diff --git a/common/alloc/buffer_test.go b/common/alloc/buffer_test.go
index 9d42170f..2b5ba9cd 100644
--- a/common/alloc/buffer_test.go
+++ b/common/alloc/buffer_test.go
@@ -1,8 +1,9 @@
-package alloc
+package alloc_test
 
 import (
 	"testing"
 
+	. "github.com/v2ray/v2ray-core/common/alloc"
 	v2testing "github.com/v2ray/v2ray-core/testing"
 	"github.com/v2ray/v2ray-core/testing/assert"
 )
diff --git a/common/log/access.go b/common/log/access.go
index f858edfb..f4501f61 100644
--- a/common/log/access.go
+++ b/common/log/access.go
@@ -1,7 +1,7 @@
 package log
 
 import (
-	"github.com/v2ray/v2ray-core/common/alloc"
+	"github.com/v2ray/v2ray-core/common/log/internal"
 	"github.com/v2ray/v2ray-core/common/serial"
 )
 
@@ -14,32 +14,12 @@ const (
 )
 
 var (
-	accessLoggerInstance logWriter = &noOpLogWriter{}
+	accessLoggerInstance internal.LogWriter = new(internal.NoOpLogWriter)
 )
 
-type accessLog struct {
-	From   serial.String
-	To     serial.String
-	Status AccessStatus
-	Reason serial.String
-}
-
-func (this *accessLog) Release() {
-	this.From = nil
-	this.To = nil
-	this.Reason = nil
-}
-
-func (this *accessLog) String() string {
-	b := alloc.NewSmallBuffer().Clear()
-	defer b.Release()
-
-	return b.AppendString(this.From.String()).AppendString(" ").AppendString(string(this.Status)).AppendString(" ").AppendString(this.To.String()).AppendString(" ").AppendString(this.Reason.String()).String()
-}
-
 // InitAccessLogger initializes the access logger to write into the give file.
 func InitAccessLogger(file string) error {
-	logger, err := newFileLogWriter(file)
+	logger, err := internal.NewFileLogWriter(file)
 	if err != nil {
 		Error("Failed to create access logger on file (", file, "): ", file, err)
 		return err
@@ -50,10 +30,10 @@ func InitAccessLogger(file string) error {
 
