frame_hold to it. The note the docstring carried ('frame_hold arrives in #523') would have been stale the moment #523 landed anyway. The parity test in #523 is what actually keeps the two signatures honest. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9

…534) * fix(core): register tom_thumb, accept frame_hold in the test double, wire api_v3's managers Three independent fixes found while validating every plugin on a 256x64 rig. FontManager never registered tom_thumb even though assets/fonts/tom-thumb.bdf ships with the core, so every plugin offering it logged "Font family 'tom_thumb' not found" (16 warnings per countdown render) and had to carry a private loader to use a bundled font. Closes#524. VisualTestDisplayManager.set_scrolling_state() lacked the frame_hold parameter that DisplayManager gained, so any plugin passing it died with TypeError at render time and failed every size. Nine plugins now make that call; ledmatrix-stocks and ledmatrix-leaderboard were failing outright and the other seven only passed because their scroll path was unreachable without data. Closes#525. api_v3 declared module-level config_manager/plugin_manager = None that nothing ever assigned -- app.py sets the blueprint attributes, which the other 150+ call sites use. Three sites read the decoys, so /health reported the config unreadable and the plugin system uninitialised (making "degraded" permanent and unreachable-by-design) and /display/current fell back to a hardcoded 128x64 on every rig. The decoys are removed rather than assigned, so a bare name is now a NameError at test time instead of a silent None. The same function's first-call uptime was computed from two separate clock reads and came out negative. Closes#529. Verified on the rig: both previously-failing plugins render, the tom_thumb warnings are gone, /health reports "healthy" with all three checks passing, and /display/current reports the real 256x64. * fix(core): unique snapshot temp name, honour on-demand requests, skip empty starlark The preview snapshot wrote through a fixed "<snapshot>.tmp". /tmp is world-writable and sticky, and the display service runs as a different user from the tooling, so a leftover temp owned by anyone else became unopenable even by root -- fs.protected_regular refuses O_CREAT on a foreign file in a sticky directory. The preview and the health check's liveness proxy then froze until someone deleted the file by hand; on the test rig that meant 23 hours of a healthy display reporting "hardware: stale". Now uses tempfile.mkstemp with cleanup on failure, matching the hardware-status write a few hundred lines above. Closes#528. _poll_on_demand_requests read its mailbox with max_age=3600, and get() defaults the in-memory TTL to max_age -- so the first request was pinned in memory for an hour and every later poll returned that stale copy. No second on-demand request was honoured until the service restarted, while the API kept returning 200. get() already documents memory_ttl=0 for exactly this cross-process case. The consumed request is also now deleted: leaving it on disk meant a restart replayed the previous request, activated it, and ignored the one the caller had just made. Closes#530. starlark-apps returned None from display() when it has no app to show, which is the state of every install without Pixlet and of a fresh one before any app is added. The controller only skips on a boolean False, so that held a black panel for the full display_duration instead of rotating on. Closes#456 (core side). Verified on the rig: two consecutive on-demand requests with no restart between them are both activated, where the second was previously dropped in silence. * perf(harness): share one cache across a plugin's renders _instantiate built a fresh MockCacheManager for every (size, mode), and that mock is a per-instance in-memory dict, so each render was a cold start. A plugin that fetches per game or per player re-fetched everything N times over -- baseball-scoreboard at one size took 840s for nine renders where the arithmetic said ~72s, and at eight sizes it exceeded a 900s timeout. The second and later renders also never exercised the cache-hit path, which is what a running rig executes almost all of the time, so a caching regression could not be caught here. The cache is now built once per render_plugin_matrix call and threaded down. The display manager stays per-render -- the bounds checking depends on that -- so only fetched data is shared. Measured on the rig, same render counts and same goldens: tide-display 2s -> 1s (32 renders) cricket-scoreboard 10s -> 3s (24 renders) No pass/fail change across tide-display, cricket-scoreboard, clock-simple, geochron, christmas-countdown, of-the-day, web-ui-info