It isn't implemented in C++ yet but I will try to get a patch up for that soon (today maybe). I think we should create a branch where we can stack the patches that implement this for each language.
On Fri, Aug 23, 2019 at 4:04 AM Paul Taylor <ptaylor.apa...@gmail.com> wrote: > > I'll do the JS updates. Is it safe to validate against the Arrow C++ > integration tests? > > > On 8/22/19 7:28 PM, Micah Kornfield wrote: > > I created https://issues.apache.org/jira/browse/ARROW-6313 as a tracking > > issue with sub-issues on the development work. So far no-one has claimed > > Java and Javascript tasks. > > > > Would it make sense to have a separate dev branch for this work? > > > > Thanks, > > Micah > > > > On Thu, Aug 22, 2019 at 3:24 PM Wes McKinney <wesmck...@gmail.com> wrote: > > > >> The vote carries with 4 binding +1 votes and 1 non-binding +1 > >> > >> I'll merge the specification patch later today and we can begin > >> working on implementations so we can get this done for 0.15.0 > >> > >> On Tue, Aug 20, 2019 at 12:30 PM Bryan Cutler <cutl...@gmail.com> wrote: > >>> +1 (non-binding) > >>> > >>> On Tue, Aug 20, 2019, 7:43 AM Antoine Pitrou <solip...@pitrou.net> > >> wrote: > >>>> Sorry, had forgotten to send my vote on this. > >>>> > >>>> +1 from me. > >>>> > >>>> Regards > >>>> > >>>> Antoine. > >>>> > >>>> > >>>> On Wed, 14 Aug 2019 17:42:33 -0500 > >>>> Wes McKinney <wesmck...@gmail.com> wrote: > >>>>> hi all, > >>>>> > >>>>> As we've been discussing [1], there is a need to introduce 4 bytes of > >>>>> padding into the preamble of the "encapsulated IPC message" format to > >>>>> ensure that the Flatbuffers metadata payload begins on an 8-byte > >>>>> aligned memory offset. The alternative to this would be for Arrow > >>>>> implementations where alignment is important (e.g. C or C++) to copy > >>>>> the metadata (which is not always small) into memory when it is > >>>>> unaligned. > >>>>> > >>>>> Micah has proposed to address this by adding a > >>>>> 4-byte "continuation" value at the beginning of the payload > >>>>> having the value 0xFFFFFFFF. The reason to do it this way is that > >>>>> old clients will see an invalid length (what is currently the > >>>>> first 4 bytes of the message -- a 32-bit little endian signed > >>>>> integer indicating the metadata length) rather than potentially > >>>>> crashing on a valid length. We also propose to expand the "end of > >>>>> stream" marker used in the stream and file format from 4 to 8 > >>>>> bytes. This has the additional effect of aligning the file footer > >>>>> defined in File.fbs. > >>>>> > >>>>> This would be a backwards incompatible protocol change, so older > >> Arrow > >>>>> libraries would not be able to read these new messages. Maintaining > >>>>> forward compatibility (reading data produced by older libraries) > >> would > >>>>> be possible as we can reason that a value other than the continuation > >>>>> value was produced by an older library (and then validate the > >>>>> Flatbuffer message of course). Arrow implementations could offer a > >>>>> backward compatibility mode for the sake of old readers if they > >> desire > >>>>> (this may also assist with testing). > >>>>> > >>>>> Additionally with this vote, we want to formally approve the change > >> to > >>>>> the Arrow "file" format to always write the (new 8-byte) > >> end-of-stream > >>>>> marker, which enables code that processes Arrow streams to safely > >> read > >>>>> the file's internal messages as though they were a normal stream. > >>>>> > >>>>> The PR making these changes to the IPC documentation is here > >>>>> > >>>>> https://github.com/apache/arrow/pull/4951 > >>>>> > >>>>> Please vote to accept these changes. This vote will be open for at > >>>>> least 72 hours > >>>>> > >>>>> [ ] +1 Adopt these Arrow protocol changes > >>>>> [ ] +0 > >>>>> [ ] -1 I disagree because... > >>>>> > >>>>> Here is my vote: +1 > >>>>> > >>>>> Thanks, > >>>>> Wes > >>>>> > >>>>> [1]: > >> https://lists.apache.org/thread.html/8440be572c49b7b2ffb76b63e6d935ada9efd9c1c2021369b6d27786@%3Cdev.arrow.apache.org%3E > >>>> > >>>> > >>>>
