Struct RateLimiter 

pub struct RateLimiter<K, C>
where
    C: Clock,
{ /* private fields */ }

A rate limiter that enforces different quotas per key using the GCRA algorithm.

This implementation allows setting different rate limits for different keys, with an optional default quota for keys that don’t have specific quotas.

Implementations

impl<K> RateLimiter<K, MonotonicClock>

where K: Eq + Hash,

pub fn new_with_quota( base_quota: Option<Quota>, keyed_quotas: Vec<(K, Quota)>, ) -> Self

Creates a new rate limiter with a base quota and keyed quotas.

The base quota applies to all keys that don’t have specific quotas. Keyed quotas override the base quota for specific keys.

impl<K, C> RateLimiter<K, C>

where K: Eq + Hash, C: Clock,

pub fn new_with_clock( base_quota: Option<Quota>, keyed_quotas: Vec<(K, Quota)>, clock: C, ) -> Self

Creates a new rate limiter with an explicit clock.

The base quota applies to all keys that do not have specific quotas. Keyed quotas override the base quota for specific keys.

impl<K> RateLimiter<K, FakeRelativeClock>

where K: Hash + Eq + Clone,

pub fn advance_clock(&self, by: Duration)

Advances the fake clock by the specified duration.

This is only available for testing with FakeRelativeClock.

impl<K, C> RateLimiter<K, C>

where K: Hash + Eq + Clone, C: Clock,

pub fn add_quota_for_key(&self, key: K, value: Quota)

Adds or updates a quota for a specific key.

pub fn check_key(&self, key: &K) -> Result<(), NotUntil<C::Instant>>

Checks if the given key is allowed under the rate limit.

Errors

Returns Err(NotUntil) if the key is rate-limited, indicating when it will be allowed.

pub async fn until_key_ready(&self, key: &K)

Waits until the specified key is ready (not rate-limited).

pub async fn await_keys_ready(&self, keys: Option<&[K]>)

Waits until all specified keys are ready (not rate-limited).

If no keys are provided, this function returns immediately. Uses fast paths for 0-2 keys to avoid stream scheduling overhead.

Trait Implementations

impl<K, C> Debug for RateLimiter<K, C>

where K: Debug, C: Clock,

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

Formats the value using the given formatter.