What are the different LRU cache eviction strategies?

What are the different LRU cache eviction strategies?

LRU, or Least Recently Used, is a cache eviction strategy that removes the least recently accessed items first. There are several strategies to implement LRU, including using a linked list, a hash map, or a combination of both.

Can you explain how a linked list works in LRU caching?

In an LRU cache using a linked list, each node represents a cache entry. The most recently accessed node is moved to the front, while the least recently accessed node is at the back. When the cache reaches its limit, the node at the back is removed.

What are the advantages of using a hash map with a linked list?

Using a hash map allows for O(1) time complexity for lookups, while the linked list maintains the order of access. This combination optimizes both access speed and eviction efficiency.

Are there any downsides to LRU caching?

Yes, LRU caching can consume more memory due to the overhead of maintaining the linked list and hash map. Additionally, it may not perform well if access patterns are highly irregular.