1. A storage system comprising: a storage medium; a cache device; and a controller communicatively coupled with the storage medium and with the cache device and configured to interface with a processor or a memory of a computer system, the controller being further configured to: receive a specified quantity of address references associated with the storage system; determine a spatial distribution of references to addresses of the storage system based at least in part on the received specified quantity of the address references, and combine the determined spatial distribution with a previously determined spatial distribution into a spatial locality metric of the storage system, wherein the spatial locality metric includes a weighted sum of the determined spatial distribution and the previously determined spatial distribution; and output the spatial locality metric to use in caching data from the storage medium to the cache device.