Targets the content-addressable dedup write path (the ROUND15-deferred
"dedup_service hash-String re-allocations") from both ends — the streaming
ingest loop and the delta-commit verification read — plus a CardDAV vCard
micro-cut. Every change is benchmark-gated with a hard rollback rule; no
PostgreSQL needed for any arm (benches/ROUND17.md).
Backend (counting-allocator, examples/bench_round17_micro.rs):
- D2 chunk-ingest (store_from_stream, the hottest write path — every chunk of
every upload): the 64-char hex hash String was allocated 3x per chunk
(to_hex + chunk_hashes clone + session_seen insert-clone, the last dropped on
a duplicate). The intra-upload dedup set now keys on the raw 32-byte BLAKE3
digest ([u8;32], Copy, no heap) and the manifest push is branch-split so a
duplicate moves the hex in: 3 -> 2 allocs/new chunk, 3 -> 1/duplicate.
Measured 214 -> 149 allocs/op (1.14x wall) on a 64-chunk 1-in-2-dup batch;
smaller/faster set too (32B inline keys vs 64B heap Strings).
- D1 hash_chunk_sequence (delta-commit verification): took chunks by
&[(String,u64)] and fed the backend stream with iter().cloned(), re-cloning
every chunk hash a second time on top of the owned Vec the caller already
built. Take the Vec by value + into_iter(): 65 -> 0 internal allocs/op, ~2.5us
of clone work removed per verify.
- V1 vCard TYPE tokens (contact_to_vcard + generate_vcard, 5 sites): each
EMAIL/TEL/ADR TYPE= param used ty.to_uppercase() — a throw-away String per
token per contact. New shared fmt::push_upper writes the upper-cased chars
straight into the buffer (byte-identical to str::to_uppercase, unit-tested):
13 -> 5 allocs/op, 1.19x wall.
Gates: each section asserts byte/-value equivalence (D2 the ordered manifest +
sizes + write-set; D1 the removed clone is a pure copy; V1 the full vCard) and
exits non-zero if an AFTER arm fails to reduce allocations. push_upper is
unit-tested byte-equal to str::to_uppercase (fmt::tests). Verified end-to-end:
cargo fmt clean, clippy --release --all-targets --features bench -D warnings
clean, and the harness prints GATE PASS against the built release lib.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XMmt7vNETYUbEG3Hc17LDx
Claude
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