async_net/
addr.rs

1use std::fmt;
2use std::future::Future;
3use std::io;
4use std::mem;
5use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
6use std::net::{SocketAddr, SocketAddrV4, SocketAddrV6, ToSocketAddrs};
7use std::pin::Pin;
8use std::task::{Context, Poll};
9
10use blocking::unblock;
11use futures_lite::future;
12
13/// Converts or resolves addresses to [`SocketAddr`] values.
14///
15/// This trait currently only appears in function signatures and cannot be used directly.
16///
17/// However, you can use the [`resolve()`][`super::resolve()`] function to resolve addresses.
18pub trait AsyncToSocketAddrs: Sealed {}
19
20pub trait Sealed {
21    /// Returned iterator over socket addresses which this type may correspond to.
22    type Iter: Iterator<Item = SocketAddr> + Unpin;
23
24    /// Converts this object to an iterator of resolved `SocketAddr`s.
25    ///
26    /// The returned iterator may not actually yield any values depending on the outcome of any
27    /// resolution performed.
28    ///
29    /// Note that this function may block a backend thread while resolution is performed.
30    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter>;
31}
32
33pub enum ToSocketAddrsFuture<I> {
34    Resolving(future::Boxed<io::Result<I>>),
35    Ready(io::Result<I>),
36    Done,
37}
38
39impl<I> fmt::Debug for ToSocketAddrsFuture<I> {
40    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
41        write!(f, "ToSocketAddrsFuture")
42    }
43}
44
45impl<I: Iterator<Item = SocketAddr> + Unpin> Future for ToSocketAddrsFuture<I> {
46    type Output = io::Result<I>;
47
48    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
49        let state = mem::replace(&mut *self, ToSocketAddrsFuture::Done);
50
51        match state {
52            ToSocketAddrsFuture::Resolving(mut task) => {
53                let poll = Pin::new(&mut task).poll(cx);
54                if poll.is_pending() {
55                    *self = ToSocketAddrsFuture::Resolving(task);
56                }
57                poll
58            }
59            ToSocketAddrsFuture::Ready(res) => Poll::Ready(res),
60            ToSocketAddrsFuture::Done => panic!("polled a completed future"),
61        }
62    }
63}
64
65impl AsyncToSocketAddrs for SocketAddr {}
66
67impl Sealed for SocketAddr {
68    type Iter = std::option::IntoIter<SocketAddr>;
69
70    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
71        ToSocketAddrsFuture::Ready(Ok(Some(*self).into_iter()))
72    }
73}
74
75impl AsyncToSocketAddrs for SocketAddrV4 {}
76
77impl Sealed for SocketAddrV4 {
78    type Iter = std::option::IntoIter<SocketAddr>;
79
80    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
81        Sealed::to_socket_addrs(&SocketAddr::V4(*self))
82    }
83}
84
85impl AsyncToSocketAddrs for SocketAddrV6 {}
86
87impl Sealed for SocketAddrV6 {
88    type Iter = std::option::IntoIter<SocketAddr>;
89
90    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
91        Sealed::to_socket_addrs(&SocketAddr::V6(*self))
92    }
93}
94
95impl AsyncToSocketAddrs for (IpAddr, u16) {}
96
97impl Sealed for (IpAddr, u16) {
98    type Iter = std::option::IntoIter<SocketAddr>;
99
100    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
101        let (ip, port) = *self;
102        match ip {
103            IpAddr::V4(a) => Sealed::to_socket_addrs(&(a, port)),
104            IpAddr::V6(a) => Sealed::to_socket_addrs(&(a, port)),
105        }
106    }
107}
108
109impl AsyncToSocketAddrs for (Ipv4Addr, u16) {}
110
111impl Sealed for (Ipv4Addr, u16) {
112    type Iter = std::option::IntoIter<SocketAddr>;
113
114    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
115        let (ip, port) = *self;
116        Sealed::to_socket_addrs(&SocketAddrV4::new(ip, port))
117    }
118}
119
120impl AsyncToSocketAddrs for (Ipv6Addr, u16) {}
121
122impl Sealed for (Ipv6Addr, u16) {
123    type Iter = std::option::IntoIter<SocketAddr>;
124
125    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
126        let (ip, port) = *self;
127        Sealed::to_socket_addrs(&SocketAddrV6::new(ip, port, 0, 0))
128    }
129}
130
131impl AsyncToSocketAddrs for (&str, u16) {}
132
133impl Sealed for (&str, u16) {
134    type Iter = std::vec::IntoIter<SocketAddr>;
135
136    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
137        let (host, port) = *self;
138
139        if let Ok(addr) = host.parse::<Ipv4Addr>() {
140            let addr = SocketAddrV4::new(addr, port);
141            return ToSocketAddrsFuture::Ready(Ok(vec![SocketAddr::V4(addr)].into_iter()));
142        }
143
144        if let Ok(addr) = host.parse::<Ipv6Addr>() {
145            let addr = SocketAddrV6::new(addr, port, 0, 0);
146            return ToSocketAddrsFuture::Ready(Ok(vec![SocketAddr::V6(addr)].into_iter()));
147        }
148
149        let host = host.to_string();
150        let future = unblock(move || {
151            let addr = (host.as_str(), port);
152            ToSocketAddrs::to_socket_addrs(&addr)
153        });
154        ToSocketAddrsFuture::Resolving(Box::pin(future))
155    }
156}
157
158impl AsyncToSocketAddrs for (String, u16) {}
159
160impl Sealed for (String, u16) {
161    type Iter = std::vec::IntoIter<SocketAddr>;
162
163    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
164        Sealed::to_socket_addrs(&(&*self.0, self.1))
165    }
166}
167
168impl AsyncToSocketAddrs for str {}
169
170impl Sealed for str {
171    type Iter = std::vec::IntoIter<SocketAddr>;
172
173    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
174        if let Ok(addr) = self.parse() {
175            return ToSocketAddrsFuture::Ready(Ok(vec![addr].into_iter()));
176        }
177
178        let addr = self.to_string();
179        let future = unblock(move || std::net::ToSocketAddrs::to_socket_addrs(addr.as_str()));
180        ToSocketAddrsFuture::Resolving(Box::pin(future))
181    }
182}
183
184impl AsyncToSocketAddrs for &[SocketAddr] {}
185
186impl<'a> Sealed for &'a [SocketAddr] {
187    type Iter = std::iter::Cloned<std::slice::Iter<'a, SocketAddr>>;
188
189    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
190        ToSocketAddrsFuture::Ready(Ok(self.iter().cloned()))
191    }
192}
193
194impl<T: AsyncToSocketAddrs + ?Sized> AsyncToSocketAddrs for &T {}
195
196impl<T: Sealed + ?Sized> Sealed for &T {
197    type Iter = T::Iter;
198
199    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
200        Sealed::to_socket_addrs(&**self)
201    }
202}
203
204impl AsyncToSocketAddrs for String {}
205
206impl Sealed for String {
207    type Iter = std::vec::IntoIter<SocketAddr>;
208
209    fn to_socket_addrs(&self) -> ToSocketAddrsFuture<Self::Iter> {
210        Sealed::to_socket_addrs(&**self)
211    }
212}
async_net/addr.rs

async_net/
addr.rs
