b2histogram

A fast and efficient 64-bit integer histogram with power-of-2 spaced buckets.

• Fixed memory footprint (520 bytes) with no dynamic allocations
• Constant time record and retrieve operations that compile down to a few instructions
• no_std support

• Work in progress: Compact binary serialization

• Documentation

• Release Notes

Usage

Add this to your Cargo.toml:

toml [dependencies] b2histogram = "1.0"

and this to your crate root:

```rust

[macro_use]

extern crate b2histogram; ```

Quick Example

```rust extern crate b2histogram;

use b2histogram::Base2Histogram;

fn main() { let mut hist = Base2Histogram::new();

hist.record(0); // Record a single observation of '0' hist.record(11); // hist.record(11); // Two observations of '11' hist.recordn(300000, 6); // Six observations of 300,000

// Retrieve counts directly println!("Observations for 300,000: {}", hist.observations(300_000));

// Retrieve the Bucket covering a given value println!("Bucket corresponding to '11': {:?}", hist.bucket_for(11));

// Iterate buckets that have observations for bucket in hist.iter().filter(|b| b.count > 0) { println!("({:5}, {:5}): {}", bucket.begin, bucket.end, bucket.count); } } ```

See the documentation for more.