diagnostics: Improve performance with large # of diagnostics (#20189)

Related to: https://github.com/zed-industries/zed/issues/19022

Release Notes:

- Improve editor performance with large # of diagnostics.

---------

Co-authored-by: Conrad <conrad@zed.dev>
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

Cargo.lock

@@ -3491,7 +3491,6 @@ dependencies = [
  "ctor",
  "editor",
  "env_logger 0.11.5",
- "futures 0.3.30",
  "gpui",
  "language",
  "log",

crates/diagnostics/Cargo.toml

@@ -18,7 +18,6 @@ collections.workspace = true
 ctor.workspace = true
 editor.workspace = true
 env_logger.workspace = true
-futures.workspace = true
 gpui.workspace = true
 language.workspace = true
 log.workspace = true

crates/diagnostics/src/diagnostics.rs

@@ -14,10 +14,6 @@ use editor::{
     scroll::Autoscroll,
     Editor, EditorEvent, ExcerptId, ExcerptRange, MultiBuffer, ToOffset,
 };
-use futures::{
-    channel::mpsc::{self, UnboundedSender},
-    StreamExt as _,
-};
 use gpui::{
     actions, div, svg, AnyElement, AnyView, AppContext, Context, EventEmitter, FocusHandle,
     FocusableView, HighlightStyle, InteractiveElement, IntoElement, Model, ParentElement, Render,
@@ -62,11 +58,10 @@ struct ProjectDiagnosticsEditor {
     summary: DiagnosticSummary,
     excerpts: Model<MultiBuffer>,
     path_states: Vec<PathState>,
-    paths_to_update: BTreeSet<(ProjectPath, LanguageServerId)>,
+    paths_to_update: BTreeSet<(ProjectPath, Option<LanguageServerId>)>,
     include_warnings: bool,
     context: u32,
-    update_paths_tx: UnboundedSender<(ProjectPath, Option<LanguageServerId>)>,
+    update_excerpts_task: Option<Task<Result<()>>>,
-    _update_excerpts_task: Task<Result<()>>,
     _subscription: Subscription,
 }
 
@@ -129,14 +124,14 @@ impl ProjectDiagnosticsEditor {
                 }
                 project::Event::DiskBasedDiagnosticsFinished { language_server_id } => {
                     log::debug!("disk based diagnostics finished for server {language_server_id}");
-                    this.enqueue_update_stale_excerpts(Some(*language_server_id));
+                    this.update_stale_excerpts(cx);
                 }
                 project::Event::DiagnosticsUpdated {
                     language_server_id,
                     path,
                 } => {
                     this.paths_to_update
-                        .insert((path.clone(), *language_server_id));
+                        .insert((path.clone(), Some(*language_server_id)));
                     this.summary = project.read(cx).diagnostic_summary(false, cx);
                     cx.emit(EditorEvent::TitleChanged);
 
@@ -144,7 +139,7 @@ impl ProjectDiagnosticsEditor {
                         log::debug!("diagnostics updated for server {language_server_id}, path {path:?}. recording change");
                     } else {
                         log::debug!("diagnostics updated for server {language_server_id}, path {path:?}. updating excerpts");
-                        this.enqueue_update_stale_excerpts(Some(*language_server_id));
+                        this.update_stale_excerpts(cx);
                     }
                 }
                 _ => {}
@@ -171,14 +166,12 @@ impl ProjectDiagnosticsEditor {
                         cx.focus(&this.focus_handle);
                     }
                 }
-                EditorEvent::Blurred => this.enqueue_update_stale_excerpts(None),
+                EditorEvent::Blurred => this.update_stale_excerpts(cx),
                 _ => {}
             }
         })
         .detach();
 
