refactor(core)!: remove EitherUpgrade (#3339)

We don't need to define our own type here, we can simply implement `UpgradeInfo`, `InboundUpgrade` and `OutboundUpgrade` on `either::Either`.

core/CHANGELOG.md

@@ -16,13 +16,16 @@
 
 - Remove `EitherTransport` in favor of implementing `Transport` on `either::Either`. See [PR 3338].
 
+- Remove `EitherUpgrade` in favor of implementing `UpgradeInfo`, `InboundUpgrade` and `OutboundUpgrade` on `either::Either`. See [PR 3339].
+
 [PR 3031]: https://github.com/libp2p/rust-libp2p/pull/3031
 [PR 3058]: https://github.com/libp2p/rust-libp2p/pull/3058
 [PR 3097]: https://github.com/libp2p/rust-libp2p/pull/3097
 [PR 3090]: https://github.com/libp2p/rust-libp2p/pull/3090
 [PR 2972]: https://github.com/libp2p/rust-libp2p/pull/2972
 [PR 3337]: https://github.com/libp2p/rust-libp2p/pull/3337
 [PR 3338]: https://github.com/libp2p/rust-libp2p/pull/3338
+[PR 3339]: https://github.com/libp2p/rust-libp2p/pull/3339
 
 # 0.37.0
 

core/src/upgrade.rs

@@ -74,7 +74,6 @@ use futures::future::Future;
 pub use self::{
     apply::{apply, apply_inbound, apply_outbound, InboundUpgradeApply, OutboundUpgradeApply},
     denied::DeniedUpgrade,
-    either::EitherUpgrade,
     error::UpgradeError,
     from_fn::{from_fn, FromFnUpgrade},
     map::{MapInboundUpgrade, MapInboundUpgradeErr, MapOutboundUpgrade, MapOutboundUpgradeErr},

core/src/upgrade/either.rs

@@ -24,14 +24,7 @@ use crate::{
 };
 use either::Either;
 
-/// A type to represent two possible upgrade types (inbound or outbound).
-#[derive(Debug, Clone)]
-pub enum EitherUpgrade<A, B> {
-    A(A),
-    B(B),
-}
-
-impl<A, B> UpgradeInfo for EitherUpgrade<A, B>
+impl<A, B> UpgradeInfo for Either<A, B>
 where
     A: UpgradeInfo,
     B: UpgradeInfo,
@@ -44,13 +37,13 @@ where
 
     fn protocol_info(&self) -> Self::InfoIter {
         match self {
-            EitherUpgrade::A(a) => EitherIter::A(a.protocol_info().into_iter()),
-            EitherUpgrade::B(b) => EitherIter::B(b.protocol_info().into_iter()),
+            Either::Left(a) => EitherIter::A(a.protocol_info().into_iter()),
+            Either::Right(b) => EitherIter::B(b.protocol_info().into_iter()),
         }
     }
 }
 
-impl<C, A, B, TA, TB, EA, EB> InboundUpgrade<C> for EitherUpgrade<A, B>
+impl<C, A, B, TA, TB, EA, EB> InboundUpgrade<C> for Either<A, B>
 where
     A: InboundUpgrade<C, Output = TA, Error = EA>,
     B: InboundUpgrade<C, Output = TB, Error = EB>,
@@ -61,18 +54,18 @@ where
 
     fn upgrade_inbound(self, sock: C, info: Self::Info) -> Self::Future {
         match (self, info) {
-            (EitherUpgrade::A(a), EitherName::A(info)) => {
+            (Either::Left(a), EitherName::A(info)) => {
                 EitherFuture2::A(a.upgrade_inbound(sock, info))
             }
-            (EitherUpgrade::B(b), EitherName::B(info)) => {
+            (Either::Right(b), EitherName::B(info)) => {
                 EitherFuture2::B(b.upgrade_inbound(sock, info))
             }
             _ => panic!("Invalid invocation of EitherUpgrade::upgrade_inbound"),
         }
     }
 }
 
