v3.3.101's gate removed the get-history parse on tab switch, but the log still
showed tab clicks at ~216ms with a ~197ms renderer long-task and NO get-history
(proc=0ms → pure browser layout, not JS). Cause: `.view{display:none}` ->
`.active{display:flex}` and the History table built up to 2000 non-virtualized
<tr>, so making the view visible laid out 2000 rows (~197ms on the RDP VM). The
queue was already virtualized; the History table was the only large non-virtual
one.
Measured the options with Playwright on the real DOM (this machine; the user's VM
is ~1.7x slower):
- current 2000 rows (auto layout): 118ms
- content-visibility + table-layout:fixed: 117ms (no help — rows still laid out)
- cap to 300 rows: 16ms, but rejected: History rows are per-file-per-hoster, so a
single 1280-file batch is ~3840 rows and a small cap would hide a recent batch's
links
- virtualize (40 visible of 2000): 2.3ms
Fix — virtualize renderHistoryTable, mirroring the queue's _renderVirtualRows:
- The header is always rendered; tbody#historyBody gets only the visible rows plus
top/bottom spacer <tr> sized from VIRTUAL_ROW_HEIGHT. A rAF-coalesced scroll
handler and a ResizeObserver on #historyContainer re-render the visible window;
the ResizeObserver also serves as the show-trigger (a hidden 0x0 container that
gains size on tab activation re-renders at the correct height). Sorting resets
scrollTop and re-renders; the copy-link / sort-header click delegation is
unchanged. _historyWorking holds the sorted working set.
- styles.css: .history-table gets table-layout:fixed plus scoped column widths so
columns do not jump as rows scroll in and out. This is scoped to .history-table
and does not touch the .col-* classes the queue shares.
Verified end-to-end with Playwright at 6000 rows: show cost 1.1ms (was 118ms), DOM
stays 32-42 rows, scroll maps to the right rows (top/middle/bottom), scrollbar
height exact, column widths stable, rows update on scroll. All rows remain
scrollable (no UX loss); the show cost drops ~100x.
407 tests pass; clean Electron boot.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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