Preserve process log history when updating a process

ffmpeg/parse/parser.go

@@ -33,6 +33,9 @@ type Parser interface {
 
 	// ReportHistory returns an array of previews logs
 	ReportHistory() []Report
+
+	// TransferReportHistory transfers the report history to another parser
+	TransferReportHistory(Parser) error
 }
 
 // Config is the config for the Parser implementation
@@ -767,3 +770,21 @@ func (p *parser) ReportHistory() []Report {
 
 	return history
 }
+
+func (p *parser) TransferReportHistory(dst Parser) error {
+	pp, ok := dst.(*parser)
+	if !ok {
+		return fmt.Errorf("the target parser is not of the required type")
+	}
+
+	p.logHistory.Do(func(l interface{}) {
+		if l == nil {
+			return
+		}
+
+		pp.logHistory.Value = l
+		pp.logHistory = pp.logHistory.Next()
+	})
+
+	return nil
+}