Add a generic Ack message, use it instead of Pong

Remove the `id` field from `Ping`, because it isn't used.
There is already an id on the message envelope.

server/src/rpc.rs

@@ -246,14 +246,7 @@ impl Server {
     }
 
     async fn ping(self: Arc<Server>, request: TypedEnvelope<proto::Ping>) -> tide::Result<()> {
-        self.peer
-            .respond(
-                request.receipt(),
-                proto::Pong {
-                    id: request.payload.id,
-                },
-            )
-            .await?;
+        self.peer.respond(request.receipt(), proto::Ack {}).await?;
         Ok(())
     }
 

zed/src/rpc.rs

@@ -139,13 +139,9 @@ impl Client {
                 let this = self.clone();
                 let foreground = cx.foreground();
                 state._maintain_connection = Some(cx.foreground().spawn(async move {
-                    let mut next_ping_id = 0;
                     loop {
                         foreground.timer(heartbeat_interval).await;
-                        this.request(proto::Ping { id: next_ping_id })
-                            .await
-                            .unwrap();
-                        next_ping_id += 1;
+                        this.request(proto::Ping {}).await.unwrap();
                     }
                 }));
             }
@@ -543,13 +539,11 @@ mod tests {
 
         cx.foreground().advance_clock(Duration::from_secs(10));
         let ping = server.receive::<proto::Ping>().await.unwrap();
-        assert_eq!(ping.payload.id, 0);
-        server.respond(ping.receipt(), proto::Pong { id: 0 }).await;
+        server.respond(ping.receipt(), proto::Ack {}).await;
 
         cx.foreground().advance_clock(Duration::from_secs(10));
         let ping = server.receive::<proto::Ping>().await.unwrap();
-        assert_eq!(ping.payload.id, 1);
-        server.respond(ping.receipt(), proto::Pong { id: 1 }).await;
+        server.respond(ping.receipt(), proto::Ack {}).await;
 
         client.disconnect(&cx.to_async()).await.unwrap();
         assert!(server.receive::<proto::Ping>().await.is_err());

zrpc/proto/zed.proto

@@ -6,9 +6,9 @@ message Envelope {
     optional uint32 responding_to = 2;
     optional uint32 original_sender_id = 3;
     oneof payload {
-        Error error = 4;
-        Ping ping = 5;
-        Pong pong = 6;
+        Ack ack = 4;
+        Error error = 5;
+        Ping ping = 6;
         ShareWorktree share_worktree = 7;
         ShareWorktreeResponse share_worktree_response = 8;
         OpenWorktree open_worktree = 9;
@@ -40,13 +40,9 @@ message Envelope {
 
 // Messages
 
-message Ping {
-    int32 id = 1;
-}
+message Ping {}
 
-message Pong {
-    int32 id = 2;
-}
+message Ack {}
 
 message Error {
     string message = 1;

zrpc/src/peer.rs

@@ -371,18 +371,18 @@ mod tests {
 
             assert_eq!(
                 client1
-                    .request(client1_conn_id, proto::Ping { id: 1 },)
+                    .request(client1_conn_id, proto::Ping {},)
                     .await
                     .unwrap(),
-                proto::Pong { id: 1 }
+                proto::Ack {}
             );
 
             assert_eq!(
                 client2
-                    .request(client2_conn_id, proto::Ping { id: 2 },)
+                    .request(client2_conn_id, proto::Ping {},)
                     .await
                     .unwrap(),
-                proto::Pong { id: 2 }
+                proto::Ack {}
             );
 
             assert_eq!(
@@ -438,13 +438,7 @@ mod tests {
                     let envelope = envelope.into_any();
                     if let Some(envelope) = envelope.downcast_ref::<TypedEnvelope<proto::Ping>>() {
                         let receipt = envelope.receipt();
-                        peer.respond(
-                            receipt,
-                            proto::Pong {
-                                id: envelope.payload.id,
-                            },
-                        )
-                        .await?
+                        peer.respond(receipt, proto::Ack {}).await?
                     } else if let Some(envelope) =
                         envelope.downcast_ref::<TypedEnvelope<proto::OpenBuffer>>()
                     {
@@ -536,7 +530,7 @@ mod tests {
             smol::spawn(async move { incoming.next().await }).detach();
 
             let err = client
-                .request(connection_id, proto::Ping { id: 42 })
+                .request(connection_id, proto::Ping {})
                 .await
                 .unwrap_err();
             assert_eq!(err.to_string(), "connection was closed");

zrpc/src/proto.rs

@@ -120,6 +120,7 @@ macro_rules! entity_messages {
 }
 
 messages!(
+    Ack,
     AddPeer,
     BufferSaved,
     ChannelMessageSent,
@@ -140,7 +141,6 @@ messages!(
     OpenWorktree,
     OpenWorktreeResponse,
     Ping,
-    Pong,
     RemovePeer,
     SaveBuffer,
     SendChannelMessage,
@@ -157,7 +157,7 @@ request_messages!(
     (JoinChannel, JoinChannelResponse),
     (OpenBuffer, OpenBufferResponse),
     (OpenWorktree, OpenWorktreeResponse),
-    (Ping, Pong),
+    (Ping, Ack),
     (SaveBuffer, BufferSaved),
     (ShareWorktree, ShareWorktreeResponse),
     (SendChannelMessage, SendChannelMessageResponse),