diff --git a/Cargo.toml b/Cargo.toml index a0f17252..df8d2ab5 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -24,7 +24,7 @@ include = [ ] edition = "2021" resolver = "2" -rust-version = "1.71" +rust-version = "1.73" [package.metadata.docs.rs] all-features = true @@ -104,7 +104,9 @@ js-sys = { version = "0.3.55", optional = true } wasm-bindgen = { version = "0.2.78", optional = true } wasm-bindgen-futures = { version = "0.4.28", optional = true } web-sys = { version = "0.3.28", default-features = false, features = [ + "Document", "Performance", + "VisibilityState", "Window", ], optional = true } diff --git a/src/platform/wasm/web/time.rs b/src/platform/wasm/web/time.rs index e6844743..ddeac2fb 100644 --- a/src/platform/wasm/web/time.rs +++ b/src/platform/wasm/web/time.rs @@ -1,8 +1,8 @@ use js_sys::{Date, Reflect}; -use std::ops::Sub; +use std::{cell::Cell, ops::Sub}; use time::UtcOffset; use wasm_bindgen::{prelude::*, JsCast}; -use web_sys::Performance; +use web_sys::{Performance, VisibilityState}; pub use time::{Duration, OffsetDateTime as DateTime}; @@ -10,16 +10,73 @@ pub use time::{Duration, OffsetDateTime as DateTime}; #[repr(transparent)] pub struct Instant(Duration); +// Every browser's `performance.now()` implementation is not spec compliant, +// unless the browser is running on Windows. On every other operating system, +// `performance.now()` does not properly keep ticking while the operating system +// is suspended / sleeping. There isn't much that we can do. What we can do is +// we calculate the initial difference between `performance.now()` and +// `Date.now()` and store it in a thread local. Later, when the phone gets +// locked, `performance.now()` starts to break. However, we can detect when the +// phone gets unlocked again by listening to the `visibilitychange` event. This +// is where we can update the difference again. This of course isn't ideal, as +// `Date.now()` gets adjusted by NTP synchronizations, but it's the best we can +// do. +// +// More information: +// https://developer.mozilla.org/en-US/docs/Web/API/Performance/now#ticking_during_sleep +fn init_fallback(performance: &Performance) { + let Some(window) = web_sys::window() else { + // Not running in a browser environment. + return; + }; + + if window.navigator().platform().is_ok_and(|v| v == "Win32") { + // Windows is not affected by this issue. + return; + } + + let Some(document) = window.document() else { + // Not running in a browser environment. + return; + }; + + DIFF_TO_DATE_NOW.set(Date::now() - performance.now()); + + let callback = Closure::wrap(Box::new({ + let document = document.clone(); + move || { + if document.visibility_state() == VisibilityState::Visible { + PERFORMANCE.with(|p| DIFF_TO_DATE_NOW.set(Date::now() - p.now())); + } + } + }) as Box); + + if document + .add_event_listener_with_callback("visibilitychange", callback.as_ref().unchecked_ref()) + .is_ok() + { + // Leak the callback to keep it alive. This is only done once, and we + // need it for the entire duration of the web app anyway. + callback.forget(); + } +} + thread_local! { - static PERFORMANCE: Performance = - Reflect::get(&js_sys::global(), &JsValue::from_str("performance")) + static DIFF_TO_DATE_NOW: Cell = const { Cell::new(0.0) }; + static PERFORMANCE: Performance = { + let performance: Performance = Reflect::get(&js_sys::global(), &JsValue::from_str("performance")) .expect("Failed to get performance from global object") .unchecked_into(); + + init_fallback(&performance); + + performance + }; } impl Instant { pub fn now() -> Self { - let secs = PERFORMANCE.with(|p| p.now()) * 0.001; + let secs = PERFORMANCE.with(|p| p.now() + DIFF_TO_DATE_NOW.get()) * 0.001; Instant(Duration::seconds_f64(secs)) } }