perf(app): batch scroll surface flushes

crates/ely_app/src/shell/web_surface.rs

@@ -48,20 +48,19 @@ impl WebSurfaceStore {
         tab: &BrowserTab,
         profile_data_mode: ProfileDataMode,
         permissions: &[WebSurfaceSitePermission],
-    ) -> WebSurfaceEnsureOutcome {
+    ) -> bool {
         if !is_external_web_url(tab.url().as_str()) {
-            return WebSurfaceEnsureOutcome::default();
+            return false;
         }
-
         let requested_url = tab.url().as_str().to_string();
         let Some(size) = self.surfaces.get(tab.id()).and_then(|surface| surface.viewport_size)
         else {
-            return WebSurfaceEnsureOutcome::default();
+            return false;
         };
         let ensure_key =
             WebSurfaceEnsureKey::new(requested_url.clone(), size, tab.zoom_percent(), permissions);
         if self.surfaces.get(tab.id()).is_some_and(|surface| !surface.should_ensure(&ensure_key)) {
-            return WebSurfaceEnsureOutcome::default();
+            return false;
         }
         let input = self.take_pending_input(tab.id(), requested_url.as_str());
         let previous_frame =
@@ -75,14 +74,14 @@ impl WebSurfaceStore {
                         requested_url: result.requested_url,
                         previous_frame,
                     });
-                    return WebSurfaceEnsureOutcome { changed: true, url_change: None };
+                    return true;
                 }
-                WebSurfaceEnsureOutcome::default()
+                false
             }
             Err(message) => {
                 self.surface_mut(tab.id()).mark_ensured(ensure_key);
                 self.surface_mut(tab.id()).state = Some(WebSurfaceState::Failed { message });
-                WebSurfaceEnsureOutcome { changed: true, url_change: None }
+                true
             }
         }
     }
@@ -162,7 +161,7 @@ impl WebSurfaceStore {
         let stale_tab_ids = self
             .surfaces
             .keys()
-            .filter(|tab_id| !open_tab_ids.iter().any(|open_tab_id| open_tab_id == *tab_id))
+            .filter(|tab_id| !open_tab_ids.contains(*tab_id))
             .cloned()
             .collect::<Vec<_>>();
         for tab_id in stale_tab_ids {
@@ -170,10 +169,6 @@ impl WebSurfaceStore {
         }
     }
 
-    pub(super) fn close_surface(&mut self, tab_id: &TabId) {
-        self.close_surface_for_tab(tab_id);
-    }
-
     pub(super) fn record_scroll_delta(
         &mut self,
         tab_id: &TabId,
@@ -196,6 +191,7 @@ impl WebSurfaceStore {
         };
 
         let surface = self.surface_mut(tab_id);
+        let flush_throttled = surface.input_flush_is_throttled(Instant::now());
         let scroll = surface
             .scroll_offset
             .get_or_insert_with(|| WebSurfaceScrollState::new(requested_url.to_string()));
@@ -211,8 +207,12 @@ impl WebSurfaceStore {
         surface.pending_scroll_point = Some(point);
         surface.mark_pending_input_started();
         surface.click_point = None;
+        if flush_throttled {
+            WebSurfaceInputOutcome::Buffered
+        } else {
             WebSurfaceInputOutcome::Applied
         }
+    }
 
     pub(super) fn record_viewport_size(
         &mut self,
@@ -381,6 +381,13 @@ impl WebSurfaceStore {
             .map(|state| state.text);
         let hover_point = surface.hover_point.take();
         let enqueued_at = surface.pending_input_started_at.take();
+        if scroll_delta.is_some()
+            || click_point.is_some()
+            || hover_point.is_some()
+            || typed_text.is_some()
+        {
+            surface.mark_input_flushed(Instant::now());
+        }
 
         WebSurfacePendingInput {
             enqueued_at,
@@ -453,7 +460,7 @@ impl WebSurfaceStore {
         self.surfaces.entry(tab_id.clone()).or_insert_with(PerTabSurface::new)
     }
 
-    fn close_surface_for_tab(&mut self, tab_id: &TabId) {
+    pub(super) fn close_surface(&mut self, tab_id: &TabId) {
         self.runtime.close_tab(tab_id);
         self.surfaces.remove(tab_id);
         if self.keyboard_focus.as_ref().is_some_and(|focus| focus.tab_id == *tab_id) {
@@ -476,12 +483,6 @@ pub(super) fn is_external_web_url(url: &str) -> bool {
     url.starts_with("https://") || url.starts_with("http://")
 }
 
-#[derive(Default)]
-pub(super) struct WebSurfaceEnsureOutcome {
-    pub(super) changed: bool,
-    pub(super) url_change: Option<WebSurfaceUrlChange>,
-}
-
 #[derive(Default)]
 pub(super) struct WebSurfaceTickResult {
     pub(super) changed: bool,

crates/ely_app/src/shell/web_surface_controller.rs

@@ -182,20 +182,15 @@ impl ElyShell {
 
 impl ElyShell {
     fn ensure_visible_web_surfaces(&mut self, visible_tabs: Vec<VisibleWebSurfaceTab>) -> bool {
-        let mut url_changed = false;
         let mut changed = false;
         for visible in visible_tabs {
-            let outcome = self.web_surfaces.ensure_surface(
+            changed |= self.web_surfaces.ensure_surface(
                 &visible.tab,
                 visible.profile_data_mode,
                 &visible.permissions,
             );
-            changed |= outcome.changed;
-            if let Some(url_change) = outcome.url_change {
-                url_changed |= self.apply_web_surface_url_change(url_change);
         }
-        }
+        changed
-        changed || url_changed
     }
 
     fn apply_web_surface_url_change(&mut self, change: WebSurfaceUrlChange) -> bool {

crates/ely_app/src/shell/web_surface_runtime_tests.rs

@@ -103,11 +103,11 @@ fn unchanged_surface_without_input_skips_runtime_ensure() -> Result<(), String>
         store.record_viewport_size(tab.id(), viewport_bounds(), 1.0),
         WebSurfaceInputOutcome::Applied,
     );
-    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]).changed);
+    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]));
     store.flush_runtime_for_test();
     assert_eq!(IDLE_SKIP_ENSURE_COUNT.load(Ordering::SeqCst), 1);
 
