content-hash-cache-pattern

You can cache file processing results using a SHA-256 content hash as the cache key, storing outputs as disk-based JSON. This provides path-independence and automatically invalidates the cache when file content changes.

Path-based cache keys break on file moves because they rely on file location. Using a SHA-256 content hash as the cache key instead ensures your cache survives file renames and directory changes while automatically invalidating on content modifications.

The best way to cache OCR and text extraction results across recurring batch runs is wrapping your processing pipeline in a service layer that uses SHA-256 content hashes as cache keys with disk-based JSON storage for persistent retrieval.

Yes, content-hash caching works with PDF parsing pipelines by applying a SHA-256 hash cache key wrapper to input files. This safely caches expensive parsing results and gracefully handles cache misses or storage corruption.

You keep file processing logic pure by using a service-layer wrapper that separates the cache as a distinct concern. This wrapper manages disk-based JSON storage and hash generation while leaving your core processing function untouched.

During a content-hash cache miss or file corruption, the service-layer wrapper provides safe, lazy storage with graceful handling. It falls back to re-running the expensive file processing operation and regenerating the cached result.