Struct BoundedKeyedLimiter 

pub struct BoundedKeyedLimiter<K: Eq + Hash + Clone> { /* private fields */ }

Memory-bounded keyed rate limiter.

Cheaply cloneable; clones share state.

Implementations

impl<K: Eq + Hash + Clone + Send + Sync + 'static> BoundedKeyedLimiter<K>

pub fn with_per_minute( requests_per_minute: u32, max_tracked_keys: usize, idle_eviction: Duration, ) -> Self

Construct a BoundedKeyedLimiter with a per-minute quota.

Convenience constructor that builds a per-minute Quota from requests_per_minute. The rate is clamped to a minimum of 1 request/min so a misconfigured 0 does not panic at startup.

• requests_per_minute – per-key rate, clamped to >= 1.
• max_tracked_keys – hard cap on simultaneously tracked keys. When reached, an insert first prunes idle entries then falls back to LRU eviction.
• idle_eviction – entries whose last_seen is older than this are eligible for opportunistic pruning.

pub fn with_per_second( requests_per_second: u32, max_tracked_keys: usize, idle_eviction: Duration, ) -> Self

Construct a BoundedKeyedLimiter with a per-second quota.

Convenience constructor that builds a per-second Quota from requests_per_second. The rate is clamped to a minimum of 1 request/sec so a misconfigured 0 does not panic at startup.

• requests_per_second – per-key rate, clamped to >= 1.
• max_tracked_keys – hard cap on simultaneously tracked keys. When reached, an insert first prunes idle entries then falls back to LRU eviction.
• idle_eviction – entries whose last_seen is older than this are eligible for opportunistic pruning.

pub fn check_key(&self, key: &K) -> Result<(), BoundedLimiterError>

Test the per-key quota for key.

Returns Ok(()) if the request is allowed. The last_seen timestamp is updated on every call – including rate-limit rejections – so an actively firing attacker cannot age out into a fresh quota by appearing idle.

When inserting a new key into a full table, idle entries are pruned first; if the table is still full, the entry with the oldest last_seen is evicted (LRU). The new key is always inserted – honest new clients are never rejected because the table is full.

Errors

Returns BoundedLimiterError::RateLimited when key has exceeded its per-key quota for the current window.

pub fn check_key_wait(&self, key: &K) -> Result<(), Duration>

Test the per-key quota for key, returning the wait time on deny.

Identical admission semantics to check_key (same last_seen refresh, idle-prune, and LRU-eviction behavior); the two methods share one code path.

Errors

On deny, returns the best-effort current wait until the next request for this key could be admitted, measured against governor’s default clock at the moment of the failed check. The value is a raw Duration; rounding (e.g. ceiling to whole seconds for a Retry-After header) is the caller’s concern.

pub fn len(&self) -> usize

Number of currently tracked keys. Used by tests and admin endpoints.

pub fn is_empty(&self) -> bool

true when no keys are currently tracked.

Trait Implementations

impl<K: Eq + Hash + Clone> Clone for BoundedKeyedLimiter<K>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.