reactor_trait/
lib.rs

1//! A collection of traits to define a common interface across reactors
2
3// We want to forbid unsafe code but need to unsafe impl for async-io...
4#![allow(unsafe_code)]
5#![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)]
6
7use async_trait::async_trait;
8use executor_trait::BlockingExecutor;
9use futures_core::Stream;
10use futures_io::{AsyncRead, AsyncWrite};
11use std::{
12    fmt,
13    io::{self, IoSlice, IoSliceMut, Read, Write},
14    net::{SocketAddr, ToSocketAddrs},
15    ops::Deref,
16    time::{Duration, Instant},
17};
18use sys::IO;
19
20/// A synchronous IO handle
21pub struct IOHandle(Box<dyn IO + Send>);
22
23impl IOHandle {
24    /// Instantiate a new IO handle
25    pub fn new<H: IO + Send + 'static>(io: H) -> Self {
26        Self(Box::new(io))
27    }
28}
29
30impl Read for IOHandle {
31    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
32        self.0.read(buf)
33    }
34
35    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
36        self.0.read_vectored(bufs)
37    }
38
39    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
40        self.0.read_to_end(buf)
41    }
42
43    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
44        self.0.read_to_string(buf)
45    }
46
47    fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
48        self.0.read_exact(buf)
49    }
50}
51
52impl Write for IOHandle {
53    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
54        self.0.write(buf)
55    }
56
57    fn flush(&mut self) -> io::Result<()> {
58        self.0.flush()
59    }
60
61    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
62        self.0.write_vectored(bufs)
63    }
64
65    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
66        self.0.write_all(buf)
67    }
68
69    fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
70        self.0.write_fmt(fmt)
71    }
72}
73
74impl fmt::Debug for IOHandle {
75    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
76        f.debug_tuple("IOHandle").finish()
77    }
78}
79
80#[cfg(feature = "async_io_safe")]
81unsafe impl async_io::IoSafe for IOHandle {}
82
83/// A trait representing an asynchronous IO handle
84pub trait AsyncIOHandle: AsyncRead + AsyncWrite {}
85impl<IO: AsyncRead + AsyncWrite> AsyncIOHandle for IO {}
86
87/// A common interface for registering IO handles in a reactor.
88pub trait Reactor {
89    /// Register a synchronous handle, returning an asynchronous one
90    fn register(&self, socket: IOHandle) -> io::Result<Box<dyn AsyncIOHandle + Send>>;
91}
92
93/// A common interface for registering timers in a reactor.
94#[async_trait]
95pub trait TimeReactor {
96    /// Sleep for the given duration
97    async fn sleep(&self, dur: Duration);
98    /// Stream that yields at every given interval
99    fn interval(&self, dur: Duration) -> Box<dyn Stream<Item = Instant>>;
100}
101
102/// A common interface for registering TCP handles in a reactor.
103#[async_trait]
104pub trait TcpReactor {
105    /// Create a TcpStream by connecting to a remote host
106    async fn connect(&self, addr: SocketAddr) -> io::Result<Box<dyn AsyncIOHandle + Send>>;
107}
108
109/// A common interface for resolving domain name + port to `SocketAddr`
110#[async_trait]
111pub trait AsyncToSocketAddrs {
112    /// Resolve the domain name through DNS and return an `Iterator` of `SocketAddr`
113    async fn to_socket_addrs(
114        &self,
115    ) -> io::Result<Box<dyn Iterator<Item = SocketAddr> + Send + Sync>>;
116}
117
118#[async_trait]
119impl<E: Deref + Send + Sync, A: ToSocketAddrs + Clone + Send + Sync + 'static> AsyncToSocketAddrs
120    for (E, A)
121where
122    E::Target: BlockingExecutor + Send + Sync,
123{
124    /// Resolve the domain name through DNS and return an `Iterator` of `SocketAddr`
125    /// For this generic impl, we spawn the `std::net::ToSocketAddrs` impl on a blocking executor
126    async fn to_socket_addrs(
127        &self,
128    ) -> io::Result<Box<dyn Iterator<Item = SocketAddr> + Send + Sync>> {
129        let (executor, addrs) = self;
130        let addrs = addrs.clone();
131        let (sender, receiver) = flume::bounded(1);
132
133        executor
134            .spawn_blocking(Box::new(move || {
135                sender
136                    .send(
137                        addrs
138                            .to_socket_addrs()
139                            .map(|addrs| addrs.collect::<Vec<_>>()),
140                    )
141                    .unwrap();
142            }))
143            .await;
144        let addrs = receiver.recv_async().await.map_err(io::Error::other)??;
145        Ok(Box::new(addrs.into_iter()))
146    }
147}
148
149#[cfg(unix)]
150mod sys {
151    use crate::IOHandle;
152    use std::{
153        io::{Read, Write},
154        os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd},
155    };
156
157    pub trait IO: Read + Write + AsFd {}
158    impl<H: Read + Write + AsFd> IO for H {}
159
160    impl AsFd for IOHandle {
161        fn as_fd(&self) -> BorrowedFd<'_> {
162            self.0.as_fd()
163        }
164    }
165
166    impl AsRawFd for IOHandle {
167        fn as_raw_fd(&self) -> RawFd {
168            self.as_fd().as_raw_fd()
169        }
170    }
171}
172
173#[cfg(windows)]
174mod sys {
175    use crate::IOHandle;
176    use std::{
177        io::{Read, Write},
178        os::windows::io::{AsRawSocket, AsSocket, BorrowedSocket, RawSocket},
179    };
180
181    pub trait IO: Read + Write + AsSocket {}
182    impl<H: Read + Write + AsSocket> IO for H {}
183
184    impl AsSocket for IOHandle {
185        fn as_socket(&self) -> BorrowedSocket<'_> {
186            self.0.as_socket()
187        }
188    }
189
190    impl AsRawSocket for IOHandle {
191        fn as_raw_socket(&self) -> RawSocket {
192            self.as_socket().as_raw_socket()
193        }
194    }
195}
reactor_trait/lib.rs

reactor_trait/
lib.rs
