v0.13.0

src/api/websocket.rs

@@ -14,21 +14,60 @@ async fn websocket(
     Ok(ws.on_upgrade(move |socket| websocket_loop(state, socket)))
 }
 
-async fn websocket_loop(state: AppState, mut socket: WebSocket) {
-    let initial = match build_bootstrap(&state).await {
-        Ok(data) => json!({"event":"bootstrap","timestamp":Utc::now(),"data":data}),
-        Err(err) => {
-            json!({"event":"error","timestamp":Utc::now(),"data":{"message":err.to_string()}})
+fn control_plan_ws_message(snapshot: &crate::state::ControlPlanSnapshot) -> Value {
+    json!({
+        "event": "control_plan.updated",
+        "timestamp": Utc::now(),
+        "data": {
+            "revision": snapshot.revision,
+            "plan": snapshot.plan.as_ref(),
         }
+    })
+}
+
+async fn send_ws_bootstrap(state: &AppState, socket: &mut WebSocket) -> Result<Option<u64>, ()> {
+    let (message, revision) = match build_bootstrap(state).await {
+        Ok(data) => {
+            let revision = data.get("control_plan_revision").and_then(Value::as_u64);
+            (
+                json!({"event":"bootstrap","timestamp":Utc::now(),"data":data}),
+                revision,
+            )
+        }
+        Err(err) => (
+            json!({"event":"error","timestamp":Utc::now(),"data":{"message":err.to_string()}}),
+            None,
+        ),
     };
-    if socket
-        .send(Message::Text(initial.to_string()))
+    socket
+        .send(Message::Text(message.to_string()))
         .await
-        .is_err()
-    {
-        return;
-    }
+        .map_err(|_| ())?;
+    Ok(revision)
+}
+
+async fn websocket_loop(state: AppState, mut socket: WebSocket) {
+    // Subscribe before building the bootstrap so state changes during bootstrap generation are
+    // queued and can be applied immediately after the first frame.
     let mut receiver = state.events.subscribe();
+    let mut control_plan = state.subscribe_control_plan();
+
+    let bootstrap_revision = match send_ws_bootstrap(&state, &mut socket).await {
+        Ok(revision) => revision,
+        Err(()) => return,
+    };
+    let mut last_control_plan_revision = bootstrap_revision;
+
+    // If the watch value is exactly the plan embedded in bootstrap, mark it seen to avoid a
+    // duplicate control_plan.updated frame. A newer revision remains pending and is sent below.
+    let current_revision = control_plan
+        .borrow()
+        .as_ref()
+        .map(|snapshot| snapshot.revision);
+    if current_revision == bootstrap_revision {
+        control_plan.borrow_and_update();
+    }
+
     loop {
         tokio::select! {
             event = receiver.recv() => {
@@ -38,10 +77,31 @@ async fn websocket_loop(state: AppState, mut socket: WebSocket) {
                             if socket.send(Message::Text(text)).await.is_err() { break; }
                         }
                     }
-                    Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => continue,
+                    Err(tokio::sync::broadcast::error::RecvError::Lagged(skipped)) => {
+                        tracing::warn!(skipped, "websocket client lagged; sending full bootstrap resync");
+                        // Drop the retained stale backlog before taking the replacement snapshot.
+                        // Events created while bootstrap is built are queued on this fresh receiver.
+                        receiver = state.events.subscribe();
+                        match send_ws_bootstrap(&state, &mut socket).await {
+                            Ok(revision) => last_control_plan_revision = revision,
+                            Err(()) => break,
+                        }
+                    }
                     Err(_) => break,
                 }
             }
+            changed = control_plan.changed() => {
+                if changed.is_err() { break; }
+                let snapshot = control_plan.borrow_and_update().clone();
+                if let Some(snapshot) = snapshot {
+                    if last_control_plan_revision == Some(snapshot.revision) {
+                        continue;
+                    }
+                    let text = control_plan_ws_message(snapshot.as_ref()).to_string();
+                    if socket.send(Message::Text(text)).await.is_err() { break; }
+                    last_control_plan_revision = Some(snapshot.revision);
+                }
+            }
             message = socket.next() => {
                 match message {
                     Some(Ok(Message::Ping(value))) => { if socket.send(Message::Pong(value)).await.is_err() { break; } }