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// Copyright 2018 Developers of the Rand project.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![feature(test)]
#![allow(non_snake_case)]
extern crate test;
use test::Bencher;
use rand::prelude::*;
use rand::seq::*;
use std::mem::size_of;
// We force use of 32-bit RNG since seq code is optimised for use with 32-bit
// generators on all platforms.
use rand_pcg::Pcg32 as SmallRng;
const RAND_BENCH_N: u64 = 1000;
#[bench]
fn seq_shuffle_100(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &mut [usize] = &mut [1; 100];
b.iter(|| {
x.shuffle(&mut rng);
x[0]
})
}
#[bench]
fn seq_slice_choose_1_of_1000(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &mut [usize] = &mut [1; 1000];
for i in 0..1000 {
x[i] = i;
}
b.iter(|| {
let mut s = 0;
for _ in 0..RAND_BENCH_N {
s += x.choose(&mut rng).unwrap();
}
s
});
b.bytes = size_of::<usize>() as u64 * crate::RAND_BENCH_N;
}
macro_rules! seq_slice_choose_multiple {
($name:ident, $amount:expr, $length:expr) => {
#[bench]
fn $name(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &[i32] = &[$amount; $length];
let mut result = [0i32; $amount];
b.iter(|| {
// Collect full result to prevent unwanted shortcuts getting
// first element (in case sample_indices returns an iterator).
for (slot, sample) in result.iter_mut().zip(x.choose_multiple(&mut rng, $amount)) {
*slot = *sample;
}
result[$amount - 1]
})
}
};
}
seq_slice_choose_multiple!(seq_slice_choose_multiple_1_of_1000, 1, 1000);
seq_slice_choose_multiple!(seq_slice_choose_multiple_950_of_1000, 950, 1000);
seq_slice_choose_multiple!(seq_slice_choose_multiple_10_of_100, 10, 100);
seq_slice_choose_multiple!(seq_slice_choose_multiple_90_of_100, 90, 100);
#[bench]
fn seq_iter_choose_from_1000(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &mut [usize] = &mut [1; 1000];
for i in 0..1000 {
x[i] = i;
}
b.iter(|| {
let mut s = 0;
for _ in 0..RAND_BENCH_N {
s += x.iter().choose(&mut rng).unwrap();
}
s
});
b.bytes = size_of::<usize>() as u64 * crate::RAND_BENCH_N;
}
#[derive(Clone)]
struct UnhintedIterator<I: Iterator + Clone> {
iter: I,
}
impl<I: Iterator + Clone> Iterator for UnhintedIterator<I> {
type Item = I::Item;
fn next(&mut self) -> Option<Self::Item> {
self.iter.next()
}
}
#[derive(Clone)]
struct WindowHintedIterator<I: ExactSizeIterator + Iterator + Clone> {
iter: I,
window_size: usize,
}
impl<I: ExactSizeIterator + Iterator + Clone> Iterator for WindowHintedIterator<I> {
type Item = I::Item;
fn next(&mut self) -> Option<Self::Item> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
(std::cmp::min(self.iter.len(), self.window_size), None)
}
}
#[bench]
fn seq_iter_unhinted_choose_from_1000(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &[usize] = &[1; 1000];
b.iter(|| {
UnhintedIterator { iter: x.iter() }
.choose(&mut rng)
.unwrap()
})
}
#[bench]
fn seq_iter_window_hinted_choose_from_1000(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &[usize] = &[1; 1000];
b.iter(|| {
WindowHintedIterator {
iter: x.iter(),
window_size: 7,
}
.choose(&mut rng)
})
}
#[bench]
fn seq_iter_choose_multiple_10_of_100(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &[usize] = &[1; 100];
b.iter(|| x.iter().cloned().choose_multiple(&mut rng, 10))
}
#[bench]
fn seq_iter_choose_multiple_fill_10_of_100(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
let x: &[usize] = &[1; 100];
let mut buf = [0; 10];
b.iter(|| x.iter().cloned().choose_multiple_fill(&mut rng, &mut buf))
}
macro_rules! sample_indices {
($name:ident, $fn:ident, $amount:expr, $length:expr) => {
#[bench]
fn $name(b: &mut Bencher) {
let mut rng = SmallRng::from_rng(thread_rng()).unwrap();
b.iter(|| index::$fn(&mut rng, $length, $amount))
}
};
}
sample_indices!(misc_sample_indices_1_of_1k, sample, 1, 1000);
sample_indices!(misc_sample_indices_10_of_1k, sample, 10, 1000);
sample_indices!(misc_sample_indices_100_of_1k, sample, 100, 1000);
sample_indices!(misc_sample_indices_100_of_1M, sample, 100, 1000_000);
sample_indices!(misc_sample_indices_100_of_1G, sample, 100, 1000_000_000);
sample_indices!(misc_sample_indices_200_of_1G, sample, 200, 1000_000_000);
sample_indices!(misc_sample_indices_400_of_1G, sample, 400, 1000_000_000);
sample_indices!(misc_sample_indices_600_of_1G, sample, 600, 1000_000_000);
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