ORC-2223 : [Java] RecordReaderImpl reads and parses each StripeFooter twice per stripe during scans

[BsoBird]

(java): reuse stripe footer in RecordReaderImpl to avoid duplicate read

• Add an overloaded StripePlanner.parseStripe that accepts an OrcProto.StripeFooter already read by the caller, keeping the existing two-arg parseStripe as a thin wrapper that reads the footer itself (java/core/src/java/org/apache/orc/impl/reader/ StripePlanner.java).
• RecordReaderImpl.readStripe now passes the footer obtained in beginReadStripe to planner.parseStripe, eliminating one readStripeFooter call per stripe during scans (java/core/src/java/org/apache/orc/impl/RecordReaderImpl.java).
• Lower read-percentage thresholds in TestMinSeekSize, TestRowFilteringComplexTypesNulls, and TestRowFilteringIOSkip to reflect the reduced bytes read per stripe.
• Add TestRecordReaderImpl.testNoDuplicateStripeFooterRead, a regression test asserting exactly one footer read per stripe for both plain and SArg-filtered scans.

What changes were proposed in this pull request?

This PR eliminates a duplicate StripeFooter read in the Java reader: each stripe's footer was being read and parsed twice per scan.

RecordReaderImpl.beginReadStripe() already reads the OrcProto.StripeFooter for the current stripe, but RecordReaderImpl.readStripe() then called StripePlanner.parseStripe(stripe, fileIncluded), which read the same footer again internally.

Changes:

1. Add an overloaded StripePlanner.parseStripe(StripeInformation, boolean[], OrcProto.StripeFooter) that accepts a footer already read by the caller. The existing two-argument parseStripe is kept as a thin wrapper that reads the footer itself, so other callers are unaffected.
2. RecordReaderImpl.readStripe() now passes the footer obtained in beginReadStripe() to the new overload, removing one DataReader.readStripeFooter call per stripe.
3. Lowered read-percentage thresholds in TestMinSeekSize, TestRowFilteringComplexTypesNulls, and TestRowFilteringIOSkip to reflect the genuinely reduced bytes read per stripe.

Why are the changes needed?

Every stripe read during a scan performed a redundant footer read (plus protobuf re-parse) from the underlying DataReader. On remote/object stores or for files with many stripes, this is a measurable and avoidable source of extra I/O and CPU that scales linearly with the number of stripes read. The fix removes the duplication without changing any read semantics: both reads previously fetched the identical footer bytes for the same stripe.

How was this patch tested?

Added a new regression test TestRecordReaderImpl.testNoDuplicateStripeFooterRead. It installs a Mockito spy on the DataReader (stubbing clone() to return the spy, since RecordReaderImpl clones the supplied reader) and verifies readStripeFooter is invoked exactly once per stripe — covering both a plain scan and an SArg-filtered scan (a predicate that evaluates to YES_NO for every row group, so pickRowGroups is exercised without skipping whole stripes).

Also adjusted the read-percentage assertions in TestMinSeekSize, TestRowFilteringComplexTypesNulls, and TestRowFilteringIOSkip: those tests assert lower bounds on bytes read, and the fix legitimately reduces bytes read, so thresholds were lowered accordingly (e.g. 5.9 -> 5.0, 0.06 -> 0.03) with comments explaining why.

Run: cd java && ./mvnw test -pl core

Was this patch authored or co-authored using generative AI tooling?

Yes. co-authored-by: Claude (Anthropic)