private Long recursionSessionData()

in backup-core/src/main/java/org/apache/iotdb/backup/core/service/ExportPipelineService.java [480:546]
66 lines of code
11 McCabe index (conditional complexity)

  private Long recursionSessionData(
      int loopi,
      int loopMark,
      Long mark,
      int size,
      SessionDataSet set,
      Map<Long, List<IField>[]> sinkPoolMap,
      DeviceModel deviceModel,
      List<TimeseriesModel> timeseries)
      throws StatementExecutionException, IoTDBConnectionException {
    if (set.hasNext()) {
      RowRecord rowRecord = set.next();
      List<String> columnName = set.getColumnNames();
      columnName.remove(0);
      List<IField> fieldList =
          columnName.stream()
              .map(
                  clname -> {
                    int position = columnName.indexOf(clname);
                    Field field = rowRecord.getFields().get(position);
                    IField iField = new IField();
                    FieldCopy fieldCopy = FieldCopy.copy(field);
                    if (fieldCopy.getDataType() == null) {
                      timeseries.stream()
                          .forEach(
                              timeseriesModel -> {
                                String colName =
                                    timeseriesModel
                                        .getName()
                                        .substring(deviceModel.getDeviceName().length() + 1);
                                if (colName.equals(clname)) {
                                  iField.setTsDataType(timeseriesModel.getType());
                                }
                              });
                    }
                    iField.setField(fieldCopy);
                    iField.setColumnName(clname);
                    return iField;
                  })
              .collect(Collectors.toList());
      // 以loopMark对应的数据为时间基准
      if (loopi == loopMark) {
        mark = rowRecord.getTimestamp();
      }
      if (sinkPoolMap.get(rowRecord.getTimestamp()) != null) {
        if (mark != 0 && rowRecord.getTimestamp() < mark) {
          recursionSessionData(
              loopi, loopMark, mark, size, set, sinkPoolMap, deviceModel, timeseries);
        }
        List<IField>[] array = sinkPoolMap.get(rowRecord.getTimestamp());
        if (array != null) {
          array[loopi] = fieldList;
          sinkPoolMap.putIfAbsent(rowRecord.getTimestamp(), array);
        }
      } else {
        if (mark != 0 && rowRecord.getTimestamp() < mark) {
          recursionSessionData(
              loopi, loopMark, mark, size, set, sinkPoolMap, deviceModel, timeseries);
        }
        List<IField>[] array = new List[size];
        array[loopi] = fieldList;
        sinkPoolMap.put(rowRecord.getTimestamp(), array);
      }
      return mark;
    }
    return mark;
  }