rename file and add some test case

Author: hjweddie

mysql/util.go

@@ -13,6 +13,7 @@ import (
 	mrand "math/rand"
 	"runtime"
 	"strings"
+	"time"
 
 	"github.com/Masterminds/semver"
 	"github.com/go-mysql-org/go-mysql/utils"
@@ -132,7 +133,7 @@ func RandomBuf(size int) []byte {
 	// When this project supports golang 1.20 as a minimum, then this mrand.New(...)
 	// line can be eliminated and the random number can be generated by simply
 	// calling mrand.Intn()
-	random := mrand.New(mrand.NewSource(utils.Now().UTC().UnixNano()))
+	random := mrand.New(mrand.NewSource(time.Now().UTC().UnixNano()))
 	min, max := 30, 127
 	for i := 0; i < size; i++ {
 		buf[i] = byte(min + random.Intn(max-min))

utils/now.go

@@ -1,19 +1,7 @@
-//go:build linux || darwin
+//go:build !unix
 
 package utils
 
-import (
-	"syscall"
-	"time"
-)
+import "time"
 
-// Now is a faster method to get current time
-func Now() time.Time {
-	var tv syscall.Timeval
-	if err := syscall.Gettimeofday(&tv); nil != err {
-		// If it failed at syscall, use time package instead
-		return time.Now()
-	}
-
-	return time.Unix(0, syscall.TimevalToNsec(tv))
-}
+var Now = time.Now

utils/now2.go

@@ -0,0 +1,19 @@
+//go:build unix
+
+package utils
+
+import (
+	"syscall"
+	"time"
+)
+
+// Now is a faster method to get current time
+func Now() time.Time {
+	var tv syscall.Timeval
+	if err := syscall.Gettimeofday(&tv); nil != err {
+		// If it failed at syscall, use time package instead
+		return time.Now()
+	}
+
+	return time.Unix(0, syscall.TimevalToNsec(tv))
+}

utils/now_unix.go

@@ -0,0 +1,44 @@
+//go:build unix
+
+package utils
+
+import (
+	"fmt"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCustomTimeNow(t *testing.T) {
+	precision = time.Millisecond
+
+	for i := 0; i < 1000; i++ {
+		timestamp := time.Now().UnixNano()
+		customTimestamp := Now().UnixNano()
+
+		// two timestamp should within 1 percistion
+		assert.Equal(t, timestamp <= customTimestamp, true, fmt.Sprintf("Loop %d: timestamp <= customTimestamp should be true. timestamp: %d, customTimestamp: %d", i, timestamp, customTimestamp))
+		assert.Equal(t, timestamp+int64(precision) >= customTimestamp, true, fmt.Sprintf("Loop: %d: customTimestamp should within %s. timestamp: %d, customTimestamp: %d", i, precision.String(), timestamp, customTimestamp))
+
+		os.Setenv("TZ", fmt.Sprintf("UTC%d", 14-i%27))
+		time.Sleep(time.Nanosecond)
+	}
+}
+
+func BenchmarkGoTimeNow(t *testing.B) {
+	t.ResetTimer()
+	for n := 0; n < t.N; n++ {
+		_ = time.Now()
+	}
+	t.StopTimer()
+}
+
+func BenchmarkCustomTimeNow(t *testing.B) {
+	t.ResetTimer()
+	for n := 0; n < t.N; n++ {
+		_ = Now()
+	}
+	t.StopTimer()
+}