Struct Cache 

pub struct Cache<K, V>
where
    K: Eq + Hash + Clone,
{ /* private fields */ }

A thread-safe in-memory LRU cache with TTL and tag-based invalidation.

Implementations

impl<K, V> Cache<K, V>

where K: Eq + Hash + Clone,

pub fn new(max_size: usize, default_ttl: Option<Duration>) -> Self

Create a new cache with the given max size and optional default TTL.

pub fn set(&self, key: K, value: V)

Set a value with optional TTL and tags.

pub fn set_with(&self, key: K, value: V, ttl: Option<Duration>, tags: &[&str])

Set a value with custom TTL and tags.

pub fn get(&self, key: &K) -> Option<V>

where V: Clone,

Get a value from the cache. Returns None if not found or expired.

Increments the hit counter on success, or the miss counter on failure.

pub fn has(&self, key: &K) -> bool

Check if a key exists and is not expired.

pub fn delete(&self, key: &K) -> bool

Delete an entry by key.

pub fn invalidate_by_tag(&self, tag: &str) -> usize

Invalidate all entries with the given tag. Returns count removed.

pub fn clear(&self)

Remove all entries.

pub fn size(&self) -> usize

Return the number of entries.

pub fn is_empty(&self) -> bool

Returns true if the cache has no entries.

pub fn max_size(&self) -> usize

Returns the maximum number of entries the cache can hold.

pub fn keys(&self) -> Vec<K>

Returns a list of all non-expired keys in the cache.

pub fn remove_expired(&self) -> usize

Remove all expired entries from the cache. Returns the number of entries removed.

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

where V: Clone, F: FnOnce() -> V,

Get a value from the cache, or insert one computed by the given closure if absent or expired.

pub fn stats(&self) -> CacheStats

Return a snapshot of cache performance counters.

pub fn get_many(&self, keys: &[K]) -> HashMap<K, V>

where V: Clone,

Retrieve multiple values at once. Returns a map of keys to their cached values, omitting any keys that are absent or expired.

pub fn delete_where<F>(&self, predicate: F) -> usize

where F: Fn(&K, &V) -> bool,

Delete all entries for which the predicate returns true. Returns the number of entries removed.

pub fn len(&self) -> usize

Return the number of entries (alias for size()).

Trait Implementations

impl<K, V> Clone for Cache<K, V>

where K: Eq + Hash + Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<K, V> Debug for Cache<K, V>

where K: Eq + Hash + Clone,

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

Formats the value using the given formatter.

impl<K, V> Default for Cache<K, V>

where K: Eq + Hash + Clone,

fn default() -> Self

Returns the “default value” for a type.