Struct LruReplacer

pub struct LruReplacer<F: FrameId> { /* private fields */ }

Least Recently Used (LRU) frame replacer.

This implementation uses a priority queue to manage the frames. The priority queue is ordered by the last access time of the frames. The most recently accessed frame is pushed to the back of the queue, while the least recently accessed item is the first to be evicted.

Implementations

impl<F: FrameId> LruReplacer<F>

pub fn new(capacity: usize) -> Self

Creates a new LRU replacer.

Trait Implementations

impl<F: FrameId> EvictionPolicy<F> for LruReplacer<F>

type Error = EvictError<F>

Error type for the eviction policy.

fn evict(&self) -> Option<F>

Find the next frame to be evicted and evict it.

fn peek(&self) -> Option<F>

Peek into the next frame to be evicted.

fn touch(&self, id: F) -> EvictResult<(), F>

Notifies the policy manager that a page controlled by the frame has been referenced/accessed.

fn touch_with<T: AccessType>( &self, id: F, _access_type: T, ) -> EvictResult<(), F>

Notifies the policy manager that a page controlled by the frame has been referenced/accessed. In addition to mere occurrence of access, this method also logs the type of the access.

fn pin(&self, id: F) -> EvictResult<(), F>

Pin a frame, marking it as non-evictable.

fn unpin(&self, id: F) -> EvictResult<(), F>

Unpin a frame, marking it as evictable.

fn remove(&self, id: F) -> EvictResult<(), F>

Removes an evictable frame.

fn capacity(&self) -> usize

Returns the maximum number of frames that can be stored.

fn size(&self) -> usize

The number of elements that can be evicted. Essentially, this is the number of non-pinned frames.