Files
bytes/benches/bytes.rs
T
Stepan KoltsovandCarl Lerche b9ccd2a866 Optimize Bytes::slice for short slices (#136)
Slice operation should return inline when possible

It is cheaper than atomic increment/decrement.

Before this patch:

```
test slice_avg_le_inline_from_arc   ... bench:      28,582 ns/iter (+/- 3,880)
test slice_empty                    ... bench:       8,797 ns/iter (+/- 1,325)
test slice_large_le_inline_from_arc ... bench:      27,684 ns/iter (+/- 5,920)
test slice_short_from_arc           ... bench:      27,439 ns/iter (+/- 5,783)
```

After this patch:

```
test slice_avg_le_inline_from_arc   ... bench:      18,872 ns/iter (+/- 2,937)
test slice_empty                    ... bench:       9,136 ns/iter (+/- 1,908)
test slice_large_le_inline_from_arc ... bench:      18,052 ns/iter (+/- 2,981)
test slice_short_from_arc           ... bench:      18,200 ns/iter (+/- 2,534)
```
2017-07-01 14:10:09 -07:00

206 lines
4.4 KiB
Rust

#![feature(test)]
extern crate bytes;
extern crate test;
use test::Bencher;
use bytes::{Bytes, BytesMut, BufMut};
#[bench]
fn alloc_small(b: &mut Bencher) {
b.iter(|| {
for _ in 0..1024 {
test::black_box(BytesMut::with_capacity(12));
}
})
}
#[bench]
fn alloc_mid(b: &mut Bencher) {
b.iter(|| {
test::black_box(BytesMut::with_capacity(128));
})
}
#[bench]
fn alloc_big(b: &mut Bencher) {
b.iter(|| {
test::black_box(BytesMut::with_capacity(4096));
})
}
#[bench]
fn deref_unique(b: &mut Bencher) {
let mut buf = BytesMut::with_capacity(4096);
buf.put(&[0u8; 1024][..]);
b.iter(|| {
for _ in 0..1024 {
test::black_box(&buf[..]);
}
})
}
#[bench]
fn deref_unique_unroll(b: &mut Bencher) {
let mut buf = BytesMut::with_capacity(4096);
buf.put(&[0u8; 1024][..]);
b.iter(|| {
for _ in 0..128 {
test::black_box(&buf[..]);
test::black_box(&buf[..]);
test::black_box(&buf[..]);
test::black_box(&buf[..]);
test::black_box(&buf[..]);
test::black_box(&buf[..]);
test::black_box(&buf[..]);
test::black_box(&buf[..]);
}
})
}
#[bench]
fn deref_shared(b: &mut Bencher) {
let mut buf = BytesMut::with_capacity(4096);
buf.put(&[0u8; 1024][..]);
let _b2 = buf.split_off(1024);
b.iter(|| {
for _ in 0..1024 {
test::black_box(&buf[..]);
}
})
}
#[bench]
fn deref_inline(b: &mut Bencher) {
let mut buf = BytesMut::with_capacity(8);
buf.put(&[0u8; 8][..]);
b.iter(|| {
for _ in 0..1024 {
test::black_box(&buf[..]);
}
})
}
#[bench]
fn deref_two(b: &mut Bencher) {
let mut buf1 = BytesMut::with_capacity(8);
buf1.put(&[0u8; 8][..]);
let mut buf2 = BytesMut::with_capacity(4096);
buf2.put(&[0u8; 1024][..]);
b.iter(|| {
for _ in 0..512 {
test::black_box(&buf1[..]);
test::black_box(&buf2[..]);
}
})
}
#[bench]
fn alloc_write_split_to_mid(b: &mut Bencher) {
b.iter(|| {
let mut buf = BytesMut::with_capacity(128);
buf.put_slice(&[0u8; 64]);
test::black_box(buf.split_to(64));
})
}
#[bench]
fn drain_write_drain(b: &mut Bencher) {
let data = [0u8; 128];
b.iter(|| {
let mut buf = BytesMut::with_capacity(1024);
let mut parts = Vec::with_capacity(8);
for _ in 0..8 {
buf.put(&data[..]);
parts.push(buf.split_to(128));
}
test::black_box(parts);
})
}
#[bench]
fn fmt_write(b: &mut Bencher) {
use std::fmt::Write;
let mut buf = BytesMut::with_capacity(128);
let s = "foo bar baz quux lorem ipsum dolor et";
b.bytes = s.len() as u64;
b.iter(|| {
let _ = write!(buf, "{}", s);
test::black_box(&buf);
unsafe { buf.set_len(0); }
})
}
#[bench]
fn from_long_slice(b: &mut Bencher) {
let data = [0u8; 128];
b.bytes = data.len() as u64;
b.iter(|| {
let buf = BytesMut::from(&data[..]);
test::black_box(buf);
})
}
#[bench]
fn slice_empty(b: &mut Bencher) {
b.iter(|| {
let b = Bytes::from(vec![17; 1024]).clone();
for i in 0..1000 {
test::black_box(b.slice(i % 100, i % 100));
}
})
}
#[bench]
fn slice_short_from_arc(b: &mut Bencher) {
b.iter(|| {
// `clone` is to convert to ARC
let b = Bytes::from(vec![17; 1024]).clone();
for i in 0..1000 {
test::black_box(b.slice(1, 2 + i % 10));
}
})
}
// Keep in sync with bytes.rs
#[cfg(target_pointer_width = "64")]
const INLINE_CAP: usize = 4 * 8 - 1;
#[cfg(target_pointer_width = "32")]
const INLINE_CAP: usize = 4 * 4 - 1;
#[bench]
fn slice_avg_le_inline_from_arc(b: &mut Bencher) {
b.iter(|| {
// `clone` is to convert to ARC
let b = Bytes::from(vec![17; 1024]).clone();
for i in 0..1000 {
// [1, INLINE_CAP]
let len = 1 + i % (INLINE_CAP - 1);
test::black_box(b.slice(i % 10, i % 10 + len));
}
})
}
#[bench]
fn slice_large_le_inline_from_arc(b: &mut Bencher) {
b.iter(|| {
// `clone` is to convert to ARC
let b = Bytes::from(vec![17; 1024]).clone();
for i in 0..1000 {
// [INLINE_CAP - 10, INLINE_CAP]
let len = INLINE_CAP - 9 + i % 10;
test::black_box(b.slice(i % 10, i % 10 + len));
}
})
}