Add support for microseconds, closes #684

doc/hyperfine.1

@@ -224,7 +224,7 @@ order benchmarks by mean runtime
 .HP
 \fB\-u\fR, \fB\-\-time\-unit\fR \fIUNIT\fP
 .IP
-Set the time unit to be used. Possible values: millisecond, second. If
+Set the time unit to be used. Possible values: microsecond, millisecond, second. If
 the option is not given, the time unit is determined automatically.
 This option affects the standard output as well as all export formats
 except for CSV and JSON.

src/cli.rs

@@ -227,8 +227,8 @@ fn build_command() -> Command {
                 .short('u')
                 .action(ArgAction::Set)
                 .value_name("UNIT")
-                .value_parser(["millisecond", "second"])
-                .help("Set the time unit to be used. Possible values: millisecond, second. \
+                .value_parser(["microsecond", "millisecond", "second"])
+                .help("Set the time unit to be used. Possible values: microsecond, millisecond, second. \
                        If the option is not given, the time unit is determined automatically. \
                        This option affects the standard output as well as all export formats except for CSV and JSON."),
         )

src/options.rs

@@ -391,6 +391,7 @@ impl Options {
         }
 
         options.time_unit = match matches.get_one::<String>("time-unit").map(|s| s.as_str()) {
+            Some("microsecond") => Some(Unit::MicroSecond),
             Some("millisecond") => Some(Unit::MilliSecond),
             Some("second") => Some(Unit::Second),
             _ => None,

src/output/format.rs

@@ -16,7 +16,9 @@ pub fn format_duration_unit(duration: Second, unit: Option<Unit>) -> (String, Un
 
 /// Like `format_duration`, but returns the target unit as well.
 pub fn format_duration_value(duration: Second, unit: Option<Unit>) -> (String, Unit) {
-    if (duration < 1.0 && unit.is_none()) || unit == Some(Unit::MilliSecond) {
+    if (duration < 0.001 && unit.is_none()) || unit == Some(Unit::MicroSecond) {
+        (Unit::MicroSecond.format(duration), Unit::MicroSecond)
+    } else if (duration < 1.0 && unit.is_none()) || unit == Some(Unit::MilliSecond) {
         (Unit::MilliSecond.format(duration), Unit::MilliSecond)
     } else {
         (Unit::Second.format(duration), Unit::Second)
@@ -40,10 +42,15 @@ fn test_format_duration_unit_basic() {
     assert_eq!("999.0 ms", out_str);
     assert_eq!(Unit::MilliSecond, out_unit);
 
+    let (out_str, out_unit) = format_duration_unit(0.0005, None);
+
+    assert_eq!("500.0 µs", out_str);
+    assert_eq!(Unit::MicroSecond, out_unit);
+
     let (out_str, out_unit) = format_duration_unit(0.0, None);
 
-    assert_eq!("0.0 ms", out_str);
-    assert_eq!(Unit::MilliSecond, out_unit);
+    assert_eq!("0.0 µs", out_str);
+    assert_eq!(Unit::MicroSecond, out_unit);
 
     let (out_str, out_unit) = format_duration_unit(1000.0, None);
 
@@ -62,4 +69,9 @@ fn test_format_duration_unit_with_unit() {
 
     assert_eq!("1300.0 ms", out_str);
     assert_eq!(Unit::MilliSecond, out_unit);
+
+    let (out_str, out_unit) = format_duration_unit(1.3, Some(Unit::MicroSecond));
+
+    assert_eq!("1300000.0 µs", out_str);
+    assert_eq!(Unit::MicroSecond, out_unit);
 }

src/util/units.rs

@@ -10,6 +10,7 @@ pub type Second = Scalar;
 pub enum Unit {
     Second,
     MilliSecond,
+    MicroSecond,
 }
 
 impl Unit {
@@ -18,6 +19,7 @@ impl Unit {
         match self {
             Unit::Second => String::from("s"),
             Unit::MilliSecond => String::from("ms"),
+            Unit::MicroSecond => String::from("µs"),
         }
     }
 
@@ -26,6 +28,7 @@ impl Unit {
         match self {
             Unit::Second => format!("{:.3}", value),
             Unit::MilliSecond => format!("{:.1}", value * 1e3),
+            Unit::MicroSecond => format!("{:.1}", value * 1e6),
         }
     }
 }
@@ -34,6 +37,7 @@ impl Unit {
 fn test_unit_short_name() {
     assert_eq!("s", Unit::Second.short_name());
     assert_eq!("ms", Unit::MilliSecond.short_name());
+    assert_eq!("µs", Unit::MicroSecond.short_name());
 }
 
 // Note - the values are rounded when formatted.
@@ -42,4 +46,6 @@ fn test_unit_format() {
     let value: Second = 123.456789;
     assert_eq!("123.457", Unit::Second.format(value));
     assert_eq!("123456.8", Unit::MilliSecond.format(value));
+
+    assert_eq!("1234.6", Unit::MicroSecond.format(0.00123456));
 }

tests/integration_tests.rs

@@ -261,6 +261,15 @@ fn returns_mean_time_in_correct_unit() {
         .assert()
         .success()
         .stdout(predicate::str::contains("Time (mean ± σ):     1234.0 ms ±"));
+
+    hyperfine_debug()
+        .arg("--time-unit=microsecond")
+        .arg("sleep 1.234")
+        .assert()
+        .success()
+        .stdout(predicate::str::contains(
+            "Time (mean ± σ):     1234000.0 µs ±",
+        ));
 }
 
 #[test]