Add benchmarks for DateTime parsing and formatting

src/datetime.rs

@@ -2213,4 +2213,53 @@ mod tests {
         assert_eq!(format!("{}  ", ymd_formatted), format!("{:<17}", ymd));
         assert_eq!(format!(" {} ", ymd_formatted), format!("{:^17}", ymd));
     }
+
+    #[cfg(feature = "bench")]
+    #[bench]
+    fn bench_datetime_parse_from_rfc2822(bh: &mut test::Bencher) {
+        bh.iter(|| {
+            let str = test::black_box("Wed, 18 Feb 2015 23:16:09 +0000");
+            DateTime::parse_from_rfc2822(str).unwrap()
+        });
+    }
+
+    #[cfg(feature = "bench")]
+    #[bench]
+    fn bench_datetime_parse_from_rfc3339(bh: &mut test::Bencher) {
+        bh.iter(|| {
+            let str = test::black_box("2015-02-18T23:59:60.234567+05:00");
+            DateTime::parse_from_rfc3339(str).unwrap()
+        });
+    }
+
+    #[cfg(feature = "bench")]
+    #[bench]
+    fn bench_datetime_from_str(bh: &mut test::Bencher) {
+        use std::str::FromStr;
+
+        bh.iter(|| {
+            let str = test::black_box("2019-03-30T18:46:57.193Z");
+            DateTime::<Utc>::from_str(str).unwrap()
+        });
+    }
+
+    #[cfg(feature = "bench")]
+    #[bench]
+    fn bench_datetime_to_rfc2822(bh: &mut test::Bencher) {
+        let pst = FixedOffset::east(8 * 60 * 60);
+        let dt = pst.ymd(2018, 1, 11).and_hms_nano(10, 5, 13, 084_660_000);
+        bh.iter(|| {
+            test::black_box(dt).to_rfc2822()
+        });
+    }
+
+    #[cfg(feature = "bench")]
+    #[bench]
+    fn bench_datetime_to_rfc3339(bh: &mut test::Bencher) {
+        let pst = FixedOffset::east(8 * 60 * 60);
+        let dt = pst.ymd(2018, 1, 11).and_hms_nano(10, 5, 13, 084_660_000);
+        bh.iter(|| {
+            test::black_box(dt).to_rfc3339()
+        });
+    }
 }