chrono/benches/chrono.rs

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//! Benchmarks for chrono that just depend on std
extern crate chrono;
extern crate criterion;
use criterion::{black_box, criterion_group, criterion_main, Criterion, BenchmarkId};
use chrono::prelude::*;
use chrono::{Utc, FixedOffset, DateTime, __BenchYearFlags};
fn bench_datetime_parse_from_rfc2822(c: &mut Criterion) {
c.bench_function("bench_datetime_parse_from_rfc2822", |b| {
b.iter(|| {
let str = black_box("Wed, 18 Feb 2015 23:16:09 +0000");
DateTime::parse_from_rfc2822(str).unwrap()
})
});
}
fn bench_datetime_parse_from_rfc3339(c: &mut Criterion) {
c.bench_function("bench_datetime_parse_from_rfc3339", |b| {
b.iter(|| {
let str = black_box("2015-02-18T23:59:60.234567+05:00");
DateTime::parse_from_rfc3339(str).unwrap()
})
});
}
fn bench_datetime_from_str(c: &mut Criterion) {
c.bench_function("bench_datetime_from_str", |b| {
b.iter(|| {
use std::str::FromStr;
let str = black_box("2019-03-30T18:46:57.193Z");
DateTime::<Utc>::from_str(str).unwrap()
})
});
}
fn bench_datetime_to_rfc2822(c: &mut Criterion) {
let pst = FixedOffset::east(8 * 60 * 60);
let dt = pst.ymd(2018, 1, 11).and_hms_nano(10, 5, 13, 084_660_000);
c.bench_function("bench_datetime_to_rfc2822", |b| {
b.iter(|| black_box(dt).to_rfc2822())
});
}
fn bench_datetime_to_rfc3339(c: &mut Criterion) {
let pst = FixedOffset::east(8 * 60 * 60);
let dt = pst.ymd(2018, 1, 11).and_hms_nano(10, 5, 13, 084_660_000);
c.bench_function("bench_datetime_to_rfc3339", |b| {
b.iter(|| black_box(dt).to_rfc3339())
});
}
fn bench_year_flags_from_year(c: &mut Criterion) {
c.bench_function("bench_year_flags_from_year", |b|
b.iter(|| {
for year in -999i32..1000 {
__BenchYearFlags::from_year(year);
}
}));
/// Returns the number of multiples of `div` in the range `start..end`.
///
/// If the range `start..end` is back-to-front, i.e. `start` is greater than `end`, the
/// behaviour is defined by the following equation:
/// `in_between(start, end, div) == - in_between(end, start, div)`.
///
/// When `div` is 1, this is equivalent to `end - start`, i.e. the length of `start..end`.
///
/// # Panics
///
/// Panics if `div` is not positive.
fn in_between(start: i32, end: i32, div: i32) -> i32 {
assert!(div > 0, "in_between: nonpositive div = {}", div);
let start = (start.div_euclid(div), start.rem_euclid(div));
let end = (end.div_euclid(div), end.rem_euclid(div));
// The lowest multiple of `div` greater than or equal to `start`, divided.
let start = start.0 + (start.1 != 0) as i32;
// The lowest multiple of `div` greater than or equal to `end`, divided.
let end = end.0 + (end.1 != 0) as i32;
end - start
}
/// Alternative implementation to `Datelike::num_days_from_ce`
fn num_days_from_ce_alt<Date: Datelike>(date: &Date) -> i32 {
let year = date.year();
let diff = move |div| in_between(1, year, div);
// 365 days a year, one more in leap years. In the gregorian calendar, leap years are all
// the multiples of 4 except multiples of 100 but including multiples of 400.
date.ordinal() as i32 + 365 * diff(1) + diff(4) - diff(100) + diff(400)
}
fn bench_num_days_from_ce(c: &mut Criterion) {
let mut group = c.benchmark_group("num_days_from_ce");
for year in &[1, 500, 2000, 2019] {
let d = NaiveDate::from_ymd(*year, 1, 1);
group.bench_with_input(
BenchmarkId::new("new", year),
&d,
|b, y| b.iter(|| num_days_from_ce_alt(y)),
);
group.bench_with_input(
BenchmarkId::new("classic", year),
&d,
|b, y| b.iter(|| y.num_days_from_ce()),
);
}
}
criterion_group!(
benches,
bench_datetime_parse_from_rfc2822,
bench_datetime_parse_from_rfc3339,
bench_datetime_from_str,
bench_datetime_to_rfc2822,
bench_datetime_to_rfc3339,
bench_year_flags_from_year,
bench_num_days_from_ce,
);
criterion_main!(benches);