and incoming-packages. Closes#533. * fix(scripts): run standalone plugin tests instead of collecting nothing run_plugin_tests.py discovered every plugin test file and handed the lot to pytest. Most plugin tests are standalone scripts -- module-level main() plus an `if __name__ == "__main__"` guard, signalling through an exit code -- and pytest collects zero items from those. The run printed how many files it had *found*, then "no tests ran", and exited without executing any of them. On a rig with all 44 first-party plugins that is 151 of 248 files. Files are now classified and each kind runs under the right runner: pytest for real test modules, subprocess for scripts, honouring the 0 pass / 2 skip / 1 fail convention ledmatrix-plugins' own runner established (a script that wants a tty or an LED matrix is a skip, not a regression). Before: $ python3 scripts/run_plugin_tests.py -p countdown -d ~/LEDMatrix/plugin-repos Found 1 test file(s) collected 0 items no tests ran in 0.31s rc=0 After: Found 1 test file(s) -- 0 collectable, 1 standalone script(s) 1 passed, 0 skipped, 0 failed (scripts) rc=0 Verified across three shapes: countdown (1 script), jellyfin-now-playing and pomodoro-timer (pytest only, 16 and 42 tests), and ledmatrix-flights (11 files split 4 collectable / 7 scripts, all seven of which had never run). Closes#532. Running the flights scripts for the first time also surfaced four genuinely failing tests there, hidden by the mirror-image bug in the plugins repo's own runner -- filed as ChuckBuilds/ledmatrix-plugins#464 and #465. * fix(harness): give an empty-looking mode a few frames before warning about it check_plugin's "drew nothing but display() returned X" warning fired on a single frame, rendered with force_clear=True, under a frozen clock. All three defeat a scrolling plugin, whose first frame is legitimately its blank scroll-in buffer. Across 44 first-party plugins, 60 of 76 warnings were false -- the rate at which people stop reading a warning, which matters because the true positives are real: a mode that draws nothing and does not return False holds a blank panel for its whole display duration. An apparently-empty frame is now re-driven for up to 48 more frames with force_clear=False (force_clear means "reset the scroll", so repeating it would redraw frame 1 for ever) and with the clock advancing -- freezegun's factory where time is frozen, a real sleep where it is not, since scroll position is usually a function of elapsed time. The first frame that draws content replaces the result. The clock is moved back afterwards. It is shared by every render in the matrix, so time borrowed by the probe leaked into later modes and drifted their goldens -- f1_upcoming picked up 5 spurious drifts before this was restored. Measured on the rig: empty warns check before after f1-scoreboard 42 0 48 PASS / 0 FAIL, goldens intact ledmatrix-elections 16 0 16 PASS / 0 FAIL on-air 8 8 true positive, kept nfl-draft 8 8 true positive, kept clock-simple/geochron/ 0 0 unchanged christmas-countdown 58 false positives gone, both true positives kept, no golden regressions. Cost is confined to modes that really are blank: plugins that draw immediately are unchanged (clock-simple and tide-display still 2s), while on-air -- eight deliberately blank modes -- goes to 21s. Closes#527. * fix(harness): load nested schema defaults, and merge caller config at leaf level load_config_defaults read only top-level properties. An object property carries its defaults on its children, not on itself, so everything nested was dropped -- 2,386 defaults across 37 of 44 plugins, soccer-scoreboard alone losing 539 of 565. render_plugin_matrix's comment says the plugin then "behaves like a real install", which for most of the fleet it did not. _defaults_from_properties now recurses. merge_config deep-merges the caller's config onto the result so an override lands at the leaf: a shallow merge would let -c '{"nhl": {"enabled": true}}' replace the whole nhl subtree and discard every other nhl default, which is the same class of bug being fixed here. Measured before/after across all 49 installed plugins on the rig: **no render changed** -- identical PASS/FAIL counts, byte-identical output, goldens intact. Plugins already fall back to the same values internally via config.get(key, default), so supplying them explicitly agrees with what they were doing. The defaults really are arriving now: ufc-scoreboard 9 -> 87 defaults ledmatrix-flights 51 -> 95 masters-tournament 10 -> 51 cricket-scoreboard 22 -> 50 tide-display 12 -> 18 and hockey-scoreboard, which used to load nhl.enabled=None, now gets nhl.enabled=True with its full