Struct Histogram 

pub struct Histogram { /* private fields */ }

Open Metrics Histogram to measure distributions of discrete events.

let histogram = Histogram::new(exponential_buckets(1.0, 2.0, 10));
histogram.observe(4.2);

Histogram does not implement Default, given that the choice of bucket values depends on the situation Histogram is used in. As an example, to measure HTTP request latency, the values suggested in the Golang implementation might work for you:

// Default values from go client(https://github.com/prometheus/client_golang/blob/5d584e2717ef525673736d72cd1d12e304f243d7/prometheus/histogram.go#L68)
let custom_buckets = [
   0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 10.0,
];
let histogram = Histogram::new(custom_buckets);
histogram.observe(4.2);

Implementations

impl Histogram

pub fn new(buckets: impl IntoIterator<Item = f64>) -> Self

Create a new Histogram.

let histogram = Histogram::new([10.0, 100.0, 1_000.0]);

pub fn new_native(native: NativeHistogramConfig) -> Self

Create a new native Histogram without classic buckets.

Native-only histograms can only be encoded by the Prometheus protobuf encoder. Text and OpenMetrics protobuf encoders do not have native histogram fields and reject native-only histograms.

pub fn new_classic_and_native( buckets: impl IntoIterator<Item = f64>, native: NativeHistogramConfig, ) -> Self

Create a new Histogram with both classic and native buckets.

Prometheus protobuf encodes both representations in one histogram message. Encoders without native histogram support encode the classic buckets.

pub fn observe(&self, v: f64)

Observe the given value.

pub fn sum(&self) -> f64

Available on crate features test-util only.

Returns the current sum of all observations.

pub fn count(&self) -> u64

Available on crate features test-util only.

Returns the current number of observations.

Trait Implementations

impl Clone for Histogram

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 Histogram

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

Formats the value using the given formatter.

impl EncodeMetric for Histogram

fn encode(&self, encoder: MetricEncoder<'_>) -> Result<(), Error>

Encode the given instance in the OpenMetrics text encoding.

fn metric_type(&self) -> MetricType

The OpenMetrics metric type of the instance.

fn is_empty(&self) -> bool

Check if the metric is empty.

impl TypedMetric for Histogram

const TYPE: MetricType = MetricType::Histogram

The OpenMetrics metric type.