LRU behavior and structure

Pick all that apply

• 1Choice 1.

  The hit rate is high when data used recently is likely to be used again soon (temporal locality)

• 2Choice 2.

  For an access pattern that scans a data set larger than the cache once each, the hit rate is close to zero

• 3Choice 3.

  A hash map alone finds the least recently used item in O(1), so a linked list is unnecessary

• 4Choice 4.

  A doubly linked list alone makes key lookup O(n), so you combine a hash map to make both lookup and reordering O(1)

• 5Choice 5.

  NSCache guarantees an LRU policy in its documentation, so there's no reason to write your own