Struct ExponentialHistogram 

pub struct ExponentialHistogram { /* private fields */ }

Exponential histogram with configurable scale

Bucket boundaries follow exponential growth: boundary[i] = base^i where base = 2^(2^(-scale))

Implementations

impl ExponentialHistogram

pub fn new(scale: i32) -> Self

Create a new exponential histogram

Arguments

• scale - Scale parameter (-10 to 20 typical)
  • scale=0: base=2.0, coarse buckets
  • scale=3: base≈1.09, ~8 buckets per doubling (good default)
  • scale=5: base≈1.02, ~32 buckets per doubling (high precision)

pub fn default_scale() -> Self

Create with default scale (3 = good balance of precision and memory)

pub fn record(&mut self, value: f64)

Record a value

pub fn merge(&mut self, other: &ExponentialHistogram)

Merge another histogram into this one

O(buckets) merge - critical for rollups

pub fn count(&self) -> u64

Get count

pub fn sum(&self) -> f64

Get sum

pub fn mean(&self) -> f64

Get mean

pub fn min(&self) -> f64

Get min

pub fn max(&self) -> f64

Get max

pub fn quantile(&self, q: f64) -> f64

Estimate a quantile

pub fn is_empty(&self) -> bool

Check if empty

pub fn clear(&mut self)

Clear all data

pub fn bucket_count(&self) -> usize

Get number of buckets used

pub fn memory_usage(&self) -> usize

Get memory usage in bytes

Trait Implementations

impl Clone for ExponentialHistogram

fn clone(&self) -> ExponentialHistogram

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExponentialHistogram

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

Formats the value using the given formatter.

impl Default for ExponentialHistogram

fn default() -> Self

Returns the “default value” for a type.