content-hash-cache-pattern

Content hashes cache file processing by generating SHA-256 keys for each file, preventing reprocessing of identical data. This file-based cache storage system keys results by the hash value to automatically skip duplicate inputs.

File caches keyed by file paths break on rename, but content hashing uses the SHA-256 hash of the file data itself. This ensures the cache remains valid and identifies the file correctly regardless of moves or renames.

The best approach is to separate processing logic from caching using a dedicated service layer. This keeps file processing functions pure while the service layer manages SHA-256 hash generation and file-based cache lookups.

You need content-hash based caching for PDF, image, or text pipelines when the same input files are processed repeatedly. It automatically invalidates the cache when file content changes, saving compute costs on expensive processing tasks.

Yes, content hash caching supports auto-invalidation because the cache key is derived from the SHA-256 hash of the file. If the file content changes, the hash changes, automatically creating a new cache entry instead of serving stale data.

Yes, you can use file-based cache storage keyed directly by the content hash without maintaining a separate index. The hash itself serves as the unique identifier, allowing the system to retrieve cached processing results directly.