-impl<C, A, B, TA, TB, EA, EB> OutboundUpgrade<C> for EitherUpgrade<A, B>
+impl<C, A, B, TA, TB, EA, EB> OutboundUpgrade<C> for Either<A, B>
 where
     A: OutboundUpgrade<C, Output = TA, Error = EA>,
     B: OutboundUpgrade<C, Output = TB, Error = EB>,
@@ -83,10 +76,10 @@ where
 
     fn upgrade_outbound(self, sock: C, info: Self::Info) -> Self::Future {
         match (self, info) {
-            (EitherUpgrade::A(a), EitherName::A(info)) => {
+            (Either::Left(a), EitherName::A(info)) => {
                 EitherFuture2::A(a.upgrade_outbound(sock, info))
             }
-            (EitherUpgrade::B(b), EitherName::B(info)) => {
+            (Either::Right(b), EitherName::B(info)) => {
                 EitherFuture2::B(b.upgrade_outbound(sock, info))
             }
             _ => panic!("Invalid invocation of EitherUpgrade::upgrade_outbound"),

protocols/dcutr/src/handler.rs

@@ -21,7 +21,7 @@
 use crate::protocol;
 use either::Either;
 use libp2p_core::connection::ConnectionId;
-use libp2p_core::upgrade::{self, DeniedUpgrade};
+use libp2p_core::upgrade::DeniedUpgrade;
 use libp2p_core::{ConnectedPoint, PeerId};
 use libp2p_swarm::dummy;
 use libp2p_swarm::handler::SendWrapper;
@@ -70,11 +70,11 @@ impl IntoConnectionHandler for Prototype {
 
     fn inbound_protocol(&self) -> <Self::Handler as ConnectionHandler>::InboundProtocol {
         match self {
-            Prototype::UnknownConnection => upgrade::EitherUpgrade::A(SendWrapper(
-                upgrade::EitherUpgrade::A(protocol::inbound::Upgrade {}),
-            )),
+            Prototype::UnknownConnection => {
+                Either::Left(SendWrapper(Either::Left(protocol::inbound::Upgrade {})))
+            }
             Prototype::DirectConnection { .. } => {
-                upgrade::EitherUpgrade::A(SendWrapper(upgrade::EitherUpgrade::B(DeniedUpgrade)))
+                Either::Left(SendWrapper(Either::Right(DeniedUpgrade)))
             }
         }
     }

protocols/dcutr/src/handler/relayed.rs

@@ -26,7 +26,7 @@ use futures::future::{BoxFuture, FutureExt};
 use instant::Instant;
 use libp2p_core::either::EitherOutput;
 use libp2p_core::multiaddr::Multiaddr;
-use libp2p_core::upgrade::{self, DeniedUpgrade, NegotiationError, UpgradeError};
+use libp2p_core::upgrade::{DeniedUpgrade, NegotiationError, UpgradeError};
 use libp2p_core::ConnectedPoint;
 use libp2p_swarm::handler::{
     ConnectionEvent, DialUpgradeError, FullyNegotiatedInbound, FullyNegotiatedOutbound,
@@ -305,23 +305,23 @@ impl ConnectionHandler for Handler {
     type Error = ConnectionHandlerUpgrErr<
         Either<protocol::inbound::UpgradeError, protocol::outbound::UpgradeError>,
     >;
-    type InboundProtocol = upgrade::EitherUpgrade<protocol::inbound::Upgrade, DeniedUpgrade>;
+    type InboundProtocol = Either<protocol::inbound::Upgrade, DeniedUpgrade>;
     type OutboundProtocol = protocol::outbound::Upgrade;
     type OutboundOpenInfo = u8; // Number of upgrade attempts.
     type InboundOpenInfo = ();
 
     fn listen_protocol(&self) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo> {
         match self.endpoint {
             ConnectedPoint::Dialer { .. } => {
-                SubstreamProtocol::new(upgrade::EitherUpgrade::A(protocol::inbound::Upgrade {}), ())
+                SubstreamProtocol::new(Either::Left(protocol::inbound::Upgrade {}), ())
             }
             ConnectedPoint::Listener { .. } => {
                 // By the protocol specification the listening side of a relayed connection
                 // initiates the _direct connection upgrade_. In other words the listening side of
                 // the relayed connection opens a substream to the dialing side. (Connection roles
                 // and substream roles are reversed.) The listening side on a relayed connection
                 // never expects incoming substreams, hence the denied upgrade below.
-                SubstreamProtocol::new(upgrade::EitherUpgrade::B(DeniedUpgrade), ())
+                SubstreamProtocol::new(Either::Right(DeniedUpgrade), ())
             }
         }
     }

protocols/identify/src/handler.rs

@@ -27,7 +27,7 @@ use futures::prelude::*;
 use futures::stream::FuturesUnordered;
 use futures_timer::Delay;
 use libp2p_core::either::EitherOutput;
-use libp2p_core::upgrade::{EitherUpgrade, SelectUpgrade};
+use libp2p_core::upgrade::SelectUpgrade;
 use libp2p_core::{ConnectedPoint, Multiaddr, PeerId, PublicKey};
 use libp2p_swarm::handler::{
     ConnectionEvent, DialUpgradeError, FullyNegotiatedInbound, FullyNegotiatedOutbound,
@@ -102,8 +102,7 @@ pub struct Handler {
     inbound_identify_push: Option<BoxFuture<'static, Result<Info, UpgradeError>>>,
     /// Pending events to yield.
     events: SmallVec<
-        [ConnectionHandlerEvent<EitherUpgrade<Identify, Push<OutboundPush>>, (), Event, io::Error>;
-            4],
+        [ConnectionHandlerEvent<Either<Identify, Push<OutboundPush>>, (), Event, io::Error>; 4],
     >,
 
