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 std::{
22    error::Error,
23    fmt, io,
24    pin::Pin,
25    task::{Context, Poll},
26};
27
28use futures::{prelude::*, stream::FusedStream};
29use multiaddr::Multiaddr;
30
31use crate::transport::{DialOpts, ListenerId, Transport, TransportError, TransportEvent};
32
33/// Creates a new [`Boxed`] transport from the given transport.
34pub(crate) fn boxed<T>(transport: T) -> Boxed<T::Output>
35where
36    T: Transport + Send + Unpin + 'static,
37    T::Error: Send + Sync,
38    T::Dial: Send + 'static,
39    T::ListenerUpgrade: Send + 'static,
40{
41    Boxed {
42        inner: Box::new(transport) as Box<_>,
43    }
44}
45
46/// A `Boxed` transport is a `Transport` whose `Dial`, `Listener`
47/// and `ListenerUpgrade` futures are `Box`ed and only the `Output`
48/// type is captured in a type variable.
49pub struct Boxed<O> {
50    inner: Box<dyn Abstract<O> + Send + Unpin>,
51}
52
53type Dial<O> = Pin<Box<dyn Future<Output = io::Result<O>> + Send>>;
54type ListenerUpgrade<O> = Pin<Box<dyn Future<Output = io::Result<O>> + Send>>;
55
56trait Abstract<O> {
57    fn listen_on(
58        &mut self,
59        id: ListenerId,
60        addr: Multiaddr,
61    ) -> Result<(), TransportError<io::Error>>;
62    fn remove_listener(&mut self, id: ListenerId) -> bool;
63    fn dial(
64        &mut self,
65        addr: Multiaddr,
66        opts: DialOpts,
67    ) -> Result<Dial<O>, TransportError<io::Error>>;
68    fn poll(
69        self: Pin<&mut Self>,
70        cx: &mut Context<'_>,
71    ) -> Poll<TransportEvent<ListenerUpgrade<O>, io::Error>>;
72}
73
74impl<T, O> Abstract<O> for T
75where
76    T: Transport<Output = O> + 'static,
77    T::Error: Send + Sync,
78    T::Dial: Send + 'static,
79    T::ListenerUpgrade: Send + 'static,
80{
81    fn listen_on(
82        &mut self,
83        id: ListenerId,
84        addr: Multiaddr,
85    ) -> Result<(), TransportError<io::Error>> {
86        Transport::listen_on(self, id, addr).map_err(|e| e.map(box_err))
87    }
88
89    fn remove_listener(&mut self, id: ListenerId) -> bool {
90        Transport::remove_listener(self, id)
91    }
92
93    fn dial(
94        &mut self,
95        addr: Multiaddr,
96        opts: DialOpts,
97    ) -> Result<Dial<O>, TransportError<io::Error>> {
98        let fut = Transport::dial(self, addr, opts)
99            .map(|r| r.map_err(box_err))
100            .map_err(|e| e.map(box_err))?;
101        Ok(Box::pin(fut) as Dial<_>)
102    }
103
104    fn poll(
105        self: Pin<&mut Self>,
106        cx: &mut Context<'_>,
107    ) -> Poll<TransportEvent<ListenerUpgrade<O>, io::Error>> {
108        self.poll(cx).map(|event| {
109            event
110                .map_upgrade(|upgrade| {
111                    let up = upgrade.map_err(box_err);
112                    Box::pin(up) as ListenerUpgrade<O>
113                })
114                .map_err(box_err)
115        })
116    }
117}
118
119impl<O> fmt::Debug for Boxed<O> {
120    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
121        write!(f, "BoxedTransport")
122    }
123}
124
125impl<O> Transport for Boxed<O> {
126    type Output = O;
127    type Error = io::Error;
128    type ListenerUpgrade = ListenerUpgrade<O>;
129    type Dial = Dial<O>;
130
131    fn listen_on(
132        &mut self,
133        id: ListenerId,
134        addr: Multiaddr,
135    ) -> Result<(), TransportError<Self::Error>> {
136        self.inner.listen_on(id, addr)
137    }
138
139    fn remove_listener(&mut self, id: ListenerId) -> bool {
140        self.inner.remove_listener(id)
141    }
142
143    fn dial(
144        &mut self,
145        addr: Multiaddr,
146        opts: DialOpts,
147    ) -> Result<Self::Dial, TransportError<Self::Error>> {
148        self.inner.dial(addr, opts)
149    }
150
151    fn poll(
152        mut self: Pin<&mut Self>,
153        cx: &mut Context<'_>,
154    ) -> Poll<TransportEvent<Self::ListenerUpgrade, Self::Error>> {
155        Pin::new(self.inner.as_mut()).poll(cx)
156    }
157}
158
159impl<O> Stream for Boxed<O> {
160    type Item = TransportEvent<ListenerUpgrade<O>, io::Error>;
161
162    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
163        Transport::poll(self, cx).map(Some)
164    }
165}
166
167impl<O> FusedStream for Boxed<O> {
168    fn is_terminated(&self) -> bool {
169        false
170    }
171}
172
173fn box_err<E: Error + Send + Sync + 'static>(e: E) -> io::Error {
174    io::Error::new(io::ErrorKind::Other, e)
175}
libp2p_core/transport/boxed.rs

libp2p_core/transport/
boxed.rs
