@Override
  public int hashCode() {
    int result = 1;
    result = result * 31 + blockType.hashCode();
    result = result * 31 + nextBlockOnDiskSize;
    result = result * 31 + (int) (offset ^ (offset >>> 32));
    result = result * 31 + onDiskSizeWithoutHeader;
    result = result * 31 + (int) (prevBlockOffset ^ (prevBlockOffset >>> 32));
    result = result * 31 + uncompressedSizeWithoutHeader;
    result = result * 31 + bufWithoutChecksum.hashCode();
    return result;
  }
Adds metadata at current position (position is moved forward). Does not flip or reset.
@return The passed <code>destination</code> with metadata added.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlock.java