content-hash-cache-pattern

Cache expensive file processing results by generating SHA-256 content hashes for each file. These hashes serve as cache keys, storing results in {hash}.json files for fast, deterministic lookups without external indices.

File caches break on rename because path-based keys change. Content-hash caching uses SHA-256 to ensure path-independence, so cached results survive moves and renames automatically without invalidation.

Content hashing for caching works by hashing file contents with SHA-256. The resulting hash becomes the cache key, ensuring identical files reuse cached processing outputs across different runs without recomputation.

The best way to invalidate a file cache is content-hash caching. By computing SHA-256 hashes, the cache automatically invalidates when file content changes, generating a new hash and preventing stale results.

Yes, you can apply caching without modifying core logic. A service-layer wrapper decouples processing from caching, keeping the processing pure while the wrapper handles hash-based cache lookups and storage.

No, you do not need an external database. The cache uses file-based storage with {hash}.json files, providing fast and deterministic lookups for batch tasks directly on the local filesystem without external indices.