Struct TimeBucketedCounter 

pub struct TimeBucketedCounter<K> { /* private fields */ }

Available on crate feature tracker only.

Per-key event counter over a sliding time window.

The window is divided into fixed-width buckets; counts are summed across buckets for queries. Lazily evicts buckets older than now - window on demand.

Implementations

impl<K> TimeBucketedCounter<K>

where K: Hash + Eq + Clone,

pub fn new(window: Duration, bucket_width: Duration, capacity: usize) -> Self

Construct a new counter.

window = total observation period; bucket_width = resolution; capacity = max distinct keys held across all buckets (best-effort, enforced by per-bucket cap).

bucket_width must be ≥ 1 ns; window should be ≥ bucket_width.

pub fn new_unbounded(window: Duration, bucket_width: Duration) -> Self

Unbounded capacity convenience constructor — equivalent to Self::new(window, bucket_width, usize::MAX). Prefer Self::new with an explicit cap when memory pressure matters; this avoids the cap arithmetic in code paths that don’t need it. New in 0.12.0.

pub fn bump(&mut self, key: K, now: Timestamp)

Increment the counter for key at now.

pub fn count(&self, key: &K, now: Timestamp) -> u64

Sum counts for key across buckets within [now - window, now]. Buckets older than the window are excluded.

pub fn entries_above( &self, threshold: u64, now: Timestamp, ) -> impl Iterator<Item = (&K, u64)> + '_

Iterate keys whose summed count is >= threshold over the active window.

pub fn evict_expired(&mut self, now: Timestamp)

Drop buckets older than now - window.

pub fn len(&self) -> usize

Current number of distinct keys held across all live buckets (approximate; double-counts a key that appears in multiple buckets).

pub fn is_empty(&self) -> bool

Trait Implementations

impl<K: Debug> Debug for TimeBucketedCounter<K>

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

Formats the value using the given formatter.