We could build an abstraction layer on top of the memory interface provided by DataSketches. When the JDK gets the new stuff, we can just change the implementation of the abstraction.
On Wed, Feb 5, 2020 at 9:43 AM Gian Merlino <g...@apache.org> wrote: > The thing that worries me about JEP 370 is that if historical Java user > migration patterns hold up, we will need to support Java 11 for a while > (probably another 2–3 years), and we would therefore need to wait that long > to use JEP 370. It seems like a long time and until then we would be stuck > with a pretty inferior API. > > I also would prefer not having to rewrite code a bunch of times, but that's > why I suggested starting by using Memory for the VectorAggregator interface > and stuff that interacts with it. There isn't that much code there yet > (only a few aggregators implement VectorAggregator). So we will need to > write most of it for the first time, and since it is fresh code, I think > it'd be nice to use the best API currently available in Java 8 / 11. From > what I see that is Memory. > > On Wed, Feb 5, 2020 at 9:21 AM Slim Bouguerra <bs...@apache.org> wrote: > > > Hi Gian, > > Thanks for bringing this up. > > IMO for the long run and looking at how much code will have to change, it > > makes more sense to rely on JDK based API JEP 370 and have this work done > > ONCE as oppose to multiple iteration. FYI i do not think it is far away, > > seems like there is a good momentum around it. > > This does not exclude or means we should not use Memory API for other > stuff > > like sketches et al, in fact i think even for project like Sketches it > > makes more sense to move to newer API offered by the JDK rather that do > it > > your self. > > > > > > On Tue, Feb 4, 2020 at 10:12 PM Gian Merlino <g...@apache.org> wrote: > > > > > Hey Druids, > > > > > > There has generally been a lot of talk about moving away from > ByteBuffer > > > and towards the DataSketches Memory package ( > > > https://datasketches.apache.org/docs/Memory/MemoryPackage.html) or > even > > > using Unsafe directly. Much of that discussion happened on > > > https://github.com/apache/druid/issues/3892. > > > > > > Recently a patch was merged that added datasketches-memory as a > > dependency > > > of druid-processing: https://github.com/apache/druid/pull/9308. The > > reason > > > was partially due to better performance and partially due to nicer API > > > (both reasons mentioned in #3892 as well). > > > > > > JEP 370 is a potential long term solution but it seems a while away > from > > > being ready: https://openjdk.java.net/jeps/370 > > > > > > I wanted to bring the larger discussion back up and see what people > think > > > is a good path forward. > > > > > > My suggestion is that we migrate the VectorAggregator interface to use > > > Memory, but keep BufferAggregator the way it is. That way, as we build > > out > > > support for vectorization (right now, only timeseries/groupby support > it, > > > and only a few aggregators, but we should be building this out) we'll > be > > > doing it with a nicer and potentially faster API. But we won't need to > go > > > back and redo a bunch of old code, since we'll keep the non-vectorized > > code > > > paths the way they are. (And hopefully, one day, delete them all > > outright.) > > > > > > Gian > > > > > >
