Struct TimedSizedCache

pub struct TimedSizedCache<K, V> { /* private fields */ }

Timed LRU Cache

Stores a limited number of values, evicting expired and least-used entries. Time expiration is determined based on entry insertion time.. The TTL of an entry is not updated when retrieved.

Note: This cache is in-memory only

Implementations

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

pub fn with_size_and_lifespan( size: usize, seconds: u64, ) -> TimedSizedCache<K, V>

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

pub fn with_size_and_lifespan_and_refresh( size: usize, seconds: u64, refresh: bool, ) -> TimedSizedCache<K, V>

Creates a new SizedCache with a given size limit and pre-allocated backing data. Also set if the ttl should be refreshed on retrieving

Panics

Will panic if size is 0

pub fn try_with_size_and_lifespan( size: usize, seconds: u64, ) -> Result<TimedSizedCache<K, V>>

Creates a new TimedSizedCache with a specified lifespan and a given size limit and pre-allocated backing data

Errors

Will return a std::io::Error, depending on the error

pub fn key_order(&self) -> impl Iterator<Item = &K>

Return an iterator of keys in the current order from most to least recently used. Items passed their expiration seconds will be excluded.

pub fn value_order(&self) -> impl Iterator<Item = &(Instant, V)>

Return an iterator of timestamped values in the current order from most to least recently used. Items passed their expiration seconds will be excluded.

pub fn refresh(&self) -> bool

Returns if the lifetime is refreshed when the value is retrieved

pub fn set_refresh(&mut self, refresh: bool)

Sets if the lifetime is refreshed when the value is retrieved

pub fn get_store(&self) -> &SizedCache<K, (Instant, V)>

Returns a reference to the cache’s store

pub fn flush(&mut self)

Remove any expired values from the cache

Trait Implementations

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

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

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

Attempt to retrieve a cached value

fn cache_get_mut<Q>(&mut self, key: &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, key: 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, key: K, f: F, ) -> Result<&mut V, E>

Get or insert a key, value pair with error handling

fn cache_set(&mut self, key: K, val: 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_reset_metrics(&mut self)

Reset misses/hits counters

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_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, V: Clone> Clone for TimedSizedCache<K, V>

fn clone(&self) -> TimedSizedCache<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: Clone> CloneCached<K, V> for TimedSizedCache<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, V: Debug> Debug for TimedSizedCache<K, V>

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

Formats the value using the given formatter.