US Patent 10055351 Low-overhead index for a flash cache

Systems and methods for a low-overhead index for a cache. The index is used to access content or segments in the cache by storing at least an identifier and a location. The index is accessed using the identifier. The identifier may be shortened or be a short identifier. Because a collision may occur, the index may also include one or more meta-data values associated with the data segment. Collisions can be resolved by also comparing the metadata of the segment with the metadata stored in the index. If both the short identifier and metadata match those of the segment, the segment is likely in the cache and can be accessed. Segments can also be inserted into the cache.