diff --git a/components/profile/time.rs b/components/profile/time.rs index 9c9debdb738..e6cb6d45f59 100644 --- a/components/profile/time.rs +++ b/components/profile/time.rs @@ -327,6 +327,23 @@ impl Profiler { true } + /// Get tuple (mean, median, min, max) for profiler statistics. + pub fn get_statistics(data: &[f64]) -> (f64, f64, f64, f64) { + data.iter().fold(-f64::INFINITY, |a, &b| { + debug_assert!(a < b, "Data must be sorted"); + b + }); + + let data_len = data.len(); + debug_assert!(data_len > 0); + let (mean, median, min, max) = + (data.iter().sum::() / (data_len as f64), + data[data_len / 2], + data[0], + data[data_len - 1]); + (mean, median, min, max) + } + fn print_buckets(&mut self) { match self.output { Some(OutputOptions::FileName(ref filename)) => { @@ -349,11 +366,7 @@ impl Profiler { }); let data_len = data.len(); if data_len > 0 { - let (mean, median, min, max) = - (data.iter().sum::() / (data_len as f64), - data[data_len / 2], - data.iter().fold(f64::INFINITY, |a, &b| a.min(b)), - data.iter().fold(-f64::INFINITY, |a, &b| a.max(b))); + let (mean, median, min, max) = Self::get_statistics(data); write!(file, "{}\t{}\t{:15.4}\t{:15.4}\t{:15.4}\t{:15.4}\t{:15}\n", category.format(&self.output), meta.format(&self.output), mean, median, min, max, data_len).unwrap(); @@ -378,11 +391,7 @@ impl Profiler { }); let data_len = data.len(); if data_len > 0 { - let (mean, median, min, max) = - (data.iter().sum::() / (data_len as f64), - data[data_len / 2], - data.iter().fold(f64::INFINITY, |a, &b| a.min(b)), - data.iter().fold(-f64::INFINITY, |a, &b| a.max(b))); + let (mean, median, min, max) = Self::get_statistics(data); writeln!(&mut lock, "{:-35}{} {:15.4} {:15.4} {:15.4} {:15.4} {:15}", category.format(&self.output), meta.format(&self.output), mean, median, min, max, data_len).unwrap(); diff --git a/tests/unit/profile/time.rs b/tests/unit/profile/time.rs index 70daaf2cb73..911f1cf95c0 100644 --- a/tests/unit/profile/time.rs +++ b/tests/unit/profile/time.rs @@ -15,3 +15,40 @@ fn time_profiler_smoke_test() { chan.send(ProfilerMsg::Exit(ipcchan)); assert!(true, "Can tell the profiler thread to exit"); } + +#[test] +fn time_profiler_stats_test() { + let even_data = vec![1.234, 3.24567, 3.54578, 5.0, 5.324, 7.345, + 9.2345, 10.2342345, 13.2599, 15.0]; + let (even_mean, even_median, even_min, even_max) = time::Profiler::get_statistics(&even_data); + + assert_eq!(7.34230845, even_mean); + assert_eq!(7.345, even_median); + assert_eq!(1.234, even_min); + assert_eq!(15.0, even_max); + + let odd_data = vec![1.234, 3.24567, 3.54578, 5.0, 5.324, 7.345, + 9.2345, 10.2342345, 13.2599]; + let (odd_mean, odd_median, odd_min, odd_max) = time::Profiler::get_statistics(&odd_data); + + assert_eq!(6.491453833333334, odd_mean); + assert_eq!(5.324, odd_median); + assert_eq!(1.234, odd_min); + assert_eq!(13.2599, odd_max); +} + +#[cfg(debug_assertions)] +#[test] +#[should_panic] +fn time_profiler_unsorted_stats_test() { + let unsorted_data = vec![5.0, 7.5, 1.0, 8.9]; + time::Profiler::get_statistics(&unsorted_data); +} + +#[cfg(debug_assertions)] +#[test] +#[should_panic] +fn time_profiler_data_len_zero() { + let zero_data = vec![]; + time::Profiler::get_statistics(&zero_data); +}