mirror of https://github.com/rust-lang/rust.git
81 lines
2.4 KiB
Rust
81 lines
2.4 KiB
Rust
//! This primarily benchmarks `impl Debug for str`,
|
|
//! and it also explicitly tests that we minimizes calls to the underlying `Write`r.
|
|
//! While that is an implementation detail and there are no guarantees about it,
|
|
//! we should still try to minimize those calls over time rather than regress them.
|
|
|
|
use std::fmt::{self, Write};
|
|
|
|
use test::{Bencher, black_box};
|
|
|
|
#[derive(Default)]
|
|
struct CountingWriter {
|
|
buf: String,
|
|
write_calls: usize,
|
|
}
|
|
|
|
impl Write for CountingWriter {
|
|
fn write_str(&mut self, s: &str) -> fmt::Result {
|
|
self.buf.push_str(s);
|
|
self.write_calls += 1;
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
fn assert_fmt(s: &str, expected: &str, expected_write_calls: usize) {
|
|
let mut w = CountingWriter::default();
|
|
|
|
write!(&mut w, "{s:?}").unwrap();
|
|
assert_eq!(s.len(), 64);
|
|
assert_eq!(w.buf, expected);
|
|
assert_eq!(w.write_calls, expected_write_calls);
|
|
}
|
|
|
|
#[bench]
|
|
fn ascii_only(b: &mut Bencher) {
|
|
let s = "just a bit of ascii text that has no escapes. 64 bytes exactly!!";
|
|
assert_fmt(s, r#""just a bit of ascii text that has no escapes. 64 bytes exactly!!""#, 3);
|
|
b.iter(|| {
|
|
black_box(format!("{:?}", black_box(s)));
|
|
});
|
|
}
|
|
|
|
#[bench]
|
|
fn ascii_escapes(b: &mut Bencher) {
|
|
let s = "some\tmore\tascii\ttext\nthis time with some \"escapes\", also 64 byte";
|
|
assert_fmt(
|
|
s,
|
|
r#""some\tmore\tascii\ttext\nthis time with some \"escapes\", also 64 byte""#,
|
|
15,
|
|
);
|
|
b.iter(|| {
|
|
black_box(format!("{:?}", black_box(s)));
|
|
});
|
|
}
|
|
|
|
#[bench]
|
|
fn some_unicode(b: &mut Bencher) {
|
|
let s = "egy kis szöveg néhány unicode betűvel. legyen ez is 64 byte.";
|
|
assert_fmt(s, r#""egy kis szöveg néhány unicode betűvel. legyen ez is 64 byte.""#, 3);
|
|
b.iter(|| {
|
|
black_box(format!("{:?}", black_box(s)));
|
|
});
|
|
}
|
|
|
|
#[bench]
|
|
fn mostly_unicode(b: &mut Bencher) {
|
|
let s = "предложение из кириллических букв.";
|
|
assert_fmt(s, r#""предложение из кириллических букв.""#, 3);
|
|
b.iter(|| {
|
|
black_box(format!("{:?}", black_box(s)));
|
|
});
|
|
}
|
|
|
|
#[bench]
|
|
fn mixed(b: &mut Bencher) {
|
|
let s = "\"❤️\"\n\"hűha ez betű\"\n\"кириллических букв\".";
|
|
assert_fmt(s, r#""\"❤\u{fe0f}\"\n\"hűha ez betű\"\n\"кириллических букв\".""#, 21);
|
|
b.iter(|| {
|
|
black_box(format!("{:?}", black_box(s)));
|
|
});
|
|
}
|