Cachedirectories

Cachedirectories are directory structures used to store cached copies of data to speed up future access. They are employed by operating systems, applications, and networks to reduce latency and bandwidth usage by serving recent or frequently requested resources from local storage.

A typical cachedirectories layout places a top-level cache directory with many subdirectories created from resource identifiers, often via hashing. This distributes files to avoid performance problems when a single folder contains thousands of entries.

On request, the system checks the cache. A hit serves the cached file; a miss fetches from the origin and stores a copy for future use.

Invalidation and eviction are governed by policies such as time-to-live, size limits, and expiration checks, using algorithms like least-recently-used or least-frequently-used. Some implementations also use content-addressing to ensure data integrity, naming cached files by a hash of their contents.

Management includes monitoring disk usage and cleaning stale entries; security concerns include access control and preventing leakage of sensitive data stored in the cache.

Common examples include web proxies, content delivery caches, build tool caches, package managers, and container image layers. Cachedirectories play a supporting role in performance optimization by balancing quick access with controlled freshness and storage constraints.