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#![feature(test)]
extern crate test;
use test::Bencher;
use indexmap::IndexMap;
use std::collections::HashMap;
use rand::rngs::SmallRng;
use rand::seq::SliceRandom;
use rand::SeedableRng;
use std::hash::{Hash, Hasher};
use std::borrow::Borrow;
use std::ops::Deref;
/// Use a consistently seeded Rng for benchmark stability
fn small_rng() -> SmallRng {
let seed = u64::from_le_bytes(*b"indexmap");
SmallRng::seed_from_u64(seed)
}
#[derive(PartialEq, Eq, Copy, Clone)]
#[repr(transparent)]
pub struct OneShot<T: ?Sized>(pub T);
impl Hash for OneShot<str> {
fn hash<H: Hasher>(&self, h: &mut H) {
h.write(self.0.as_bytes())
}
}
impl<'a, S> From<&'a S> for &'a OneShot<str>
where
S: AsRef<str>,
{
fn from(s: &'a S) -> Self {
let s: &str = s.as_ref();
unsafe { &*(s as *const str as *const OneShot<str>) }
}
}
impl Hash for OneShot<String> {
fn hash<H: Hasher>(&self, h: &mut H) {
h.write(self.0.as_bytes())
}
}
impl Borrow<OneShot<str>> for OneShot<String> {
fn borrow(&self) -> &OneShot<str> {
<&OneShot<str>>::from(&self.0)
}
}
impl<T> Deref for OneShot<T> {
type Target = T;
fn deref(&self) -> &T {
&self.0
}
}
fn shuffled_keys<I>(iter: I) -> Vec<I::Item>
where
I: IntoIterator,
{
let mut v = Vec::from_iter(iter);
let mut rng = small_rng();
v.shuffle(&mut rng);
v
}
#[bench]
fn insert_hashmap_string_10_000(b: &mut Bencher) {
let c = 10_000;
b.iter(|| {
let mut map = HashMap::with_capacity(c);
for x in 0..c {
map.insert(x.to_string(), ());
}
map
});
}
#[bench]
fn insert_hashmap_string_oneshot_10_000(b: &mut Bencher) {
let c = 10_000;
b.iter(|| {
let mut map = HashMap::with_capacity(c);
for x in 0..c {
map.insert(OneShot(x.to_string()), ());
}
map
});
}
#[bench]
fn insert_indexmap_string_10_000(b: &mut Bencher) {
let c = 10_000;
b.iter(|| {
let mut map = IndexMap::with_capacity(c);
for x in 0..c {
map.insert(x.to_string(), ());
}
map
});
}
#[bench]
fn lookup_hashmap_10_000_exist_string(b: &mut Bencher) {
let c = 10_000;
let mut map = HashMap::with_capacity(c);
let keys = shuffled_keys(0..c);
for &key in &keys {
map.insert(key.to_string(), 1);
}
let lookups = (5000..c).map(|x| x.to_string()).collect::<Vec<_>>();
b.iter(|| {
let mut found = 0;
for key in &lookups {
found += map.get(key).is_some() as i32;
}
found
});
}
#[bench]
fn lookup_hashmap_10_000_exist_string_oneshot(b: &mut Bencher) {
let c = 10_000;
let mut map = HashMap::with_capacity(c);
let keys = shuffled_keys(0..c);
for &key in &keys {
map.insert(OneShot(key.to_string()), 1);
}
let lookups = (5000..c)
.map(|x| OneShot(x.to_string()))
.collect::<Vec<_>>();
b.iter(|| {
let mut found = 0;
for key in &lookups {
found += map.get(key).is_some() as i32;
}
found
});
}
#[bench]
fn lookup_indexmap_10_000_exist_string(b: &mut Bencher) {
let c = 10_000;
let mut map = IndexMap::with_capacity(c);
let keys = shuffled_keys(0..c);
for &key in &keys {
map.insert(key.to_string(), 1);
}
let lookups = (5000..c).map(|x| x.to_string()).collect::<Vec<_>>();
b.iter(|| {
let mut found = 0;
for key in &lookups {
found += map.get(key).is_some() as i32;
}
found
});
}
#[bench]
fn lookup_indexmap_10_000_exist_string_oneshot(b: &mut Bencher) {
let c = 10_000;
let mut map = IndexMap::with_capacity(c);
let keys = shuffled_keys(0..c);
for &key in &keys {
map.insert(OneShot(key.to_string()), 1);
}
let lookups = (5000..c)
.map(|x| OneShot(x.to_string()))
.collect::<Vec<_>>();
b.iter(|| {
let mut found = 0;
for key in &lookups {
found += map.get(key).is_some() as i32;
}
found
});
}
|
