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// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
//! This module helps deno implement timers and performance APIs.
use deno_core::error::AnyError;
use deno_core::include_js_files;
use deno_core::op_async;
use deno_core::op_sync;
use deno_core::CancelFuture;
use deno_core::CancelHandle;
use deno_core::Extension;
use deno_core::OpState;
use deno_core::Resource;
use deno_core::ResourceId;
use std::borrow::Cow;
use std::cell::RefCell;
use std::rc::Rc;
use std::time::Duration;
use std::time::Instant;
pub trait TimersPermission {
fn allow_hrtime(&mut self) -> bool;
fn check_unstable(&self, state: &OpState, api_name: &'static str);
}
pub fn init<P: TimersPermission + 'static>() -> Extension {
Extension::builder()
.js(include_js_files!(
prefix "deno:ext/timers",
"01_timers.js",
"02_performance.js",
))
.ops(vec![
("op_now", op_sync(op_now::<P>)),
("op_timer_handle", op_sync(op_timer_handle)),
("op_sleep", op_async(op_sleep)),
("op_sleep_sync", op_sync(op_sleep_sync::<P>)),
])
.state(|state| {
state.put(StartTime::now());
Ok(())
})
.build()
}
pub type StartTime = Instant;
// Returns a milliseconds and nanoseconds subsec
// since the start time of the deno runtime.
// If the High precision flag is not set, the
// nanoseconds are rounded on 2ms.
pub fn op_now<TP>(
state: &mut OpState,
_argument: (),
_: (),
) -> Result<f64, AnyError>
where
TP: TimersPermission + 'static,
{
let start_time = state.borrow::<StartTime>();
let seconds = start_time.elapsed().as_secs();
let mut subsec_nanos = start_time.elapsed().subsec_nanos() as f64;
let reduced_time_precision = 2_000_000.0; // 2ms in nanoseconds
// If the permission is not enabled
// Round the nano result on 2 milliseconds
// see: https://developer.mozilla.org/en-US/docs/Web/API/DOMHighResTimeStamp#Reduced_time_precision
if !state.borrow_mut::<TP>().allow_hrtime() {
subsec_nanos -= subsec_nanos % reduced_time_precision;
}
let result = (seconds * 1_000) as f64 + (subsec_nanos / 1_000_000.0);
Ok(result)
}
pub struct TimerHandle(Rc<CancelHandle>);
impl Resource for TimerHandle {
fn name(&self) -> Cow<str> {
"timer".into()
}
fn close(self: Rc<Self>) {
self.0.cancel();
}
}
/// Creates a [`TimerHandle`] resource that can be used to cancel invocations of
/// [`op_sleep`].
pub fn op_timer_handle(
state: &mut OpState,
_: (),
_: (),
) -> Result<ResourceId, AnyError> {
let rid = state
.resource_table
.add(TimerHandle(CancelHandle::new_rc()));
Ok(rid)
}
/// Waits asynchronously until either `millis` milliseconds have passed or the
/// [`TimerHandle`] resource given by `rid` has been canceled.
pub async fn op_sleep(
state: Rc<RefCell<OpState>>,
millis: u64,
rid: ResourceId,
) -> Result<(), AnyError> {
let handle = state.borrow().resource_table.get::<TimerHandle>(rid)?;
tokio::time::sleep(Duration::from_millis(millis))
.or_cancel(handle.0.clone())
.await?;
Ok(())
}
pub fn op_sleep_sync<TP>(
state: &mut OpState,
millis: u64,
_: (),
) -> Result<(), AnyError>
where
TP: TimersPermission + 'static,
{
state.borrow::<TP>().check_unstable(state, "Deno.sleepSync");
std::thread::sleep(Duration::from_millis(millis));
Ok(())
}
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