Struct hdrhist::HDRHist

pub struct HDRHist { /* fields omitted */ }

An hdr histogram that collects u64 sample with 5 bit precision.

Methods

impl HDRHist

pub fn new() -> Self

Construct an empty hdr histogram.

pub fn add_value(&mut self, value: u64)

Add a sample to the histogram.

This is guaranteed to be constant time and never re-allocates.

pub fn combined(self, other: Self) -> Self

Combine this histogram with another. This doesn't normalize, and only adds the per-bucket counts. Only use it for histograms that have captured a comparable number of samples.

pub fn ccdf<'a>(
    &'a self
) -> impl Iterator<Item = (u64, f64, u64)> + 'a

Output the complementary cumulative distribution function (ccdf) of the samples

Returns an iterator over increasing sample values such that, for every triple (value, prob, count), prob is the ratio of samples >= value, and count is the number of samples >= the current value and < the next value.

pub fn ccdf_upper_bound<'a>(
    &'a self
) -> impl Iterator<Item = (u64, f64)> + 'a

Outputs an upper bound of the complementary cumulative distribution function (ccdf) of the samples.

You can use these points to plot with linear interpolation and never report intermediate sample values that underestimate quantiles. In other words, all the actual quantile values will be below the reported curve.

pub fn ccdf_lower_bound<'a>(
    &'a self
) -> impl Iterator<Item = (u64, f64)> + 'a

Outputs an upper bound of the complementary cumulative distribution function (ccdf) of the samples.

You can use these points to plot with linear interpolation and never report intermediate sample values that overestimate quantiles. In other words, all the actual quantile values will be above the reported curve.

pub fn quantiles<'a>(
    &'a self,
    quantiles: impl Iterator<Item = f64> + 'a
) -> impl Iterator<Item = (f64, u64, u64)> + 'a

Output estimated quantiles as (quantile, lower_bound, upper_bound) pairs

Each quantile's value is somewhere >= lower_bound and < upper_bound

pub fn summary<'a>(
    &'a self
) -> impl Iterator<Item = (f64, u64, u64)> + 'a

Output a summary of estimated quantiles

pub fn summary_string(&self) -> String

Output a text summary of estimated quantiles

Trait Implementations

impl Clone for HDRHist

fn clone(&self) -> HDRHist

Returns a copy of the value.

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

Performs copy-assignment from source.