logger: change logger interface

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

logger/default.go

@@ -40,7 +40,6 @@ func (l *defaultLogger) Init(opts ...Option) error {
 		l.logFunc = l.opts.Wrappers[i-1].Log(l.logFunc)
 		l.logfFunc = l.opts.Wrappers[i-1].Logf(l.logfFunc)
 	}
-
 	l.Unlock()
 	return nil
 }
@@ -56,26 +55,20 @@ func (l *defaultLogger) V(level Level) bool {
 	return ok
 }
 
-func (l *defaultLogger) Fields(fields map[string]interface{}) Logger {
+func (l *defaultLogger) Fields(fields ...interface{}) Logger {
 	nl := &defaultLogger{opts: l.opts, enc: l.enc}
-	nl.opts.Fields = make(map[string]interface{}, len(l.opts.Fields)+len(fields))
+	if len(fields) == 0 {
-	l.RLock()
+		return nl
-	for k, v := range l.opts.Fields {
+	} else if len(fields)%2 != 0 {
-		nl.opts.Fields[k] = v
+		fields = fields[:len(fields)-1]
-	}
-	l.RUnlock()
-
-	for k, v := range fields {
-		nl.opts.Fields[k] = v
 	}
+	nl.opts.Fields = append(l.opts.Fields, fields...)
 	return nl
 }
 
-func copyFields(src map[string]interface{}) map[string]interface{} {
+func copyFields(src []interface{}) []interface{} {
-	dst := make(map[string]interface{}, len(src))
+	dst := make([]interface{}, len(src))
-	for k, v := range src {
+	copy(dst, src)
-		dst[k] = v
-	}
 	return dst
 }
 
@@ -162,19 +155,23 @@ func (l *defaultLogger) Log(ctx context.Context, level Level, args ...interface{
 	fields := copyFields(l.opts.Fields)
 	l.RUnlock()
 
-	fields["level"] = level.String()
+	fields = append(fields, "level", level.String())
 
 	if _, file, line, ok := runtime.Caller(l.opts.CallerSkipCount); ok {
-		fields["caller"] = fmt.Sprintf("%s:%d", logCallerfilePath(file), line)
+		fields = append(fields, "caller", fmt.Sprintf("%s:%d", logCallerfilePath(file), line))
 	}
+	fields = append(fields, "timestamp", time.Now().Format("2006-01-02 15:04:05"))
 
-	fields["timestamp"] = time.Now().Format("2006-01-02 15:04:05")
 	if len(args) > 0 {
-		fields["msg"] = fmt.Sprint(args...)
+		fields = append(fields, "msg", fmt.Sprint(args...))
 	}
 
+	out := make(map[string]interface{}, len(fields)/2)
+	for i := 0; i < len(fields); i += 2 {
+		out[fields[i].(string)] = fields[i+1]
+	}
 	l.RLock()
-	_ = l.enc.Encode(fields)
+	_ = l.enc.Encode(out)
 	l.RUnlock()
 }
 
@@ -187,30 +184,30 @@ func (l *defaultLogger) Logf(ctx context.Context, level Level, msg string, args
 	fields := copyFields(l.opts.Fields)
 	l.RUnlock()
 
-	fields["level"] = level.String()
+	fields = append(fields, "level", level.String())
 
 	if _, file, line, ok := runtime.Caller(l.opts.CallerSkipCount); ok {
-		fields["caller"] = fmt.Sprintf("%s:%d", logCallerfilePath(file), line)
+		fields = append(fields, "caller", fmt.Sprintf("%s:%d", logCallerfilePath(file), line))
 	}
 
