diff options
| author | tobo <tobo@yandex-team.com> | 2025-02-10 23:07:18 +0300 |
|---|---|---|
| committer | tobo <tobo@yandex-team.com> | 2025-02-10 23:57:24 +0300 |
| commit | cc4962f760e1d454f0ce1dbe54ed92f9bf7eaf6a (patch) | |
| tree | 139953c2ae965e5ef333734c80a1738d6ab43604 /util | |
| parent | 1bc386a79e88f4b16c5f3016a36c29564e506bfc (diff) | |
| download | ydb-cc4962f760e1d454f0ce1dbe54ed92f9bf7eaf6a.tar.gz | |
[util] GmTimeR: speedup a bit
perf before
```
-------------------------------------------------------------------------------
Benchmark Time CPU Iterations
-------------------------------------------------------------------------------
BM_GmTimeR 3.61 ns 3.61 ns 194952699
BM_GmTimeRRandom/last_hour 5.04 ns 5.04 ns 136121940
BM_GmTimeRRandom/last_day 5.03 ns 5.03 ns 139883239
BM_GmTimeRRandom/last_month 8.03 ns 8.03 ns 87839823
BM_GmTimeRRandom/last_year 14.9 ns 14.9 ns 46401773
BM_GmTimeRRandom/last_decade 16.9 ns 16.9 ns 41439312
BM_GmTimeRRandom/last_half_centry 16.9 ns 16.9 ns 41225553
```
perf after
```
-------------------------------------------------------------------------------
Benchmark Time CPU Iterations
-------------------------------------------------------------------------------
BM_GmTimeR 3.27 ns 3.27 ns 215390890
BM_GmTimeRRandom/last_hour 4.52 ns 4.52 ns 154869504
BM_GmTimeRRandom/last_day 4.53 ns 4.53 ns 155409964
BM_GmTimeRRandom/last_month 7.24 ns 7.24 ns 96972146
BM_GmTimeRRandom/last_year 13.5 ns 13.5 ns 51957829
BM_GmTimeRRandom/last_decade 15.5 ns 15.5 ns 45192135
BM_GmTimeRRandom/last_half_centry 15.4 ns 15.4 ns 45526906
```
commit_hash:ac9db56d93a25c3a3018cfbb6bc5800da3d001ee
Diffstat (limited to 'util')
| -rw-r--r-- | util/datetime/systime.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/util/datetime/systime.cpp b/util/datetime/systime.cpp index d9f31fbc5a..ade1737168 100644 --- a/util/datetime/systime.cpp +++ b/util/datetime/systime.cpp @@ -193,11 +193,13 @@ namespace { days -= DaysSinceEpoch[TableSize - 1]; return TableSize + UNIX_TIME_BASE_YEAR; } - ui64 yearIndex = days / DAYS_IN_YEAR; + const ui64 yearIndex = days / DAYS_IN_LEAP_YEAR; // we can miss by at most 1 year - if (yearIndex > 0 && DaysSinceEpoch[yearIndex - 1] >= days) { - --yearIndex; + Y_ASSERT(yearIndex < TableSize); + if (const auto diff = DaysSinceEpoch[yearIndex]; diff <= days) { + days -= diff; + return static_cast<int>(yearIndex + UNIX_TIME_BASE_YEAR + 1); } if (yearIndex > 0) { |