log: fix global logger (#2034)

* log: fix global logger

log/global.go

@@ -38,7 +38,7 @@ func SetLogger(logger Logger) {
 
 // GetLogger returns global logger appliance as logger in current process.
 func GetLogger() Logger {
-	return global
+	return global.GetLogger()
 }
 
 // Log Print log by level and keyvals.

log/helper_test.go

@@ -73,7 +73,10 @@ func TestContext(t *testing.T) {
 
 func Trace() Valuer {
 	return func(ctx context.Context) interface{} {
-		s := ctx.Value(traceKey{}).(string)
+		s, ok := ctx.Value(traceKey{}).(string)
+		if !ok {
+			return nil
+		}
 		return s
 	}
 }

log/log.go

@@ -14,7 +14,7 @@ type Logger interface {
 }
 
 type logger struct {
-	logs      []Logger
+	logger    Logger
 	prefix    []interface{}
 	hasValuer bool
 	ctx       context.Context
@@ -27,10 +27,8 @@ func (c *logger) Log(level Level, keyvals ...interface{}) error {
 		bindValues(c.ctx, kvs)
 	}
 	kvs = append(kvs, keyvals...)
-	for _, l := range c.logs {
-		if err := l.Log(level, kvs...); err != nil {
-			return err
-		}
+	if err := c.logger.Log(level, kvs...); err != nil {
+		return err
 	}
 	return nil
 }
@@ -39,13 +37,13 @@ func (c *logger) Log(level Level, keyvals ...interface{}) error {
 func With(l Logger, kv ...interface{}) Logger {
 	c, ok := l.(*logger)
 	if !ok {
-		return &logger{logs: []Logger{l}, prefix: kv, hasValuer: containsValuer(kv)}
+		return &logger{logger: l, prefix: kv, hasValuer: containsValuer(kv), ctx: context.Background()}
 	}
 	kvs := make([]interface{}, 0, len(c.prefix)+len(kv))
 	kvs = append(kvs, kv...)
 	kvs = append(kvs, c.prefix...)
 	return &logger{
-		logs:      c.logs,
+		logger:    l,
 		prefix:    kvs,
 		hasValuer: containsValuer(kvs),
 		ctx:       c.ctx,
@@ -57,17 +55,12 @@ func With(l Logger, kv ...interface{}) Logger {
 func WithContext(ctx context.Context, l Logger) Logger {
 	c, ok := l.(*logger)
 	if !ok {
-		return &logger{logs: []Logger{l}, ctx: ctx}
+		return &logger{logger: l, ctx: ctx}
 	}
 	return &logger{
-		logs:      c.logs,
+		logger:    l,
 		prefix:    c.prefix,
 		hasValuer: c.hasValuer,
 		ctx:       ctx,
 	}
 }
-
-// MultiLogger wraps multi logger.
-func MultiLogger(logs ...Logger) Logger {
-	return &logger{logs: logs}
-}

log/log_test.go

@@ -2,7 +2,6 @@ package log
 
 import (
 	"context"
-	"os"
 	"testing"
 )
 
@@ -12,14 +11,6 @@ func TestInfo(t *testing.T) {
 	_ = logger.Log(LevelInfo, "key1", "value1")
 }
 
-func TestWrapper(t *testing.T) {
-	out := NewStdLogger(os.Stdout)
-	err := NewStdLogger(os.Stderr)
-
-	l := With(MultiLogger(out, err), "ts", DefaultTimestamp, "caller", DefaultCaller)
-	_ = l.Log(LevelInfo, "msg", "test")
-}
-
 func TestWithContext(t *testing.T) {
 	WithContext(context.Background(), nil)
 }

log/value.go

@@ -9,9 +9,8 @@ import (
 )
 
 var (
-	defaultDepth = 3
 	// DefaultCaller is a Valuer that returns the file and line.
-	DefaultCaller = Caller(defaultDepth)
+	DefaultCaller = Caller(3)
 
 	// DefaultTimestamp is a Valuer that returns the current wallclock time.
 	DefaultTimestamp = Timestamp(time.RFC3339)