Streamline index queries by caching matching tables and archetypes by index.

Author: chescock

benches/benches/bevy_ecs/index/index_iter_indexed.rs

@@ -10,8 +10,8 @@ const SPAWNS: usize = 1_000_000;
 struct Planet(u16);
 
 fn find_planet_zeroes_indexed(query: QueryByIndex<Planet, &Planet>) {
-    let mut query = query.at(&Planet(0));
-    for planet in query.query().iter() {
+    let query = query.at(&Planet(0));
+    for planet in query.iter() {
         let _ = black_box(planet);
     }
 }

benches/benches/bevy_ecs/index/index_update_indexed.rs

@@ -16,8 +16,8 @@ fn increment_planet_zeroes_indexed(
     let target = Planet(*local);
     let next_planet = Planet(target.0 + 1);
 
-    let mut query = query.at(&target);
-    for (entity, _planet) in query.query().iter() {
+    let query = query.at(&target);
+    for (entity, _planet) in query.iter() {
         commands.entity(entity).insert(next_planet);
     }
 

crates/bevy_app/src/app.rs

@@ -1351,8 +1351,7 @@ impl App {
     /// app.add_index::<FavoriteColor>();
     ///
     /// fn find_red_fans(mut query: QueryByIndex<FavoriteColor, Entity>) {
-    ///     let mut lens = query.at(&FavoriteColor::Red);
-    ///     for entity in lens.query().iter() {
+    ///     for entity in &query.at(&FavoriteColor::Red) {
     ///         println!("{entity:?} likes the color Red!");
     ///     }
     /// }
@@ -1398,8 +1397,7 @@ impl App {
     /// });
     ///
     /// fn find_red_fans(mut query: QueryByIndex<FavoriteColor, Entity>) {
-    ///     let mut lens = query.at(&FavoriteColor::Red);
-    ///     for entity in lens.query().iter() {
+    ///     for entity in &query.at(&FavoriteColor::Red) {
     ///         println!("{entity:?} likes the color Red!");
     ///     }
     /// }

crates/bevy_ecs/src/index/mod.rs

@@ -92,7 +92,7 @@
 //! fn get_earthlings(mut query: QueryByIndex<Planet, Entity>) {
 //!     let mut earthlings = query.at(&Planet("Earth"));
 //!
-//!     for earthling in &earthlings.query() {
+//!     for earthling in &earthlings {
 //!         // ...
 //!     }
 //! }