Struct RestCache 

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

Concurrent TTL cache.

Use RestCache::get_or_fetch to look up a value, fetching from the loader if missing or expired. The loader is async and returns Result<V, E>.

Clone is cheap — the internal map is Arc-wrapped.

Implementations

impl<K, V> RestCache<K, V>

where K: Eq + Hash + Clone, V: Clone + Send + Sync,

pub fn new(default_ttl: Duration) -> Self

Create a new cache with the given default TTL applied by RestCache::insert.

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

Get cached value if still fresh, else None.

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

Insert with the default TTL configured at construction.

pub fn insert_with_ttl(&self, key: K, value: V, ttl: Duration)

Insert with an explicit TTL.

pub async fn get_or_fetch<F, Fut, E>(&self, key: K, loader: F) -> Result<V, E>

where F: FnOnce() -> Fut, Fut: Future<Output = Result<V, E>>,

Get or fetch.

Returns the cached value if fresh. Otherwise calls loader, caches the result with the default TTL, and returns it.

See the module-level doc for single-flight semantics (short: not single-flight).

pub fn invalidate(&self, key: &K)

Manually expire one key (next get or get_or_fetch will reload).

pub fn clear(&self)

Remove all entries.

pub fn len(&self) -> usize

Number of entries (including expired ones not yet swept).

pub fn is_empty(&self) -> bool

Returns true if no entries are present.

pub fn sweep_expired(&self) -> usize

Eviction sweep — removes all expired entries.

Returns the number of entries removed. Call periodically if the cache can accumulate many distinct keys (e.g. per-symbol caches).

Trait Implementations

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

where K: Eq + Hash + Clone, V: Clone + Send + Sync,

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.