Struct DistributedRateLimiter 

pub struct DistributedRateLimiter { /* private fields */ }

Ergonomic handle for cluster-wide rate limiting against a backend.

Pairs a DistributedRateLimitBackend with a limiter key and a RateLimitConfig. The algorithm (token bucket vs sliding window) is taken from the config, exactly as with the in-process limiters in crate::rate_limit.

Cloning is cheap: the backend is held behind an Arc and shared.

Implementations

impl DistributedRateLimiter

pub fn new( backend: Arc<dyn DistributedRateLimitBackend>, key: impl Into<String>, config: RateLimitConfig, ) -> Self

Create a new distributed rate limiter.

Arguments

• backend - Shared store implementing DistributedRateLimitBackend.
• key - Logical limiter name (e.g. a task name or queue).
• config - Rate limit configuration (selects the algorithm).

pub fn key(&self) -> &str

The limiter key.

pub fn config(&self) -> &RateLimitConfig

The active configuration.

pub fn algorithm(&self) -> DistributedAlgorithm

The active algorithm.

pub async fn try_acquire(&self) -> Result<bool>

Try to acquire a single permit cluster-wide.

Returns Ok(true) if granted, Ok(false) if rate limited.

Errors

Returns an error if the backend store is unavailable.

pub async fn try_acquire_n(&self, cost: f64) -> Result<AcquireOutcome>

Try to acquire cost permits atomically.

Returns the full AcquireOutcome so callers can inspect the remaining permits and suggested retry delay.

Errors

Returns an error if the backend store is unavailable.

pub async fn acquire(&self, max_sleep: Duration) -> Result<Duration>

Acquire a single permit, awaiting (with bounded sleeps) until granted.

Returns the total time waited. Each retry sleeps for the backend’s suggested retry_after, clamped to max_sleep to remain responsive under contention from other workers.

Errors

Returns an error if the backend store is unavailable.

pub async fn available(&self) -> Result<f64>

Available permits for this limiter (after refill).

Errors

Returns an error if the backend store is unavailable.

pub async fn time_until_available(&self) -> Result<Duration>

Estimated time until a single permit is available.

Errors

Returns an error if the backend store is unavailable.

pub async fn reset(&self) -> Result<()>

Reset the limiter state for this key in the backend.

Errors

Returns an error if the backend store is unavailable.

Trait Implementations

impl Clone for DistributedRateLimiter

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DistributedRateLimiter

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

Formats the value using the given formatter.