[PSL-1232] prevent duplicate processing for base-file volumes (#910)

Author: j-rafique

walletnode/api/services/cascade.go

@@ -127,6 +127,11 @@ func (service *CascadeAPIHandler) StartProcessing(ctx context.Context, p *cascad
 	}
 	log.WithContext(ctx).WithField("total_volumes", len(relatedFiles)).Info("Related volumes retrieved from the base file-id")
 
+	if isProcessingStarted(relatedFiles) {
+		log.WithContext(ctx).Error("task registration is already in progress")
+		return nil, cascade.MakeInternalServerError(errors.New("task registration is already in progress"))
+	}
+
 	switch {
 	case len(relatedFiles) == 1:
 		baseFile := relatedFiles.GetBase()
@@ -238,6 +243,16 @@ func isDuplicateExists(burnTxIDs []string) bool {
 	return false
 }
 
+func isProcessingStarted(files types.Files) bool {
+	for _, file := range files {
+		if file.TaskID != "" {
+			return true
+		}
+	}
+
+	return false
+}
+
 func validateBurnTxID(burnTxID *string, burnTxIDs []string) (string, error) {
 	if burnTxID != nil {
 		return *burnTxID, nil

walletnode/services/cascaderegister/service.go

@@ -631,8 +631,8 @@ func (service *CascadeRegistrationService) RegisterVolumeTicket(ctx context.Cont
 		return "", err
 	}
 
-	if len(relatedFiles) <= 1 {
-		return "", errors.New("related volumes must be greater than 1 for creating multi-volume ticket")
+	if len(relatedFiles) == 1 {
+		return "", nil
 	}
 
 	concludedCount := 0