nordisk/skade

catalog table_key — zero-copy (one alloc, byte-identical)

keys::table_key(catalog, ident) builds the redb lookup key "{catalog}\x1f{ns_joined_by_dot}\x1f{table}". It runs on every catalog op and once per commit — a hot path the warehouse-write bench (skade.funnel_append-style) flagged.

The change

ns_path also dropped its .clone().inner() (now ns.join(".")) — benefits every key builder.

Extended to the whole builder family (follow-up wave)

The same 2-alloc→1 pattern now covers every namespace/prefix builder in keys.rs, factored through two zero-alloc helpers — ns_path_len (exact byte-capacity, no allocation) and push_ns_path (append parts by reference):

Byte-identity pinned by ns_keys_are_byte_identical_to_legacy_format (single/multi-part + non-ASCII parts, length via bytes). Micro-bench bench_catalog_key now times all three shapes; light run on this box (dwarf, release, N=200k): namespace_key ~337→32 ns/op, table_key ~313→34, table_prefix ~252→33 (~8–10×). These are structural (fewer allocs), so kept regardless of micro-noise; heavy corpus sweep → the quiet bench box (Loki/Odin), never here.

Proof

• Byte-identical (mandatory — it's a lookup key): keys::tests::table_key_is_byte_identical_to_legacy_format pins the new builder against the exact old format! across single/multi-part namespaces + non-ASCII leaves. Always-on.
• Faster: in-crate #[ignore] micro-bench bench_catalog_key (run -- --ignored --nocapture): legacy 513 ns/op → zero-copy 226 ns/op (~2.3×) on this box (light, N=200k). Heavy corpus runs → the quiet bench box (Loki/Odin), never here.

Harness bencher (skade_catalog_key_build) — the bench-feature hook (DONE)

table_key & family are pub(crate) — the catalog's internal on-disk encoding, deliberately off the public API. The nornir-Bencher harness (its own skade-katalog-bench crate) still needs to time them so the warehouse no-regression gate has a real throughput number. That reach is now provided by a bench-feature pub hook: skade_katalog::bench_keys::* re-exports the builders as thin #[inline] pass-throughs only under --features bench. A normal build (and cargo publish, which never enables it) neither widens the API nor pays a byte — it only re-gates visibility of already-compiled fns, pulling no extra deps.

• Hook: src/lib.rs #[cfg(feature = "bench")] pub mod bench_keys.
• Feature: root Cargo.toml bench = []; the bench crate depends on skade-katalog = { path = "..", features = ["bench"] }.
• Bencher: bench/examples/nornir-bench.rs struct CatalogKeyBuild (id = "skade_catalog_key_build"), batched timing (a ~30 ns op — per-iter Instant::now() would swamp it, so it times the whole loop and divides, black_box-pinning the builder + a live sink). Emits ops_sec (keyed off table_key, one per commit) plus per-builder *_ns_per_op. LIGHT, pure-in-proc (no containers/S3); the heavy N sweep goes to Loki/Odin via BENCH_CATALOG_KEY_ITERS.
• The always-on #[ignore]d in-crate bench_catalog_key micro-test stays as the zero-dependency local sanity check; the harness bencher is the CI/gate number.