class BlockInfo extends Block implements LightWeightGSet.LinkedElement {

  DatanodeStorageInfo getStorageInfo(int index) {
    assert this.triplets != null : "BlockInfo is not initialized";
    assert index >= 0 && index*3 < triplets.length : "Index is out of bound";
    return (DatanodeStorageInfo)triplets[index*3];
  }

  public  BlockInfo(short size);
  public  BlockInfo(Block blk, short size);

}