2026-07-17 01:54:14
— part of check-in
[ae242f5563]
on branch zerocache
— Serve warm reads from a materialized column image instead of re-deriving RepoState, cutting a warm leaves load 178.6us to 2.12us (84x). At cache write, dense integer-addressed columns for the mtime index, leaf image, and symbolic-name table are appended to the versioned .zit-cache; on a fast_read open the freed queries (mtimeOf/isLeaf/isOpenLeaf/leaves/branchOf/resolveName per repostate 7.1/7.4/7.5/8.2) answer from those columns with zero derivation. Load-time span validation range-checks every column, CSR span, and stored id and returns a miss (fall back to derive) on any violation or CRC/layout/log-tail mismatch, so a corrupt or stale image is never a wrong answer. RepoState's public API is unchanged; only leaves opts in, cold verbs keep the derive path. Technique: on-disk zero-parse caching after Richard Feldman's Roc and Andrew Kelley's Zig compiler (common in game engines per Casey Muratori); typed enum(u32) index families after the compact_arena crate.
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2026-07-17 01:57:16
— part of check-in
[13cfa27494]
on branch trunk
— Merge zerocache: materialized-image warm reads (84x faster leaves load) with load-time-validated fallback, closing the read-path perf gap. Phase B (full SoA image) not warranted — the image load is under 1% of the derivation it replaced.
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