Documentation at https://melpa.org/#/pcache

pcache provides a persistent way of caching data, in a hashtable-like structure. It relies on `eieio-persistent in the backend, so that any object that can be serialized by EIEIO can be stored with pcache. pcache handles objects called "repositories" (`pcache-repository') and "entries" (`pcache-entry'). Each repository is identified by a unique name, that defines an entry in `pcache-directory'. Subdirectories are allowed, by the use of a directory separator in the repository name. Example: (let ((repo (pcache-repository "plop"))) (pcache-put repo foo 42) ; store value 42 with key foo (pcache-get repo foo) ; => 42 ) Keys can be pretty much any Lisp object, and are compared for equality using `eql Optionally, cache entries can expire: (let ((repo (pcache-repository "plop"))) (pcache-put repo foo 42 1) ; store value 42 with key foo for 1 second (sleep-for 1) (pcache-get repo foo) ; => nil )