Struct dynamic_lru_cache::DynamicCache

pub struct DynamicCache<K, V, S = RandomState> { /* fields omitted */ }

A cache that will only hold onto items that have been reqeuested more than once in recent memory. Single-use items are not held at all. Once an item is requested twice, it is cached until all memory of seeing it requested has expired. The length of the memory is adjustable, and must be set at initialization.

This version of the cache can be shared across threads without issue, as it is an instance of DynamicCacheLocal held by an Arc<Mutex<T>>.

Implementations

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

pub fn with_hasher(mem_len: usize, hash_builder: S) -> DynamicCache<K, V, S>

Create and initialize a new cache, using the given hash builder to hash keys. The same warnings given for HashMap::with_hasher apply here.

impl<K: Clone + Eq + Hash, V> DynamicCache<K, V>

pub fn new(mem_len: usize) -> Self

Create an initialize a new cache.

pub fn get_or_insert<F: FnOnce() -> V>(&self, key: &K, f: F) -> Arc<V>

Fetch an item via the cache, potentially filling in the cache on a miss via the function f. The cache is unlocked while calling the function, so f may be called more than once with the same parameters if there are several threads using the cache.

pub fn size(&self) -> usize

Get the number of items currently stored in the cache.

pub fn mem_len(&self) -> usize

Get the length of the cache’s recent request memory.

pub fn set_mem_len(&self, new_len: usize)

Change the length of the cache’s recent request memory. Some contents of the cache may be removed immediately if the new memory length is shorter than the old memory length.

pub fn clear_cache(&self)

Clear out all stored values and all memory in the cache.

pub fn hits_misses(&self) -> (u64, u64)

Get the cache metrics as a pair (hits, misses).

pub fn reset_metrics(&self)

Reset the cache hit/miss metrics.

Trait Implementations

impl<K: Clone, V: Clone, S: Clone> Clone for DynamicCache<K, V, S>

fn clone(&self) -> DynamicCache<K, V, S>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

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

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

Formats the value using the given formatter.