 // Access writes an access log.
 func Access(from, to serial.String, status AccessStatus, reason serial.String) {
-	accessLoggerInstance.Log(&accessLog{
+	accessLoggerInstance.Log(&internal.AccessLog{
 		From:   from,
 		To:     to,
-		Status: status,
+		Status: string(status),
 		Reason: reason,
 	})
 }
diff --git a/common/log/access_test.go b/common/log/access_test.go
deleted file mode 100644
index 30aa00aa..00000000
--- a/common/log/access_test.go
+++ /dev/null
@@ -1,36 +0,0 @@
-package log
-
-import (
-	"io/ioutil"
-	"os"
-	"testing"
-	"time"
-
-	"github.com/v2ray/v2ray-core/common/serial"
-	v2testing "github.com/v2ray/v2ray-core/testing"
-	"github.com/v2ray/v2ray-core/testing/assert"
-)
-
-func TestAccessLog(t *testing.T) {
-	v2testing.Current(t)
-
-	filename := "/tmp/test_access_log.log"
-	InitAccessLogger(filename)
-	_, err := os.Stat(filename)
-	assert.Error(err).IsNil()
-
-	Access(serial.StringLiteral("test_from"), serial.StringLiteral("test_to"), AccessAccepted, serial.StringLiteral("test_reason"))
-	<-time.After(2 * time.Second)
-
-	accessLoggerInstance.(*fileLogWriter).close()
-	accessLoggerInstance = &noOpLogWriter{}
-
-	content, err := ioutil.ReadFile(filename)
-	assert.Error(err).IsNil()
-
-	contentStr := serial.StringLiteral(content)
-	assert.String(contentStr).Contains(serial.StringLiteral("test_from"))
-	assert.String(contentStr).Contains(serial.StringLiteral("test_to"))
-	assert.String(contentStr).Contains(serial.StringLiteral("test_reason"))
-	assert.String(contentStr).Contains(serial.StringLiteral("accepted"))
-}
diff --git a/common/log/internal/log_entry.go b/common/log/internal/log_entry.go
new file mode 100644
index 00000000..abaa92d7
--- /dev/null
+++ b/common/log/internal/log_entry.go
@@ -0,0 +1,69 @@
+package internal
+
+import (
+	"fmt"
+
+	"github.com/v2ray/v2ray-core/common"
+	"github.com/v2ray/v2ray-core/common/alloc"
+	"github.com/v2ray/v2ray-core/common/serial"
+)
+
+type LogEntry interface {
+	common.Releasable
+	serial.String
+}
+
+type ErrorLog struct {
+	Prefix string
+	Values []interface{}
+}
+
+func (this *ErrorLog) Release() {
+	for index := range this.Values {
+		this.Values[index] = nil
+	}
+	this.Values = nil
+}
+
+func (this *ErrorLog) String() string {
+	b := alloc.NewSmallBuffer().Clear()
+	defer b.Release()
+
+	b.AppendString(this.Prefix)
+
+	for _, value := range this.Values {
+		switch typedVal := value.(type) {
+		case string:
+			b.AppendString(typedVal)
+		case *string:
+			b.AppendString(*typedVal)
+		case serial.String:
+			b.AppendString(typedVal.String())
+		case error:
+			b.AppendString(typedVal.Error())
+		default:
+			b.AppendString(fmt.Sprint(value))
+		}
+	}
+	return b.String()
+}
+
+type AccessLog struct {
+	From   serial.String
+	To     serial.String
+	Status string
+	Reason serial.String
+}
+
+func (this *AccessLog) Release() {
+	this.From = nil
+	this.To = nil
+	this.Reason = nil
+}
+
+func (this *AccessLog) String() string {
+	b := alloc.NewSmallBuffer().Clear()
+	defer b.Release()
+
+	return b.AppendString(this.From.String()).AppendString(" ").AppendString(this.Status).AppendString(" ").AppendString(this.To.String()).AppendString(" ").AppendString(this.Reason.String()).String()
+}
diff --git a/common/log/internal/log_entry_test.go b/common/log/internal/log_entry_test.go
new file mode 100644
index 00000000..f406320d
--- /dev/null
+++ b/common/log/internal/log_entry_test.go
@@ -0,0 +1,27 @@
+package internal_test
+
+import (
+	"testing"
+
+	. "github.com/v2ray/v2ray-core/common/log/internal"
+	"github.com/v2ray/v2ray-core/common/serial"
+	v2testing "github.com/v2ray/v2ray-core/testing"
+	"github.com/v2ray/v2ray-core/testing/assert"
+)
+
+func TestAccessLog(t *testing.T) {
+	v2testing.Current(t)
+
+	entry := &AccessLog{
+		From:   serial.StringLiteral("test_from"),
+		To:     serial.StringLiteral("test_to"),
+		Status: "Accepted",
+		Reason: serial.StringLiteral("test_reason"),
+	}
+
+	entryStr := entry.String()
+	assert.StringLiteral(entryStr).Contains(serial.StringLiteral("test_from"))
+	assert.StringLiteral(entryStr).Contains(serial.StringLiteral("test_to"))
+	assert.StringLiteral(entryStr).Contains(serial.StringLiteral("test_reason"))
+	assert.StringLiteral(entryStr).Contains(serial.StringLiteral("Accepted"))
+}
diff --git a/common/log/log_writer.go b/common/log/internal/log_writer.go
similarity index 57%
rename from common/log/log_writer.go
rename to common/log/internal/log_writer.go
index a783a86d..6e65f900 100644
--- a/common/log/log_writer.go
+++ b/common/log/internal/log_writer.go
@@ -1,50 +1,45 @@
-package log
+package internal
 
 import (
-	"io"
 	"log"
 	"os"
 
 	"github.com/v2ray/v2ray-core/common/platform"
 )
 
-func createLogger(writer io.Writer) *log.Logger {
-	return log.New(writer, "", log.Ldate|log.Ltime)
-}
-
-type logWriter interface {
+type LogWriter interface {
 	Log(LogEntry)
 }
 
-type noOpLogWriter struct {
+type NoOpLogWriter struct {
 }
 
-func (this *noOpLogWriter) Log(entry LogEntry) {
+func (this *NoOpLogWriter) Log(entry LogEntry) {
 	entry.Release()
 }
 
-type stdOutLogWriter struct {
+type StdOutLogWriter struct {
 	logger *log.Logger
 }
 
-func newStdOutLogWriter() logWriter {
-	return &stdOutLogWriter{
-		logger: createLogger(os.Stdout),
+func NewStdOutLogWriter() LogWriter {
+	return &StdOutLogWriter{
+		logger: log.New(os.Stdout, "", log.Ldate|log.Ltime),
 	}
 }
 
