Module cache 

Content-keyed JSON sidecar for ChangeSetReport, mirroring the enrichment narrative cache’s shape: plain-hex key, per-repo directory under the shared cache root, best-effort read/write, corrupt = miss.

The key covers HEAD plus the exact worktree content of every change-set path, so any edit — or a commit — moves it. Thresholds and calibration are deliberately EXCLUDED: the sidecar stores only MEASURED data, and consumers recompute verdicts on every read, so an improved gate configuration reaches warm caches without invalidation.

Functions

cache_path

The on-disk sidecar path for key: repo_cache_dir(cache_root, repo_path)/change-set/<first 16 hex>.json.

read

Read the cached report at key, or None when absent or corrupt. A missing file is the ordinary miss and stays silent; a file that no longer deserializes is logged at warn and treated as a miss.

report_key

The content key for a change set: lowercase-hex SHA-256 of head_sha | sorted "path\0content-sha256" lines | crate version | calib=<digest> | rows_limit=<n> | opts=<canonical-json digest> | [KEY_SCHEMA]. A deleted path contributes the literal "deleted" in place of its content hash.

write

Write report to the sidecar for key, creating the directory if needed. Best-effort: a cache is an optimization, so any failure is logged at warn and swallowed — a gate run must never fail because its report could not be cached.