Aligned long views over byte arrays and heap ByteBuffers

Paul Sandoz paul.sandoz at
Wed Jan 20 14:15:06 UTC 2016

> On 20 Jan 2016, at 14:27, Vitaly Davidovich <vitalyd at> 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.


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