core/upgrade/: Add ReadyUpgrade (#2855)

core/CHANGELOG.md

@@ -3,6 +3,9 @@
 - Make RSA keypair support optional. To enable RSA support, `rsa` feature should be enabled.
   See [PR 2860].
 
+- Add `ReadyUpgrade`. See [PR 2855].
+
+[PR 2855]: https://github.com/libp2p/rust-libp2p/pull/2855
 [PR 2860]: https://github.com/libp2p/rust-libp2p/pull/2860/
 
 # 0.35.1

core/src/upgrade.rs

@@ -65,6 +65,7 @@ mod from_fn;
 mod map;
 mod optional;
 mod pending;
+mod ready;
 mod select;
 mod transfer;
 
@@ -79,6 +80,7 @@ pub use self::{
     map::{MapInboundUpgrade, MapInboundUpgradeErr, MapOutboundUpgrade, MapOutboundUpgradeErr},
     optional::OptionalUpgrade,
     pending::PendingUpgrade,
+    ready::ReadyUpgrade,
     select::SelectUpgrade,
     transfer::{read_length_prefixed, read_varint, write_length_prefixed, write_varint},
 };

core/src/upgrade/ready.rs

@@ -0,0 +1,75 @@
+// Copyright 2022 Protocol Labs.
+// Copyright 2017-2018 Parity Technologies (UK) Ltd.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+use crate::upgrade::{InboundUpgrade, OutboundUpgrade, ProtocolName, UpgradeInfo};
+use futures::future;
+use std::iter;
+use void::Void;
+
+/// Implementation of [`UpgradeInfo`], [`InboundUpgrade`] and [`OutboundUpgrade`] that directly yields the substream.
+#[derive(Debug, Copy, Clone)]
+pub struct ReadyUpgrade<P> {
+    protocol_name: P,
+}
+
+impl<P> ReadyUpgrade<P> {
+    pub fn new(protocol_name: P) -> Self {
+        Self { protocol_name }
+    }
+}
+
+impl<P> UpgradeInfo for ReadyUpgrade<P>
+where
+    P: ProtocolName + Clone,
+{
+    type Info = P;
+    type InfoIter = iter::Once<P>;
+
+    fn protocol_info(&self) -> Self::InfoIter {
+        iter::once(self.protocol_name.clone())
+    }
+}
+
+impl<C, P> InboundUpgrade<C> for ReadyUpgrade<P>
+where
+    P: ProtocolName + Clone,
+{
+    type Output = C;
+    type Error = Void;
+    type Future = future::Ready<Result<Self::Output, Self::Error>>;
+
+    fn upgrade_inbound(self, stream: C, _: Self::Info) -> Self::Future {
+        future::ready(Ok(stream))
+    }
+}
+
+impl<C, P> OutboundUpgrade<C> for ReadyUpgrade<P>
+where
+    P: ProtocolName + Clone,
+{
+    type Output = C;
+    type Error = Void;
+    type Future = future::Ready<Result<Self::Output, Self::Error>>;
+
+    fn upgrade_outbound(self, stream: C, _: Self::Info) -> Self::Future {
+        future::ready(Ok(stream))
+    }
+}

protocols/ping/src/handler.rs

@@ -18,10 +18,11 @@
 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-use crate::protocol;
+use crate::{protocol, PROTOCOL_NAME};
 use futures::future::BoxFuture;
 use futures::prelude::*;
 use futures_timer::Delay;
+use libp2p_core::upgrade::ReadyUpgrade;
 use libp2p_core::{upgrade::NegotiationError, UpgradeError};
 use libp2p_swarm::{
     ConnectionHandler, ConnectionHandlerEvent, ConnectionHandlerUpgrErr, KeepAlive,
@@ -225,13 +226,13 @@ impl ConnectionHandler for Handler {
     type InEvent = Void;
     type OutEvent = crate::Result;
     type Error = Failure;
-    type InboundProtocol = protocol::Ping;
+    type InboundProtocol = ReadyUpgrade<&'static [u8]>;
-    type OutboundProtocol = protocol::Ping;
+    type OutboundProtocol = ReadyUpgrade<&'static [u8]>;
     type OutboundOpenInfo = ();
     type InboundOpenInfo = ();
 
