Use ByteBuffers for message bodies

Hi all,

I would like to propose to use ByteBuffer for message bodies. Now, the API accepts a plain byte[], which forces intermediate copies of buffers if we are already working with ByteBuffer or similar representations of a buffer.

Internally, the client implementation can use array() and arrayOffset() to get the data to be sent over the wire if hasArray() returns true; or copy the contents with get() in the other case. In pure NIO mode, we could simply write the ByteBuffer to the java.nio.Channel without any intermediate overhead.

What do you think?

Thank you!

addendum

FWIW, although I believe native support for ByteBuffer is the preferred solution, we could also avoid the copy if the API would accept an offset in the provided array (+ optionally the length) as an alternative proposal:

channel.basicPublish(..., buffer.array(), buffer.arrayOffset());
channel.basicPublish(..., buffer.array(), buffer.arrayOffset(), <length>);

Start with the channel.basicPublish(...) API and inspect how message-body byte[] values are converted and sent. Compare the proposed ByteBuffer and array-offset alternatives, including java.nio.Channel handling, then define the chosen API and verify that message bodies avoid unnecessary copies while preserving existing behavior.