Struct TokenCache 

pub struct TokenCache<T> { /* private fields */ }

Thread-safe cache for a TemporaryToken that proactively refreshes before the token expires.

Min-TTL strategy

A cached token is considered still valid only when its remaining lifetime exceeds min_ttl (default 5 minutes). Once the remaining lifetime drops below that threshold the next call to get_or_insert_with will trigger a synchronous re-fetch — while the lock is held — before returning the new token. This ensures callers always receive a token with a comfortable margin before it expires, avoiding races where a token is used just as it becomes invalid.

An additional fetch_backoff guard (default 100 ms) prevents a thundering-herd of re-fetch attempts in the window where the token is below min_ttl but has not yet expired: if the previous fetch happened within fetch_backoff and the token has not actually expired yet, the stale-but- not-yet-expired token is returned immediately.

Implementations

impl<T: Clone + Send> TokenCache<T>

pub async fn get_or_insert_with<F, Fut, E>(&self, f: F) -> Result<T, E>

where F: FnOnce() -> Fut + Send, Fut: Future<Output = Result<TemporaryToken<T>, E>> + Send,

Trait Implementations

impl<T: Debug> Debug for TokenCache<T>

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

Formats the value using the given formatter.

impl<T> Default for TokenCache<T>

fn default() -> Self

Returns the “default value” for a type.