Struct BucketedHistogramValue 

pub struct BucketedHistogramValue {
    pub buckets: Vec<(BucketBound, u64)>,
    pub sum: Option<f64>,
    pub count: u64,
    pub cumulative_count: u64,
    pub created: Option<Instant>,
    pub bucket_exemplars: Vec<Option<Exemplar>>,
}

OpenMetrics §5.3 (Histogram) and §5.4 (GaugeHistogram) explicit-bucket value: cumulative observation counts at producer-chosen le boundaries, plus optional _sum / _count / _created siblings.

Histogram (§5.3) bucket counts are required to be monotonically non-decreasing; GaugeHistogram (§5.4) permits decreases. The owning [MetricFamily::r#type()] tag distinguishes which constraint applies; the validation helper in crate::validation::check_bucket_monotonicity enforces it for Histogram families.

Difference from HistogramValue: that variant is the HDR-reservoir-backed Summary (§5.5), exposing percentile columns. This variant is the bucket-keyed form — what OpenMetrics calls a Histogram strictly.

Fields

buckets: Vec<(BucketBound, u64)>

Cumulative (le, count) pairs in ascending le order. The final pair SHOULD have le = +Inf and count == self.count per spec §5.3; producers that omit +Inf are tolerated but exposition is permitted to synthesize one.

sum: Option<f64>

Optional sum of all observations.

count: u64

Total observation count (== last bucket count) — the per-window total in a delta snapshot.

cumulative_count: u64

The cumulative total observation count (monotonic, Prometheus/VM-schematic) carried alongside the per-window count, mirroring HistogramValue::cumulative_count and CounterValue::cumulative. (The per-bucket le counts in buckets are the separate OpenMetrics bucket-cumulative thing and are unchanged.)

created: Option<Instant>

Series start time per spec §5.3 / §5.4.

bucket_exemplars: Vec<Option<Exemplar>>

Optional per-bucket exemplars, parallel to buckets. Sparse: missing slot ⇒ no exemplar for that bucket.

Implementations

impl BucketedHistogramValue

pub fn new(buckets: Vec<(BucketBound, u64)>) -> Self

Construct from cumulative (le, count) pairs. count is the final bucket’s count when present, else the max across the supplied pairs.

pub fn with_cumulative_count(self, cumulative_count: u64) -> Self

Override the cumulative total observation count.

pub fn with_sum(self, sum: f64) -> Self

pub fn with_created(self, t: Instant) -> Self

pub fn with_bucket_exemplars(self, ex: Vec<Option<Exemplar>>) -> Self

Trait Implementations

impl Clone for BucketedHistogramValue

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 BucketedHistogramValue

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

Formats the value using the given formatter.