-func (this *stdOutLogWriter) Log(log LogEntry) {
+func (this *StdOutLogWriter) Log(log LogEntry) {
 	this.logger.Print(log.String() + platform.LineSeparator())
 	log.Release()
 }
 
-type fileLogWriter struct {
+type FileLogWriter struct {
 	queue  chan LogEntry
 	logger *log.Logger
 	file   *os.File
 }
 
-func (this *fileLogWriter) Log(log LogEntry) {
+func (this *FileLogWriter) Log(log LogEntry) {
 	select {
 	case this.queue <- log:
 	default:
@@ -53,7 +48,7 @@ func (this *fileLogWriter) Log(log LogEntry) {
 	}
 }
 
-func (this *fileLogWriter) run() {
+func (this *FileLogWriter) run() {
 	for {
 		entry, open := <-this.queue
 		if !open {
@@ -65,16 +60,16 @@ func (this *fileLogWriter) run() {
 	}
 }
 
-func (this *fileLogWriter) close() {
+func (this *FileLogWriter) Close() {
 	this.file.Close()
 }
 
-func newFileLogWriter(path string) (*fileLogWriter, error) {
+func NewFileLogWriter(path string) (*FileLogWriter, error) {
 	file, err := os.OpenFile(path, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
 	if err != nil {
 		return nil, err
 	}
-	logger := &fileLogWriter{
+	logger := &FileLogWriter{
 		queue:  make(chan LogEntry, 16),
 		logger: log.New(file, "", log.Ldate|log.Ltime),
 		file:   file,
diff --git a/common/log/internal/log_writer_test.go b/common/log/internal/log_writer_test.go
new file mode 100644
index 00000000..e4a75bbb
--- /dev/null
+++ b/common/log/internal/log_writer_test.go
@@ -0,0 +1 @@
+package internal_test
diff --git a/common/log/log.go b/common/log/log.go
index 661c37e0..82f99bd6 100644
--- a/common/log/log.go
+++ b/common/log/log.go
@@ -1,13 +1,11 @@
 package log
 
 import (
-	"fmt"
-
-	"github.com/v2ray/v2ray-core/common"
-	"github.com/v2ray/v2ray-core/common/alloc"
-	"github.com/v2ray/v2ray-core/common/serial"
+	"github.com/v2ray/v2ray-core/common/log/internal"
 )
 
+type LogLevel int
+
 const (
 	DebugLevel   = LogLevel(0)
 	InfoLevel    = LogLevel(1)
@@ -16,86 +14,43 @@ const (
 	NoneLevel    = LogLevel(999)
 )
 
-type LogEntry interface {
-	common.Releasable
-	serial.String
-}
-
-type errorLog struct {
-	prefix string
-	values []interface{}
-}
-
-func (this *errorLog) Release() {
-	for index := range this.values {
-		this.values[index] = nil
-	}
-	this.values = nil
-}
-
-func (this *errorLog) String() string {
-	b := alloc.NewSmallBuffer().Clear()
-	defer b.Release()
-
-	b.AppendString(this.prefix)
-
-	for _, value := range this.values {
-		switch typedVal := value.(type) {
-		case string:
-			b.AppendString(typedVal)
-		case *string:
-			b.AppendString(*typedVal)
-		case serial.String:
-			b.AppendString(typedVal.String())
-		case error:
-			b.AppendString(typedVal.Error())
-		default:
-			b.AppendString(fmt.Sprint(value))
-		}
-	}
-	return b.String()
-}
-
 var (
-	noOpLoggerInstance   logWriter = &noOpLogWriter{}
-	streamLoggerInstance logWriter = newStdOutLogWriter()
+	streamLoggerInstance internal.LogWriter = internal.NewStdOutLogWriter()
 
-	debugLogger   = noOpLoggerInstance
-	infoLogger    = noOpLoggerInstance
-	warningLogger = streamLoggerInstance
-	errorLogger   = streamLoggerInstance
+	debugLogger   internal.LogWriter = streamLoggerInstance
+	infoLogger    internal.LogWriter = streamLoggerInstance
+	warningLogger internal.LogWriter = streamLoggerInstance
+	errorLogger   internal.LogWriter = streamLoggerInstance
 )
 
