[MINOR][CORE] Simplify the next-page index computation in BytesToBytesMap.MapIterator - #58736
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[MINOR][CORE] Simplify the next-page index computation in BytesToBytesMap.MapIterator#58736david-mollitor-db wants to merge 1 commit into
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…sMap.MapIterator
`MapIterator.advanceToNextPage()` computed the next page index as
`int nextIdx = dataPages.indexOf(currentPage) + 1;` and then decremented it inside a
conditional (`nextIdx--`). Reuse the `indexOf` result and set `nextIdx` once in an
`if`/`else` so it can be `final`:
final int idx = dataPages.indexOf(currentPage);
final int nextIdx;
if (destructive && idx >= 0) {
dataPages.remove(idx);
pageToFree = currentPage;
nextIdx = idx;
} else {
nextIdx = idx + 1;
}
`idx >= 0` is equivalent to the previous `currentPage != null` guard (whenever
`currentPage` is non-null it is an element of `dataPages`, and `indexOf(null)` is `-1`),
and reusing `idx` for `remove(idx)` avoids the redundant second linear scan that
`remove(Object)` performs. Behavior is unchanged. No lock or I/O behavior is changed.
Generated-by: Claude Opus 4.8
Co-authored-by: Isaac <no-reply@databricks.com>
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What changes were proposed in this pull request?
MapIterator.advanceToNextPage()inBytesToBytesMapcomputed the next-page index asint nextIdx = dataPages.indexOf(currentPage) + 1;and then decremented it (nextIdx--) inside aconditional. This reuses the
indexOfresult and setsnextIdxonce in anif/elseso it can befinal:Why are the changes needed?
Minor readability/consistency cleanup:
nextIdxbecomesfinaland is assigned exactly once perbranch instead of being mutated.
idx >= 0is equivalent to the previouscurrentPage != nullguard — whenever
currentPageis non-null it is an element ofdataPages(assigned fromdataPages.get(...)and only removed here), andindexOf(null)is-1. Reusingidxforremove(idx)also avoids the redundant second linear scan thatremove(Object)performs. No lock orI/O behavior is changed.
Does this PR introduce any user-facing change?
No.
How was this patch tested?
Existing
BytesToBytesMapOnHeapSuiteandBytesToBytesMapOffHeapSuitepass (34 tests, coveringdestructive iteration, spill, reset, and free); checkstyle is clean.
Was this patch authored or co-authored using generative AI tooling?
Generated-by: Claude Opus 4.8
This pull request and its description were written by Isaac.