-        let (update_excerpts_tx, mut update_excerpts_rx) = mpsc::unbounded();
-
         let project = project_handle.read(cx);
         let mut this = Self {
             project: project_handle.clone(),
@@ -191,27 +184,45 @@ impl ProjectDiagnosticsEditor {
             path_states: Default::default(),
             paths_to_update: Default::default(),
             include_warnings: ProjectDiagnosticsSettings::get_global(cx).include_warnings,
-            update_paths_tx: update_excerpts_tx,
+            update_excerpts_task: None,
-            _update_excerpts_task: cx.spawn(move |this, mut cx| async move {
-                while let Some((path, language_server_id)) = update_excerpts_rx.next().await {
-                    if let Some(buffer) = project_handle
-                        .update(&mut cx, |project, cx| project.open_buffer(path.clone(), cx))?
-                        .await
-                        .log_err()
-                    {
-                        this.update(&mut cx, |this, cx| {
-                            this.update_excerpts(path, language_server_id, buffer, cx);
-                        })?;
-                    }
-                }
-                anyhow::Ok(())
-            }),
             _subscription: project_event_subscription,
         };
-        this.enqueue_update_all_excerpts(cx);
+        this.update_all_excerpts(cx);
         this
     }
 
+    fn update_stale_excerpts(&mut self, cx: &mut ViewContext<Self>) {
+        if self.update_excerpts_task.is_some() {
+            return;
+        }
+        let project_handle = self.project.clone();
+        self.update_excerpts_task = Some(cx.spawn(|this, mut cx| async move {
+            loop {
+                let Some((path, language_server_id)) = this.update(&mut cx, |this, _| {
+                    let Some((path, language_server_id)) = this.paths_to_update.pop_first() else {
+                        this.update_excerpts_task.take();
+                        return None;
+                    };
+                    Some((path, language_server_id))
+                })?
+                else {
+                    break;
+                };
+
+                if let Some(buffer) = project_handle
+                    .update(&mut cx, |project, cx| project.open_buffer(path.clone(), cx))?
+                    .await
+                    .log_err()
+                {
+                    this.update(&mut cx, |this, cx| {
+                        this.update_excerpts(path, language_server_id, buffer, cx);
+                    })?;
+                }
+            }
+            Ok(())
+        }));
+    }
+
     fn new(
         project_handle: Model<Project>,
         workspace: WeakView<Workspace>,
@@ -239,7 +250,7 @@ impl ProjectDiagnosticsEditor {
 
     fn toggle_warnings(&mut self, _: &ToggleWarnings, cx: &mut ViewContext<Self>) {
         self.include_warnings = !self.include_warnings;
-        self.enqueue_update_all_excerpts(cx);
+        self.update_all_excerpts(cx);
         cx.notify();
     }
 
@@ -251,37 +262,28 @@ impl ProjectDiagnosticsEditor {
 
     fn focus_out(&mut self, cx: &mut ViewContext<Self>) {
         if !self.focus_handle.is_focused(cx) && !self.editor.focus_handle(cx).is_focused(cx) {
-            self.enqueue_update_stale_excerpts(None);
+            self.update_stale_excerpts(cx);
         }
     }
 
     /// Enqueue an update of all excerpts. Updates all paths that either
     /// currently have diagnostics or are currently present in this view.
-    fn enqueue_update_all_excerpts(&mut self, cx: &mut ViewContext<Self>) {
+    fn update_all_excerpts(&mut self, cx: &mut ViewContext<Self>) {
         self.project.update(cx, |project, cx| {
             let mut paths = project
                 .diagnostic_summaries(false, cx)
-                .map(|(path, _, _)| path)
+                .map(|(path, _, _)| (path, None))
                 .collect::<BTreeSet<_>>();
-            paths.extend(self.path_states.iter().map(|state| state.path.clone()));
+            paths.extend(
-            for path in paths {
+                self.path_states
-                self.update_paths_tx.unbounded_send((path, None)).unwrap();
+                    .iter()
-            }
+                    .map(|state| (state.path.clone(), None)),
+            );
+            let paths_to_update = std::mem::take(&mut self.paths_to_update);
+            paths.extend(paths_to_update.into_iter().map(|(path, _)| (path, None)));
+            self.paths_to_update = paths;
         });
-    }
+        self.update_stale_excerpts(cx);
-
-    /// Enqueue an update of the excerpts for any path whose diagnostics are known
-    /// to have changed. If a language server id is passed, then only the excerpts for
-    /// that language server's diagnostics will be updated. Otherwise, all stale excerpts
-    /// will be refreshed.
-    fn enqueue_update_stale_excerpts(&mut self, language_server_id: Option<LanguageServerId>) {
-        for (path, server_id) in &self.paths_to_update {
-            if language_server_id.map_or(true, |id| id == *server_id) {
-                self.update_paths_tx
-                    .unbounded_send((path.clone(), Some(*server_id)))
-                    .unwrap();
-            }
-        }
     }
 
     fn update_excerpts(
@@ -291,11 +293,6 @@ impl ProjectDiagnosticsEditor {
         buffer: Model<Buffer>,
         cx: &mut ViewContext<Self>,
     ) {
-        self.paths_to_update.retain(|(path, server_id)| {
-            *path != path_to_update
-                || server_to_update.map_or(false, |to_update| *server_id != to_update)
-        });
-
         let was_empty = self.path_states.is_empty();
         let snapshot = buffer.read(cx).snapshot();
         let path_ix = match self

crates/diagnostics/src/diagnostics_tests.rs

@@ -800,7 +800,7 @@ async fn test_random_diagnostics(cx: &mut TestAppContext, mut rng: StdRng) {
     }
 
     log::info!("updating mutated diagnostics view");
-    mutated_view.update(cx, |view, _| view.enqueue_update_stale_excerpts(None));
+    mutated_view.update(cx, |view, cx| view.update_stale_excerpts(cx));
     cx.run_until_parked();
 
     log::info!("constructing reference diagnostics view");

crates/diagnostics/src/toolbar_controls.rs

@@ -14,12 +14,12 @@ impl Render for ToolbarControls {
         let mut has_stale_excerpts = false;
         let mut is_updating = false;
 
-        if let Some(editor) = self.editor() {
+        if let Some(editor) = self.diagnostics() {
-            let editor = editor.read(cx);
+            let diagnostics = editor.read(cx);
-            include_warnings = editor.include_warnings;
+            include_warnings = diagnostics.include_warnings;
-            has_stale_excerpts = !editor.paths_to_update.is_empty();
+            has_stale_excerpts = !diagnostics.paths_to_update.is_empty();
-            is_updating = !editor.update_paths_tx.is_empty()
+            is_updating = diagnostics.update_excerpts_task.is_some()
-                || editor
+                || diagnostics
                     .project
                     .read(cx)
                     .language_servers_running_disk_based_diagnostics(cx)
@@ -49,9 +49,9 @@ impl Render for ToolbarControls {
                         .disabled(is_updating)
                         .tooltip(move |cx| Tooltip::text("Update excerpts", cx))
                         .on_click(cx.listener(|this, _, cx| {
-                            if let Some(editor) = this.editor() {
+                            if let Some(diagnostics) = this.diagnostics() {
-                                editor.update(cx, |editor, _| {
+                                diagnostics.update(cx, |diagnostics, cx| {
-                                    editor.enqueue_update_stale_excerpts(None);
+                                    diagnostics.update_all_excerpts(cx);
                                 });
                             }
                         })),
@@ -63,7 +63,7 @@ impl Render for ToolbarControls {
                     .shape(IconButtonShape::Square)
                     .tooltip(move |cx| Tooltip::text(tooltip, cx))
                     .on_click(cx.listener(|this, _, cx| {
-                        if let Some(editor) = this.editor() {
+                        if let Some(editor) = this.diagnostics() {
                             editor.update(cx, |editor, cx| {
                                 editor.toggle_warnings(&Default::default(), cx);
                             });
@@ -105,7 +105,7 @@ impl ToolbarControls {
         ToolbarControls { editor: None }
     }
 
-    fn editor(&self) -> Option<View<ProjectDiagnosticsEditor>> {
+    fn diagnostics(&self) -> Option<View<ProjectDiagnosticsEditor>> {
         self.editor.as_ref()?.upgrade()
     }
 }