-    assert!(!store.ensure_surface(&tab, ProfileDataMode::Transient, &[]).changed);
+    assert!(!store.ensure_surface(&tab, ProfileDataMode::Transient, &[]));
     store.flush_runtime_for_test();
     assert_eq!(IDLE_SKIP_ENSURE_COUNT.load(Ordering::SeqCst), 1);
     Ok(())
@@ -126,7 +126,7 @@ fn store_tick_delay_tracks_runtime_cadence() -> Result<(), String> {
         store.record_viewport_size(tab.id(), viewport_bounds(), 1.0),
         WebSurfaceInputOutcome::Applied,
     );
-    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]).changed);
+    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]));
     assert_eq!(store.next_tick_delay(&visible), Duration::ZERO);
 
     let _ = store.tick(&visible);
@@ -188,13 +188,13 @@ fn failed_surface_ensure_waits_for_a_new_key_before_retrying() -> Result<(), Str
         store.record_viewport_size(tab.id(), viewport_bounds(), 1.0),
         WebSurfaceInputOutcome::Applied,
     );
-    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]).changed);
+    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]));
     store.flush_runtime_for_test();
     let tick = store.tick(&[tab.id().clone()]);
     assert!(tick.changed, "the failing client must surface a state change via tick");
     assert_eq!(FAILING_ENSURE_COUNT.load(Ordering::SeqCst), 1);
 
-    assert!(!store.ensure_surface(&tab, ProfileDataMode::Transient, &[]).changed);
+    assert!(!store.ensure_surface(&tab, ProfileDataMode::Transient, &[]));
     store.flush_runtime_for_test();
     let _ = store.tick(&[tab.id().clone()]);
     assert_eq!(FAILING_ENSURE_COUNT.load(Ordering::SeqCst), 1);
@@ -203,7 +203,7 @@ fn failed_surface_ensure_waits_for_a_new_key_before_retrying() -> Result<(), Str
         store.record_viewport_size(tab.id(), resized_viewport_bounds(), 1.0),
         WebSurfaceInputOutcome::Applied,
     );
-    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]).changed);
+    assert!(store.ensure_surface(&tab, ProfileDataMode::Transient, &[]));
     store.flush_runtime_for_test();
     let _ = store.tick(&[tab.id().clone()]);
     assert_eq!(FAILING_ENSURE_COUNT.load(Ordering::SeqCst), 2);

crates/ely_app/src/shell/web_surface_state.rs

@@ -4,6 +4,7 @@ use ely_domain::TabId;
 use gpui::{Bounds, Pixels};
 
 use super::{
+    web_surface_cadence::ACTIVE_POLL_INTERVAL,
     web_surface_frame::WebSurfaceFrame,
     web_surface_geometry::{
         WebSurfaceClickPoint, WebSurfaceScrollDelta, WebSurfaceScrollOffset, WebSurfaceSize,
@@ -70,6 +71,8 @@ pub(super) struct WebSurfacePendingInput {
 pub(super) enum WebSurfaceInputOutcome {
     /// State changed and the renderer should re-notify.
     Applied,
+    /// State changed and the active cadence timer will flush it.
+    Buffered,
     /// Same value as currently recorded — nothing to flush downstream.
     NoChange,
     /// Geometry constructor rejected the input (zero/NaN/negative
@@ -124,6 +127,7 @@ pub(super) struct PerTabSurface {
     pub(super) scroll_offset: Option<WebSurfaceScrollState>,
     pub(super) typed_text: Option<WebSurfaceTextInputState>,
     pub(super) state: Option<WebSurfaceState>,
+    last_input_flushed_at: Option<Instant>,
 }
 
 impl PerTabSurface {
@@ -141,6 +145,7 @@ impl PerTabSurface {
             scroll_offset: None,
             typed_text: None,
             state: None,
+            last_input_flushed_at: None,
         }
     }
 
@@ -157,6 +162,15 @@ impl PerTabSurface {
         self.last_hover_enqueued_at = Some(now);
     }
 
+    pub(super) fn input_flush_is_throttled(&self, now: Instant) -> bool {
+        self.last_input_flushed_at
+            .is_some_and(|last| now.duration_since(last) < ACTIVE_POLL_INTERVAL)
+    }
+
+    pub(super) fn mark_input_flushed(&mut self, now: Instant) {
+        self.last_input_flushed_at = Some(now);
+    }
+
     pub(super) fn should_ensure(&self, key: &WebSurfaceEnsureKey) -> bool {
         self.last_ensure_key.as_ref() != Some(key) || self.has_pending_input()
     }
@@ -242,6 +256,17 @@ mod tests {
         assert!(surface.should_ensure(&new_key));
     }
 
+    #[test]
+    fn recent_input_flush_throttles_immediate_flush() {
+        let start = Instant::now();
+        let mut surface = PerTabSurface::new();
+
+        surface.mark_input_flushed(start);
+
+        assert!(surface.input_flush_is_throttled(start + Duration::from_millis(7)));
+        assert!(!surface.input_flush_is_throttled(start + Duration::from_millis(8)));
+    }
+
     fn ensure_key(url: &str, width: u32, height: u32) -> WebSurfaceEnsureKey {
         WebSurfaceEnsureKey::new(
             url.to_string(),