Trait TokenStore

Source

pub trait TokenStore: Send + Sync {
    // Required methods
    fn load(&self) -> impl Future<Output = Option<Token>> + Send;
    fn save(&self, token: &Token) -> impl Future<Output = ()> + Send;
}

Expand description

Pluggable persistent cache for service tokens.

Implementations are consulted by AutoRefresh whenever it has no in-memory token (cold start), and written to after every successful refresh or initial authentication. Implementations should treat both methods as best-effort — load returns None for “no token, or load failed”, save is fire-and-forget. The AutoRefresh state machine always validates freshness via Token::is_usable / Token::is_expired before returning a loaded token, so implementations don’t need to.

On native targets the trait carries Send + Sync bounds so the store can be shared across tokio::spawn background work. On wasm32 the bounds are dropped — edge runtimes are single-threaded.

Required Methods§

Source

fn load(&self) -> impl Future<Output = Option<Token>> + Send

Load the most recently saved token, or None if none has been stored (or the load failed). Errors are swallowed — the calling state machine falls back to fresh authentication when this returns None.

Source

fn save(&self, token: &Token) -> impl Future<Output = ()> + Send

Persist a token after a successful refresh or initial authentication. Best-effort — implementations should log on failure rather than returning an error.