Struct quick_cache::sync::Cache

pub struct Cache<Key, Val, We = UnitWeighter, B = DefaultHashBuilder>(_);

A concurrent cache.

Value

Cache values are cloned when fetched. Users should wrap their values with Arc<_> if necessary to avoid expensive clone operations. If interior mutability is required Arc<Mutex<_>> or Arc<RwLock<_>> can also be used.

Thread Safety and Concurrency

The cache instance can wrapped with an Arc (or equivalent) and shared between threads. All methods are accessible via non-mut references so no further synchronization (e.g. Mutex) is needed.

Implementations

impl<Key: Eq + Hash, Val: Clone> Cache<Key, Val, UnitWeighter, DefaultHashBuilder>

pub fn new(items_capacity: usize) -> Self

Creates a new cache with holds up to items_capacity items (approximately).

impl<Key: Eq + Hash, Val: Clone, We: Weighter<Key, (), Val> + Clone> Cache<Key, Val, We, DefaultHashBuilder>

pub fn with_weighter( estimated_items_capacity: usize, weight_capacity: u64, weighter: We ) -> Self

impl<Key: Eq + Hash, Val: Clone, We: Weighter<Key, (), Val> + Clone, B: BuildHasher + Clone> Cache<Key, Val, We, B>

pub fn with( estimated_items_capacity: usize, weight_capacity: u64, weighter: We, hash_builder: B ) -> Self

Creates a new cache that can hold up to weight_capacity in weight. estimated_items_capacity is the estimated number of items the cache is expected to hold, roughly equivalent to weight_capacity / average item weight.

pub fn with_options(options: Options, weighter: We, hash_builder: B) -> Self

pub fn is_empty(&self) -> bool

Returns whether the cache is empty

pub fn len(&self) -> usize

Returns the number of cached items

pub fn weight(&self) -> u64

Returns the total weight of cached items

pub fn capacity(&self) -> u64

Returns the maximum weight of cached items

pub fn misses(&self) -> u64

Returns the number of misses

pub fn hits(&self) -> u64

Returns the number of hits

pub fn reserve(&mut self, additional: usize)

Reserver additional space for additional entries. Note that this is counted in entries, and is not weighted.

pub fn get<Q>(&self, key: &Q) -> Option<Val>where Key: Borrow<Q>, Q: Eq + Hash + ?Sized,

Fetches an item from the cache. Callers should prefer get_mut whenever possible as it’s more efficient.

pub fn peek<Q>(&self, key: &Q) -> Option<Val>where Key: Borrow<Q>, Q: Eq + Hash + ?Sized,

Peeks an item from the cache. Contrary to gets, peeks don’t alter the key “hotness”.

pub fn remove<Q>(&self, key: &Q) -> boolwhere Key: Borrow<Q>, Q: Eq + Hash + ?Sized,

Peeks an item from the cache whose key is key and qey is <= highest_version. Contrary to gets, peeks don’t alter the key “hotness”.

pub fn insert(&self, key: Key, value: Val)

Inserts an item in the cache with key key and qey qey.

Trait Implementations

impl<Key, Val, We, B> Debug for Cache<Key, Val, We, B>

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

Formats the value using the given formatter.