| commit | b35d86e84cb8c61c698fbe39664949e5ab688e9a | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Tue May 21 23:13:33 2024 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Tue May 21 23:13:33 2024 +0000 |
| tree | 2f51a3a47a48163e7df79ac7f318b142945db909 | |
| parent | 85b0a802f705ebd28c18a1cd763fe1a797fac87f [diff] | |
| parent | b1278dc8ae9c8d380aad6035cd1867420bf3ed74 [diff] |
Snap for 11869550 from b1278dc8ae9c8d380aad6035cd1867420bf3ed74 to 24Q3-release Change-Id: I4edb9b20585e95a08bc6d700abc3fb2d36b242fa
If you call std::time::Instant::now() on a WASM platform, it will panic. This crate provides a partial replacement for std::time::Instant that works on WASM too. This defines the type instant::Instant which is:
wasm32-unknown-unknown or wasm32-unknown-asmjs and you enabled either the stdweb or the wasm-bindgen feature. This emulation is based on the javascript performance.now() function.std::time::Instant otherwise.Note that even if the stdweb or wasm-bindgen feature is enabled, this crate will continue to rely on std::time::Instant as long as you are not targeting wasm32. This allows for portable code that will work on both native and WASM platforms.
This crate also exports the function instant::now() which returns a representation of the current time as an f64, expressed in milliseconds, in a platform-agnostic way. instant::now() will either:
performance.now() when compiling for a WASM platform with the features stdweb or wasm-bindgen enabled, or using a custom javascript function.Note: The old feature, now, has been deprecated. instant::now() is always exported and the now feature flag no longer has any effect. It remains listed in Cargo.toml to avoid introducing breaking changes and may be removed in future versions.
instant for a native platform.Cargo.toml:
[dependencies] instant = "0.1"
main.rs:
fn main() { // Will be the same as `std::time::Instant`. let now = instant::Instant::now(); }
instant for a WASM platform.This example shows the use of the stdweb feature. It would be similar with wasm-bindgen.
Cargo.toml:
[dependencies] instant = { version = "0.1", features = [ "stdweb" ] }
main.rs:
fn main() { // Will emulate `std::time::Instant` based on `performance.now()`. let now = instant::Instant::now(); }
instant for a WASM platform where performance.now() is not available.This example shows the use of the inaccurate feature.
Cargo.toml:
[dependencies] instant = { version = "0.1", features = [ "wasm-bindgen", "inaccurate" ] }
main.rs:
fn main() { // Will emulate `std::time::Instant` based on `Date.now()`. let now = instant::Instant::now(); }
instant for any platform enabling a feature transitively.Cargo.toml:
[features] stdweb = [ "instant/stdweb" ] wasm-bindgen = [ "instant/wasm-bindgen" ] [dependencies] instant = "0.1"
lib.rs:
fn my_function() { // Will select the proper implementation depending on the // feature selected by the user. let now = instant::Instant::now(); }
instant::now()Cargo.toml:
[features] stdweb = [ "instant/stdweb" ] wasm-bindgen = [ "instant/wasm-bindgen" ] [dependencies] instant = "0.1"
lib.rs:
fn my_function() { // Will select the proper implementation depending on the // feature selected by the user. let now_instant = instant::Instant::now(); let now_milliseconds = instant::now(); // In milliseconds. }
now without stdweb or wasm-bindgen.Cargo.toml:
[dependencies] instant = "0.1"
lib.rs:
fn my_function() { // Will use the 'now' javascript implementation. let now_instant = instant::Instant::now(); let now_milliseconds = instant::now(); // In milliseconds. }
javascript WASM bindings file:
function now() { return Date.now() / 1000.0; }