Rafael, Thanks for those links. I see your point.
On 24/09/2007, Rafael Schloming <[EMAIL PROTECTED]> wrote: > > Rafael Schloming wrote: > > Rupert Smith wrote: > >> On 24/09/2007, Rafael Schloming <[EMAIL PROTECTED]> wrote: > >>> So if we were to fix AMQShortString to just use bulk put/get > operations > >>> all the time then the only issue is whether it is possible to > implement > >>> an aggregating ByteBuffer with efficient bulk put/get operations, and > >>> the answer to this question depends entirely on the details of the > >>> internal implementation of the various nio Buffer classes, which > likely > >>> means it is impossible to do without tying yourself to a specific JDK > >>> implementation. > >>> > >> > >> Its an aggregator, so bulk operations just map down onto the bulk > >> operations > >> of the aggregated buffers underneath it. So if a bulk get overlaps two > >> buffers underneath, the get it split into two calls, one to fetch the > >> relevant bit from each of the underlying buffers. > > > > Yes, this is exactly what FragmentDecoder does. > > > > I don't follow where the > >> JDK specific part comes from? > > > > The JDK specific part comes in trying to do this as a subclass of > > ByteBuffer. The various buffer implementations in the java.nio package > > share internal implementations via package protected members and code. > > In order to be able to create a subclass of ByteBuffer you would need to > > obey all the various package protected contracts. These contracts are > > implementation details of the JDK and may change between releases. > > > > A quick google on "extending ByteBuffer" also reveals the issues > > mentioned here: > > > > http://forum.java.sun.com/thread.jspa?threadID=693259&messageID=4028590 > > > > Basically ByteBuffer, although not final, has entirely private > > constructors. This prevents it from being extend from outside the > > java.nio package. > > This link would also seem to indicate that there is no intention to ever > make ByteBuffer extensible: > > http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4712383 > > --Rafael >
