From 18d43d6006940b3a8ce7f879c3f8121496b817f0 Mon Sep 17 00:00:00 2001
From: Tony Chen <zhihui_chen@foxmail.com>
Date: Mon, 22 Feb 2021 17:50:43 +0800
Subject: [PATCH] add logger wrapper (#715)

* add logger wrapper
---
 log/log.go          |  4 +++-
 log/log_test.go     |  2 +-
 log/std.go          |  6 +++---
 log/std_test.go     |  2 +-
 log/wrapper.go      | 14 ++++++++++++++
 log/wrapper_test.go | 14 ++++++++++++++
 6 files changed, 36 insertions(+), 6 deletions(-)
 create mode 100644 log/wrapper.go
 create mode 100644 log/wrapper_test.go

diff --git a/log/log.go b/log/log.go
index 3884b6b54..8a89c7e6f 100644
--- a/log/log.go
+++ b/log/log.go
@@ -1,8 +1,10 @@
 package log
 
+import "os"
+
 var (
 	// DefaultLogger is default logger.
-	DefaultLogger Logger = NewStdLogger()
+	DefaultLogger Logger = NewStdLogger(os.Stderr)
 )
 
 // Logger is a logger interface.
diff --git a/log/log_test.go b/log/log_test.go
index d99fc121c..48cc60840 100644
--- a/log/log_test.go
+++ b/log/log_test.go
@@ -5,7 +5,7 @@ import (
 )
 
 func TestLogger(t *testing.T) {
-	logger := NewStdLogger()
+	logger := DefaultLogger
 	Debug(logger).Print("log", "test debug")
 	Info(logger).Print("log", "test info")
 	Warn(logger).Print("log", "test warn")
diff --git a/log/std.go b/log/std.go
index e5eaf6ffb..6f742092b 100644
--- a/log/std.go
+++ b/log/std.go
@@ -3,8 +3,8 @@ package log
 import (
 	"bytes"
 	"fmt"
+	"io"
 	"log"
-	"os"
 	"sync"
 )
 
@@ -16,9 +16,9 @@ type stdLogger struct {
 }
 
 // NewStdLogger new a std logger with options.
-func NewStdLogger() Logger {
+func NewStdLogger(w io.Writer) Logger {
 	return &stdLogger{
-		log: log.New(os.Stderr, "", log.LstdFlags),
+		log: log.New(w, "", log.LstdFlags),
 		pool: &sync.Pool{
 			New: func() interface{} {
 				return new(bytes.Buffer)
diff --git a/log/std_test.go b/log/std_test.go
index 60975856a..2cca13941 100644
--- a/log/std_test.go
+++ b/log/std_test.go
@@ -3,7 +3,7 @@ package log
 import "testing"
 
 func TestFmtLogger(t *testing.T) {
-	logger := NewStdLogger()
+	logger := DefaultLogger
 
 	Debug(logger).Print("log", "test debug")
 	Info(logger).Print("log", "test info")
diff --git a/log/wrapper.go b/log/wrapper.go
new file mode 100644
index 000000000..0330a853d
--- /dev/null
+++ b/log/wrapper.go
@@ -0,0 +1,14 @@
+package log
+
+type wrapper []Logger
+
+func (w wrapper) Print(pairs ...interface{}) {
+	for _, p := range w {
+		p.Print(pairs...)
+	}
+}
+
+// Wrap wraps multi logger.
+func Wrap(l ...Logger) Logger {
+	return wrapper(l)
+}
diff --git a/log/wrapper_test.go b/log/wrapper_test.go
new file mode 100644
index 000000000..e3652eb8a
--- /dev/null
+++ b/log/wrapper_test.go
@@ -0,0 +1,14 @@
+package log
+
+import (
+	"os"
+	"testing"
+)
+
+func TestWrapper(t *testing.T) {
+	out := NewStdLogger(os.Stdout)
+	err := NewStdLogger(os.Stderr)
+
+	l := Wrap(out, err)
+	l.Print("message", "test")
+}