feat(swarm): deprecate ConnectionHandlerEvent::Close (#4714)

Cargo.toml

@@ -101,7 +101,7 @@ libp2p-rendezvous = { version = "0.13.1", path = "protocols/rendezvous" }
 libp2p-upnp = { version = "0.1.1", path = "protocols/upnp" }
 libp2p-request-response = { version = "0.25.2", path = "protocols/request-response" }
 libp2p-server = { version = "0.12.3", path = "misc/server" }
-libp2p-swarm = { version = "0.43.6", path = "swarm" }
+libp2p-swarm = { version = "0.43.7", path = "swarm" }
 libp2p-swarm-derive = { version = "0.33.0", path = "swarm-derive" }
 libp2p-swarm-test = { version = "0.2.0", path = "swarm-test" }
 libp2p-tcp = { version = "0.40.1", path = "transports/tcp" }

misc/metrics/src/swarm.rs

@@ -325,6 +325,7 @@ impl<E> From<&libp2p_swarm::ConnectionError<E>> for ConnectionError {
         match value {
             libp2p_swarm::ConnectionError::IO(_) => ConnectionError::Io,
             libp2p_swarm::ConnectionError::KeepAliveTimeout => ConnectionError::KeepAliveTimeout,
+            #[allow(deprecated)]
             libp2p_swarm::ConnectionError::Handler(_) => ConnectionError::Handler,
         }
     }

protocols/dcutr/src/handler/relayed.rs

@@ -69,6 +69,7 @@ pub struct Handler {
         >,
     >,
     /// Queue of events to return when polled.
+    #[allow(deprecated)]
     queued_events: VecDeque<
         ConnectionHandlerEvent<
             <Self as ConnectionHandler>::OutboundProtocol,
@@ -268,6 +269,7 @@ impl ConnectionHandler for Handler {
         KeepAlive::No
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,
@@ -282,6 +284,7 @@ impl ConnectionHandler for Handler {
         // Check for a pending (fatal) error.
         if let Some(err) = self.pending_error.take() {
             // The handler will not be polled again by the `Swarm`.
+            #[allow(deprecated)]
             return Poll::Ready(ConnectionHandlerEvent::Close(err));
         }
 
@@ -298,7 +301,9 @@ impl ConnectionHandler for Handler {
                         Event::InboundConnectNegotiated(addresses),
                     ));
                 }
-                Err(e) => {
+                Err(e) =>
+                {
+                    #[allow(deprecated)]
                     return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Apply(
                         Either::Left(e),
                     )))

protocols/gossipsub/src/handler.rs

@@ -218,6 +218,7 @@ impl EnabledHandler {
         self.outbound_substream = Some(OutboundSubstreamState::WaitingOutput(substream));
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,
@@ -451,6 +452,7 @@ impl ConnectionHandler for Handler {
         }
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,

protocols/identify/src/handler.rs

@@ -322,6 +322,7 @@ impl ConnectionHandler for Handler {
         KeepAlive::No
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,

protocols/kad/src/handler.rs

@@ -721,6 +721,7 @@ impl ConnectionHandler for Handler {
         self.keep_alive
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,

protocols/ping/src/handler.rs

@@ -229,6 +229,7 @@ impl ConnectionHandler for Handler {
         KeepAlive::No
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,

protocols/relay/src/behaviour/handler.rs

@@ -339,6 +339,7 @@ pub struct Handler {
     config: Config,
 
     /// Queue of events to return when polled.
+    #[allow(deprecated)]
     queued_events: VecDeque<
         ConnectionHandlerEvent<
             <Self as ConnectionHandler>::OutboundProtocol,
@@ -619,6 +620,7 @@ impl ConnectionHandler for Handler {
         self.keep_alive
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,
@@ -633,6 +635,7 @@ impl ConnectionHandler for Handler {
         // Check for a pending (fatal) error.
         if let Some(err) = self.pending_error.take() {
             // The handler will not be polled again by the `Swarm`.
+            #[allow(deprecated)]
             return Poll::Ready(ConnectionHandlerEvent::Close(err));
         }
 
@@ -712,14 +715,17 @@ impl ConnectionHandler for Handler {
                 ));
             }
             Poll::Ready(Err(futures_bounded::Timeout { .. })) => {
+                #[allow(deprecated)]
                 return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Timeout));
             }
             Poll::Ready(Ok(Either::Left(Err(e)))) => {
+                #[allow(deprecated)]
                 return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Apply(
                     Either::Left(e),
                 )));
             }
             Poll::Ready(Ok(Either::Right(Err(e)))) => {
+                #[allow(deprecated)]
                 return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Apply(
                     Either::Right(e),
                 )));

protocols/relay/src/priv_client/handler.rs

@@ -126,6 +126,7 @@ pub struct Handler {
     keep_alive: KeepAlive,
 
     /// Queue of events to return when polled.
+    #[allow(deprecated)]
     queued_events: VecDeque<
         ConnectionHandlerEvent<
             <Handler as ConnectionHandler>::OutboundProtocol,
@@ -331,6 +332,7 @@ impl ConnectionHandler for Handler {
         self.keep_alive
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,
@@ -345,6 +347,7 @@ impl ConnectionHandler for Handler {
         // Check for a pending (fatal) error.
         if let Some(err) = self.pending_error.take() {
             // The handler will not be polled again by the `Swarm`.
+            #[allow(deprecated)]
             return Poll::Ready(ConnectionHandlerEvent::Close(err));
         }
 
