logger: add Clone method

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

logger/default.go

@@ -39,6 +39,28 @@ func (l *defaultLogger) String() string {
 	return "micro"
 }
 
+func (l *defaultLogger) Clone(opts ...Option) Logger {
+	newopts := NewOptions(opts...)
+	oldopts := l.opts
+	for _, o := range opts {
+		o(&newopts)
+		o(&oldopts)
+	}
+
+	oldopts.Wrappers = newopts.Wrappers
+	l.Lock()
+	cl := &defaultLogger{opts: oldopts, logFunc: l.logFunc, logfFunc: l.logfFunc}
+	l.Unlock()
+
+	// wrap the Log func
+	for i := len(newopts.Wrappers); i > 0; i-- {
+		cl.logFunc = newopts.Wrappers[i-1].Log(cl.logFunc)
+		cl.logfFunc = newopts.Wrappers[i-1].Logf(cl.logfFunc)
+	}
+
+	return cl
+}
+
 func (l *defaultLogger) V(level Level) bool {
 	l.RLock()
 	ok := l.opts.Level.Enabled(level)
@@ -46,6 +68,12 @@ func (l *defaultLogger) V(level Level) bool {
 	return ok
 }
 
+func (l *defaultLogger) Level(level Level) {
+	l.Lock()
+	l.opts.Level = level
+	l.Unlock()
+}
+
 func (l *defaultLogger) Fields(fields ...interface{}) Logger {
 	nl := &defaultLogger{opts: l.opts, enc: l.enc}
 	if len(fields) == 0 {

logger/logger.go

@@ -19,8 +19,12 @@ var (
 type Logger interface {
 	// Init initialises options
 	Init(opts ...Option) error
+	// Clone create logger copy with new options
+	Clone(opts ...Option) Logger
 	// V compare provided verbosity level with current log level
 	V(level Level) bool
+	// Level sets the log level for logger
+	Level(level Level)
 	// The Logger options
 	Options() Options
 	// Fields set fields to always be logged with keyval pairs

logger/logger_test.go

@@ -7,6 +7,27 @@ import (
 	"testing"
 )
 
+func TestClone(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(WithLevel(TraceLevel), WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	nl := l.Clone(WithLevel(ErrorLevel))
+	if err := nl.Init(); err != nil {
+		t.Fatal(err)
+	}
+	nl.Info(ctx, "info message")
+	if len(buf.Bytes()) != 0 {
+		t.Fatal("message must not be logged")
+	}
+	l.Info(ctx, "info message")
+	if len(buf.Bytes()) == 0 {
+		t.Fatal("message must be logged")
+	}
+}
+
 func TestRedirectStdLogger(t *testing.T) {
 	buf := bytes.NewBuffer(nil)
 	l := NewLogger(WithLevel(TraceLevel), WithOutput(buf))

logger/wrapper.go

@@ -20,9 +20,7 @@ type Wrapper interface {
 	Logf(LogfFunc) LogfFunc
 }
 
-var (
-	_ Logger = &OmitLogger{}
-)
+var _ Logger = &OmitLogger{}
 
 type OmitLogger struct {
 	l Logger
@@ -40,6 +38,14 @@ func (w *OmitLogger) V(level Level) bool {
 	return w.l.V(level)
 }
 
+func (w *OmitLogger) Level(level Level) {
+	w.l.Level(level)
+}
+
+func (w *OmitLogger) Clone(opts ...Option) Logger {
+	return w.l.Clone(opts...)
+}
+
 func (w *OmitLogger) Options() Options {
 	return w.l.Options()
 }