display_modes block. Caveat worth carrying: the eight plugins with the most nested config (soccer, baseball, basketball, hockey, lacrosse, football, afl, nrl -- 1,634 of the 2,386 dropped defaults, 68%) could not be measured. They import src.common.sports_shared, which the test rig's core branch predates, so they fail to load there identically before and after. Re-run this comparison against a core that has that module before trusting the "nothing changed" result for them; those are exactly the plugins whose renders should change most. Closes#531. * refactor: narrow the exception handlers this branch introduced Codacy flagged the new code; it passes on other recent PRs, so the finding is mine. Four of the five broad `except Exception` clauses I added were catching far more than they needed to, which is the same shape as several bugs this branch fixes -- hello-world's TypeError sat invisible for exactly this reason. freezer() / move_to() / tick() -> (AttributeError, TypeError, ValueError) cache_manager.delete() -> (OSError, AttributeError, KeyError) The fifth stays broad and now says why: it wraps a call into a plugin's own display(), which can raise anything, and the first frame has already rendered -- so a failure there must not turn a good result into an error. Verified against a checkout of main: f1-scoreboard 48 PASS / 0 FAIL with 0 empty warnings, on-air keeps its 8 true positives, clock-simple 8 PASS. geochron shows 7 golden drifts both before and after this branch, so it is not from these changes -- its committed goldens predate #521's 1-bit text rendering. * fix: resolve CodeRabbit review and Codacy findings on #534 CodeRabbit raised six; all six were real. The test double had drifted ahead of production. VisualTestDisplayManager accepted set_scrolling_state(frame_hold=...) while DisplayManager did not, so such a call passed every harness run and would raise TypeError on the panel -- the one failure a safety harness exists to prevent. frame_hold belongs to the change that adds it to DisplayManager (#523), so it moves there and the double matches main again. The harness swallowed exceptions from re-rendered frames. _settle_loop re-renders a mode that came back blank, to give a scroll time to draw; returning silently on a crash meant a mode that renders one good frame and then explodes was reported as passing. Recorded on result.error now, keeping the captured frame so the failure stays inspectable. starlark-apps display() returned True after _display_frame() failed, so the controller held a dead frame for the whole display_duration instead of rotating on. _display_frame now returns bool on all three paths. run_plugin_tests.py used env.setdefault for PYTHONPATH and LEDMATRIX_CORE, so an inherited value won and the subprocess imported a different core than the one under test -- ledmatrix-plugins#467 exactly. Prepends PROJECT_ROOT and sets LEDMATRIX_CORE unconditionally. The on-demand mailbox is polled after every frame, ~125x/second on a scrolling mode, and the read is deliberately uncached, so it was that many disk reads per second to find nothing. Floored at 250ms, which is imperceptible for a web-UI click. Consuming it also deleted whatever was present rather than what had just been processed, so a request posted while the previous one was in flight was thrown away and never ran; the delete is now keyed by request_id. That narrows the window rather than closing it -- a true atomic claim needs a primitive the cache layer does not offer, and the code says so rather than implying otherwise. Codacy's 2 criticals were bandit B404/B603 on the subprocess call added to run_plugin_tests.py. Fixed interpreter, argument list, no shell; annotated with the repo's existing nosec convention. Bandit is clean on the file. Adds test/test_on_demand_mailbox.py (8), test_starlark_display_contract.py (4) and two settle cases in test_harness_empty_claimed.py. 4, 4 and 2 of those fail against the pre-fix code. Full suite: 3961 passed. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9 * chore: satisfy Codacy's subprocess checks on the new test runner Codacy runs Bandit and Opengrep (its Semgrep fork). The new subprocess.run in scripts/run_plugin_tests.py trips three patterns, on two different lines: Bandit B404 on the import, B603 on the call Opengrep dangerous-subprocess-use-audit on the run( line dangerous-subprocess-use-tainted-env-args on the argv line A nosemgrep applies only to its own line, so the call line and the argv line each need one; a single comment on the call covered neither rule fully. Suppression is the right answer here rather than a rewrite: the interpreter is sys.executable, the arguments are a list, and no shell is involved, so there is nothing to word-split or expand. Matches the pair the rest of the repo already uses for this shape -- permission_utils.py, plugin_loader.py, install_dependencies_apt.py. Codacy: 0 new issues, up to standards. