chore: add comments (#4618)

core/logx/logs.go

@@ -560,7 +560,7 @@ func shallLogStat() bool {
 // If we check shallLog here, the fmt.Sprint might be called even if the log level is not enabled.
 // The caller should check shallLog before calling this function.
 func writeDebug(val any, fields ...LogField) {
-	getWriter().Debug(val, combineGlobalFields(addCaller(fields...))...)
+	getWriter().Debug(val, mergeGlobalFields(addCaller(fields...))...)
 }
 
 // writeError writes v into the error log.
@@ -568,7 +568,7 @@ func writeDebug(val any, fields ...LogField) {
 // If we check shallLog here, the fmt.Sprint might be called even if the log level is not enabled.
 // The caller should check shallLog before calling this function.
 func writeError(val any, fields ...LogField) {
-	getWriter().Error(val, combineGlobalFields(addCaller(fields...))...)
+	getWriter().Error(val, mergeGlobalFields(addCaller(fields...))...)
 }
 
 // writeInfo writes v into info log.
@@ -576,7 +576,7 @@ func writeError(val any, fields ...LogField) {
 // If we check shallLog here, the fmt.Sprint might be called even if the log level is not enabled.
 // The caller should check shallLog before calling this function.
 func writeInfo(val any, fields ...LogField) {
-	getWriter().Info(val, combineGlobalFields(addCaller(fields...))...)
+	getWriter().Info(val, mergeGlobalFields(addCaller(fields...))...)
 }
 
 // writeSevere writes v into severe log.
@@ -592,7 +592,7 @@ func writeSevere(msg string) {
 // If we check shallLog here, the fmt.Sprint might be called even if the log level is not enabled.
 // The caller should check shallLog before calling this function.
 func writeSlow(val any, fields ...LogField) {
-	getWriter().Slow(val, combineGlobalFields(addCaller(fields...))...)
+	getWriter().Slow(val, mergeGlobalFields(addCaller(fields...))...)
 }
 
 // writeStack writes v into stack log.
@@ -608,5 +608,5 @@ func writeStack(msg string) {
 // If we check shallLog here, the fmt.Sprint might be called even if the log level is not enabled.
 // The caller should check shallLog before calling this function.
 func writeStat(msg string) {
-	getWriter().Stat(msg, combineGlobalFields(addCaller())...)
+	getWriter().Stat(msg, mergeGlobalFields(addCaller())...)
 }

core/logx/richlogger.go

@@ -206,8 +206,9 @@ func (l *richLogger) WithFields(fields ...LogField) Logger {
 
 func (l *richLogger) buildFields(fields ...LogField) []LogField {
 	fields = append(l.fields, fields...)
+	// caller field should always appear together with global fields
 	fields = append(fields, Field(callerKey, getCaller(callerDepth+l.callerSkip)))
-	fields = combineGlobalFields(fields)
+	fields = mergeGlobalFields(fields)
 
 	if l.ctx == nil {
 		return fields
@@ -235,7 +236,7 @@ func (l *richLogger) buildFields(fields ...LogField) []LogField {
 
 func (l *richLogger) debug(v any, fields ...LogField) {
 	if shallLog(DebugLevel) {
-		getWriter().Debug(v, (l.buildFields(fields...))...)
+		getWriter().Debug(v, l.buildFields(fields...)...)
 	}
 }
 

core/logx/writer.go

@@ -17,15 +17,27 @@ import (
 )
 
 type (
+	// Writer is the interface for writing logs.
+	// It's designed to let users customize their own log writer,
+	// such as writing logs to a kafka, a database, or using third-party loggers.
 	Writer interface {
+		// Alert sends an alert message, if your writer implemented alerting functionality.
 		Alert(v any)
+		// Close closes the writer.
 		Close() error
+		// Debug logs a message at debug level.
 		Debug(v any, fields ...LogField)
+		// Error logs a message at error level.
 		Error(v any, fields ...LogField)
+		// Info logs a message at info level.
 		Info(v any, fields ...LogField)
+		// Severe logs a message at severe level.
 		Severe(v any)
+		// Slow logs a message at slow level.
 		Slow(v any, fields ...LogField)
+		// Stack logs a message at error level.
 		Stack(v any)
+		// Stat logs a message at stat level.
 		Stat(v any, fields ...LogField)
 	}
 
@@ -324,20 +336,6 @@ func buildPlainFields(fields logEntry) []string {
 	return items
 }
 
-func combineGlobalFields(fields []LogField) []LogField {
-	globals := globalFields.Load()
-	if globals == nil {
-		return fields
-	}
-
-	gf := globals.([]LogField)
-	ret := make([]LogField, 0, len(gf)+len(fields))
-	ret = append(ret, gf...)
-	ret = append(ret, fields...)
-
-	return ret
-}
-
 func marshalJson(t interface{}) ([]byte, error) {
 	var buf bytes.Buffer
 	encoder := json.NewEncoder(&buf)
@@ -352,6 +350,20 @@ func marshalJson(t interface{}) ([]byte, error) {
 	return buf.Bytes(), err
 }
 
+func mergeGlobalFields(fields []LogField) []LogField {
+	globals := globalFields.Load()
+	if globals == nil {
+		return fields
+	}
+
+	gf := globals.([]LogField)
+	ret := make([]LogField, 0, len(gf)+len(fields))
+	ret = append(ret, gf...)
+	ret = append(ret, fields...)
+
+	return ret
+}
+
 func output(writer io.Writer, level string, val any, fields ...LogField) {
 	// only truncate string content, don't know how to truncate the values of other types.
 	if v, ok := val.(string); ok {