perf: batch modifies notify

core/src/state/stateful.rs

@@ -129,6 +129,8 @@ pub(crate) struct StateData<W> {
   /// the unsubscribe handle to this list let you can unsubscribe when this
   /// `data` drop.
   slot_link: UnsafeCell<Option<SlotNode>>,
+  /// The batched modifies of the `State` which will be notified.
+  share_scope: Rc<Cell<Option<ModifyScope>>>,
 }
 
 macro_rules! debug_borrow_location {
@@ -228,6 +230,7 @@ impl<W> StateData<W> {
       #[cfg(debug_assertions)]
       borrowed_at: Cell::new(None),
       slot_link: <_>::default(),
+      share_scope: <_>::default(),
     }
   }
 
@@ -394,10 +397,19 @@ impl<'a, W> Drop for RefState<'a, W> {
     let scope = self.forget_modifies();
 
     if !scope.is_empty() {
-      if let Some(m) = self.modifier.as_mut() {
-        let mut subject = m.raw_modifies();
-        // todo: should batch all the modifies and notify once.`
-        AppCtx::spawn_local(async move { subject.next(scope) }).unwrap();
+      if let Some(s) = self.value.share_scope.get() {
+        self.value.share_scope.set(Some(s | scope));
+      } else {
+        self.value.share_scope.set(Some(scope));
+        if let Some(m) = self.modifier.as_mut() {
+          let mut subject = m.raw_modifies();
+          let share_scope = self.value.share_scope.clone();
+          AppCtx::spawn_local(async move {
+            let scope = share_scope.replace(None);
+            subject.next(unsafe { scope.unwrap_unchecked() });
+          })
+          .unwrap();
+        }
       }
     }
   }