refactor(perf): don't use OutboundOpenInfo

Instead of passing the command along, we store it in a buffer and retrieve it once the stream is upgraded.

Related: #3268.

Pull-Request: #3763.

protocols/perf/src/client/handler.rs

@@ -61,6 +61,8 @@ pub struct Handler {
         >,
     >,
 
+    requested_streams: VecDeque<Command>,
+
     outbound: FuturesUnordered<BoxFuture<'static, Result<Event, std::io::Error>>>,
 
     keep_alive: KeepAlive,
@@ -70,6 +72,7 @@ impl Handler {
     pub fn new() -> Self {
         Self {
             queued_events: Default::default(),
+            requested_streams: Default::default(),
             outbound: Default::default(),
             keep_alive: KeepAlive::Yes,
         }
@@ -88,17 +91,18 @@ impl ConnectionHandler for Handler {
     type Error = Void;
     type InboundProtocol = DeniedUpgrade;
     type OutboundProtocol = ReadyUpgrade<&'static [u8]>;
-    type OutboundOpenInfo = Command;
+    type OutboundOpenInfo = ();
     type InboundOpenInfo = ();
 
     fn listen_protocol(&self) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo> {
         SubstreamProtocol::new(DeniedUpgrade, ())
     }
 
     fn on_behaviour_event(&mut self, command: Self::InEvent) {
+        self.requested_streams.push_back(command);
         self.queued_events
             .push_back(ConnectionHandlerEvent::OutboundSubstreamRequest {
-                protocol: SubstreamProtocol::new(ReadyUpgrade::new(crate::PROTOCOL_NAME), command),
+                protocol: SubstreamProtocol::new(ReadyUpgrade::new(crate::PROTOCOL_NAME), ()),
             })
     }
 
@@ -117,26 +121,34 @@ impl ConnectionHandler for Handler {
             }) => void::unreachable(protocol),
             ConnectionEvent::FullyNegotiatedOutbound(FullyNegotiatedOutbound {
                 protocol,
-                info: Command { params, id },
-            }) => self.outbound.push(
-                crate::protocol::send_receive(params, protocol)
-                    .map_ok(move |timers| Event {
-                        id,
-                        result: Ok(RunStats { params, timers }),
-                    })
-                    .boxed(),
-            ),
+                info: (),
+            }) => {
+                let Command { id, params } = self
+                    .requested_streams
+                    .pop_front()
+                    .expect("opened a stream without a pending command");
+                self.outbound.push(
+                    crate::protocol::send_receive(params, protocol)
+                        .map_ok(move |timers| Event {
+                            id,
+                            result: Ok(RunStats { params, timers }),
+                        })
+                        .boxed(),
+                );
+            }
 
             ConnectionEvent::AddressChange(_) => {}
-            ConnectionEvent::DialUpgradeError(DialUpgradeError {
-                info: Command { id, .. },
-                error,
-            }) => self
-                .queued_events
-                .push_back(ConnectionHandlerEvent::Custom(Event {
-                    id,
-                    result: Err(error),
-                })),
+            ConnectionEvent::DialUpgradeError(DialUpgradeError { info: (), error }) => {
+                let Command { id, .. } = self
+                    .requested_streams
+                    .pop_front()
+                    .expect("requested stream without pending command");
+                self.queued_events
+                    .push_back(ConnectionHandlerEvent::Custom(Event {
+                        id,
+                        result: Err(error),
+                    }));
+            }
             ConnectionEvent::ListenUpgradeError(ListenUpgradeError { info: (), error }) => {
                 match error {
                     ConnectionHandlerUpgrErr::Timeout => {}