third_party/rust_crates/vendor/hashbrown/benches/bench.rs

#![feature(test)]

extern crate test;

use std::hash::Hash;
use test::Bencher;

use hashbrown::HashMap;
//use rustc_hash::FxHashMap as HashMap;
//use std::collections::HashMap;

fn new_map<K: Eq + Hash, V>() -> HashMap<K, V> {
    HashMap::default()
}

#[bench]
fn new_drop(b: &mut Bencher) {
    b.iter(|| {
        let m: HashMap<i32, i32> = new_map();
        assert_eq!(m.len(), 0);
    })
}

#[bench]
fn new_insert_drop(b: &mut Bencher) {
    b.iter(|| {
        let mut m = new_map();
        m.insert(0, 0);
        assert_eq!(m.len(), 1);
    })
}

#[bench]
fn grow_by_insertion(b: &mut Bencher) {
    let mut m = new_map();

    for i in 1..1001 {
        m.insert(i, i);
    }

    let mut k = 1001;

    b.iter(|| {
        m.insert(k, k);
        k += 1;
    });
}

#[bench]
fn grow_by_insertion_kb(b: &mut Bencher) {
    let mut m = new_map();
    let kb = 1024;
    for i in 1..1001 {
        m.insert(i * kb, i);
    }

    let mut k = 1001 * kb;

    b.iter(|| {
        m.insert(k, k);
        k += kb;
    });
}

#[bench]
fn find_existing(b: &mut Bencher) {
    let mut m = new_map();

    for i in 1..1001 {
        m.insert(i, i);
    }

    b.iter(|| {
        for i in 1..1001 {
            m.contains_key(&i);
        }
    });
}

#[bench]
fn find_existing_high_bits(b: &mut Bencher) {
    let mut m = new_map();

    for i in 1..1001_u64 {
        m.insert(i << 32, i);
    }

    b.iter(|| {
        for i in 1..1001_u64 {
            m.contains_key(&(i << 32));
        }
    });
}

#[bench]
fn find_nonexisting(b: &mut Bencher) {
    let mut m = new_map();

    for i in 1..1001 {
        m.insert(i, i);
    }

    b.iter(|| {
        for i in 1001..2001 {
            m.contains_key(&i);
        }
    });
}

#[bench]
fn hashmap_as_queue(b: &mut Bencher) {
    let mut m = new_map();

    for i in 1..1001 {
        m.insert(i, i);
    }

    let mut k = 1;

    b.iter(|| {
        m.remove(&k);
        m.insert(k + 1000, k + 1000);
        k += 1;
    });
}

#[bench]
fn get_remove_insert(b: &mut Bencher) {
    let mut m = new_map();

    for i in 1..1001 {
        m.insert(i, i);
    }

    let mut k = 1;

    b.iter(|| {
        m.get(&(k + 400));
        m.get(&(k + 2000));
        m.remove(&k);
        m.insert(k + 1000, k + 1000);
        k += 1;
    })
}

#[bench]
fn insert_8_char_string(b: &mut Bencher) {
    let mut strings: Vec<_> = Vec::new();
    for i in 1..1001 {
        strings.push(format!("{:x}", -i));
    }

    let mut m = new_map();
    b.iter(|| {
        for key in &strings {
            m.insert(key, key);
        }
    })
}