short getDataBlockEncodingId() {
    if (blockType != BlockType.ENCODED_DATA) {
      throw new IllegalArgumentException("Querying encoder ID of a block " + "of type other than "
        + BlockType.ENCODED_DATA + ": " + blockType);
    }
    return bufWithoutChecksum.getShort(headerSize());
  }
Returns get data block encoding id that was used to encode this block
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlock.java