Struct uluru::LRUCache [−][src]
pub struct LRUCache<T, const N: usize> { /* fields omitted */ }
Expand description
A LRU cache using a statically-sized array for storage.
LRUCache
uses a fixed-capacity array for storage. It provides O(1)
insertion, and O(n)
lookup.
All items are stored inline within the LRUCache
, so it does not impose any heap allocation or
indirection. A linked list is used to record the cache order, so the items themselves do not
need to be moved when the order changes. (This is important for speed if the items are large.)
Example
use uluru::LRUCache; struct MyValue { id: u32, name: &'static str, } // A cache with a capacity of three. type MyCache = LRUCache<MyValue, 3>; // Create an empty cache, then insert some items. let mut cache = MyCache::default(); cache.insert(MyValue { id: 1, name: "Mercury" }); cache.insert(MyValue { id: 2, name: "Venus" }); cache.insert(MyValue { id: 3, name: "Earth" }); // Use the `find` method to retrieve an item from the cache. // This also "touches" the item, marking it most-recently-used. let item = cache.find(|x| x.id == 1); assert_eq!(item.unwrap().name, "Mercury"); // If the cache is full, inserting a new item evicts the least-recently-used item: cache.insert(MyValue { id: 4, name: "Mars" }); assert!(cache.find(|x| x.id == 2).is_none());
Implementations
Insert a given key in the cache.
This item becomes the front (most-recently-used) item in the cache. If the cache is full, the back (least-recently-used) item will be removed.
Returns the first item in the cache that matches the given predicate. Touches the result on a hit.
Performs a lookup on the cache with the given test routine. Touches the result on a hit.
Returns a mutable reference to the front entry in the list (most recently used).
Returns the n-th entry in the list (most recently used).
Touches the first item in the cache that matches the given predicate.
Returns true
on a hit, false
if no matches.