Struct LruCache 

pub struct LruCache<K, V, S = DefaultHashBuilder> { /* private fields */ }

An implementation of a Least Recently Used (LRU) cache.

The cache has a fixed capacity and supports O(1) operations for inserting, retrieving, and updating entries. When the cache reaches capacity, the least recently used entry will be evicted to make room for new entries.

Examples

use cache_rs::LruCache;
use core::num::NonZeroUsize;

let mut cache = LruCache::new(NonZeroUsize::new(2).unwrap());

// Add items to the cache
cache.put("apple", 1);
cache.put("banana", 2);

// Accessing items updates their recency
assert_eq!(cache.get(&"apple"), Some(&1));

// Adding beyond capacity evicts the least recently used item
cache.put("cherry", 3);
assert_eq!(cache.get(&"banana"), None);
assert_eq!(cache.get(&"apple"), Some(&1));
assert_eq!(cache.get(&"cherry"), Some(&3));

Implementations

impl<K: Hash + Eq, V: Clone, S: BuildHasher> LruCache<K, V, S>

pub fn with_hasher(cap: NonZeroUsize, hash_builder: S) -> Self

Creates a new LRU cache with the specified capacity and hash builder.

pub fn with_hasher_and_size( cap: NonZeroUsize, hash_builder: S, max_size_bytes: u64, ) -> Self

Creates a new LRU cache with specified capacity, hash builder, and size limit.

pub fn cap(&self) -> NonZeroUsize

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn get<Q>(&mut self, key: &Q) -> Option<&V>

where K: Borrow<Q>, Q: ?Sized + Hash + Eq,

pub fn record_miss(&mut self, object_size: u64)

pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>

where K: Borrow<Q>, Q: ?Sized + Hash + Eq,

impl<K: Hash + Eq + Clone, V: Clone, S: BuildHasher> LruCache<K, V, S>

pub fn put(&mut self, key: K, value: V) -> Option<(K, V)>

pub fn remove<Q>(&mut self, key: &Q) -> Option<V>

where K: Borrow<Q>, Q: ?Sized + Hash + Eq,

pub fn clear(&mut self)

pub fn iter(&self) -> Iter<'_, K, V>

pub fn iter_mut(&mut self) -> IterMut<'_, K, V>

impl<K: Hash + Eq, V> LruCache<K, V>

where V: Clone,

pub fn new(cap: NonZeroUsize) -> LruCache<K, V, DefaultHashBuilder>

Trait Implementations

impl<K: Hash + Eq, V: Clone, S: BuildHasher> CacheMetrics for LruCache<K, V, S>

fn metrics(&self) -> BTreeMap<String, f64>

Returns all metrics as key-value pairs in deterministic order

fn algorithm_name(&self) -> &'static str

Algorithm name for identification

impl<K: Debug, V: Debug, S: Debug> Debug for LruCache<K, V, S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.