     /// Streams awaiting `BehaviourInfo` to then send identify requests.
@@ -277,7 +276,7 @@ impl ConnectionHandler for Handler {
     type OutEvent = Event;
     type Error = io::Error;
     type InboundProtocol = SelectUpgrade<Identify, Push<InboundPush>>;
-    type OutboundProtocol = EitherUpgrade<Identify, Push<OutboundPush>>;
+    type OutboundProtocol = Either<Identify, Push<OutboundPush>>;
     type OutboundOpenInfo = ();
     type InboundOpenInfo = ();
 
@@ -306,10 +305,7 @@ impl ConnectionHandler for Handler {
             Protocol::Push => {
                 self.events
                     .push(ConnectionHandlerEvent::OutboundSubstreamRequest {
-                        protocol: SubstreamProtocol::new(
-                            EitherUpgrade::B(Push::outbound(info)),
-                            (),
-                        ),
+                        protocol: SubstreamProtocol::new(Either::Right(Push::outbound(info)), ()),
                     });
             }
             Protocol::Identify(_) => {
@@ -347,7 +343,7 @@ impl ConnectionHandler for Handler {
             Poll::Ready(()) => {
                 self.trigger_next_identify.reset(self.interval);
                 let ev = ConnectionHandlerEvent::OutboundSubstreamRequest {
-                    protocol: SubstreamProtocol::new(EitherUpgrade::A(Identify), ()),
+                    protocol: SubstreamProtocol::new(Either::Left(Identify), ()),
                 };
                 return Poll::Ready(ev);
             }

protocols/kad/src/handler.rs

@@ -23,6 +23,7 @@ use crate::protocol::{
     KademliaProtocolConfig,
 };
 use crate::record::{self, Record};
+use either::Either;
 use futures::prelude::*;
 use futures::stream::SelectAll;
 use instant::Instant;
@@ -68,9 +69,9 @@ impl<T: Clone + fmt::Debug + Send + 'static + Unpin> IntoConnectionHandler
 
     fn inbound_protocol(&self) -> <Self::Handler as ConnectionHandler>::InboundProtocol {
         if self.config.allow_listening {
-            upgrade::EitherUpgrade::A(self.config.protocol_config.clone())
+            Either::Left(self.config.protocol_config.clone())
         } else {
-            upgrade::EitherUpgrade::B(upgrade::DeniedUpgrade)
+            Either::Right(upgrade::DeniedUpgrade)
         }
     }
 }
@@ -633,7 +634,7 @@ where
     type InEvent = KademliaHandlerIn<TUserData>;
     type OutEvent = KademliaHandlerEvent<TUserData>;
     type Error = io::Error; // TODO: better error type?
-    type InboundProtocol = upgrade::EitherUpgrade<KademliaProtocolConfig, upgrade::DeniedUpgrade>;
+    type InboundProtocol = Either<KademliaProtocolConfig, upgrade::DeniedUpgrade>;
     type OutboundProtocol = KademliaProtocolConfig;
     // Message of the request to send to the remote, and user data if we expect an answer.
     type OutboundOpenInfo = (KadRequestMsg, Option<TUserData>);
@@ -642,9 +643,9 @@ where
     fn listen_protocol(&self) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo> {
         if self.config.allow_listening {
             SubstreamProtocol::new(self.config.protocol_config.clone(), ())
-                .map_upgrade(upgrade::EitherUpgrade::A)
+                .map_upgrade(Either::Left)
         } else {
-            SubstreamProtocol::new(upgrade::EitherUpgrade::B(upgrade::DeniedUpgrade), ())
+            SubstreamProtocol::new(Either::Right(upgrade::DeniedUpgrade), ())
         }
     }
 

protocols/ping/Cargo.toml

@@ -11,6 +11,7 @@ keywords = ["peer-to-peer", "libp2p", "networking"]
 categories = ["network-programming", "asynchronous"]
 
 [dependencies]
+either = "1.8.0"
 futures = "0.3.1"
 futures-timer = "3.0.2"
 instant = "0.1.11"

protocols/ping/tests/ping.rs

@@ -20,6 +20,7 @@
 
 //! Integration tests for the `Ping` network behaviour.
 