-	fields["timestamp"] = time.Now().Format("2006-01-02 15:04:05")
+	fields = append(fields, "timestamp", time.Now().Format("2006-01-02 15:04:05"))
 	if len(args) > 0 {
-		fields["msg"] = fmt.Sprintf(msg, args...)
+		fields = append(fields, "msg", fmt.Sprintf(msg, args...))
 	} else if msg != "" {
-		fields["msg"] = msg
+		fields = append(fields, "msg", msg)
+	}
+
+	out := make(map[string]interface{}, len(fields)/2)
+	for i := 0; i < len(fields); i += 2 {
+		out[fields[i].(string)] = fields[i+1]
 	}
 	l.RLock()
-	_ = l.enc.Encode(fields)
+	_ = l.enc.Encode(out)
 	l.RUnlock()
 }
 
 func (l *defaultLogger) Options() Options {
-	// not guard against options Context values
+	return l.opts
-	l.RLock()
-	opts := l.opts
-	opts.Fields = copyFields(l.opts.Fields)
-	l.RUnlock()
-	return opts
 }
 
 // NewLogger builds a new logger based on options

logger/logger.go

@@ -20,8 +20,8 @@ type Logger interface {
 	V(level Level) bool
 	// The Logger options
 	Options() Options
-	// Fields set fields to always be logged
+	// Fields set fields to always be logged with keyval pairs
-	Fields(fields map[string]interface{}) Logger
+	Fields(fields ...interface{}) Logger
 	// Info level message
 	Info(ctx context.Context, args ...interface{})
 	// Trace level message
@@ -54,6 +54,9 @@ type Logger interface {
 	String() string
 }
 
+// Field contains keyval pair
+type Field interface{}
+
 // Info writes msg to default logger on info level
 func Info(ctx context.Context, args ...interface{}) {
 	DefaultLogger.Info(ctx, args...)
@@ -125,6 +128,6 @@ func Init(opts ...Option) error {
 }
 
 // Fields create logger with specific fields
-func Fields(fields map[string]interface{}) Logger {
+func Fields(fields ...interface{}) Logger {
-	return DefaultLogger.Fields(fields)
+	return DefaultLogger.Fields(fields...)
 }

logger/logger_test.go

@@ -15,7 +15,7 @@ func TestLogger(t *testing.T) {
 	}
 	l.Trace(ctx, "trace_msg1")
 	l.Warn(ctx, "warn_msg1")
-	l.Fields(map[string]interface{}{"error": "test"}).Info(ctx, "error message")
+	l.Fields("error", "test").Info(ctx, "error message")
 	l.Warn(ctx, "first", " ", "second")
 	if !bytes.Contains(buf.Bytes(), []byte(`"level":"trace","msg":"trace_msg1"`)) {
 		t.Fatalf("logger error, buf %s", buf.Bytes())

logger/options.go

@@ -16,7 +16,7 @@ type Options struct {
 	// Context holds exernal options
 	Context context.Context
 	// Fields holds additional metadata
-	Fields map[string]interface{}
+	Fields []interface{}
 	// Name holds the logger name
 	Name string
 	// CallerSkipCount number of frmaes to skip
@@ -31,7 +31,7 @@ type Options struct {
 func NewOptions(opts ...Option) Options {
 	options := Options{
 		Level:           DefaultLevel,
-		Fields:          make(map[string]interface{}),
+		Fields:          make([]interface{}, 0, 6),
 		Out:             os.Stderr,
 		CallerSkipCount: DefaultCallerSkipCount,
 		Context:         context.Background(),
@@ -43,7 +43,7 @@ func NewOptions(opts ...Option) Options {
 }
 
 // WithFields set default fields for the logger
-func WithFields(fields map[string]interface{}) Option {
+func WithFields(fields ...interface{}) Option {
 	return func(o *Options) {
 		o.Fields = fields
 	}

logger/wrapper.go

@@ -44,8 +44,8 @@ func (w *OmitLogger) Options() Options {
 	return w.l.Options()
 }
 
-func (w *OmitLogger) Fields(fields map[string]interface{}) Logger {
+func (w *OmitLogger) Fields(fields ...interface{}) Logger {
-	return w.l.Fields(fields)
+	return w.l.Fields(fields...)
 }
 
 func (w *OmitLogger) Info(ctx context.Context, args ...interface{}) {