I'm still in need of it. I'd be interested in developing a solution
that can be used in some database APIs, e.g. using it for the result
interface for an embedded SQL database like SQLite or DuckDB would be
an interesting motivating use case.
One approach would be to create something unofficial and used only in
the C++ library's implementation of the C API so that it can make
breaking changes for a time and then propose to formalize it in the
ABI later.
On Mon, Aug 10, 2020 at 9:22 AM Antoine Pitrou <solip...@pitrou.net> wrote:
>
>
> From the absence of response, it would seem there isn't much interest
> in this. Please speak up if you think this would be useful to you.
>
> Regards
>
> Antoine.
>
>
> On Tue, 7 Jul 2020 07:49:17 -0500
> Wes McKinney <wesmck...@gmail.com> wrote:
> > Any opinions about this? It seems the next steps would be a concrete
> > API proposal and perhaps a reference implementation thereof.
> >
> > On Sun, Jun 28, 2020 at 11:26 PM Wes McKinney <wesmck...@gmail.com> wrote:
> > >
> > > In ARROW-8301 [1] and elsewhere we've been discussing how to
> > > communicate what amounts to a sequence of arrays or a sequence of
> > > RecordBatch objects using the C data interface.
> > >
> > > Example use cases:
> > >
> > > * Returning a sequence of record / row batches from a database driver
> > > * Sending a C++ arrow::ChunkedArray or arrow::Table to a consumer
> > > using only the C interface
> > >
> > > Applications could define their own custom iterator interfaces to
> > > communicate what amounts to a sequence of the ArrowArray C interface
> > > objects, but it is likely a common enough use case to have an
> > > off-the-shelf solution so that we can support this solution in our
> > > reference libraries (e.g. Arrow C++, pyarrow, Arrow R)
> > >
> > > I suggested a C structure as follows
> > >
> > > struct ArrowArrayStream {
> > > void (*get_schema)(struct ArrowSchema*);
> > > // Non-zero return value indicates an error?
> > > int (*get_next)(struct ArrowArray*);
> > > void (*get_error)(... ERROR HANDLING TODO );
> > > void (*release)(struct ArrowArrayStream*);
> > > void* private_data;
> > > };
> > >
> > > The producer would populate this object with pointers to its
> > > implementations of these functions.
> > >
> > > Thoughts about this?
> > >
> > > Thanks,
> > > Wes
> > >
> > > [1]: https://issues.apache.org/jira/browse/ARROW-8301
> >
>
>
>
