lucasfang opened a new pull request, #2616:
URL: https://github.com/apache/orc/pull/2616
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### What changes were proposed in this pull request?
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This PR introduces a new Reader API, preBufferRange(stripes, includeTypes),
which computes and returns the exact prefetch ranges (offset/length pairs),
implements it in ReaderImpl, and refactors the existing preBuffer path to reuse
that range-planning logic before populating cache.
### Why are the changes needed?
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The change is needed because preBuffer previously did not expose the planned
ranges, but external users now have a multi-Reader scenario where different
Readers prefetch different ranges of the same file and share an external
prebuffer cache, so they must know the precise ranges in advance to coordinate
prefetching and avoid duplicated work.
### Was this patch authored or co-authored using generative AI tooling?
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No
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