@@ -389,12 +392,15 @@ impl ConnectionHandler for Handler {
                         },
                     ));
                 }
-                Poll::Ready(Ok(Err(e))) => {
+                Poll::Ready(Ok(Err(e))) =>
+                {
+                    #[allow(deprecated)]
                     return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Apply(
                         Either::Right(e),
                     )))
                 }
                 Poll::Ready(Err(Timeout { .. })) => {
+                    #[allow(deprecated)]
                     return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Timeout));
                 }
                 Poll::Pending => break,
@@ -410,6 +416,7 @@ impl ConnectionHandler for Handler {
             let res = match worker_res {
                 Ok(r) => r,
                 Err(Timeout { .. }) => {
+                    #[allow(deprecated)]
                     return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Timeout));
                 }
             };
@@ -442,6 +449,7 @@ impl ConnectionHandler for Handler {
                     }
                 },
                 Err(e) => {
+                    #[allow(deprecated)]
                     return Poll::Ready(ConnectionHandlerEvent::Close(StreamUpgradeError::Apply(
                         Either::Left(e),
                     )));

protocols/request-response/src/handler.rs

@@ -288,6 +288,7 @@ where
         self.keep_alive
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,

swarm-test/src/lib.rs

@@ -27,9 +27,9 @@ use libp2p_core::{
 use libp2p_identity::{Keypair, PeerId};
 use libp2p_plaintext as plaintext;
 use libp2p_swarm::dial_opts::PeerCondition;
-use libp2p_swarm::{
-    self as swarm, dial_opts::DialOpts, NetworkBehaviour, Swarm, SwarmEvent, THandlerErr,
-};
+#[allow(deprecated)]
+use libp2p_swarm::THandlerErr;
+use libp2p_swarm::{self as swarm, dial_opts::DialOpts, NetworkBehaviour, Swarm, SwarmEvent};
 use libp2p_yamux as yamux;
 use std::fmt::Debug;
 use std::time::Duration;
@@ -63,6 +63,7 @@ pub trait SwarmExt {
     async fn dial_and_wait(&mut self, addr: Multiaddr) -> PeerId;
 
     /// Wait for specified condition to return `Some`.
+    #[allow(deprecated)]
     async fn wait<E, P>(&mut self, predicate: P) -> E
     where
         P: Fn(
@@ -78,6 +79,7 @@ pub trait SwarmExt {
     /// Returns the next [`SwarmEvent`] or times out after 10 seconds.
     ///
     /// If the 10s timeout does not fit your usecase, please fall back to `StreamExt::next`.
+    #[allow(deprecated)]
     async fn next_swarm_event(
         &mut self,
     ) -> SwarmEvent<<Self::NB as NetworkBehaviour>::ToSwarm, THandlerErr<Self::NB>>;
@@ -121,6 +123,7 @@ pub trait SwarmExt {
 /// This can "starve" the other swarm which for example may wait for another message to be sent on a connection.
 ///
 /// Using [`drive`] instead of [`futures::future::join`] ensures that a [`Swarm`] continues to be polled, even after it emitted its events.
+#[allow(deprecated)]
 pub async fn drive<
     TBehaviour1,
     const NUM_EVENTS_SWARM_1: usize,
@@ -279,6 +282,7 @@ where
         .await
     }
 
+    #[allow(deprecated)]
     async fn wait<E, P>(&mut self, predicate: P) -> E
     where
         P: Fn(SwarmEvent<<B as NetworkBehaviour>::ToSwarm, THandlerErr<B>>) -> Option<E>,
@@ -341,6 +345,7 @@ where
         (memory_multiaddr, tcp_multiaddr)
     }
 
+    #[allow(deprecated)]
     async fn next_swarm_event(
         &mut self,
     ) -> SwarmEvent<<Self::NB as NetworkBehaviour>::ToSwarm, THandlerErr<Self::NB>> {

swarm/CHANGELOG.md

@@ -1,3 +1,9 @@
+## 0.43.7
+
+- Deprecate `ConnectionHandlerEvent::Close`.
+  See [issue 3591](https://github.com/libp2p/rust-libp2p/issues/3591) for details.
+  See [PR 4714](https://github.com/libp2p/rust-libp2p/pull/4714).
+
 ## 0.43.6
 
