Struct ExpiringValueCache

pub struct ExpiringValueCache<K: Hash + Eq, V: CanExpire> { /* private fields */ }

Expiring Value Cache

Stores values that implement the CanExpire trait so that expiration is determined by the values themselves. This is useful for caching values which themselves contain an expiry timestamp.

Note: This cache is in-memory only.

Implementations

impl<K: Clone + Hash + Eq, V: CanExpire> ExpiringValueCache<K, V>

pub fn with_size(size: usize) -> ExpiringValueCache<K, V>

Creates a new ExpiringValueCache with a given size limit and pre-allocated backing data.

pub fn flush(&mut self)

Remove any expired values from the cache

Trait Implementations

impl<K: Hash + Eq + Clone, V: CanExpire> Cached<K, V> for ExpiringValueCache<K, V>

fn cache_get<Q>(&mut self, k: &Q) -> Option<&V>

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

Attempt to retrieve a cached value

fn cache_get_mut<Q>(&mut self, k: &Q) -> Option<&mut V>

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

Attempt to retrieve a cached value with mutable access

fn cache_get_or_set_with<F: FnOnce() -> V>(&mut self, k: K, f: F) -> &mut V

Get or insert a key, value pair

fn cache_try_get_or_set_with<F: FnOnce() -> Result<V, E>, E>( &mut self, k: K, f: F, ) -> Result<&mut V, E>

Get or insert a key, value pair with error handling

fn cache_set(&mut self, k: K, v: V) -> Option<V>

Insert a key, value pair and return the previous value

fn cache_remove<Q>(&mut self, k: &Q) -> Option<V>

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

Remove a cached value

fn cache_clear(&mut self)

Remove all cached values. Keeps the allocated memory for reuse.

fn cache_reset(&mut self)

Remove all cached values. Free memory and return to initial state

fn cache_size(&self) -> usize

Return the current cache size (number of elements)

fn cache_hits(&self) -> Option<u64>

Return the number of times a cached value was successfully retrieved

fn cache_misses(&self) -> Option<u64>

Return the number of times a cached value was unable to be retrieved

fn cache_reset_metrics(&mut self)

Reset misses/hits counters

fn cache_capacity(&self) -> Option<usize>

Return the cache capacity

fn cache_lifespan(&self) -> Option<u64>

Return the lifespan of cached values (time to eviction)

fn cache_set_lifespan(&mut self, _seconds: u64) -> Option<u64>

Set the lifespan of cached values, returns the old value

fn cache_unset_lifespan(&mut self) -> Option<u64>

Remove the lifespan for cached values, returns the old value.

impl<K: Clone + Hash + Eq, V: Clone + CanExpire> Clone for ExpiringValueCache<K, V>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K: Hash + Eq + Clone, V: CanExpire + Clone> CloneCached<K, V> for ExpiringValueCache<K, V>

fn cache_get_expired<Q>(&mut self, k: &Q) -> (Option<V>, bool)

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

Attempt to retrieve a cached value and indicate whether that value was evicted.

impl<K: Debug + Hash + Eq, V: Debug + CanExpire> Debug for ExpiringValueCache<K, V>

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

Formats the value using the given formatter.