Coalesce graph editor view invalidations (#6786)

Only invalidate the graph editor view at most once per frame. On develop, this saves about 70ms (2%). Testing a recent backend without #6755 as a stress-test, this saves about 5s (45%). This reflects better scalability to large numbers of `SuggestionUpdate` messages.

Fixes #6630.

# Important Notes
- Also fix intermittent profiling failures occurring since the introduction of microtasks.

app/gui/src/presenter/graph.rs

@@ -448,6 +448,7 @@ impl Model {
     }
 
     /// Look through all graph's nodes in AST and set position where it is missing.
+    #[profile(Debug)]
     fn initialize_nodes_positions(&self, default_gap_between_nodes: f32) {
         match self.controller.graph().nodes() {
             Ok(nodes) => {
@@ -562,6 +563,7 @@ struct ViewUpdate {
 
 impl ViewUpdate {
     /// Create ViewUpdate information from Graph Presenter's model.
+    #[profile(Debug)]
     fn new(model: &Model) -> FallibleResult<Self> {
         let state = model.state.clone_ref();
         let nodes = model.controller.graph().nodes()?;
@@ -572,11 +574,13 @@ impl ViewUpdate {
     }
 
     /// Remove nodes from the state and return node views to be removed.
+    #[profile(Debug)]
     fn remove_nodes(&self) -> Vec<ViewNodeId> {
         self.state.update_from_controller().retain_nodes(&self.node_ids().collect())
     }
 
     /// Returns number of nodes view should create.
+    #[profile(Debug)]
     fn count_nodes_to_add(&self) -> usize {
         self.node_ids().filter(|n| self.state.view_id_of_ast_node(*n).is_none()).count()
     }
@@ -616,6 +620,7 @@ impl ViewUpdate {
     /// input for nodes where position changed.
     ///
     /// The nodes not having views are also updated in the state.
+    #[profile(Debug)]
     fn set_node_positions(&self) -> Vec<(ViewNodeId, Vector2)> {
         self.nodes
             .iter()
@@ -629,6 +634,7 @@ impl ViewUpdate {
             .collect()
     }
 
+    #[profile(Debug)]
     fn set_node_visualizations(&self) -> Vec<(ViewNodeId, Option<visualization_view::Path>)> {
         self.nodes
             .iter()
@@ -640,11 +646,13 @@ impl ViewUpdate {
     }
 
     /// Remove connections from the state and return views to be removed.
+    #[profile(Debug)]
     fn remove_connections(&self) -> Vec<ViewConnection> {
         self.state.update_from_controller().retain_connections(&self.connections)
     }
 
     /// Add connections to the state and return endpoints of connections to be created in views.
+    #[profile(Debug)]
     fn add_connections(&self) -> Vec<(EdgeEndpoint, EdgeEndpoint)> {
         let ast_conns = self.connections.iter();
         ast_conns
@@ -654,6 +662,7 @@ impl ViewUpdate {
             .collect()
     }
 
+    #[profile(Debug)]
     fn node_ids(&self) -> impl Iterator<Item = AstNodeId> + '_ {
         self.nodes.iter().map(controller::graph::Node::id)
     }
@@ -699,10 +708,11 @@ impl Graph {
 
         frp::extend! { network
             update_view <- source::<()>();
+            update_view_once <- update_view.debounce();
             // Position initialization should go before emitting `update_data` event.
-            update_with_gap <- view.default_y_gap_between_nodes.sample(&update_view);
+            update_with_gap <- view.default_y_gap_between_nodes.sample(&update_view_once);
             eval update_with_gap ((gap) model.initialize_nodes_positions(*gap));
-            update_data <- update_view.map(f_!([model] match ViewUpdate::new(&model) {
+            update_data <- update_view_once.map(f_!([model] match ViewUpdate::new(&model) {
                 Ok(update) => Rc::new(update),
                 Err(err) => {
                     error!("Failed to update view: {err:?}");

app/gui/view/graph-editor/src/lib.rs

@@ -2029,6 +2029,7 @@ impl GraphEditorModel {
 
     /// Warning! This function does not remove connected edges. It needs to be handled by the
     /// implementation.
+    #[profile(Debug)]
     fn remove_node(&self, node_id: impl Into<NodeId>) {
         let node_id = node_id.into();
         self.nodes.remove(&node_id);
@@ -2276,6 +2277,7 @@ impl GraphEditorModel {
 
 impl GraphEditorModel {
     #[allow(missing_docs)] // FIXME[everyone] All pub functions should have docs.
+    #[profile(Debug)]
     pub fn set_node_position(&self, node_id: impl Into<NodeId>, position: Vector2) {
         let node_id = node_id.into();
         if let Some(node) = self.nodes.get_cloned_ref(&node_id) {

lib/rust/ensogl/core/src/animation/loops.rs

@@ -407,7 +407,6 @@ fn on_frame_closure(
             .then(move || on_after_animations.emit(time_info))
             .then(move || on_before_layout.emit(time_info))
             .then(move || on_before_rendering.emit(time_info))
-            .then(move || drop(_profiler))
             .schedule();
     }
 }