time: add methods to convert duration to microseconds and milliseconds

The return values are integers, as opposed to floats, since the fractionals can be derived from multiplying t.Seconds().

Fixes #28564

Change-Id: I3796227e1f64ead39ff0aacfbdce912d952f2994
GitHub-Last-Rev: b843ab740bf5a8216478322533521d6243fe1cb1
GitHub-Pull-Request: golang/go#30819
Reviewed-on: https://go-review.googlesource.com/c/go/+/167387
Run-TryBot: Robert Griesemer <[email protected]>
Reviewed-by: Robert Griesemer <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

src/time/time.go

@@ -783,6 +783,12 @@ func fmtInt(buf []byte, v uint64) int {
 // Nanoseconds returns the duration as an integer nanosecond count.
 func (d Duration) Nanoseconds() int64 { return int64(d) }
 
+// Microseconds returns the duration as an integer microsecond count.
+func (d Duration) Microseconds() int64 { return int64(d) / 1e3 }
+
+// Milliseconds returns the duration as an integer millisecond count.
+func (d Duration) Milliseconds() int64 { return int64(d) / 1e6 }
+
 // These methods return float64 because the dominant
 // use case is for printing a floating point number like 1.5s, and
 // a truncation to integer would make them not useful in those cases.

src/time/time_test.go

@@ -690,7 +690,7 @@ var gobTests = []Time{
  Date(0, 1, 2, 3, 4, 5, 6, UTC),
  Date(7, 8, 9, 10, 11, 12, 13, FixedZone("", 0)),
  Unix(81985467080890095, 0x76543210), // Time.sec: 0x0123456789ABCDEF
- {},  // nil location
+ {}, // nil location
  Date(1, 2, 3, 4, 5, 6, 7, FixedZone("", 32767*60)),
  Date(1, 2, 3, 4, 5, 6, 7, FixedZone("", -32768*60)),
 }
@@ -1021,7 +1021,39 @@ var nsDurationTests = []struct {
 func TestDurationNanoseconds(t *testing.T) {
  for _, tt := range nsDurationTests {
  if got := tt.d.Nanoseconds(); got != tt.want {
- t.Errorf("d.Nanoseconds() = %d; want: %d", got, tt.want)
+ t.Errorf("Duration(%s).Nanoseconds() = %d; want: %d", tt.d, got, tt.want)
+ }
+ }
+}
+
+var usDurationTests = []struct {
+ d Duration
+ want int64
+}{
+ {Duration(-1000), -1},
+ {Duration(1000), 1},
+}
+
+func TestDurationMicroseconds(t *testing.T) {
+ for _, tt := range usDurationTests {
+ if got := tt.d.Microseconds(); got != tt.want {
+ t.Errorf("Duration(%s).Microseconds() = %d; want: %d", tt.d, got, tt.want)
+ }
+ }
+}
+
+var msDurationTests = []struct {
+ d Duration
+ want int64
+}{
+ {Duration(-1000000), -1},
+ {Duration(1000000), 1},
+}
+
+func TestDurationMilliseconds(t *testing.T) {
+ for _, tt := range msDurationTests {
+ if got := tt.d.Milliseconds(); got != tt.want {
+ t.Errorf("Duration(%s).Milliseconds() = %d; want: %d", tt.d, got, tt.want)
  }
  }
 }
@@ -1036,7 +1068,7 @@ var secDurationTests = []struct {
 func TestDurationSeconds(t *testing.T) {
  for _, tt := range secDurationTests {
  if got := tt.d.Seconds(); got != tt.want {
- t.Errorf("d.Seconds() = %g; want: %g", got, tt.want)
+ t.Errorf("Duration(%s).Seconds() = %g; want: %g", tt.d, got, tt.want)
  }
  }
 }
@@ -1055,7 +1087,7 @@ var minDurationTests = []struct {
 func TestDurationMinutes(t *testing.T) {
  for _, tt := range minDurationTests {
  if got := tt.d.Minutes(); got != tt.want {
- t.Errorf("d.Minutes() = %g; want: %g", got, tt.want)
+ t.Errorf("Duration(%s).Minutes() = %g; want: %g", tt.d, got, tt.want)
  }
  }
 }
@@ -1074,7 +1106,7 @@ var hourDurationTests = []struct {
 func TestDurationHours(t *testing.T) {
  for _, tt := range hourDurationTests {
  if got := tt.d.Hours(); got != tt.want {
- t.Errorf("d.Hours() = %g; want: %g", got, tt.want)
+ t.Errorf("Duration(%s).Hours() = %g; want: %g", tt.d, got, tt.want)
  }
  }
 }