git » debian:golang-blitiri-go-log » commit 521063f

diff --git a/log.go b/log.go
index 87bca24..96d84b8 100644
--- a/log.go
+++ b/log.go
@@ -193,20 +193,11 @@ func (l *Logger) Log(level Level, skip int, format string, a ...interface{}) err
 		return nil
 	}
 
-	// Message.
-	msg := fmt.Sprintf(format, a...)
+	b := strings.Builder{}
 
-	// Caller.
-	if l.LogCaller {
-		_, file, line, ok := runtime.Caller(1 + l.callerSkip + skip)
-		if !ok {
-			file = "unknown"
-		}
-		fl := fmt.Sprintf("%s:%-4d", filepath.Base(file), line)
-		if len(fl) > 18 {
-			fl = fl[len(fl)-18:]
-		}
-		msg = fmt.Sprintf("%-18s", fl) + " " + msg
+	// Time.
+	if l.LogTime {
+		b.WriteString(time.Now().Format("2006-01-02 15:04:05.000000 "))
 	}
 
 	// Level.
@@ -215,20 +206,30 @@ func (l *Logger) Log(level Level, skip int, format string, a ...interface{}) err
 		if !ok {
 			letter = strconv.Itoa(int(level))
 		}
-		msg = letter + " " + msg
+		b.WriteString(letter + " ")
 	}
 
-	// Time.
-	if l.LogTime {
-		msg = time.Now().Format("2006-01-02 15:04:05.000000 ") + msg
+	// Caller.
+	if l.LogCaller {
+		_, file, line, ok := runtime.Caller(1 + l.callerSkip + skip)
+		if !ok {
+			file = "unknown"
+		}
+		fl := fmt.Sprintf("%s:%-4d", filepath.Base(file), line)
+		if len(fl) > 18 {
+			fl = fl[len(fl)-18:]
+		}
+		fmt.Fprintf(&b, "%-18s ", fl)
 	}
 
-	if !strings.HasSuffix(msg, "\n") {
-		msg += "\n"
+	// Message.
+	if !strings.HasSuffix(format, "\n") {
+		format += "\n"
 	}
+	fmt.Fprintf(&b, format, a...)
 
 	l.Lock()
-	_, err := l.w.Write([]byte(msg))
+	_, err := l.w.Write([]byte(b.String()))
 	l.Unlock()
 	return err
 }