chore: simplify SortPreservingMergeStream to be as textbook-like as possible#23702
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rluvaton wants to merge 6 commits into
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chore: simplify SortPreservingMergeStream to be as textbook-like as possible#23702rluvaton wants to merge 6 commits into
rluvaton wants to merge 6 commits into
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rluvaton
marked this pull request as ready for review
July 19, 2026 16:02
rluvaton
commented
Jul 19, 2026
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| let should_poll_next_batch_for_stream = | ||
| self.advance_cursors(winner_stream); | ||
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| // Fast path: skip the `maybe_poll_stream` call (and its `Poll` | ||
| // plumbing) unless the winner's cursor is exhausted and needs a | ||
| // fresh batch — it is live for almost every row. | ||
| if should_poll_next_batch_for_stream { | ||
| assert!( | ||
| self.cursors[winner_stream].is_none(), | ||
| "cursor should be exhausted" | ||
| ); | ||
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| drop(timer); | ||
| poll_fn(|cx| self.maybe_poll_stream(cx, winner_stream)).await?; | ||
| timer = elapsed_compute.timer(); | ||
| } |
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I wanted to move the poll stream inside the advance_cursors but got lifetime issues so kept like this
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #23702 +/- ##
==========================================
- Coverage 80.67% 80.67% -0.01%
==========================================
Files 1088 1088
Lines 367591 367618 +27
Branches 367591 367618 +27
==========================================
+ Hits 296563 296572 +9
- Misses 53374 53385 +11
- Partials 17654 17661 +7 ☔ View full report in Codecov by Harness. 🚀 New features to boost your workflow:
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Which issue does this PR close?
N/A
Rationale for this change
SortPreservingMergeStreamis a little complex, so add some guiding comments and make it as textbook-like as possibleWhat changes are included in this PR?
Added comments, reorder code
Are these changes tested?
Existing tests
Are there any user-facing changes?
No