@Override
  public int getValueLength() {
    return ByteBufferUtils.toInt(this.buf, this.offset + Bytes.SIZEOF_INT);
  }
This Cell is an implementation of {@link ByteBufferExtendedCell} where the data resides in off
heap/ on heap ByteBuffer
hbase-common/src/main/java/org/apache/hadoop/hbase/ByteBufferKeyValue.java