Memory-efficient caching methods and systems

A caching system comprising:

• a main storage element configured to store data;
• a cache configured to store data objects and metadata for the data objects that includes at least one Bloom filter;
• and
• a processor configured to reference the at least one Bloom filter registering keys denoting the data objects in the cache to identify which of the data objects in the cache to evict in response to determining that a cache eviction condition is satisfied.

A caching system comprising:

• a main storage element configured to store data;
• a cache including at least one first element configured to store metadata for data objects that includes a bit array and at least one second element configured to store the data objects, wherein the at least one second element includes keys denoting the data objects in the cache and includes bit offset information for each of the keys denoting different slots in the bit array;
• and
• a processor configured to identify, in response to determining that a cache eviction condition is satisfied, a particular data object in the cache to evict by deter Wining whether the slot in the bit array corresponding to the particular data object indicates that the particular data object was recently used.