@Override
  public Long getBlobContentCRC(MessageInfo msg) throws StoreException, IOException {
    EnumSet<StoreGetOptions> storeGetOptions =
        EnumSet.of(StoreGetOptions.Store_Include_Deleted, StoreGetOptions.Store_Include_Expired);
    MessageReadSet rdset = null;
    try {
      StoreInfo stinfo = this.get(Collections.singletonList(msg.getStoreKey()), storeGetOptions);
      rdset = stinfo.getMessageReadSet();
      MessageInfo minfo = stinfo.getMessageReadSetInfo().get(0);
      rdset.doPrefetch(0, minfo.getSize() - MessageFormatRecord.Crc_Size, MessageFormatRecord.Crc_Size);
      return rdset.getPrefetchedData(0).getLong(0);
    } finally {
      if (rdset != null && rdset.count() > 0 && rdset.getPrefetchedData(0) != null) {
        rdset.getPrefetchedData(0).release();
      }
    }
  }
Returns CRC of blob-content
@param msg Metadata of blob
@return CRC of blob-content
ambry-store/src/main/java/com/github/ambry/store/BlobStore.java