Merge pull request #2974 from leptos-rs/more-stores

Improve efficiency of keyed stores

examples/stores/src/lib.rs

@@ -95,7 +95,10 @@ pub fn App() -> impl IntoView {
             <input type="submit"/>
         </form>
         <ol>
-            <For each=move || store.todos().iter_keyed() key=|row| row.id().get() let:todo>
+            // because `todos` is a keyed field, `store.todos()` returns a struct that
+            // directly implements IntoIterator, so we can use it in <For/> and
+            // it will manage reactivity for the store fields correctly
+            <For each=move || store.todos() key=|row| row.id().get() let:todo>
                 <TodoRow store todo/>
             </For>
 
@@ -154,17 +157,14 @@ fn TodoRow(
 
             <button on:click=move |_| {
                 let id = todo.id().get();
-                store
-                    .todos()
-                    .update(|todos| {
-                        todos.remove(id);
-                    });
+                store.todos().write().retain(|todo| todo.id != id);
             }>"X"</button>
             <input
                 type="date"
                 prop:value=move || {
                     todo.status().scheduled_for_date().map(|n| n.get().to_string())
                 }
+
                 class:hidden=move || !todo.status().scheduled_for()
                 on:change:target=move |ev| {
                     if let Some(date) = todo.status().scheduled_for_date() {

reactive_stores/src/keyed.rs

@@ -95,13 +95,7 @@ where
 {
     type Value = T;
     type Reader = Mapped<Inner::Reader, T>;
-    type Writer = KeyedSubfieldWriteGuard<
-        Inner,
-        Prev,
-        K,
-        T,
-        MappedMut<WriteGuard<ArcTrigger, Inner::Writer>, T>,
-    >;
+    type Writer = MappedMut<WriteGuard<ArcTrigger, Inner::Writer>, T>;
     type UntrackedWriter =
         MappedMut<WriteGuard<ArcTrigger, Inner::UntrackedWriter>, T>;
 
@@ -125,11 +119,7 @@ where
         let path = self.path().into_iter().collect::<StorePath>();
         let trigger = self.get_trigger(path.clone());
         let guard = WriteGuard::new(trigger, self.inner.writer()?);
-        let guard = MappedMut::new(guard, self.read, self.write);
-        Some(KeyedSubfieldWriteGuard {
-            inner: self.clone(),
-            guard: Some(guard),
-        })
+        Some(MappedMut::new(guard, self.read, self.write))
     }
 
     fn untracked_writer(&self) -> Option<Self::UntrackedWriter> {
@@ -336,15 +326,21 @@ where
     type Value = T;
 
     fn try_write(&self) -> Option<impl UntrackableGuard<Target = Self::Value>> {
-        self.writer()
+        let guard = self.writer()?;
+        Some(KeyedSubfieldWriteGuard {
+            inner: self.clone(),
+            guard: Some(guard),
+        })
     }
 
     fn try_write_untracked(
         &self,
     ) -> Option<impl DerefMut<Target = Self::Value>> {
-        self.writer().map(|mut writer| {
-            writer.untrack();
-            writer
+        let mut guard = self.writer()?;
+        guard.untrack();
+        Some(KeyedSubfieldWriteGuard {
+            inner: self.clone(),
+            guard: Some(guard),
         })
     }
 }
@@ -642,18 +638,21 @@ where
     }
 }
 
-impl<Inner, Prev, K, T> KeyedSubfield<Inner, Prev, K, T>
+impl<Inner, Prev, K, T> IntoIterator for KeyedSubfield<Inner, Prev, K, T>
 where
     Self: Clone,
     for<'a> &'a T: IntoIterator,
-    Inner: StoreField<Value = Prev>,
+    Inner: Clone + StoreField<Value = Prev> + 'static,
     Prev: 'static,
     K: Debug + Send + Sync + PartialEq + Eq + Hash + 'static,
-    T: IndexMut<usize>,
+    T: IndexMut<usize> + 'static,
     T::Output: Sized,
 {
+    type Item = AtKeyed<Inner, Prev, K, T>;
+    type IntoIter = StoreFieldKeyedIter<Inner, Prev, K, T>;
+
     #[track_caller]
-    pub fn iter_keyed(self) -> StoreFieldKeyedIter<Inner, Prev, K, T> {
+    fn into_iter(self) -> StoreFieldKeyedIter<Inner, Prev, K, T> {
         // reactively track changes to this field
         let trigger = self.get_trigger(self.path().into_iter().collect());
         trigger.track();

reactive_stores/src/lib.rs

@@ -60,20 +60,21 @@ impl TriggerMap {
 pub struct FieldKeys<K> {
     spare_keys: Vec<StorePathSegment>,
     current_key: usize,
-    keys: HashMap<K, (StorePathSegment, usize)>,
+    keys: FxHashMap<K, (StorePathSegment, usize)>,
 }
 
 impl<K> FieldKeys<K>
 where
     K: Debug + Hash + PartialEq + Eq,
 {
-    pub fn new(from_iter: impl IntoIterator<Item = K>) -> Self {
-        let mut current_key = 0;
-        let mut keys = HashMap::new();
-        for (idx, key) in from_iter.into_iter().enumerate() {
-            let segment = current_key.into();
+    pub fn new(from_keys: Vec<K>) -> Self {
+        let mut keys = FxHashMap::with_capacity_and_hasher(
+            from_keys.len(),
+            Default::default(),
+        );
+        for (idx, key) in from_keys.into_iter().enumerate() {
+            let segment = idx.into();
             keys.insert(key, (segment, idx));
-            current_key += 1;
         }
 
         Self {
@@ -104,7 +105,7 @@ where
             .into_iter()
             .enumerate()
             .map(|(idx, key)| (key, idx))
-            .collect::<HashMap<K, usize>>();
+            .collect::<FxHashMap<K, usize>>();
 
         // remove old keys and recycle the slots
         self.keys.retain(|key, old_entry| match new_keys.get(key) {