1 //! Benchmarks for chrono that just depend on std
2
3 extern crate chrono;
4 extern crate criterion;
5
6 use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
7
8 use chrono::prelude::*;
9 use chrono::{DateTime, FixedOffset, Utc, __BenchYearFlags};
10
bench_datetime_parse_from_rfc2822(c: &mut Criterion)11 fn bench_datetime_parse_from_rfc2822(c: &mut Criterion) {
12 c.bench_function("bench_datetime_parse_from_rfc2822", |b| {
13 b.iter(|| {
14 let str = black_box("Wed, 18 Feb 2015 23:16:09 +0000");
15 DateTime::parse_from_rfc2822(str).unwrap()
16 })
17 });
18 }
19
bench_datetime_parse_from_rfc3339(c: &mut Criterion)20 fn bench_datetime_parse_from_rfc3339(c: &mut Criterion) {
21 c.bench_function("bench_datetime_parse_from_rfc3339", |b| {
22 b.iter(|| {
23 let str = black_box("2015-02-18T23:59:60.234567+05:00");
24 DateTime::parse_from_rfc3339(str).unwrap()
25 })
26 });
27 }
28
bench_datetime_from_str(c: &mut Criterion)29 fn bench_datetime_from_str(c: &mut Criterion) {
30 c.bench_function("bench_datetime_from_str", |b| {
31 b.iter(|| {
32 use std::str::FromStr;
33 let str = black_box("2019-03-30T18:46:57.193Z");
34 DateTime::<Utc>::from_str(str).unwrap()
35 })
36 });
37 }
38
bench_datetime_to_rfc2822(c: &mut Criterion)39 fn bench_datetime_to_rfc2822(c: &mut Criterion) {
40 let pst = FixedOffset::east(8 * 60 * 60);
41 let dt = pst.ymd(2018, 1, 11).and_hms_nano(10, 5, 13, 084_660_000);
42 c.bench_function("bench_datetime_to_rfc2822", |b| b.iter(|| black_box(dt).to_rfc2822()));
43 }
44
bench_datetime_to_rfc3339(c: &mut Criterion)45 fn bench_datetime_to_rfc3339(c: &mut Criterion) {
46 let pst = FixedOffset::east(8 * 60 * 60);
47 let dt = pst.ymd(2018, 1, 11).and_hms_nano(10, 5, 13, 084_660_000);
48 c.bench_function("bench_datetime_to_rfc3339", |b| b.iter(|| black_box(dt).to_rfc3339()));
49 }
50
bench_year_flags_from_year(c: &mut Criterion)51 fn bench_year_flags_from_year(c: &mut Criterion) {
52 c.bench_function("bench_year_flags_from_year", |b| {
53 b.iter(|| {
54 for year in -999i32..1000 {
55 __BenchYearFlags::from_year(year);
56 }
57 })
58 });
59 }
60
61 /// Returns the number of multiples of `div` in the range `start..end`.
62 ///
63 /// If the range `start..end` is back-to-front, i.e. `start` is greater than `end`, the
64 /// behaviour is defined by the following equation:
65 /// `in_between(start, end, div) == - in_between(end, start, div)`.
66 ///
67 /// When `div` is 1, this is equivalent to `end - start`, i.e. the length of `start..end`.
68 ///
69 /// # Panics
70 ///
71 /// Panics if `div` is not positive.
in_between(start: i32, end: i32, div: i32) -> i3272 fn in_between(start: i32, end: i32, div: i32) -> i32 {
73 assert!(div > 0, "in_between: nonpositive div = {}", div);
74 let start = (start.div_euclid(div), start.rem_euclid(div));
75 let end = (end.div_euclid(div), end.rem_euclid(div));
76 // The lowest multiple of `div` greater than or equal to `start`, divided.
77 let start = start.0 + (start.1 != 0) as i32;
78 // The lowest multiple of `div` greater than or equal to `end`, divided.
79 let end = end.0 + (end.1 != 0) as i32;
80 end - start
81 }
82
83 /// Alternative implementation to `Datelike::num_days_from_ce`
num_days_from_ce_alt<Date: Datelike>(date: &Date) -> i3284 fn num_days_from_ce_alt<Date: Datelike>(date: &Date) -> i32 {
85 let year = date.year();
86 let diff = move |div| in_between(1, year, div);
87 // 365 days a year, one more in leap years. In the gregorian calendar, leap years are all
88 // the multiples of 4 except multiples of 100 but including multiples of 400.
89 date.ordinal() as i32 + 365 * diff(1) + diff(4) - diff(100) + diff(400)
90 }
91
bench_num_days_from_ce(c: &mut Criterion)92 fn bench_num_days_from_ce(c: &mut Criterion) {
93 let mut group = c.benchmark_group("num_days_from_ce");
94 for year in &[1, 500, 2000, 2019] {
95 let d = NaiveDate::from_ymd(*year, 1, 1);
96 group.bench_with_input(BenchmarkId::new("new", year), &d, |b, y| {
97 b.iter(|| num_days_from_ce_alt(y))
98 });
99 group.bench_with_input(BenchmarkId::new("classic", year), &d, |b, y| {
100 b.iter(|| y.num_days_from_ce())
101 });
102 }
103 }
104
105 criterion_group!(
106 benches,
107 bench_datetime_parse_from_rfc2822,
108 bench_datetime_parse_from_rfc3339,
109 bench_datetime_from_str,
110 bench_datetime_to_rfc2822,
111 bench_datetime_to_rfc3339,
112 bench_year_flags_from_year,
113 bench_num_days_from_ce,
114 );
115
116 criterion_main!(benches);
117