Complete drop-in replacement for std::time that works in browsers.
Currently Instant::now() and SystemTime::now() will simply panic when using the
wasm32-unknown-unknown target. This implementation uses Performance.now() for Instant and
Date.now() for SystemTime to offer a drop-in replacement that works in browsers.
At the same time the library will simply re-export std::time when not using the
wasm32-unknown-unknown or wasm32v1-none target and will not pull in any dependencies.
Additionally, if compiled with target-feature = "atomics" it will synchronize the timestamps to
account for different context's, like web workers. See Performance.timeOrigin for more
information.
This library specifically targets browsers, that support Performance.now(), with the
wasm32-unknown-unknown or wasm32v1-none target. Emscripten is not supported. WASI doesn't
require support as it has it's own native API to deal with std::time.
Furthermore it depends on wasm-bindgen, which is required. This library will continue to depend
on it until a viable alternative presents itself, in which case multiple ecosystems could be
supported.
Currently a known bug is affecting browsers on operating system other then Windows. This bug
prevents Instant from continuing to tick when the context is asleep. While this doesn't conflict
with Rusts requirements of Instant, by chance Rust's Std
has the same problem.
See the MDN documentation on this for more information.
The implementation of Instant::now() relies on the availability of the Performance object, a
lack thereof will cause a panic. This can happen if called from a worklet.
You can simply import the types you need:
use web_time::{Instant, SystemTime};
let now = Instant::now();
let time = SystemTime::now();Using -Ctarget-feature=+nontrapping-fptoint will improve the performance of Instant::now() and
SystemTime::now(), but the vast majority of the time is still spent going through JS.
Enables the corresponding crate feature in all dependencies and allows for some optimized instruction output.
Without this crate feature compilation the standard library is not included. Has no effect on
targets other then wasm32-unknown-unknown or wasm32v1-none.
Allows web-time to make use of features only available in higher MSRVs. This offers compile-time
detection and does not break compilation when enabled with the crates MSRV.
- Rust v1.77 +
std: Enables the use of thef64.nearestinstruction. Which will significantly reduce the instruction count forInstant::now(). - Rust Nightly: Enables the use of the
f64.truncandf64.nearestinstruction. Which will significantly reduce the instruction count forInstant::now().
Implements serde::Deserialize and serde::Serialize for SystemTime.
This requires Rust nightly and enhances the documentation. It must only be used with RUSTDOCFLAGS,
not with RUSTFLAGS.
The MSRV is v1.60. Changes to the MSRV will be accompanied by a minor version bump.
See the CHANGELOG file for details.
See the CONTRIBUTING file for details.
Inspiration was taken from the instant project.
Additional insight was taken from the time project.
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
A majority of the code and documentation was taken from std::time. For license information see
#License.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.