 - Deprecate `libp2p::swarm::SwarmBuilder`.

swarm/Cargo.toml

@@ -3,7 +3,7 @@ name = "libp2p-swarm"
 edition = "2021"
 rust-version = { workspace = true }
 description = "The libp2p swarm"
-version = "0.43.6"
+version = "0.43.7"
 authors = ["Parity Technologies <[email protected]>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"

swarm/src/behaviour/toggle.rs

@@ -269,6 +269,7 @@ where
 {
     type FromBehaviour = TInner::FromBehaviour;
     type ToBehaviour = TInner::ToBehaviour;
+    #[allow(deprecated)]
     type Error = TInner::Error;
     type InboundProtocol = Either<SendWrapper<TInner::InboundProtocol>, SendWrapper<DeniedUpgrade>>;
     type OutboundProtocol = TInner::OutboundProtocol;
@@ -300,6 +301,7 @@ where
             .unwrap_or(KeepAlive::No)
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         cx: &mut Context<'_>,

swarm/src/connection.rs

@@ -221,6 +221,7 @@ where
 
     /// Polls the handler and the substream, forwarding events from the former to the latter and
     /// vice versa.
+    #[allow(deprecated)]
     pub(crate) fn poll(
         self: Pin<&mut Self>,
         cx: &mut Context<'_>,
@@ -267,6 +268,7 @@ where
                 Poll::Ready(ConnectionHandlerEvent::NotifyBehaviour(event)) => {
                     return Poll::Ready(Ok(Event::Handler(event)));
                 }
+                #[allow(deprecated)]
                 Poll::Ready(ConnectionHandlerEvent::Close(err)) => {
                     return Poll::Ready(Err(ConnectionError::Handler(err)));
                 }
@@ -429,6 +431,7 @@ where
     }
 
     #[cfg(test)]
+    #[allow(deprecated)]
     fn poll_noop_waker(
         &mut self,
     ) -> Poll<Result<Event<THandler::ToBehaviour>, ConnectionError<THandler::Error>>> {
@@ -1082,6 +1085,7 @@ mod tests {
             KeepAlive::Until(self.until)
         }
 
+        #[allow(deprecated)]
         fn poll(
             &mut self,
             _: &mut Context<'_>,
@@ -1312,6 +1316,7 @@ mod tests {
             KeepAlive::Yes
         }
 
+        #[allow(deprecated)]
         fn poll(
             &mut self,
             _: &mut Context<'_>,
@@ -1389,6 +1394,7 @@ mod tests {
             KeepAlive::Yes
         }
 
+        #[allow(deprecated)]
         fn poll(
             &mut self,
             _: &mut Context<'_>,

swarm/src/connection/error.rs

@@ -34,6 +34,9 @@ pub enum ConnectionError<THandlerErr> {
     KeepAliveTimeout,
 
     /// The connection handler produced an error.
+    #[deprecated(
+        note = "Will be removed together with `ConnectionHandlerEvent::Close`. See <https://github.com/libp2p/rust-libp2p/issues/3591> for details."
+    )]
     Handler(THandlerErr),
 }
 
@@ -47,6 +50,7 @@ where
             ConnectionError::KeepAliveTimeout => {
                 write!(f, "Connection closed due to expired keep-alive timeout.")
             }
+            #[allow(deprecated)]
             ConnectionError::Handler(err) => write!(f, "Connection error: Handler error: {err}"),
         }
     }
@@ -60,6 +64,7 @@ where
         match self {
             ConnectionError::IO(err) => Some(err),
             ConnectionError::KeepAliveTimeout => None,
+            #[allow(deprecated)]
             ConnectionError::Handler(err) => Some(err),
         }
     }

swarm/src/connection/pool.rs

@@ -225,6 +225,7 @@ impl<THandler: ConnectionHandler> fmt::Debug for Pool<THandler> {
 
 /// Event that can happen on the `Pool`.
 #[derive(Debug)]
+#[allow(deprecated)]
 pub(crate) enum PoolEvent<THandler: ConnectionHandler> {
     /// A new connection has been established.
     ConnectionEstablished {

swarm/src/connection/pool/task.rs

@@ -66,6 +66,7 @@ pub(crate) enum PendingConnectionEvent {
 }
 
 #[derive(Debug)]
+#[allow(deprecated)]
 pub(crate) enum EstablishedConnectionEvent<THandler: ConnectionHandler> {
     /// A node we are connected to has changed its address.
     AddressChange {

swarm/src/dummy.rs

@@ -102,6 +102,7 @@ impl crate::handler::ConnectionHandler for ConnectionHandler {
         KeepAlive::No
     }
 
+    #[allow(deprecated)]
     fn poll(
         &mut self,
         _: &mut Context<'_>,