runtime/event_loop/
future.rs

1/*
2 * This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
5 */
6
7use std::task;
8use std::task::Poll;
9
10use futures_util::StreamExt as _;
11use futures_util::stream::FuturesUnordered;
12use ion::conversions::BoxedIntoValue;
13use ion::{Context, Error, ErrorKind, ErrorReport, Promise, ThrowException as _, Value};
14use mozjs::jsapi::JSObject;
15use tokio::task::JoinHandle;
16
17type FutureOutput = (Result<BoxedIntoValue, BoxedIntoValue>, *mut JSObject);
18
19#[derive(Default)]
20pub struct FutureQueue {
21	queue: FuturesUnordered<JoinHandle<FutureOutput>>,
22}
23
24impl FutureQueue {
25	pub fn run_futures(&mut self, cx: &Context, wcx: &mut task::Context) -> Result<(), Option<ErrorReport>> {
26		let mut results = Vec::new();
27
28		while let Poll::Ready(Some(item)) = self.queue.poll_next_unpin(wcx) {
29			match item {
30				Ok(item) => results.push(item),
31				Err(error) => {
32					Error::new(error.to_string(), ErrorKind::Normal).throw(cx);
33					return Err(None);
34				}
35			}
36		}
37
38		for (result, promise) in results {
39			let mut value = Value::undefined(cx);
40			let promise = Promise::from(cx.root(promise)).unwrap();
41
42			let result = match result {
43				Ok(o) => {
44					o.into_value(cx, &mut value);
45					promise.resolve(cx, &value)
46				}
47				Err(e) => {
48					e.into_value(cx, &mut value);
49					promise.reject(cx, &value)
50				}
51			};
52
53			if !result {
54				return Err(ErrorReport::new_with_exception_stack(cx).unwrap());
55			}
56		}
57
58		Ok(())
59	}
60
61	pub fn enqueue(&self, handle: JoinHandle<FutureOutput>) {
62		self.queue.push(handle);
63	}
64
65	pub fn is_empty(&self) -> bool {
66		self.queue.is_empty()
67	}
68}
runtime/event_loop/future.rs

runtime/event_loop/
future.rs
