Crate sketches_rust
source ·Expand description
This crate provides a direct port of the Java DDSketch implementation to Rust.
Usage
Add multiple samples to a DDSketch and invoke the get_value_at_quantile
method to pull any quantile from
0.0 to 1.0.
use self::sketches_rust::DDSketch;
let mut d = DDSketch::collapsing_lowest_dense(0.02,100).unwrap();
d.accept(1.0);
d.accept(2.0);
d.accept(3.0);
let c = d.get_count();
assert_eq!(c, 3.0);
let q = d.get_value_at_quantile(0.5).unwrap();
assert!(q < 2.01 && q > 1.99);
Also you could merge other DDSketch:
use self::sketches_rust::DDSketch;
let mut d1 = DDSketch::collapsing_lowest_dense(0.02,100).unwrap();
d1.accept(1.0);
d1.accept(2.0);
d1.accept(3.0);
assert_eq!(3.0, d1.get_count());
let mut d2 = DDSketch::collapsing_lowest_dense(0.02,100).unwrap();
d2.accept(1.0);
d2.accept(2.0);
d2.accept(3.0);
assert_eq!(3.0, d2.get_count());
d2.merge_with(&mut d1).unwrap();
assert_eq!(6.0, d2.get_count());
Encode to bytes:
use self::sketches_rust::{DDSketch};
let mut d = DDSketch::unbounded_dense(2e-2).unwrap();
d.accept(1.0);
d.accept(2.0);
d.accept(3.0);
d.accept(4.0);
d.accept(5.0);
println!("encode: {:?}", d.encode().unwrap());
Decode from bytes:
use self::sketches_rust::{DDSketch};
let mut input = vec![
2, 42, 120, 57, 5, 47, 167, 240, 63, 0, 0, 0, 0, 0, 0, 0, 0, 13, 50, 130, 1, 2, 136, 32, 0,
3, 0, 0, 0, 3, 0, 2, 0, 0, 3, 3, 2, 2, 3, 3, 2, 0, 0, 0, 0, 2, 0, 2, 2, 2, 4, 4, 132, 64,
0, 4, 2, 0, 2, 2, 3, 132, 64, 4, 132, 64, 4, 2, 2, 0, 6, 4, 6, 132, 64, 2, 6,
];
let mut d = DDSketch::decode(&input).unwrap();
assert_eq!(d.get_count(), 100.0);