fix(docs): correct chart asset paths; reuse ResizeObserver and destroy old uPlot

Per Gemini review on PR #24.

1. `docs/benchmarks.md` and `docs/assets/bench-charts.js`: `./assets/`
   resolves to `/<version>/benchmarks/assets/` under mkdocs
   `use_directory_urls` (default true), which 404s — assets actually
   live at `/<version>/assets/`. Switch to `../assets/` so the chart
   page reaches them via one level up.

2. `.github/workflows/docs.yml` mike-asset verifier: same path bug —
   was probing `/dev/benchmarks/assets/bench-results/latest.json` which
   would have returned 404 once the snapshot landed (the verify step
   only runs on devel push, so the bug wouldn't surface until then).
   Aligned with the page's `../assets/` path.

3. `bench-charts.js` ResizeObserver leak on log-scale toggle:
   `attachResizeObserver` was called from inside `rebuild()` which
   fires on every toggle. Each click left a stranded observer + a
   stale `plot` reference its setSize closure was still firing on.
   Refactored to a single observer attached after the first build,
   which resolves `plot` lazily through a getter — toggle just swaps
   the underlying instance.

4. `bench-charts.js` orphaned uPlot DOM/listeners: `rebuild()` mounted
   a new uPlot without destroying the previous one. Added
   `if (plot) plot.destroy()` at the top of `rebuild()`. Combined with
   the observer fix above, the toggle is now state-clean across
   arbitrarily many flips.

Syntax-checked bench-charts.js with `node --check`.

Author: elijahr

.github/workflows/docs.yml

@@ -73,7 +73,7 @@ jobs:
           github.ref == 'refs/heads/devel'
         run: |
           set -euo pipefail
-          URL="https://elijahr.github.io/lockfreequeues/dev/benchmarks/assets/bench-results/latest.json"
+          URL="https://elijahr.github.io/lockfreequeues/dev/assets/bench-results/latest.json"
           sleep 30
           HTTP_CODE=$(curl -sS -o /tmp/latest.json -w "%{http_code}" "$URL")
           if [ "$HTTP_CODE" != "200" ]; then

docs/assets/bench-charts.js

@@ -1,8 +1,10 @@
 /* lockfreequeues bench charts — uPlot wiring for docs/benchmarks.md.
  *
  * Loads the merged Bencher Metric Format (BMF) snapshot from
- * `./assets/bench-results/latest.json` (relative path so the same page
- * works under /dev/, /latest/, and /v*\/ mike aliases without rewrite),
+ * `../assets/bench-results/latest.json` — page lives at
+ * `/<version>/benchmarks/` under mike + mkdocs `use_directory_urls`,
+ * so we go up one level to reach `/<version>/assets/`. The same
+ * relative path works under /dev/, /latest/, and /v*\/ aliases,
  * groups slugs by library, and renders a single uPlot line chart of
  * throughput_ops_ms across (P,C) shapes. The X axis is the producer/
  * consumer-count index; the Y axis is throughput in ops/ms with an
@@ -27,7 +29,7 @@
 (function () {
   'use strict';
 
-  const SNAPSHOT_URL = './assets/bench-results/latest.json';
+  const SNAPSHOT_URL = '../assets/bench-results/latest.json';
   const CHART_MEASURE = 'throughput_ops_ms';
 
   // Stable colour palette (uPlot has no default cycle for many series).
@@ -269,10 +271,17 @@
     };
   }
 
-  function attachResizeObserver(host, plot) {
+  /* Single persistent ResizeObserver — `getPlot` is a closure that
+   * always returns the *current* uPlot instance, so the toggle's
+   * rebuild() can destroy + replace `plot` without re-attaching the
+   * observer. Re-attaching on every rebuild leaks an observer +
+   * orphaned setSize callbacks per toggle.
+   */
+  function attachResizeObserver(host, getPlot) {
     if (typeof ResizeObserver === 'undefined') return;
     const ro = new ResizeObserver(() => {
-      plot.setSize({ width: host.clientWidth, height: 420 });
+      const plot = getPlot();
+      if (plot) plot.setSize({ width: host.clientWidth, height: 420 });
     });
     ro.observe(host);
   }
@@ -331,13 +340,17 @@
     const data = toUplotData(xLabels, libraries);
 
     const rebuild = () => {
+      // Drop the previous uPlot instance before mounting the next.
+      // Without destroy() the toggle accumulates uPlot DOM/listeners
+      // per click; the observer attaches once below and re-resolves
+      // `plot` via the closure on each setSize.
+      if (plot) plot.destroy();
       plotMount.innerHTML = '';
       plot = new window.uPlot(
         makeOpts(plotMount, libraries, xLabels, logScale),
         data,
         plotMount
       );
-      attachResizeObserver(plotMount, plot);
     };
 
     const controls = buildControls(logScale, (next) => {
@@ -356,6 +369,12 @@
     host.appendChild(plotMount);
     host.appendChild(legend);
     rebuild();
+
+    // Attach the ResizeObserver once, after plotMount is mounted and
+    // sized. The closure resolves `plot` on each callback so a later
+    // rebuild() (log-scale toggle) just hands the observer a new
+    // instance — no observer churn.
+    attachResizeObserver(plotMount, () => plot);
   }
 
   if (document.readyState === 'loading') {

docs/benchmarks.md

@@ -63,12 +63,12 @@ underlying measure carries one.
   <div id="bench-chart">
     <noscript>
       Charts require JavaScript. The raw data is published at
-      <code>./assets/bench-results/latest.json</code>; download the JSON
+      <code>../assets/bench-results/latest.json</code>; download the JSON
       snapshot if you need to consume it programmatically.
     </noscript>
   </div>
-  <script src="./assets/uplot-1.6.27.iife.min.js"></script>
-  <script src="./assets/bench-charts.js"></script>
+  <script src="../assets/uplot-1.6.27.iife.min.js"></script>
+  <script src="../assets/bench-charts.js"></script>
 </div>
 
 ### Methodology and fairness caveats