+use either::Either;
 use futures::{channel::mpsc, prelude::*};
 use libp2p_core::{
     identity,
@@ -251,8 +252,8 @@ fn mk_transport(muxer: MuxerChoice) -> (PeerId, transport::Boxed<(PeerId, Stream
             .upgrade(upgrade::Version::V1)
             .authenticate(noise::NoiseAuthenticated::xx(&id_keys).unwrap())
             .multiplex(match muxer {
-                MuxerChoice::Yamux => upgrade::EitherUpgrade::A(yamux::YamuxConfig::default()),
-                MuxerChoice::Mplex => upgrade::EitherUpgrade::B(mplex::MplexConfig::default()),
+                MuxerChoice::Yamux => Either::Left(yamux::YamuxConfig::default()),
+                MuxerChoice::Mplex => Either::Right(mplex::MplexConfig::default()),
             })
             .boxed(),
     )

protocols/relay/src/behaviour/handler.rs

@@ -355,7 +355,7 @@ impl IntoConnectionHandler for Prototype {
     }
 
     fn inbound_protocol(&self) -> <Self::Handler as ConnectionHandler>::InboundProtocol {
-        upgrade::EitherUpgrade::A(SendWrapper(inbound_hop::Upgrade {
+        Either::Left(SendWrapper(inbound_hop::Upgrade {
             reservation_duration: self.config.reservation_duration,
             max_circuit_duration: self.config.max_circuit_duration,
             max_circuit_bytes: self.config.max_circuit_bytes,

protocols/relay/src/priv_client/handler.rs

@@ -155,7 +155,7 @@ impl IntoConnectionHandler for Prototype {
     }
 
     fn inbound_protocol(&self) -> <Self::Handler as ConnectionHandler>::InboundProtocol {
-        upgrade::EitherUpgrade::A(SendWrapper(inbound_stop::Upgrade {}))
+        Either::Left(SendWrapper(inbound_stop::Upgrade {}))
     }
 }
 

swarm/src/behaviour/toggle.rs

@@ -28,9 +28,7 @@ use crate::upgrade::SendWrapper;
 use crate::{NetworkBehaviour, NetworkBehaviourAction, PollParameters};
 use either::Either;
 use libp2p_core::{
-    either::EitherOutput,
-    upgrade::{DeniedUpgrade, EitherUpgrade},
-    ConnectedPoint, Multiaddr, PeerId,
+    either::EitherOutput, upgrade::DeniedUpgrade, ConnectedPoint, Multiaddr, PeerId,
 };
 use std::{task::Context, task::Poll};
 
@@ -143,9 +141,9 @@ where
 
     fn inbound_protocol(&self) -> <Self::Handler as ConnectionHandler>::InboundProtocol {
         if let Some(inner) = self.inner.as_ref() {
-            EitherUpgrade::A(SendWrapper(inner.inbound_protocol()))
+            Either::Left(SendWrapper(inner.inbound_protocol()))
         } else {
-            EitherUpgrade::B(SendWrapper(DeniedUpgrade))
+            Either::Right(SendWrapper(DeniedUpgrade))
         }
     }
 }
@@ -235,8 +233,7 @@ where
     type InEvent = TInner::InEvent;
     type OutEvent = TInner::OutEvent;
     type Error = TInner::Error;
-    type InboundProtocol =
-        EitherUpgrade<SendWrapper<TInner::InboundProtocol>, SendWrapper<DeniedUpgrade>>;
+    type InboundProtocol = Either<SendWrapper<TInner::InboundProtocol>, SendWrapper<DeniedUpgrade>>;
     type OutboundProtocol = TInner::OutboundProtocol;
     type OutboundOpenInfo = TInner::OutboundOpenInfo;
     type InboundOpenInfo = Either<TInner::InboundOpenInfo, ()>;
@@ -245,13 +242,10 @@ where
         if let Some(inner) = self.inner.as_ref() {
             inner
                 .listen_protocol()
-                .map_upgrade(|u| EitherUpgrade::A(SendWrapper(u)))
+                .map_upgrade(|u| Either::Left(SendWrapper(u)))
                 .map_info(Either::Left)
         } else {
-            SubstreamProtocol::new(
-                EitherUpgrade::B(SendWrapper(DeniedUpgrade)),
-                Either::Right(()),
-            )
+            SubstreamProtocol::new(Either::Right(SendWrapper(DeniedUpgrade)), Either::Right(()))
         }
     }