Skip to content

fix(time): use default DOM clock resolution #381

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
ldm0 wants to merge 1 commit into
base: main
Choose a base branch
from
+12 −6
Open

fix(time): use default DOM clock resolution #381

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion moli-renderer-v8/src/worker/global_scope/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6742,7 +6742,9 @@ fn worker_performance_now_callback<'s>(
rv.set(
v8::Number::new(
scope,
(monotonic_unix_epoch_millis() - time_origin).max(0.0),
moli_time::coarsened_dom_time_millis(
(monotonic_unix_epoch_millis() - time_origin).max(0.0),
),
)
.into(),
);
Expand Down
14 changes: 9 additions & 5 deletions moli-time/src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -52,8 +52,11 @@ pub fn monotonic_timestamp_micros() -> u64 {
}

pub fn coarsened_dom_time_millis(millis: f64) -> f64 {
const FIVE_MICROSECONDS_PER_MILLISECOND: f64 = 200.0;
(millis * FIVE_MICROSECONDS_PER_MILLISECOND).floor() / FIVE_MICROSECONDS_PER_MILLISECOND
// High Resolution Time requires the default, non-isolated clock to expose
// no finer than 100 microseconds. Keep the shared clock on that safe
// default; cross-origin-isolated realms may opt into a finer clock later.
const TEN_TICKS_PER_MILLISECOND: f64 = 10.0;
(millis * TEN_TICKS_PER_MILLISECOND).floor() / TEN_TICKS_PER_MILLISECOND
}

pub fn dom_time_since_origin_millis(time_origin: f64) -> f64 {
Expand Down Expand Up @@ -241,9 +244,10 @@ mod tests {
}

#[test]
fn dom_time_coarsening_uses_five_microsecond_resolution() {
assert_eq!(coarsened_dom_time_millis(1.234_567), 1.23);
assert_eq!(coarsened_dom_time_millis(1.239_999), 1.235);
fn dom_time_coarsening_uses_default_hundred_microsecond_resolution() {
assert_eq!(coarsened_dom_time_millis(1.234_567), 1.2);
assert_eq!(coarsened_dom_time_millis(1.299_999), 1.2);
assert_eq!(coarsened_dom_time_millis(1.3), 1.3);
assert_eq!(
dom_time_since_origin_millis(unix_epoch_millis() + 1000.0),
0.0
Expand Down
Loading