content-hash-cache-pattern

Cache file processing results by generating a SHA-256 content hash for cache keys instead of using file paths. This content-hash caching approach makes the cache path-independent, so moving or renaming files does not invalidate previously computed results.

Using a content-hash based cache key automatically invalidates the cache when file content changes. Because the SHA-256 hash is derived from the file's contents, any modification generates a new hash and bypasses the old cache entry.

Wrap your pure file processing function with a thin service layer that handles the caching logic. This frozen-cache service layer intercepts the call, checks the JSON-structured cache store using the content hash, and returns existing results before executing the processing function.

Content-hash caching works for repeated image analysis and text extraction across different workflows. By identifying files by their SHA-256 content hash rather than path, identical files processed in separate workflows share the same cache entry automatically.

Path-based caching misses when files are renamed because the file path changes. Switching to a content-hash based cache key fixes this by using the SHA-256 file content hash for cache identity, ensuring renames do not force a cache miss.

You need a content-hash based key derived from SHA-256, a JSON-structured cache store named by the hash, and a thin service layer wrapping your pure processing function to enable content-hash caching for expensive file processing pipelines.