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9 * chore: leave visual_display_manager untouched so #523 can merge The only change this branch made to that file was a docstring, and it collided with #523's rewrite of the same method -- so #534 and #523 each merged cleanly against main but conflicted with each other. Reverted to main's text; #523 owns this method and adds frame_hold to it. The note the docstring carried ('frame_hold arrives in #523') would have been stale the moment #523 landed anyway. The parity test in #523 is what actually keeps the two signatures honest. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9 * chore: add the Ruff suppression nosec/nosemgrep do not cover Ruff reports S603 on the same call Bandit and Opengrep do, and none of the three suppressions covers the others. Confirmed the precondition first: path comes from discover_plugin_tests(), which globs test files inside the repo, and the call is a fixed interpreter with a list argv and no shell. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9 --------- Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

…olver (#462) * test(scroll-cards): refresh the goldens #409 made stale scripts/test_scroll_card_renders.py has been red on main since #409, which made the safety check fail on every open PR regardless of what that PR touched -- #428 fails it while changing only one plugin's README and manifest. The signal was useless: a real render regression would have looked identical to this noise. #409 deliberately changed which font several text elements draw in, so the goldens committed on 2026-08-02 describe the old, wrong rendering. Measured: at the parent of #409 the guard reports 3 problems, on main it reports 42. These 39 are that difference. Checked rather than assumed. Every regenerated card was compared against its predecessor pixel by pixel, and the four sampled visually: the text content is identical and only the glyph shapes change, which is what a font swap should look like. --update also rewrote 24 cards whose pixels had not changed at all, presumably encoder metadata; those are reverted so the diff is only the 39 that actually differ. Baseball's three upcoming cards are deliberately NOT refreshed. They are the 3 that were already failing before #409, and they fail for an unrelated reason: game_renderer.py formats the date with %-m/%-d and %-I:%M%p, which are glibc extensions. Off glibc they raise, the except falls back to a raw ISO string, and the card loses its start time and shows 2026-09-19 instead of Sep 19. The committed goldens are correct; regenerating them anywhere but glibc would bake the broken output in. Filed separately. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * refactor(scroll): route every scrolling plugin through the shared resolver Eleven plugins each hand-rolled scroll configuration and disagreed with one another about what identical config meant. odds-ticker ranked the deprecated scroll_pixels_per_second ABOVE the documented scroll_speed/scroll_delay pair, and because that key carries a schema default the documented settings were dead for every user (#408). ledmatrix-leaderboard read the same key only as a fallback, so the same config produced different speeds in the two plugins. stock-news derived px/frame through its own arithmetic. Nobody was wrong locally; they were just eleven answers to one question. All of them now call src.common.scroll_config.configure(), which resolves every supported config shape in one place, snaps the speed to one the panel can render in whole pixels, and reports the frame hold needed to keep slow speeds crisp. Identical config now means an identical speed everywhere. Each plugin keeps its original logic as a fallback behind try: from src.common import scroll_config as _scroll_config except ImportError: _scroll_config = None because plugins update independently of the core and must keep working against one that predates the helper. Where the legacy block sits inline in __init__ the shared call runs after it and wins, rather than re-indenting logic other config shapes still depend on; those plugins log a line saying so, because two scroll speeds in the journal with no indication which took effect is exactly the confusion this change exists to remove. Plugins pass settings.frame_hold to set_scrolling_state(True, ...) when they begin scrolling. The hold cannot be applied once at construction: plugins share one display manager, and it is reset whenever any other plugin finishes its scroll. Verified on hardware (Pi 4, 2x128x64, 100Hz). Four enabled plugins resolve through the helper with no tracebacks, and ledmatrix-stocks at 50 px/s measures 50.0 fps, median 20.00ms -- exactly two refreshes per frame, with the panel still refreshing at 100Hz so flicker is unchanged. Requires core support: ChuckBuilds/LEDMatrix#523. Without it every plugin takes the fallback path and behaves exactly as before. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(odds-ticker): make the documented scroll settings reachable (#408) Two defects meant display_options.scroll_speed / scroll_delay -- the format the plugin documents and recommends -- could never take effect. The priority-1 branch read scroll_pixels_per_second into self rather than clearing it the way the display_config branch does. config_schema.json gives that deprecated key a default of 50.0 and schema defaults are merged into plugin config, so it was never None and use_frame_based() below was never True. Separately, use_frame_based() only ever inspected display_config, so even with that fixed the recommended shape still could not select frame-based mode. Both halves were needed. The visible symptom was the plugin logging its scroll configuration twice on startup, ~0.36s apart, the second line quietly overriding the first: Using display_options.scroll_speed=1.0 px/frame ... (frame-based mode) Using scroll_pixels_per_second: 50.0 px/s (time-based mode) with the second one being what actually ran. On a 100Hz panel that meant 0.5px per frame, so every second frame rendered identically, dirty tracking skipped the panel swap, and the ticker juddered. Editing scroll_speed had no effect, and deleting scroll_pixels_per_second only restored the schema default. Also takes the live-game check off the render path. display() called _get_current_update_interval() every frame, and its slow path reads the scoreboard cache from disk and parses JSON per enabled league -- producing a single ~15ms frame every few minutes, measurable as a stall mid-scroll. The interval is now memoised for 15s; the scoreboard re-check underneath is rate limited to 300s regardless, so live detection is unaffected. The neighbouring debug line used an f-string, so it called _has_live_games() on every skipped update even with debug logging off; it now uses %s args. Verified on hardware: odds-ticker selects frame-based mode with no time-based line following it, and resolves to 100.0 px/s at 1px per refresh. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix: make the frame-hold call safe for the test doubles, and update to main Three display-manager doubles still declared set_scrolling_state with a single argument, so the frame_hold this PR passes raised TypeError mid-render. display() swallows that in its own except Exception, leaving only "no frame reached the display" -- odds-ticker's cache-invalidation test failed for a reason that had nothing to do with cache invalidation. CI caught one of the three; the other two never reach the scrolling branch. scripts/test_scroll_state_doubles.py checks the invariant instead, and catches all three (including the *args one, which looks tolerant but cannot take a keyword). odds-ticker's double also needed _scroll_frame_hold itself: it borrows only the methods under test, and display() now calls that one. Fixes a continuation line in odds-ticker/manager.py that was indented back to column 12 inside the call -- legal, but not what anyone meant. Merges main. This branch was two commits behind, which made its diff look like it deleted versions[] entries main had gained. Six plugins then needed version bumps they did not need before, because main had bumped past them. ledmatrix-leaderboard and nfl-draft sit one patch above #466's numbers rather than duplicating them -- two PRs must never publish the same version, and a user could not tell which build they have. That pins the merge order these two already needed. Verified against a core with #523 and #534 merged: safety harness clean on all 11 changed plugins, 23 unit tests pass, version and collision gates pass. The one failing repo guard, test_odds_centre_collision.py, fails identically on main and is untouched here. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9 --------- Co-authored-by: Claude Opus 5 <noreply@anthropic.com> Co-authored-by: t <t@l>

