add string tokens

pkg/etcdmtr/log.go

@@ -25,40 +25,66 @@ type ELog struct {
 	Format       *LogFormat
 }
 
-type LogFormatToken int64
+type LogFormatTokenValue int64
 
 const (
-	LOGFORMAT_TIMESTAMP LogFormatToken = iota
+	LOGFORMAT_STRING LogFormatTokenValue = iota
+	LOGFORMAT_TIMESTAMP
 	LOGFORMAT_NAME
 	LOGFORMAT_MESSAGE
 )
 
-type LogFormat struct {
-	Next  *LogFormat
-	Token LogFormatToken
+type LogFormatToken struct {
+	Next  *LogFormatToken
+	Token LogFormatTokenValue
+	Value string
 }
 
-func NewFormat(firstToken LogFormatToken) *LogFormat {
-	return &LogFormat{
-		Token: firstToken,
-	}
+type LogFormat struct {
+	Head *LogFormatToken
+}
+
+func NewFormat() *LogFormat {
+	return &LogFormat{}
 }
 
 // Append appends the token/node to the end of the chain, and returns the node Append was called on.
-func (f *LogFormat) Append(token LogFormatToken) *LogFormat {
-	tail := f
+func (f *LogFormat) Append(token *LogFormatToken) *LogFormat {
+	if f.Head == nil {
+		f.Head = token
+		return f
+	}
+	tail := f.Head
 	for tail.Next != nil {
 		tail = tail.Next
 	}
-	tail.Next = &LogFormat{
-		Token: token,
-	}
+	tail.Next = token
 	return f
 }
 
+// AppendToken isn't valid for LOGFORMAT_STRING
+func (f *LogFormat) AppendToken(token LogFormatTokenValue) *LogFormat {
+	return f.Append(&LogFormatToken{
+		Token: token,
+	})
+}
+
+func (f *LogFormat) AppendString(str string) *LogFormat {
+	return f.Append(&LogFormatToken{
+		Token: LOGFORMAT_STRING,
+		Value: str,
+	})
+}
+
 func NewRootLogger() *ELog {
 	logger := &ELog{
-		Format: NewFormat(LOGFORMAT_TIMESTAMP).Append(LOGFORMAT_NAME).Append(LOGFORMAT_MESSAGE),
+		Format: NewFormat().
+			AppendString("[").
+			AppendToken(LOGFORMAT_TIMESTAMP).
+			AppendString("] ").
+			AppendToken(LOGFORMAT_NAME).
+			AppendString(": ").
+			AppendToken(LOGFORMAT_MESSAGE),
 	}
 	return logger
 }
@@ -68,9 +94,11 @@ func (e *ELog) _Log(level LogLevel, message string, a ...any) (n int, err error)
 		return 0, nil
 	}
 	log := strings.Builder{}
-	tail := e.Format
+	tail := e.Format.Head
 	for tail != nil {
 		switch token := tail.Token; token {
+		case LOGFORMAT_STRING:
+			log.WriteString(tail.Value)
 		case LOGFORMAT_TIMESTAMP:
 			log.WriteString("TS")
 		case LOGFORMAT_NAME: