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68115a705f
Fixes https://github.com/flutter/flutter/issues/173097 The semantics flush is ~200 μs slower with the shortcuircut removed + #177477 (which reduces the time increase by ~ 100 μs, from 876 μs to 773 μs) I tried to introduce caching in [a different patch](https://github.com/flutter/flutter/compare/master...LongCatIsLooong:semantics-geometry?expand=1) but that patch is more risky and still needs a cleanup. 773 μs doesn't seem bad considering there were little to no geometry updates between frames before the fix. Introducing cache currently only improves `Semantics.ensureGeometry` by less than 100 μs and is much more risky / harder to ensure the correctness. ### BEFORE ``` [bench_material3_scroll_semantics] name: bench_material3_scroll_semantics SEMANTICS: (samples: 98 clean/2 outliers/100 measured/300 total) | average: 567.0510204081633 μs | outlier average: 799 μs | outlier/clean ratio: 1.4090442856885785x | noise: 13.95% Semantics.updateChildren: (samples: 91 clean/9 outliers/100 measured/300 total) | average: 58.9010989010989 μs | outlier average: 199.88888888888889 μs | outlier/clean ratio: 3.3936359867330017x | noise: 82.78% Semantics.ensureGeometry: (samples: 95 clean/5 outliers/100 measured/300 total) | average: 95.46315789473684 μs | outlier average: 299 μs | outlier/clean ratio: 3.1320983570404675x | noise: 64.29% Semantics.ensureSemanticsNode: (samples: 100 clean/0 outliers/100 measured/300 total) | average: 78.59 μs | outlier average: 78.59 μs | outlier/clean ratio: 1x | noise: 80.86% drawFrameDuration: (samples: 98 clean/2 outliers/100 measured/300 total) | average: 1685.6938775510205 μs | outlier average: 2000 μs | outlier/clean ratio: 1.1864550418285935x | noise: 7.77%``` ``` ### AFTER (with this and https://github.com/flutter/flutter/pull/177477) ``` [bench_material3_scroll_semantics] name: bench_material3_scroll_semantics SEMANTICS: (samples: 91 clean/9 outliers/100 measured/300 total) | average: 773.1098901098901 μs | outlier average: 1000 μs | outlier/clean ratio: 1.2934771793669069x | noise: 10.65% Semantics.updateChildren: (samples: 94 clean/6 outliers/100 measured/300 total) | average: 48.648936170212764 μs | outlier average: 200 μs | outlier/clean ratio: 4.111086813907719x | noise: 102.15% Semantics.ensureGeometry: (samples: 95 clean/5 outliers/100 measured/300 total) | average: 239.55789473684212 μs | outlier average: 399.6 μs | outlier/clean ratio: 1.6680727656208807x | noise: 22.05% Semantics.ensureSemanticsNode: (samples: 99 clean/1 outliers/100 measured/300 total) | average: 194.5151515151515 μs | outlier average: 400 μs | outlier/clean ratio: 2.0563950771148156x | noise: 31.31% drawFrameDuration: (samples: 95 clean/5 outliers/100 measured/300 total) | average: 1775.8315789473684 μs | outlier average: 2099.6 μs | outlier/clean ratio: 1.1823193285280729x | noise: 7.56% ``` ## Pre-launch Checklist - [ ] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [ ] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [ ] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [ ] I signed the [CLA]. - [ ] I listed at least one issue that this PR fixes in the description above. - [ ] I updated/added relevant documentation (doc comments with `///`). - [ ] I added new tests to check the change I am making, or this PR is [test-exempt]. - [ ] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing. 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