Aligned long views over byte arrays and heap ByteBuffers

[Paul Sandoz]

> On 20 Jan 2016, at 14:27, Vitaly Davidovich <vitalyd at gmail.com> wrote:
> 
> Hi Paul,
> 
> isAligned(int,int) could probably use a better name since it's not returning a boolean.

Yeah, "isAligned(…) == 0” is the boolean producing expression.


> How about alignIndex(int,int)?
> 

That might work, although it implies returning an aligned index rather than a modulus associated with the current index and unit size. I think that would be more precise if we include boolean argument for rounding up/down to the nearest aligned index:

  alignedIndex(int index, int unitSize, boolean roundUp)

For rounding down a negative value might be returned. I still prefer a modulus returning method.


> By the way, what's the rationale behind adding new APIs vs the runtime detection option we discussed earlier?
> 

So we don’t have to deal with two separate software and hardware implementations, with a runtime switch, since alignment cannot always be determined statically for buffers.

Requiring explicit alignment is simpler, and arguably the performance characteristics are clearer.

Paul.