Module proof_cache 

Proof Caching Layer

Caches proof results keyed by (goal_hash, kb_version) to avoid redundant inference. Supports LFU-style eviction (lowest access_count first) and TTL-based expiry.

Design

• Linear scan over a Vec<CachedProof> (suitable for small caches ≤ 256).
• LFU eviction: when at capacity, the entry with the lowest access_count is removed to make room for a new entry.
• TTL: entries are considered stale if now_secs - cached_at_secs >= ttl_secs.
• Optional invalidation on KB version change via invalidate_on_kb_change.

Structs

CachedProof

A single cached proof result together with its bookkeeping metadata.

ProofCacheConfig

Configuration for ProofCachingLayer.

ProofCacheKey

Composite key for a cached proof: goal identity × KB version.

ProofCacheStats

Cumulative statistics for a ProofCachingLayer.

ProofCachingLayer

An LFU-evicting, TTL-expiring cache for proof results.

Functions

fnv1a_hash

Compute the FNV-1a hash of a string.