Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-06-06 16:45:39 +00:00
Code Issues Projects Releases Packages Wiki Activity

Expose DOMHighResTimeStamps at lower res

Browse source
This commit is contained in:
Patrick Shaughnessy 2020-01-30 21:45:18 -05:00
parent 5f55cd5d71
commit 8e65782efb
10 changed files with 46 additions and 51 deletions
Download patch file Download diff file Expand all files Collapse all files

15
components/script/dom/performance.rs
View file

@ -401,12 +401,12 @@ impl PerformanceMethods for Performance {
// https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/HighResolutionTime/Overview.html#dom-performance-now
fn Now(&self) -> DOMHighResTimeStamp {
Finite::wrap(self.now())
reduce_timing_resolution(self.now())
}
// https://www.w3.org/TR/hr-time-2/#dom-performance-timeorigin
fn TimeOrigin(&self) -> DOMHighResTimeStamp {
Finite::wrap(self.navigation_start_precise as f64)
reduce_timing_resolution(self.navigation_start_precise as f64)
}
// https://www.w3.org/TR/performance-timeline-2/#dom-performance-getentries
@ -525,3 +525,14 @@ impl PerformanceMethods for Performance {
SetOnresourcetimingbufferfull
);
}
// https://www.w3.org/TR/hr-time-2/#clock-resolution
pub fn reduce_timing_resolution(exact: f64) -> DOMHighResTimeStamp {
// We need a granularity no finer than 5 microseconds.
// 5 microseconds isn't an exactly representable f64 so WPT tests
// might occasionally corner-case on rounding.
// web-platform-tests/wpt#21526 wants us to use an integer number of
// microseconds; the next divisor of milliseconds up from 5 microseconds
// is 10, which is 1/100th of a millisecond.
Finite::wrap((exact * 100.0).floor() / 100.0)
}