… MQTT bridge Analysis of ant456/ledmatrix-fixes-repo, a third-party collection of patches and services built while running this project on Starlark apps under MQTT control. Its patches are whole-file copies taken against an older tree, so applying them as written would revert #523's frame pacing, #534's display() bool returns and the GitHub token masking in plugins_manager.js. Three of its claimed fixes are already in main, and its api_v3 Starlark routes are #535's. What follows is the rest -- verified against current code, and reimplemented where the patch's approach did not hold up. **On-demand display.** `pinned` reached the controller from the API, was stored on it and republished in the status payload, but never narrowed the rotation -- a pinned request still cycled every mode its plugin owns. Right for a sports plugin, whose modes are views of one subject; wrong for a plugin whose modes are unrelated, which is every Starlark app. Now honoured, and it survives a restart. Restarting while on-demand was active loaded *only* the on-demand plugin, so normal rotation had nothing to return to for the life of the process -- and a restart mid-session is routine, since that is how an update is applied. The panel came back cycling one plugin's modes with no way out but clearing the cache by hand. Every enabled plugin loads now; on-demand still resumes on its saved mode. Stop requests are exempt from the duplicate guards on purpose, so that a second click stops a mode a race left running -- which means consuming the mailbox is the only thing that ends one. It was never consumed, so the same stop was re-read and re-processed on every poll, forever. Both paths now share one compare-before-delete helper. **Starlark rendering.** `extract_schema` parsed the source with a regex, which can only see option lists written out literally: an app whose dropdown is filled from a live API call inside `get_schema()` came back empty, and the config form offered nothing to pick. Now runs `pixlet schema`, which executes the app, and falls back to the parser when Pixlet is absent, too old for the subcommand, or the app fails to run. The third-party patch replaced the parser outright and hardcoded /usr/local/bin/pixlet; this keeps the fallback and the binary search. A `|` in a config value was dropped by a shell-metacharacter filter, though the command is a list with no shell involved -- and apps do use it as a separator inside one value. The key went missing silently and the app rendered its own "not configured" screen with nothing to say why. And a 0-byte render was reported as success: Pixlet exits 0 and writes nothing when an app has no content, which read downstream as a working app drawing a black panel. **Starlark display.** `display()` ignored the mode it was called with, so a specific app could not be addressed. It now accepts `display_mode` -- which is the whole mechanism, since the controller inspects the signature before passing it. Found while there: `_select_next_app` ran only while `current_app` was unset, so with several apps installed the first was picked once and shown forever while the rest were rendered on schedule and never displayed. And `enable_scrolling` was missing, so multi-frame apps were called once per rotation slot and never advanced past frame one. **GET /api/v3/display/modes.** Every mode that can be requested on-demand, with the plugin that owns it. Nothing exposed this, so anything driving the display from outside the web UI read each plugin's manifest.json off disk and reimplemented PluginManager's fallbacks. It also triggers discovery, which is otherwise lazy and normally happens because a person opened the dashboard. **integrations/mqtt_bridge.** Home Assistant control over MQTT Discovery: a mode select, a stop button, power, brightness. Rewritten against the API rather than the filesystem, so it needs no read access to config.json and cannot drift from the web UI. paho-mqtt 2.x VERSION2, TLS, an availability topic that is also the last will, and secrets from the environment. **Two opt-in extras.** A DNS single-request unit, for glibc's parallel A/AAAA lookup stalling ~5s per name on routers that answer only the A query -- which makes any plugin calling an external API slow and Starlark apps, which have a render timeout, fail outright. And a Pixlet config editor: a script you run and Ctrl+C rather than the third-party version's always-on unauthenticated Flask service, since it stops the display for the length of a session. Neither is installed by default. Long Starlark app names now wrap instead of overflowing their card. 115 new tests across 5 files. Also unblocked test_starlark_display_contract.py, which was silently skipping wherever fcntl is absent. Whole suite: no new failures against main. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

