[middleware](Placeholder) Significantly improve perf when log message not contains % char (#83)

Author: instabledesign

middleware/benchmark_test.go

@@ -55,6 +55,16 @@ func getEntries() []logger.Entry {
 				Add("my_key4", "my_value4").
 				Add("my_key5", "my_value5"),
 		},
+		{
+			Message: "test message",
+			Level:   logger.WarningLevel,
+			Context: logger.NewContext().
+				Add("my_key", "my_value").
+				Add("my_key2", "my_value2").
+				Add("my_key3", "my_value3").
+				Add("my_key4", "my_value4").
+				Add("my_key5", "my_value5"),
+		},
 	}
 }
 

middleware/placeholder.go

@@ -10,7 +10,7 @@ import (
 func Placeholder() logger.MiddlewareInterface {
 	return func(handler logger.HandlerInterface) logger.HandlerInterface {
 		return func(entry logger.Entry) error {
-			if entry.Context != nil {
+			if entry.Context != nil && strings.Contains(entry.Message, "%") {
 				msg := entry.Message
 				for n, f := range *entry.Context {
 					msg = strings.Replace(msg, "%"+n+"%", f.String(), -1)