ORC-2619: Fix estimateRgEndOffset slop calculation for incompressible data#2620
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… data The stretchFactor calculation in estimateRgEndOffset did not account for the 2-byte RLEv2 DIRECT run header. This caused insufficient buffer allocation when data is incompressible, leading to 'Buffer size too small' errors. Fix: Include RLE_V2_HEADER_SIZE in the worst-case payload calculation. Add test demonstrating the issue with the old formula.
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What changes were proposed in this pull request?
Fix the
estimateRgEndOffsetslop calculation inRecordReaderUtils.javato account for the 2-byte RLEv2 DIRECT run header.Problem
The old formula:
only considers the value payload (512 * 8 = 4096 bytes) but ignores the 2-byte RLE header. For
bufferSize = 1024, this givesstretchFactor = 5, which is one block short when data is incompressible.Fix
This correctly yields
stretchFactor = 6, ensuring enough compressed blocks are allocated.How was this patch tested?
Added
testTruncatedRleV2DirectRunAtEstimatedEndFailsinTestInStream.javathat:IllegalArgumentException: Buffer size too smallThis proves the old slop estimation was insufficient.
Closes #2619