apollo_network: change the interface to have an abstraction (#11171)

Author: noamsp-starkware

crates/apollo_network/src/authentication/negotiator.rs

@@ -4,6 +4,11 @@ use async_trait::async_trait;
 use futures::{Sink, Stream};
 use libp2p::PeerId;
 
+pub enum NegotiationSide {
+    Inbound,
+    Outbound,
+}
+
 pub enum NegotiatorOutput {
     None,
     /// Returned when the handshake concluded that the currently connecting peer is a duplicate of
@@ -20,34 +25,25 @@ pub enum NegotiatorError {
     AuthenticationFailed,
 }
 
+pub type ConnectionSender = dyn Sink<Vec<u8>, Error = IoError> + Unpin + Send;
+pub type ConnectionReceiver = dyn Stream<Item = Result<Vec<u8>, IoError>> + Unpin + Send;
+
 #[async_trait]
 pub trait Negotiator: Send + Clone {
-    /// Performs the handshake protocol when we are the incoming connection side.
-    /// `connection` is the channel that can be used to communicate with the other peer.
-    async fn negotiate_incoming_connection<NegotiatorChannel>(
-        &mut self,
-        my_peer_id: PeerId,
-        other_peer_id: PeerId,
-        connection: &mut NegotiatorChannel,
-    ) -> Result<NegotiatorOutput, NegotiatorError>
-    where
-        NegotiatorChannel:
-            Sink<Vec<u8>, Error = IoError> + Stream<Item = Result<Vec<u8>, IoError>> + Unpin + Send;
-
-    /// Performs the handshake protocol when we are the outgoing connection side.
-    /// `connection` is the channel that can be used to communicate with the other peer.
-    async fn negotiate_outgoing_connection<NegotiatorChannel>(
+    /// Performs the handshake protocol.
+    /// `connection_sender` is the channel that can be used to send data to the remote peer.
+    /// `connection_receiver` is the channel that can be used to receive data from the remote peer.
+    async fn negotiate_connection(
         &mut self,
         my_peer_id: PeerId,
         other_peer_id: PeerId,
-        connection: &mut NegotiatorChannel,
-    ) -> Result<NegotiatorOutput, NegotiatorError>
-    where
-        NegotiatorChannel:
-            Sink<Vec<u8>, Error = IoError> + Stream<Item = Result<Vec<u8>, IoError>> + Unpin + Send;
+        connection_sender: &mut ConnectionSender,
+        connection_receiver: &mut ConnectionReceiver,
+        side: NegotiationSide,
+    ) -> Result<NegotiatorOutput, NegotiatorError>;
 
     /// A unique identified for your authentication protocol. For example: "strk_id" or
     /// "strk_id_v2".
-    // TODO(guy.f): Consider making this a const.
+    // TODO(noam.s): Consider making this a const.
     fn protocol_name(&self) -> &'static str;
 }