Memory Segment efficient array handling

[Maurizio Cimadamore]

On 01/04/2021 12:48, Uwe Schindler wrote:
> In our investigations, we also see some slowdown in contrast to our ByteBuffer implementation. It is not yet clear if it comes from loops over long instead of ints or if it is caused by the number of object allocations.

It would be helpful if we could narrow this down. I suppose you refer to 
the benchmark regressions here:

https://github.com/apache/lucene-solr/pull/2176#issuecomment-758175143

Which are probably not related to the issue of bulk copying.

See my other email: having better MemoryAccess routines for bulk copying 
is mostly an usability thing. There's nothing to suggest that a straight 
unsafe call is faster than slicing and calling copyFrom, so I wouldn't 
look there to explain performance differences.

Maurizio