Get the value for a given (datasetId, partition), or null if it is not found.
Get the value for a given (datasetId, partition), or null if it is not found.
Report the capacity of the cache partition.
Report the capacity of the cache partition. By default this just reports zero. Specific implementations can choose to provide the capacity number.
Attempt to put a value in the cache; returns CachePutFailure if this was not successful (e.
Attempt to put a value in the cache; returns CachePutFailure if this was not successful (e.g. because the cache replacement policy forbids it), and CachePutSuccess if successful. If size estimation is available, the cache implementation should set the size field in CachePutSuccess.
Spill the given entry to disk.
Spill the given entry to disk. Assumes that a lock is held on the DiskSpillingCache. Assumes that entry.value is a byte array.