Benchmark-gated (equivalence + BEFORE/AFTER; results + reproduce commands in
benches/ROUND7.md):
- Photos timeline re-grouped + re-laid-out the whole accumulated library on
every 60-item page (both `groups` and `photoRows` were $derived over the
full list), Σ ≈ O(N²/60) main-thread work during a scroll. Pages arrive
newest-first so grouping is append-only: the new PhotoTimeline
(lib/utils/photoTimeline.ts) re-buckets only the fresh page and re-lays-out
only changed groups, reusing untouched groups' cached rows, falling back to
a full rebuild on any config/deletion/non-append change. The pure
buildPhotoRows is the verbatim reference the gate holds it equal to at every
page. 50×60 drain: 76 500 → 3 000 grouping ops (25.5x), 23.0 → 2.2 ms
(10.6x).
- Range downloads paid authz + access-notify twice: download_file_impl
resolves the file via get_file_with_perms, then the Range branch re-ran
require_file + notify_file_accessed per request. Media/PDF viewers fetch
exclusively via Range (one request per seek), so every seek in a scrub
re-authorized an already-cleared file. Now routed through the non-perms
get_file_range_preloaded (matching the share-landing + WebDAV range paths);
the unused _with_perms range method is removed. The request-level gate still
denies before the branch runs (bench asserts member granted, outsider
denied). Per seek removed: WARM 0.67 µs, COLD 1362.66 µs — a grant-cascade
drive-resolve query per seek for a shared-drive recipient on a cold cache.
- /api/folders/{id}/resources row→DTO mapping cloned row.name into the DTO
though the row is owned; folders move it (fixed icons), files compute the
name-derived icon/category classes first then move it. 500-row page:
10.004 → 9.004 allocs/row (500 clones removed), output identical.
Deferred with rationale in ROUND7.md: thumbnail ACL-before-304 (security
posture — needs a security review, not a perf tweak), batch_operations
Arc<str>→String widening, list-view O(N²) on smaller lists, and the serial→
join! pairs (decide-by-bench with injected latency, per the round-6 rejection).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017aJu9ghvuT8WqC31ZEGTBA
Claude
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