LLM::Cache

0700, and entries below are written 0600 (see store). A cache entry is the model's answer about a specific chunk of the user's source, and the prompt it answers is that source — private code, on a box that may have other accounts. The default 0755/0644 published it to every local user. $NOIR_HOME/config.yaml is already 0600 for the same reason.

All cache entries are stored as <sha256>.json flat in cache_dir. The bulk operations below (clear, purge_older_than, stats) filter on this suffix so a stray .lock or user-dropped file in the directory is left alone.

Infix store stamps onto its in-flight temp file (see store). Kept as a constant so the writer and the sweepers below can't drift apart: a stranded temp file whose name the sweepers don't recognize is a file nothing can ever delete.

The prompts themselves are part of every key. Bump this when a change outside them (adapter-side wrapping, how a reply is read) should stop older cached replies from being replayed.

Responses served from disk this run, for the end-of-run usage line.

Build a deterministic cache key from inputs

• provider: "openai", "ollama", url, etc.
• model: "gpt-4o", "llama3", etc.
• kind: logical operation e.g. "FILTER", "ANALYZE", "BUNDLE_ANALYZE"
• format: response_format string (e.g., "json" or JSON schema string)
• payload: variable content (file list, source code, bundle, etc.)

The sampling settings are folded in too, so a reply sampled at another temperature or seed is not replayed.

Returns a hex-encoded SHA256 digest.

Where the swallowed cache failures below are reported.

They used to go to Crystal's global Log at debug level, which was wrong twice over: that logger's default backend writes to STDOUT, the stream carrying the -f json / -f sarif report, and nothing in Noir ever lowers its Info threshold, so the messages could not surface at all. A diagnostic that is simultaneously invisible and aimed at the report stream is the worst of both.

NoirLogger (STDERR, gated on --debug) is where every other Noir diagnostic goes. Nil until a run installs one, so a library caller constructing no logger stays silent exactly as before.

Write atomically: a partially-written file from a crash mid-write would parse as broken JSON on the next fetch, forcing a spurious fresh API call. By writing to a tmp sibling and renaming we either leave the previous (valid) entry in place or atomically publish the new one.

True for a temp file stranded by a crash between File.write and File.rename. These do not end in .json, so the bulk operations used to skip them entirely — clear could not remove them and stats did not count their bytes, leaving files that grew the cache directory with no way to reclaim them from the CLI.