-    fn listen_protocol(&self) -> SubstreamProtocol<protocol::Ping, ()> {
+    fn listen_protocol(&self) -> SubstreamProtocol<ReadyUpgrade<&'static [u8]>, ()> {
-        SubstreamProtocol::new(protocol::Ping, ())
+        SubstreamProtocol::new(ReadyUpgrade::new(PROTOCOL_NAME), ())
     }
 
     fn inject_fully_negotiated_inbound(&mut self, stream: NegotiatedSubstream, (): ()) {
@@ -274,7 +275,8 @@ impl ConnectionHandler for Handler {
     fn poll(
         &mut self,
         cx: &mut Context<'_>,
-    ) -> Poll<ConnectionHandlerEvent<protocol::Ping, (), crate::Result, Self::Error>> {
+    ) -> Poll<ConnectionHandlerEvent<ReadyUpgrade<&'static [u8]>, (), crate::Result, Self::Error>>
+    {
         match self.state {
             State::Inactive { reported: true } => {
                 return Poll::Pending; // nothing to do on this connection
@@ -366,7 +368,7 @@ impl ConnectionHandler for Handler {
                 }
                 None => {
                     self.outbound = Some(PingState::OpenStream);
-                    let protocol = SubstreamProtocol::new(protocol::Ping, ())
+                    let protocol = SubstreamProtocol::new(ReadyUpgrade::new(PROTOCOL_NAME), ())
                         .with_timeout(self.config.timeout);
                     return Poll::Ready(ConnectionHandlerEvent::OutboundSubstreamRequest {
                         protocol,

protocols/ping/src/protocol.rs

@@ -20,13 +20,10 @@
 
 use futures::prelude::*;
 use instant::Instant;
-use libp2p_core::{InboundUpgrade, OutboundUpgrade, UpgradeInfo};
-use libp2p_swarm::NegotiatedSubstream;
 use rand::{distributions, prelude::*};
-use std::{io, iter, time::Duration};
+use std::{io, time::Duration};
-use void::Void;
 
-pub const PROTOCOL_NAME: &[u8; 16] = b"/ipfs/ping/1.0.0";
+pub const PROTOCOL_NAME: &[u8] = b"/ipfs/ping/1.0.0";
 
 /// The `Ping` protocol upgrade.
 ///
@@ -52,35 +49,6 @@ pub struct Ping;
 
 const PING_SIZE: usize = 32;
 
-impl UpgradeInfo for Ping {
-    type Info = &'static [u8];
-    type InfoIter = iter::Once<Self::Info>;
-
-    fn protocol_info(&self) -> Self::InfoIter {
-        iter::once(PROTOCOL_NAME)
-    }
-}
-
-impl InboundUpgrade<NegotiatedSubstream> for Ping {
-    type Output = NegotiatedSubstream;
-    type Error = Void;
-    type Future = future::Ready<Result<Self::Output, Self::Error>>;
-
-    fn upgrade_inbound(self, stream: NegotiatedSubstream, _: Self::Info) -> Self::Future {
-        future::ok(stream)
-    }
-}
-
-impl OutboundUpgrade<NegotiatedSubstream> for Ping {
-    type Output = NegotiatedSubstream;
-    type Error = Void;
-    type Future = future::Ready<Result<Self::Output, Self::Error>>;
-
-    fn upgrade_outbound(self, stream: NegotiatedSubstream, _: Self::Info) -> Self::Future {
-        future::ok(stream)
-    }
-}
-
 /// Sends a ping and waits for the pong.
 pub async fn send_ping<S>(mut stream: S) -> io::Result<(S, Duration)>
 where