switch to using criterion for benchmarks

It has a ton of great features[1], including stronger statistical signifance
tests, making comparisons to previous or baseline runs, nice plots, and being
able to be run on stable.

1: https://bheisler.github.io/criterion.rs/book/

CHANGELOG.md

@@ -8,6 +8,12 @@ Chrono obeys the principle of [Semantic Versioning](http://semver.org/).
 There were/are numerous minor versions before 1.0 due to the language changes.
 Versions with only mechanical changes will be omitted from the following list.
 
+## next
+
+### Internal improvements
+
+* Use Criterion for benchmarks (@quodlibetor)
+
 ## 0.4.10
 
 ### Improvements

Cargo.toml

@@ -48,6 +48,7 @@ serde_derive = { version = "1", default-features = false }
 bincode = { version = "0.8.0" }
 num-iter = { version = "0.1.35", default-features = false }
 doc-comment = "0.3"
+criterion = "0.3"
 
 [target.'cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))'.dev-dependencies]
 wasm-bindgen-test = "0.2"
@@ -57,3 +58,7 @@ all-features = true
 
 [package.metadata.playground]
 all-features = true
+
+[[bench]]
+name = "parsing"
+harness = false

benches/parsing.rs

@@ -0,0 +1,62 @@
+extern crate chrono;
+extern crate criterion;
+
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+use chrono::prelude::*;
+use chrono::{Utc, FixedOffset, DateTime};
+
+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())
+    });
+}
+
+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
+);
+
+criterion_main!(benches);