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From Gang Wu <gan...@apache.org>
Subject Re: Sub-classing implementation classes(e.g., ReaderImpl)
Date Thu, 30 May 2019 02:34:31 GMT
This is exactly what we do internally. We can port it back upon request.

Gang

On Thu, May 30, 2019 at 5:54 AM Owen O'Malley <owen.omalley@gmail.com>
wrote:

> Inheritance, especially in C++ is very hard to maintain compatibility
> across versions.
>
> Based on my experience on the Java side with LLAP, I’d suggest adding an
> optional cache manager than can be supplied to the reader. As Deepak says,
> there is already an interface for passing in the file tail. I’d suspect
> that we should have an API to supply a cache (memory or local file based)
> for:
>
> * file footer & tail
> * stripe footers
> * stripe statistics
> * row indexes
> * row data
>
> .. Owen
>
> > On May 29, 2019, at 5:12 AM, naveen mahadevuni <nmahadevuni@gmail.com>
> wrote:
> >
> > Hi,
> >
> > We are using ORC C++ API. We would like to be able to sub-class the ORC
> > implementation classes such as ReaderImpl, StatisticsImpl,
> > StripeInformationImpl... The reason being, when ORC files are stored on a
> > cloud store such as S3, we would like to have the metadata/statistics
> > stored on a file on local disk and create wrapper implementation classes
> > which read metadata/statistics from locally stored file and delegates
> only
> > the data stream reads to the cloud store.
> >
> > Will there be any problems if these implementation classes are published?
> >
> > Thanks,
> > Naveen
>
>

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