-type LogLevel int
-
 func SetLogLevel(level LogLevel) {
-	debugLogger = noOpLoggerInstance
+	debugLogger = new(internal.NoOpLogWriter)
 	if level <= DebugLevel {
 		debugLogger = streamLoggerInstance
 	}
 
-	infoLogger = noOpLoggerInstance
+	infoLogger = new(internal.NoOpLogWriter)
 	if level <= InfoLevel {
 		infoLogger = streamLoggerInstance
 	}
 
-	warningLogger = noOpLoggerInstance
+	warningLogger = new(internal.NoOpLogWriter)
 	if level <= WarningLevel {
 		warningLogger = streamLoggerInstance
 	}
 
-	errorLogger = noOpLoggerInstance
+	errorLogger = new(internal.NoOpLogWriter)
 	if level <= ErrorLevel {
 		errorLogger = streamLoggerInstance
 	}
 
 	if level == NoneLevel {
-		accessLoggerInstance = noOpLoggerInstance
+		accessLoggerInstance = new(internal.NoOpLogWriter)
 	}
 }
 
 func InitErrorLogger(file string) error {
-	logger, err := newFileLogWriter(file)
+	logger, err := internal.NewFileLogWriter(file)
 	if err != nil {
 		Error("Failed to create error logger on file (", file, "): ", err)
 		return err
@@ -106,32 +61,32 @@ func InitErrorLogger(file string) error {
 
 // Debug outputs a debug log with given format and optional arguments.
 func Debug(v ...interface{}) {
-	debugLogger.Log(&errorLog{
-		prefix: "[Debug]",
-		values: v,
+	debugLogger.Log(&internal.ErrorLog{
+		Prefix: "[Debug]",
+		Values: v,
 	})
 }
 
 // Info outputs an info log with given format and optional arguments.
 func Info(v ...interface{}) {
-	infoLogger.Log(&errorLog{
-		prefix: "[Info]",
-		values: v,
+	infoLogger.Log(&internal.ErrorLog{
+		Prefix: "[Info]",
+		Values: v,
 	})
 }
 
 // Warning outputs a warning log with given format and optional arguments.
 func Warning(v ...interface{}) {
-	warningLogger.Log(&errorLog{
-		prefix: "[Warning]",
-		values: v,
+	warningLogger.Log(&internal.ErrorLog{
+		Prefix: "[Warning]",
+		Values: v,
 	})
 }
 
 // Error outputs an error log with given format and optional arguments.
 func Error(v ...interface{}) {
-	errorLogger.Log(&errorLog{
-		prefix: "[Error]",
-		values: v,
+	errorLogger.Log(&internal.ErrorLog{
+		Prefix: "[Error]",
+		Values: v,
 	})
 }
diff --git a/common/log/log_test.go b/common/log/log_test.go
deleted file mode 100644
index 2741024a..00000000
--- a/common/log/log_test.go
+++ /dev/null
@@ -1,40 +0,0 @@
-package log
-
-import (
-	"bytes"
-	"log"
-	"testing"
-
-	"github.com/v2ray/v2ray-core/common/platform"
-	"github.com/v2ray/v2ray-core/common/serial"
-	v2testing "github.com/v2ray/v2ray-core/testing"
-	"github.com/v2ray/v2ray-core/testing/assert"
-)
-
-func TestLogLevelSetting(t *testing.T) {
-	v2testing.Current(t)
-
-	assert.Pointer(debugLogger).Equals(noOpLoggerInstance)
-	SetLogLevel(DebugLevel)
-	assert.Pointer(debugLogger).Equals(streamLoggerInstance)
-
-	SetLogLevel(InfoLevel)
-	assert.Pointer(debugLogger).Equals(noOpLoggerInstance)
-	assert.Pointer(infoLogger).Equals(streamLoggerInstance)
-}
-
-func TestStreamLogger(t *testing.T) {
-	v2testing.Current(t)
-
-	buffer := bytes.NewBuffer(make([]byte, 0, 1024))
-	infoLogger = &stdOutLogWriter{
-		logger: log.New(buffer, "", 0),
-	}
-	Info("Test ", "Stream Logger", " Format")
-	assert.StringLiteral(string(buffer.Bytes())).Equals("[Info]Test Stream Logger Format" + platform.LineSeparator())
-
-	buffer.Reset()
-	errorLogger = infoLogger
-	Error("Test ", serial.StringLiteral("literal"), " Format")
-	assert.StringLiteral(string(buffer.Bytes())).Equals("[Error]Test literal Format" + platform.LineSeparator())
-}