using PD's ScanRegions API

[marsishandsome]

Is your feature request related to a problem? Please describe.

currently tispark use the following api to get region info

public static List<TiRegion> getRegionsByTable(TiSession session, TiTableInfo table) {
    ArrayList<TiRegion> regionList = new ArrayList<>();
    Key key = RowKey.createMin(table.getId());
    RowKey endRowKey = RowKey.createBeyondMax(table.getId());

    while (key.compareTo(endRowKey) < 0) {
      TiRegion region = session.getRegionManager().getRegionByKey(key.toByteString());
      regionList.add(region);
      key = Key.toRawKey(region.getEndKey());
    }
    return regionList;
  }

it's better to use ScanRegions API