92 lines
2.3 KiB
Rust
92 lines
2.3 KiB
Rust
|
use std::collections::BinaryHeap;
|
||
|
|
|
||
|
|
use rand::{seq::SliceRandom, thread_rng};
|
||
|
|
use test::{black_box, Bencher};
|
||
|
|
|
||
|
|
#[bench]
|
||
|
|
fn bench_find_smallest_1000(b: &mut Bencher) {
|
||
|
|
let mut rng = thread_rng();
|
||
|
|
let mut vec: Vec<u32> = (0..100_000).collect();
|
||
|
|
vec.shuffle(&mut rng);
|
||
|
|
|
||
|
|
b.iter(|| {
|
||
|
|
let mut iter = vec.iter().copied();
|
||
|
|
let mut heap: BinaryHeap<_> = iter.by_ref().take(1000).collect();
|
||
|
|
|
||
|
|
for x in iter {
|
||
|
|
let mut max = heap.peek_mut().unwrap();
|
||
|
|
// This comparison should be true only 1% of the time.
|
||
|
|
// Unnecessary `sift_down`s will degrade performance
|
||
|
|
if x < *max {
|
||
|
|
*max = x;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
heap
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
#[bench]
|
||
|
|
fn bench_peek_mut_deref_mut(b: &mut Bencher) {
|
||
|
|
let mut bheap = BinaryHeap::from(vec![42]);
|
||
|
|
let vec: Vec<u32> = (0..1_000_000).collect();
|
||
|
|
|
||
|
|
b.iter(|| {
|
||
|
|
let vec = black_box(&vec);
|
||
|
|
let mut peek_mut = bheap.peek_mut().unwrap();
|
||
|
|
// The compiler shouldn't be able to optimize away the `sift_down`
|
||
|
|
// assignment in `PeekMut`'s `DerefMut` implementation since
|
||
|
|
// the loop may not run.
|
||
|
|
for &i in vec.iter() {
|
||
|
|
*peek_mut = i;
|
||
|
|
}
|
||
|
|
// Remove the already minimal overhead of the sift_down
|
||
|
|
std::mem::forget(peek_mut);
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
#[bench]
|
||
|
|
fn bench_from_vec(b: &mut Bencher) {
|
||
|
|
let mut rng = thread_rng();
|
||
|
|
let mut vec: Vec<u32> = (0..100_000).collect();
|
||
|
|
vec.shuffle(&mut rng);
|
||
|
|
|
||
|
|
b.iter(|| BinaryHeap::from(vec.clone()))
|
||
|
|
}
|
||
|
|
|
||
|
|
#[bench]
|
||
|
|
fn bench_into_sorted_vec(b: &mut Bencher) {
|
||
|
|
let bheap: BinaryHeap<i32> = (0..10_000).collect();
|
||
|
|
|
||
|
|
b.iter(|| bheap.clone().into_sorted_vec())
|
||
|
|
}
|
||
|
|
|
||
|
|
#[bench]
|
||
|
|
fn bench_push(b: &mut Bencher) {
|
||
|
|
let mut bheap = BinaryHeap::with_capacity(50_000);
|
||
|
|
let mut rng = thread_rng();
|
||
|
|
let mut vec: Vec<u32> = (0..50_000).collect();
|
||
|
|
vec.shuffle(&mut rng);
|
||
|
|
|
||
|
|
b.iter(|| {
|
||
|
|
for &i in vec.iter() {
|
||
|
|
bheap.push(i);
|
||
|
|
}
|
||
|
|
black_box(&mut bheap);
|
||
|
|
bheap.clear();
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
#[bench]
|
||
|
|
fn bench_pop(b: &mut Bencher) {
|
||
|
|
let mut bheap = BinaryHeap::with_capacity(10_000);
|
||
|
|
|
||
|
|
b.iter(|| {
|
||
|
|
bheap.extend((0..10_000).rev());
|
||
|
|
black_box(&mut bheap);
|
||
|
|
while let Some(elem) = bheap.pop() {
|
||
|
|
black_box(elem);
|
||
|
|
}
|
||
|
|
})
|
||
|
|
}
|