libp2p_core/transport/
boxed.rs

1// Copyright 2018 Parity Technologies (UK) Ltd.
2//
3// Permission is hereby granted, free of charge, to any person obtaining a
4// copy of this software and associated documentation files (the "Software"),
5// to deal in the Software without restriction, including without limitation
6// the rights to use, copy, modify, merge, publish, distribute, sublicense,
7// and/or sell copies of the Software, and to permit persons to whom the
8// Software is furnished to do so, subject to the following conditions:
9//
10// The above copyright notice and this permission notice shall be included in
11// all copies or substantial portions of the Software.
12//
13// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
14// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
19// DEALINGS IN THE SOFTWARE.
20
21use crate::transport::{DialOpts, ListenerId, Transport, TransportError, TransportEvent};
22use futures::{prelude::*, stream::FusedStream};
23use multiaddr::Multiaddr;
24use std::{
25    error::Error,
26    fmt, io,
27    pin::Pin,
28    task::{Context, Poll},
29};
30
31/// Creates a new [`Boxed`] transport from the given transport.
32pub(crate) fn boxed<T>(transport: T) -> Boxed<T::Output>
33where
34    T: Transport + Send + Unpin + 'static,
35    T::Error: Send + Sync,
36    T::Dial: Send + 'static,
37    T::ListenerUpgrade: Send + 'static,
38{
39    Boxed {
40        inner: Box::new(transport) as Box<_>,
41    }
42}
43
44/// A `Boxed` transport is a `Transport` whose `Dial`, `Listener`
45/// and `ListenerUpgrade` futures are `Box`ed and only the `Output`
46/// type is captured in a type variable.
47pub struct Boxed<O> {
48    inner: Box<dyn Abstract<O> + Send + Unpin>,
49}
50
51type Dial<O> = Pin<Box<dyn Future<Output = io::Result<O>> + Send>>;
52type ListenerUpgrade<O> = Pin<Box<dyn Future<Output = io::Result<O>> + Send>>;
53
54trait Abstract<O> {
55    fn listen_on(
56        &mut self,
57        id: ListenerId,
58        addr: Multiaddr,
59    ) -> Result<(), TransportError<io::Error>>;
60    fn remove_listener(&mut self, id: ListenerId) -> bool;
61    fn dial(
62        &mut self,
63        addr: Multiaddr,
64        opts: DialOpts,
65    ) -> Result<Dial<O>, TransportError<io::Error>>;
66    fn poll(
67        self: Pin<&mut Self>,
68        cx: &mut Context<'_>,
69    ) -> Poll<TransportEvent<ListenerUpgrade<O>, io::Error>>;
70}
71
72impl<T, O> Abstract<O> for T
73where
74    T: Transport<Output = O> + 'static,
75    T::Error: Send + Sync,
76    T::Dial: Send + 'static,
77    T::ListenerUpgrade: Send + 'static,
78{
79    fn listen_on(
80        &mut self,
81        id: ListenerId,
82        addr: Multiaddr,
83    ) -> Result<(), TransportError<io::Error>> {
84        Transport::listen_on(self, id, addr).map_err(|e| e.map(box_err))
85    }
86
87    fn remove_listener(&mut self, id: ListenerId) -> bool {
88        Transport::remove_listener(self, id)
89    }
90
91    fn dial(
92        &mut self,
93        addr: Multiaddr,
94        opts: DialOpts,
95    ) -> Result<Dial<O>, TransportError<io::Error>> {
96        let fut = Transport::dial(self, addr, opts)
97            .map(|r| r.map_err(box_err))
98            .map_err(|e| e.map(box_err))?;
99        Ok(Box::pin(fut) as Dial<_>)
100    }
101
102    fn poll(
103        self: Pin<&mut Self>,
104        cx: &mut Context<'_>,
105    ) -> Poll<TransportEvent<ListenerUpgrade<O>, io::Error>> {
106        self.poll(cx).map(|event| {
107            event
108                .map_upgrade(|upgrade| {
109                    let up = upgrade.map_err(box_err);
110                    Box::pin(up) as ListenerUpgrade<O>
111                })
112                .map_err(box_err)
113        })
114    }
115}
116
117impl<O> fmt::Debug for Boxed<O> {
118    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
119        write!(f, "BoxedTransport")
120    }
121}
122
123impl<O> Transport for Boxed<O> {
124    type Output = O;
125    type Error = io::Error;
126    type ListenerUpgrade = ListenerUpgrade<O>;
127    type Dial = Dial<O>;
128
129    fn listen_on(
130        &mut self,
131        id: ListenerId,
132        addr: Multiaddr,
133    ) -> Result<(), TransportError<Self::Error>> {
134        self.inner.listen_on(id, addr)
135    }
136
137    fn remove_listener(&mut self, id: ListenerId) -> bool {
138        self.inner.remove_listener(id)
139    }
140
141    fn dial(
142        &mut self,
143        addr: Multiaddr,
144        opts: DialOpts,
145    ) -> Result<Self::Dial, TransportError<Self::Error>> {
146        self.inner.dial(addr, opts)
147    }
148
149    fn poll(
150        mut self: Pin<&mut Self>,
151        cx: &mut Context<'_>,
152    ) -> Poll<TransportEvent<Self::ListenerUpgrade, Self::Error>> {
153        Pin::new(self.inner.as_mut()).poll(cx)
154    }
155}
156
157impl<O> Stream for Boxed<O> {
158    type Item = TransportEvent<ListenerUpgrade<O>, io::Error>;
159
160    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
161        Transport::poll(self, cx).map(Some)
162    }
163}
164
165impl<O> FusedStream for Boxed<O> {
166    fn is_terminated(&self) -> bool {
167        false
168    }
169}
170
171fn box_err<E: Error + Send + Sync + 'static>(e: E) -> io::Error {
172    io::Error::new(io::ErrorKind::Other, e)
173}
libp2p_core/transport/boxed.rs

libp2p_core/transport/
boxed.rs
