content-hash-cache-pattern

Cache file processing results using SHA-256 content hashes as cache keys. This decouples cache identity from file paths, ensuring cached data automatically survives file moves or renames across processing runs.

You need content-hash based caching when processing recurring PDF, image, or text files. It automatically invalidates caches when file content changes, skipping expensive reprocessing for identical inputs across pipeline runs.

Set up a file-based cache by wrapping your processing function with a cache service layer. It stores results as {hash}.json files in a specified cache directory, enabling O(1) lookups and simple maintenance.

Yes, content-hash caching works with PDF, image, and text processing tasks. It is applicable to any file processing pipeline where inputs recur across runs and processing costs are expensive.

Using SHA-256 content hashing is the best way to invalidate caches when source documents change. The hash changes automatically when file content is modified, preventing stale cache lookups without manual path tracking.

Keeping core file processing logic separate from caching concerns maintains pure processing functions. A dedicated service layer wraps the processing function to handle caching, ensuring better testability and maintainability.