refactor: use syscall to set time on Linux and macOS

go.mod

@@ -5,6 +5,7 @@ go 1.18
 require (
 	github.com/spf13/cobra v1.4.0
 	golang.org/x/exp v0.0.0-20220414153411-bcd21879b8fd
+	golang.org/x/sys v0.0.0-20220422013727-9388b58f7150
 )
 
 require (

go.sum

@@ -8,5 +8,7 @@ github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 golang.org/x/exp v0.0.0-20220414153411-bcd21879b8fd h1:zVFyTKZN/Q7mNRWSs1GOYnHM9NiFSJ54YVRsD0rNWT4=
 golang.org/x/exp v0.0.0-20220414153411-bcd21879b8fd/go.mod h1:lgLbSvA5ygNOMpwM/9anMpWVlVJ7Z+cHWq/eFuinpGE=
+golang.org/x/sys v0.0.0-20220422013727-9388b58f7150 h1:xHms4gcpe1YE7A3yIllJXP16CMAGuqwO2lX1mTyyRRc=
+golang.org/x/sys v0.0.0-20220422013727-9388b58f7150/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

pkg/htp/service.go

@@ -1,18 +1,5 @@
 package htp
 
-import (
-	"fmt"
-	"os/exec"
-	"runtime"
-	"time"
-)
-
-const (
-	// isoFormat   = "2006-01-02T15:04:05.000Z07:00"
-	// unixFormat  = "Mon Jan _2 15:04:05.000 MST 2006"
-	macosFormat = "0102150406.05"
-)
-
 type SyncTrace struct {
 	Before func(i int) bool
 	After  func(i int, round *SyncRound) bool
@@ -47,24 +34,3 @@ func Sync(client *SyncClient, model *SyncModel, trace *SyncTrace) error {
 
 	return nil
 }
-
-func SyncSystem(model *SyncModel) error {
-	switch runtime.GOOS {
-	case "windows":
-		arg := fmt.Sprintf("Set-Date -Adjust $([TimeSpan]::FromSeconds(%+.3f))", -model.Offset().Sec())
-		return exec.Command("powershell", "-Command", arg).Run()
-
-	case "linux":
-		arg := fmt.Sprintf("%+.3f seconds", -model.Offset().Sec())
-		return exec.Command("date", "-s", arg).Run()
-
-	case "darwin":
-		arg := model.Now().Add(time.Second).Format(macosFormat)
-		sleep := time.Duration(int(time.Second) - model.Now().Nanosecond())
-		time.Sleep(sleep)
-		return exec.Command("date", arg).Run()
-
-	default:
-		return fmt.Errorf("system not supported: %s", runtime.GOOS)
-	}
-}

pkg/htp/service_darwin.go

@@ -0,0 +1,14 @@
+//go:build darwin
+
+package htp
+
+import "golang.org/x/sys/unix"
+
+func SyncSystem(model *SyncModel) error {
+	now := model.Now()
+	tv := &unix.Timeval{
+		Sec:  now.Unix(),
+		Usec: int32(now.UnixMicro() % 1_000_000),
+	}
+	return unix.Settimeofday(tv)
+}

pkg/htp/service_linux_386.go

@@ -0,0 +1,14 @@
+//go:build linux && 386
+
+package htp
+
+import "golang.org/x/sys/unix"
+
+func SyncSystem(model *SyncModel) error {
+	now := model.Now()
+	tv := &unix.Timeval{
+		Sec:  int32(now.Unix()),
+		Usec: int32(now.UnixMicro() % 1_000_000),
+	}
+	return unix.Settimeofday(tv)
+}

pkg/htp/service_linux_x64.go

@@ -0,0 +1,14 @@
+//go:build linux && (amd64 || arm64)
+
+package htp
+
+import "golang.org/x/sys/unix"
+
+func SyncSystem(model *SyncModel) error {
+	now := model.Now()
+	tv := &unix.Timeval{
+		Sec:  now.Unix(),
+		Usec: now.UnixMicro() % 1_000_000,
+	}
+	return unix.Settimeofday(tv)
+}

pkg/htp/service_unknown.go

@@ -0,0 +1,12 @@
+//go:build !(darwin || (linux && (amd64 || arm64 || 386)) || windows)
+
+package htp
+
+import (
+	"fmt"
+	"runtime"
+)
+
+func SyncSystem(model *SyncModel) error {
+	return fmt.Errorf("system not supported: %s", runtime.GOOS)
+}

pkg/htp/service_windows.go

@@ -0,0 +1,13 @@
+//go:build windows
+
+package htp
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+func SyncSystem(model *SyncModel) error {
+	arg := fmt.Sprintf("Set-Date -Adjust $([TimeSpan]::FromSeconds(%+.3f))", -model.Offset().Sec())
+	return exec.Command("powershell", "-Command", arg).Run()
+}