libp2p_core/upgrade/
select.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::either::EitherFuture;
22use crate::upgrade::{InboundUpgrade, OutboundUpgrade, UpgradeInfo};
23use either::Either;
24use futures::future;
25use std::iter::{Chain, Map};
26
27/// Upgrade that combines two upgrades into one. Supports all the protocols supported by either
28/// sub-upgrade.
29///
30/// The protocols supported by the first element have a higher priority.
31#[derive(Debug, Clone)]
32pub struct SelectUpgrade<A, B>(A, B);
33
34impl<A, B> SelectUpgrade<A, B> {
35    /// Combines two upgrades into an `SelectUpgrade`.
36    ///
37    /// The protocols supported by the first element have a higher priority.
38    pub fn new(a: A, b: B) -> Self {
39        SelectUpgrade(a, b)
40    }
41}
42
43impl<A, B> UpgradeInfo for SelectUpgrade<A, B>
44where
45    A: UpgradeInfo,
46    B: UpgradeInfo,
47{
48    type Info = Either<A::Info, B::Info>;
49    type InfoIter = Chain<
50        Map<<A::InfoIter as IntoIterator>::IntoIter, fn(A::Info) -> Self::Info>,
51        Map<<B::InfoIter as IntoIterator>::IntoIter, fn(B::Info) -> Self::Info>,
52    >;
53
54    fn protocol_info(&self) -> Self::InfoIter {
55        let a = self
56            .0
57            .protocol_info()
58            .into_iter()
59            .map(Either::Left as fn(A::Info) -> _);
60        let b = self
61            .1
62            .protocol_info()
63            .into_iter()
64            .map(Either::Right as fn(B::Info) -> _);
65
66        a.chain(b)
67    }
68}
69
70impl<C, A, B, TA, TB, EA, EB> InboundUpgrade<C> for SelectUpgrade<A, B>
71where
72    A: InboundUpgrade<C, Output = TA, Error = EA>,
73    B: InboundUpgrade<C, Output = TB, Error = EB>,
74{
75    type Output = future::Either<TA, TB>;
76    type Error = Either<EA, EB>;
77    type Future = EitherFuture<A::Future, B::Future>;
78
79    fn upgrade_inbound(self, sock: C, info: Self::Info) -> Self::Future {
80        match info {
81            Either::Left(info) => EitherFuture::First(self.0.upgrade_inbound(sock, info)),
82            Either::Right(info) => EitherFuture::Second(self.1.upgrade_inbound(sock, info)),
83        }
84    }
85}
86
87impl<C, A, B, TA, TB, EA, EB> OutboundUpgrade<C> for SelectUpgrade<A, B>
88where
89    A: OutboundUpgrade<C, Output = TA, Error = EA>,
90    B: OutboundUpgrade<C, Output = TB, Error = EB>,
91{
92    type Output = future::Either<TA, TB>;
93    type Error = Either<EA, EB>;
94    type Future = EitherFuture<A::Future, B::Future>;
95
96    fn upgrade_outbound(self, sock: C, info: Self::Info) -> Self::Future {
97        match info {
98            Either::Left(info) => EitherFuture::First(self.0.upgrade_outbound(sock, info)),
99            Either::Right(info) => EitherFuture::Second(self.1.upgrade_outbound(sock, info)),
100        }
101    }
102}
libp2p_core/upgrade/select.rs

libp2p_core/upgrade/
select.rs
