perf: make truncate 4x faster in simple cases #16615
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ritchie46
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May 31, 2024
crates/polars-time/src/truncate.rs
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| let offset: Duration = Duration::parse(offset); | ||
| let time_zone = self.time_zone(); | ||
| // A sqrt(n) cache is not too small, not too large. | ||
| let mut duration_cache = FastFixedCache::new((every.len() as f64).sqrt() as usize); |
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Can we allocate the cache below the fast path. The fast path only accesses the cache (and misses) once.
ritchie46
reviewed
May 31, 2024
| && (every.months() == 0 && every.weeks() == 0) | ||
| { | ||
| // ... yes we can! Weeks, months, and time zones require extra logic. | ||
| // But in this simple case, it's just simple integer arithmetic. |
Codecov ReportAll modified and coverable lines are covered by tests ✅
Additional details and impacted files@@ Coverage Diff @@
## main #16615 +/- ##
==========================================
- Coverage 81.51% 81.51% -0.01%
==========================================
Files 1414 1414
Lines 185906 185940 +34
Branches 3027 3027
==========================================
+ Hits 151535 151561 +26
- Misses 33840 33848 +8
Partials 531 531 ☔ View full report in Codecov by Sentry. |
ritchie46
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May 31, 2024
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closes #16531
This introduces a fastpath for the simplest case
I think the non-simple case can also be optimised, but that's a separate task. I've made a tracker: #16617. I'll work on it
timings on the OPs issue: