What problem does it solve? Repeatedly processing the same files (PDF parsing, OCR, text extraction) wastes compute time, and path-based caches break whenever files are moved or renamed. This Skill provides a Python pattern that keys cache entries on file content, so renames still hit the cache and content edits automatically invalidate stale entries. ## Core Features & Use Cases - Content-Hash Cache Keys: Computes chunked SHA-256 hashes of file contents so cache identity survives moves and renames while auto-invalidating on edits. - File-Based Storage: Stores each result as {hash}.json for O(1) lookup with no index file, and treats corrupted entries as cache misses instead of crashing. - Service Layer Separation: Wraps pure extraction functions in a caching layer, keeping single-responsibility design and enabling a --cache/--no-cache CLI option. - Use Case: A batch pipeline that extracts text from hundreds of PDFs across nightly runs can skip re-processing unchanged files even after the folder structure is reorganized. ## Quick Start Add content-hash based caching to my PDF text extraction function so repeated runs skip unchanged files and support a --no-cache flag.