HBASE-14832 is not enough to handle this. Doing the remaining needed here.
We have done this but it is not really helping us!
So for DBB it is so costly op writing byte by byte reading each to on heap.
Even if we use writeByteBuffer(OutputStream out, ByteBuffer b, int offset, int length), it won't help us as the underlying stream is a ByteArrayOutputStream and so we will end up in copying.