1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
use crate::resources::Resource;
use futures;
use futures::Future;
use futures::Poll;
use std::io;
use std::mem;
use std::net::SocketAddr;
use tokio;
use tokio::net::TcpStream;
use tokio_executor;
pub fn block_on<F, R, E>(future: F) -> Result<R, E>
where
F: Send + 'static + Future<Item = R, Error = E>,
R: Send + 'static,
E: Send + 'static,
{
let (tx, rx) = futures::sync::oneshot::channel();
tokio::spawn(future.then(move |r| tx.send(r).map_err(|_| unreachable!())));
rx.wait().unwrap()
}
// Set the default executor so we can use tokio::spawn(). It's difficult to
// pass around mut references to the runtime, so using with_default is
// preferable. Ideally Tokio would provide this function.
pub fn init<F>(f: F)
where
F: FnOnce(),
{
let rt = tokio::runtime::Runtime::new().unwrap();
let mut executor = rt.executor();
let mut enter = tokio_executor::enter().expect("Multiple executors at once");
tokio_executor::with_default(&mut executor, &mut enter, move |_enter| f());
}
#[derive(Debug)]
enum AcceptState {
Pending(Resource),
Empty,
}
/// Simply accepts a connection.
pub fn accept(r: Resource) -> Accept {
Accept {
state: AcceptState::Pending(r),
}
}
/// A future which can be used to easily read available number of bytes to fill
/// a buffer.
///
/// Created by the [`read`] function.
#[derive(Debug)]
pub struct Accept {
state: AcceptState,
}
impl Future for Accept {
type Item = (TcpStream, SocketAddr);
type Error = io::Error;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
let (stream, addr) = match self.state {
// Similar to try_ready!, but also track/untrack accept task
// in TcpListener resource.
// In this way, when the listener is closed, the task can be
// notified to error out (instead of stuck forever).
AcceptState::Pending(ref mut r) => match r.poll_accept() {
Ok(futures::prelude::Async::Ready(t)) => {
// Notice: it is possible to be Ready on the first poll.
// When eager accept fails due to WouldBlock,
// a next poll() might still be immediately Ready.
// See https://github.com/denoland/deno/issues/1756.
r.untrack_task();
t
}
Ok(futures::prelude::Async::NotReady) => {
// Would error out if another accept task is being tracked.
r.track_task()?;
return Ok(futures::prelude::Async::NotReady);
}
Err(e) => {
r.untrack_task();
return Err(e);
}
},
AcceptState::Empty => panic!("poll Accept after it's done"),
};
match mem::replace(&mut self.state, AcceptState::Empty) {
AcceptState::Pending(_) => Ok((stream, addr).into()),
AcceptState::Empty => panic!("invalid internal state"),
}
}
}
/// `futures::future::poll_fn` only support `F: FnMut()->Poll<T, E>`
/// However, we require that `F: FnOnce()->Poll<T, E>`.
/// Therefore, we created our version of `poll_fn`.
pub fn poll_fn<T, E, F>(f: F) -> PollFn<F>
where
F: FnOnce() -> Poll<T, E>,
{
PollFn { inner: Some(f) }
}
pub struct PollFn<F> {
inner: Option<F>,
}
impl<T, E, F> Future for PollFn<F>
where
F: FnOnce() -> Poll<T, E>,
{
type Item = T;
type Error = E;
fn poll(&mut self) -> Poll<T, E> {
let f = self.inner.take().expect("Inner fn has been taken.");
f()
}
}
pub fn panic_on_error<I, E, F>(f: F) -> impl Future<Item = I, Error = ()>
where
F: Future<Item = I, Error = E>,
E: std::fmt::Debug,
{
f.map_err(|err| panic!("Future got unexpected error: {:?}", err))
}
|
