optimize: improve performance on log disabled (#3916)

core/logx/logs.go

@@ -18,13 +18,12 @@ const callerDepth = 4
 
 var (
 	timeFormat        = "2006-01-02T15:04:05.000Z07:00"
-	logLevel   uint32
 	encoding   uint32 = jsonEncodingType
 	// maxContentLength is used to truncate the log content, 0 for not truncating.
 	maxContentLength uint32
 	// use uint32 for atomic operations
-	disableLog  uint32
 	disableStat uint32
+	logLevel    uint32
 	options     logOptions
 	writer      = new(atomicWriter)
 	setupOnce   sync.Once
@@ -96,7 +95,7 @@ func Debugw(msg string, fields ...LogField) {
 
 // Disable disables the logging.
 func Disable() {
-	atomic.StoreUint32(&disableLog, 1)
+	atomic.StoreUint32(&logLevel, disableLevel)
 	writer.Store(nopWriter{})
 }
 
@@ -250,7 +249,7 @@ func SetLevel(level uint32) {
 
 // SetWriter sets the logging writer. It can be used to customize the logging.
 func SetWriter(w Writer) {
-	if atomic.LoadUint32(&disableLog) == 0 {
+	if atomic.LoadUint32(&logLevel) != disableLevel {
 		writer.Store(w)
 	}
 }

core/logx/logs_test.go

@@ -666,6 +666,7 @@ func TestDisable(t *testing.T) {
 	WithMaxSize(1024)(&opt)
 	assert.Nil(t, Close())
 	assert.Nil(t, Close())
+	assert.Equal(t, uint32(disableLevel), atomic.LoadUint32(&logLevel))
 }
 
 func TestDisableStat(t *testing.T) {
@@ -680,7 +681,7 @@ func TestDisableStat(t *testing.T) {
 }
 
 func TestSetWriter(t *testing.T) {
-	atomic.StoreUint32(&disableLog, 0)
+	atomic.StoreUint32(&logLevel, 0)
 	Reset()
 	SetWriter(nopWriter{})
 	assert.NotNil(t, writer.Load())

core/logx/vars.go

@@ -15,6 +15,8 @@ const (
 	ErrorLevel
 	// SevereLevel only log severe messages
 	SevereLevel
+	// disableLevel doesn't log any messages
+	disableLevel = 0xff
 )
 
 const (