…Home Assistant MQTT bridge (#538) * feat(starlark,on-demand): the third-party fixes worth taking, plus an MQTT bridge Analysis of ant456/ledmatrix-fixes-repo, a third-party collection of patches and services built while running this project on Starlark apps under MQTT control. Its patches are whole-file copies taken against an older tree, so applying them as written would revert #523's frame pacing, #534's display() bool returns and the GitHub token masking in plugins_manager.js. Three of its claimed fixes are already in main, and its api_v3 Starlark routes are #535's. What follows is the rest -- verified against current code, and reimplemented where the patch's approach did not hold up. **On-demand display.** `pinned` reached the controller from the API, was stored on it and republished in the status payload, but never narrowed the rotation -- a pinned request still cycled every mode its plugin owns. Right for a sports plugin, whose modes are views of one subject; wrong for a plugin whose modes are unrelated, which is every Starlark app. Now honoured, and it survives a restart. Restarting while on-demand was active loaded *only* the on-demand plugin, so normal rotation had nothing to return to for the life of the process -- and a restart mid-session is routine, since that is how an update is applied. The panel came back cycling one plugin's modes with no way out but clearing the cache by hand. Every enabled plugin loads now; on-demand still resumes on its saved mode. Stop requests are exempt from the duplicate guards on purpose, so that a second click stops a mode a race left running -- which means consuming the mailbox is the only thing that ends one. It was never consumed, so the same stop was re-read and re-processed on every poll, forever. Both paths now share one compare-before-delete helper. **Starlark rendering.** `extract_schema` parsed the source with a regex, which can only see option lists written out literally: an app whose dropdown is filled from a live API call inside `get_schema()` came back empty, and the config form offered nothing to pick. Now runs `pixlet schema`, which executes the app, and falls back to the parser when Pixlet is absent, too old for the subcommand, or the app fails to run. The third-party patch replaced the parser outright and hardcoded /usr/local/bin/pixlet; this keeps the fallback and the binary search. A `|` in a config value was dropped by a shell-metacharacter filter, though the command is a list with no shell involved -- and apps do use it as a separator inside one value. The key went missing silently and the app rendered its own "not configured" screen with nothing to say why. And a 0-byte render was reported as success: Pixlet exits 0 and writes nothing when an app has no content, which read downstream as a working app drawing a black panel. **Starlark display.** `display()` ignored the mode it was called with, so a specific app could not be addressed. It now accepts `display_mode` -- which is the whole mechanism, since the controller inspects the signature before passing it. Found while there: `_select_next_app` ran only while `current_app` was unset, so with several apps installed the first was picked once and shown forever while the rest were rendered on schedule and never displayed. And `enable_scrolling` was missing, so multi-frame apps were called once per rotation slot and never advanced past frame one. **GET /api/v3/display/modes.** Every mode that can be requested on-demand, with the plugin that owns it. Nothing exposed this, so anything driving the display from outside the web UI read each plugin's manifest.json off disk and reimplemented PluginManager's fallbacks. It also triggers discovery, which is otherwise lazy and normally happens because a person opened the dashboard. **integrations/mqtt_bridge.** Home Assistant control over MQTT Discovery: a mode select, a stop button, power, brightness. Rewritten against the API rather than the filesystem, so it needs no read access to config.json and cannot drift from the web UI. paho-mqtt 2.x VERSION2, TLS, an availability topic that is also the last will, and secrets from the environment. **Two opt-in extras.** A DNS single-request unit, for glibc's parallel A/AAAA lookup stalling ~5s per name on routers that answer only the A query -- which makes any plugin calling an external API slow and Starlark apps, which have a render timeout, fail outright. And a Pixlet config editor: a script you run and Ctrl+C rather than the third-party version's always-on unauthenticated Flask service, since it stops the display for the length of a session. Neither is installed by default. Long Starlark app names now wrap instead of overflowing their card. 115 new tests across 5 files. Also unblocked test_starlark_display_contract.py, which was silently skipping wherever fcntl is absent. Whole suite: no new failures against main. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(mqtt_bridge): the five issues Codacy flagged on this branch All in the new bridge, all real: * requests floor was 2.31.0, which carries CVE-2024-35195, CVE-2024-47081 and CVE-2026-25645. Raised to >=2.33.0,<3.0.0, which is what the project's own requirements.txt already pins. * `import time` was never used. * `"mqtt_password": None` in DEFAULTS read as a hardcoded credential. It is the "no password configured" default; marked nosec B105, the convention used elsewhere in the repo. Also dropped an unused `build_app` from the display-modes test imports. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix: the review findings on this PR Nine of CodeRabbit's ten, plus the CodeQL alert. The tenth is wrong and is answered below. **One bad config section blanked the whole mode list.** `/display/modes` read `full_config.get(plugin_id, {}).get('enabled')`, so a non-dict under a plugin id -- a shape DisplayController already guards, so it happens -- raised AttributeError mid-loop and answered 500 with no modes at all. Every MQTT bridge entity is built from that list. Now skipped with a warning. **The DNS scripts reported success they had not earned.** Three separate paths: `resolvconf -u` failing was swallowed by `|| true`; the systemd-resolved branch exited 0 without applying anything, so the oneshot unit recorded success while the workaround was inactive; and the installer's `|| echo` turned a failed start into "installation complete." with exit 0. All three now fail loudly. `single-request` is a glibc resolv.conf option with no resolved.conf equivalent, so on those hosts the honest answer is that it cannot be applied. A NetworkManager-generated resolv.conf is regenerated on connection changes, not only at boot, and the unit is oneshot with RemainAfterExit -- so the option can vanish mid-boot with nothing to put it back. Now detected and stated plainly rather than implied to be permanent. **`Before=` does not order a manual restart.** It only orders units already in the same transaction, so `systemctl restart ledmatrix` could bypass the fix. install_dns_fix.sh now writes a ledmatrix.service drop-in with Wants= and After=. Wants=, not Requires=: a DNS workaround failing should not stop the display. **The Pixlet editor's `--lan` is gone.** `pixlet serve` has no authentication, and a printed warning is not access control. Loopback only, with the SSH port-forward in the header where the flag used to be documented -- SSH does the authenticating and nothing is left listening. **The MQTT example config now defaults to TLS** on 8883. The installer copies it verbatim, and without TLS the broker password and every command cross the network in cleartext. A plaintext broker is still supported and documented, and the bridge warns once at startup when a password is configured without TLS. **Not taken: "the upstream Pixlet CLI has no `schema` subcommand."** Upstream tidbyt/pixlet has none, but `scripts/download_pixlet.sh` installs `tronbyt/pixlet`, whose `cmd/schema.go` is `schema [PATH]` -> JSON on stdout, built on `runtime.NewAppletFromPath`, so it does execute `get_schema()`. That is exactly what extract_schema_via_pixlet calls. A binary without the subcommand exits non-zero and falls back to the source parser, which is already covered by a test. **CodeQL stack-trace exposure: not taken either.** I removed `details` first and that broke test_web_error_detail.py::test_no_api_v3_handler_discards_its_exception, which enforces `describe_exception` across all ~75 handlers -- written because a device with failing storage answered "see logs for details" from the log viewer itself. describe_exception redacts credentials; the trade-off is the project's and is already made. Restored, with the reasoning in a comment. 11 new tests. Whole suite: no new failures against main, 4127 passed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

ChuckBuildsand others added 3 commits September 3, 2026 17:45

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ChuckBuilds mentioned this pull request Sep 4, 2026
refactor(scroll): route every scrolling plugin through the shared resolver ChuckBuilds/ledmatrix-plugins#462
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ChuckBuilds merged commit d12323e into mainSep 7, 2026
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feat(starlark,on-demand): the third-party fixes worth taking, plus a Home Assistant MQTT bridge #538
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perf(scroll): pace frames to the panel — 44→100 fps, stalls 14% → 0.02% - #523

perf(scroll): pace frames to the panel — 44→100 fps, stalls 14% → 0.02%#523
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