Seven behaviour-preserving allocation / copy / bandwidth cuts, each behind a
counting-allocator BEFORE/AFTER gate that exit(1)s unless AFTER allocates
strictly fewer than BEFORE (benches/ROUND29.md, examples/bench_round29_micro.rs).
- [B] Content-cache serve fast path (optimized_inner Tier 1 +
get_file_range_preloaded — the video-scrub hot path): probe the cache with a
borrow first and build the owned get_or_load args (quoted-etag / key / id
Strings) only on a miss, instead of allocating them before every probe and
discarding them on a hit. 6 -> 0 allocs per cache hit. Splits get_or_load into
get + load_and_cache so the miss path is not re-probed and the hit/miss stat
counters stay byte-identical. Also drops the unconditional content_hash/name
clones that ran for the >=10 MB streaming tier that used neither.
- [A] NextCloud REPORT emit loops: per-row href String (and format! per folder
row) -> one reused href_buf via nc_href_into / nc_collection_href_into with the
URL-encoded user computed once per page. 1497 fewer allocs on a 500-row page.
- [C] read_full: a single-frame blob is returned zero-copy instead of a second
whole-payload memcpy into a fresh BytesMut; multi-frame path unchanged.
- [D] login-lockout key: to_lowercase()+format! -> one pre-sized ASCII buffer
(non-ASCII keeps str::to_lowercase). 3 -> 1 alloc/req, byte-identical key.
- [E] NC composite-username parse: owned clone/to_string -> &str borrow of the
already-owned raw_username. 1 -> 0 alloc on the common no-marker path.
- [F] get_contacts_in_group: stop SELECTing the discarded multi-KB vcard column
(the live method ROUND25 §Q2 missed; ContactDto has no vcard field).
- [G] count_admin_users: add count_users_by_role -> scalar COUNT(*) instead of
hydrating every admin's full row (incl. up-to-512 KiB avatar + ui_preferences
JSONB) only to .len() it, on a bootstrap-polled status endpoint.
All seven gates pass; cargo fmt --check and cargo clippy --all-features
--all-targets -D warnings clean. §F/§G additionally validated against a live
PostgreSQL 16 with the full migration set (query validity, result equivalence,
600000 -> 8 byte wire delta on the admin count).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhpDZxSQTAGnAqCHUdtG5N
Claude