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// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
use criterion::{black_box, criterion_group, criterion_main, Criterion};
use std::fmt;
use writeable::LengthHint;
use writeable::Writeable;
/// A sample type implementing Writeable
struct WriteableMessage<'s> {
message: &'s str,
}
impl Writeable for WriteableMessage<'_> {
fn write_to<W: fmt::Write + ?Sized>(&self, sink: &mut W) -> fmt::Result {
sink.write_str(self.message)
}
fn writeable_length_hint(&self) -> LengthHint {
LengthHint::exact(self.message.len())
}
}
writeable::impl_display_with_writeable!(WriteableMessage<'_>);
/// A sample type implementing Display
struct DisplayMessage<'s> {
message: &'s str,
}
impl fmt::Display for DisplayMessage<'_> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str(self.message)
}
}
const SHORT_STR: &str = "short";
const MEDIUM_STR: &str = "this is a medium-length string";
const LONG_STR: &str = "this string is very very very very very very very very very very very very very very very very very very very very very very very very long";
fn overview_bench(c: &mut Criterion) {
c.bench_function("writeable/overview", |b| {
b.iter(|| {
// This benchmark runs to_string on short, medium, and long strings in one batch.
WriteableMessage {
message: black_box(SHORT_STR),
}
.write_to_string();
WriteableMessage {
message: black_box(MEDIUM_STR),
}
.write_to_string();
WriteableMessage {
message: black_box(LONG_STR),
}
.write_to_string();
});
});
#[cfg(feature = "bench")]
{
writeable_benches(c);
writeable_dyn_benches(c);
display_benches(c);
}
}
#[cfg(feature = "bench")]
fn writeable_benches(c: &mut Criterion) {
c.bench_function("writeable/to_string/short", |b| {
b.iter(|| {
WriteableMessage {
message: black_box(SHORT_STR),
}
.write_to_string()
.into_owned()
});
});
c.bench_function("writeable/to_string/medium", |b| {
b.iter(|| {
WriteableMessage {
message: black_box(MEDIUM_STR),
}
.write_to_string()
.into_owned()
});
});
c.bench_function("writeable/to_string/long", |b| {
b.iter(|| {
WriteableMessage {
message: black_box(LONG_STR),
}
.write_to_string()
.into_owned()
});
});
}
#[cfg(feature = "bench")]
fn writeable_dyn_benches(c: &mut Criterion) {
// Same as `write_to_string`, but casts to a `dyn fmt::Write`
fn writeable_dyn_to_string(w: &impl Writeable) -> String {
let mut output = String::with_capacity(w.writeable_length_hint().capacity());
w.write_to(&mut output as &mut dyn fmt::Write)
.expect("impl Write for String is infallible");
output
}
c.bench_function("writeable_dyn/to_string/short", |b| {
b.iter(|| {
writeable_dyn_to_string(&WriteableMessage {
message: black_box(SHORT_STR),
})
});
});
c.bench_function("writeable_dyn/to_string/medium", |b| {
b.iter(|| {
writeable_dyn_to_string(&WriteableMessage {
message: black_box(MEDIUM_STR),
})
});
});
c.bench_function("writeable_dyn/to_string/long", |b| {
b.iter(|| {
writeable_dyn_to_string(&WriteableMessage {
message: black_box(LONG_STR),
})
});
});
}
#[cfg(feature = "bench")]
fn display_benches(c: &mut Criterion) {
c.bench_function("display/to_string/short", |b| {
b.iter(|| {
DisplayMessage {
message: black_box(SHORT_STR),
}
.to_string()
});
});
c.bench_function("display/to_string/medium", |b| {
b.iter(|| {
DisplayMessage {
message: black_box(MEDIUM_STR),
}
.to_string()
});
});
c.bench_function("display/to_string/long", |b| {
b.iter(|| {
DisplayMessage {
message: black_box(LONG_STR),
}
.to_string()
});
});
}
criterion_group!(benches, overview_bench,);
criterion_main!(benches);
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