PINCache is a fork of TMCache re-architected to fix issues with deadlocking caused by heavy use. It is a key/value store designed for persisting temporary objects that are expensive to reproduce, such as downloaded data or the results of slow processing. It is comprised of two self-similar stores, one in memory (PINMemoryCache) and one on disk (PINDiskCache), all backed by GCD and safe to access from multiple threads simultaneously. On iOS, PINMemoryCache will clear itself when the app receives a memory warning or goes into the background. Objects stored in PINDiskCache remain until you trim the cache yourself, either manually or by setting a byte or age limit. Both PINMemoryCache and PINDiskCache use locks to protect reads and writes. PINCache coordinates them so that objects added to memory are available immediately to other threads while being written to disk safely in the background. Both caches are public properties of PINCache, so it's easy to manipulate one or the other separately if necessary.