Compare rust fast hashers

main.rs

/*

count = 10000000
len = 512


name    min     max     spent (s)
----    ---     ---     ----
fnv     19525   19537   2.417305
fx      19531   19532   0.48344

*/

extern crate fnv;
extern crate rustc_hash;

use fnv::FnvHasher;
use rustc_hash::FxHasher;
use std::hash::{Hash, Hasher};
use std::time::Instant;

const N: usize = 512;
const K: usize = 10_000_000;

fn check<H: Hasher + Default>(name: &str) {
    let mut counters = [0; N];

    let start = Instant::now();

    for i in 0..K {
        let mut hasher = H::default();

        i.hash(&mut hasher);

        counters[hasher.finish() as usize % N] += 1;
    }

    let dur = start.elapsed();

    let min = counters.iter().min().unwrap();
    let max = counters.iter().max().unwrap();

    let spent = dur.as_secs() as f64 + dur.subsec_micros() as f64 / 1_000_000.;

    println!("{}\t{}\t{}\t{}", name, min, max, spent);
}

fn main() {
    println!("count = {}\nlen = {}\n\n", K, N);
    println!("name\tmin\tmax\tspent (s)\n----\t---\t---\t----");

    check::<FnvHasher>("fnv");
    check::<FxHasher>("fx");
}