return from Claude:
The bench measures nothing reliable at this scale. afterMs=13.21 vs beforeMs=12.56 is ~650ns
per lookup for both paths; at that granularity a single GC pause or scheduler hiccup easily
swamps the actual gain, and the "after" path happens to run first (cold caches), so it gets
penalised on unlucky runs. Your local station happens to warm up before the noise lands; CI
shared-runners often don't.
Fix: run each path a few times and take the minimum (min is noise-proof — noise only slows
things down, never speeds them up):
Four SPA hot-path fixes, each shipping with a vitest benchmark gate
(verbatim BEFORE replica + equivalence + perf assertion) so CI
re-verifies the win on every run:
- fetchFolderListing invoked onPage after EVERY 200-row page with the
whole accumulated listing, and the files view re-sorts everything per
emission — O(N²/page) main-thread work on large folders. Page one and
the final page always emit; intermediates coalesce to one per 150 ms.
25×200 load: 30.9 → 4.0 ms (7.8x), 65 000 → 5 200 sorted elements.
- selected/favoriteIds/sharedIds (files) and favoriteIds (recent) were
$state<Set>s copied whole on every toggle. Now one SvelteSet each,
mutated in place (the useSelection pattern): 1 000 toggles @ N=5 000
771.9 → 1.9 ms (399x); one-toggle fan-out across 40 mounted rows
40 → 3 re-runs when refining a select-all.
- batchDelete/moveInto awaited one request per item serially and
probed listing.folders.find per id (O(N·M)). Now an id index built
once + mapLimit(6) fan-out, failure semantics preserved: 100-item
delete @ 5 ms RTT 525 → 89 ms (5.9x), 38 825 → 500 probes.
- t() re-split its dotted key and walked the nested dict on every call,
and interpolate regex-scanned strings without placeholders. Resolved
values now memoize per (dict, key) in a WeakMap + a {{ guard:
20k mixed calls 22.7 → 8.6 ms (2.63x).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017aJu9ghvuT8WqC31ZEGTBA
Edouard Vanbelle