Mahdi ramezaan zaadeandAlexander Medvednikov
459a8daa32
* cache: add LRU and TTL caches (fixes #30317) * cache: use monotonic TTL expiry and document cache APIs * cache: convert generic TTL durations without alias method lookup --------- Co-authored-by: Alexander Medvednikov <alexander@medvednikov.com>
cache
new_lru[K, V](capacity) creates a least-recently-used cache with a positive capacity.
put inserts or replaces a value; get returns an option and promotes a hit.
get_or_compute calls its factory only on a miss. contains does not change recency.
delete reports whether a key was present, and len counts stored entries.
Recency maintenance is linear in the number of cached entries.
new_ttl[K, V](ttl) creates a cache whose entries expire after the given duration.
set restarts an entry's TTL; get removes an expired entry and returns none.
purge_expired removes all expired entries and returns their count.
len includes expired entries until they are accessed or purged.
Expiry has millisecond resolution; a TTL below one millisecond expires immediately.
The default clock is monotonic. new_ttl_with_clock[K, V](ttl, now) accepts a callback
returning millisecond timestamps; custom clocks should be monotonic too.
Both caches are single-threaded. Synchronize access before sharing a cache between threads. Keys must be supported V map keys.