Contiguous access

Cargo.toml

@@ -4877,3 +4877,14 @@ name = "Pan Camera"
 description = "Example Pan-Camera Styled Camera Controller for 2D scenes"
 category = "Camera"
 wasm = true
+
+[[example]]
+name = "contiguous_query"
+path = "examples/ecs/contiguous_query.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.contiguous_query]
+name = "Contiguous Query"
+description = "Demonstrates contiguous queries"
+category = "ECS (Entity Component System)"
+wasm = false

benches/benches/bevy_ecs/iteration/iter_simple_contiguous.rs

@@ -0,0 +1,47 @@
+use bevy_ecs::prelude::*;
+use glam::*;
+
+#[derive(Component, Copy, Clone)]
+struct Transform(Mat4);
+
+#[derive(Component, Copy, Clone)]
+struct Position(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Rotation(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Velocity(Vec3);
+
+pub struct Benchmark<'w>(World, QueryState<(&'w Velocity, &'w mut Position)>);
+
+impl<'w> Benchmark<'w> {
+    pub fn new() -> Self {
+        let mut world = World::new();
+
+        world.spawn_batch(core::iter::repeat_n(
+            (
+                Transform(Mat4::from_scale(Vec3::ONE)),
+                Position(Vec3::X),
+                Rotation(Vec3::X),
+                Velocity(Vec3::X),
+            ),
+            10_000,
+        ));
+
+        let query = world.query::<(&Velocity, &mut Position)>();
+        Self(world, query)
+    }
+
+    #[inline(never)]
+    pub fn run(&mut self) {
+        let mut iter = self.1.iter_mut(&mut self.0);
+        for (velocity, (position, mut ticks)) in iter.as_contiguous_iter().unwrap() {
+            for (v, p) in velocity.iter().zip(position.iter_mut()) {
+                p.0 += v.0;
+            }
+            // to match the iter_simple benchmark
+            ticks.mark_all_as_updated();
+        }
+    }
+}

benches/benches/bevy_ecs/iteration/iter_simple_contiguous_avx2.rs

@@ -0,0 +1,65 @@
+use bevy_ecs::prelude::*;
+use glam::*;
+
+#[derive(Component, Copy, Clone)]
+struct Transform(Mat4);
+
+#[derive(Component, Copy, Clone)]
+struct Position(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Rotation(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Velocity(Vec3);
+
+pub struct Benchmark<'w>(World, QueryState<(&'w Velocity, &'w mut Position)>);
+
+impl<'w> Benchmark<'w> {
+    pub fn supported() -> bool {
+        is_x86_feature_detected!("avx2")
+    }
+
+    pub fn new() -> Option<Self> {
+        if !Self::supported() {
+            return None;
+        }
+
+        let mut world = World::new();
+
+        world.spawn_batch(core::iter::repeat_n(
+            (
+                Transform(Mat4::from_scale(Vec3::ONE)),
+                Position(Vec3::X),
+                Rotation(Vec3::X),
+                Velocity(Vec3::X),
+            ),
+            10_000,
+        ));
+
+        let query = world.query::<(&Velocity, &mut Position)>();
+        Some(Self(world, query))
+    }
+
+    #[inline(never)]
+    pub fn run(&mut self) {
+        /// # Safety
+        /// avx2 must be supported
+        #[target_feature(enable = "avx2")]
+        fn exec(position: &mut [Position], velocity: &[Velocity]) {
+            for i in 0..position.len() {
+                position[i].0 += velocity[i].0;
+            }
+        }
+
+        let mut iter = self.1.iter_mut(&mut self.0);
+        for (velocity, (position, mut ticks)) in iter.as_contiguous_iter().unwrap() {
+            // SAFETY: checked in new
+            unsafe {
+                exec(position, velocity);
+            }
+            // to match the iter_simple benchmark
+            ticks.mark_all_as_updated();
+        }
+    }
+}

benches/benches/bevy_ecs/iteration/iter_simple_no_detection.rs

@@ -0,0 +1,42 @@
+use bevy_ecs::prelude::*;
+use glam::*;
+
+#[derive(Component, Copy, Clone)]
+struct Transform(Mat4);
+
+#[derive(Component, Copy, Clone)]
+struct Position(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Rotation(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Velocity(Vec3);
+
+pub struct Benchmark<'w>(World, QueryState<(&'w Velocity, &'w mut Position)>);
+
+impl<'w> Benchmark<'w> {
+    pub fn new() -> Self {
+        let mut world = World::new();
+
+        world.spawn_batch(core::iter::repeat_n(
+            (
+                Transform(Mat4::from_scale(Vec3::ONE)),
+                Position(Vec3::X),
+                Rotation(Vec3::X),
+                Velocity(Vec3::X),
+            ),
+            10_000,
+        ));
+
+        let query = world.query::<(&Velocity, &mut Position)>();
+        Self(world, query)
+    }
+
+    #[inline(never)]
+    pub fn run(&mut self) {
+        for (velocity, mut position) in self.1.iter_mut(&mut self.0) {
+            position.bypass_change_detection().0 += velocity.0;
+        }
+    }
+}

benches/benches/bevy_ecs/iteration/iter_simple_no_detection_contiguous.rs

@@ -0,0 +1,45 @@
+use bevy_ecs::prelude::*;
+use glam::*;
+
+#[derive(Component, Copy, Clone)]
+struct Transform(Mat4);
+
+#[derive(Component, Copy, Clone)]
+struct Position(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Rotation(Vec3);
+
+#[derive(Component, Copy, Clone)]
+struct Velocity(Vec3);
+
+pub struct Benchmark<'w>(World, QueryState<(&'w Velocity, &'w mut Position)>);
+
+impl<'w> Benchmark<'w> {
+    pub fn new() -> Self {
+        let mut world = World::new();
+
+        world.spawn_batch(core::iter::repeat_n(
+            (
+                Transform(Mat4::from_scale(Vec3::ONE)),
+                Position(Vec3::X),
+                Rotation(Vec3::X),
+                Velocity(Vec3::X),
+            ),
+            10_000,
+        ));
+
+        let query = world.query::<(&Velocity, &mut Position)>();
+        Self(world, query)
+    }
+
+    #[inline(never)]
+    pub fn run(&mut self) {
+        let mut iter = self.1.iter_mut(&mut self.0);
+        for (velocity, (position, _ticks)) in iter.as_contiguous_iter().unwrap() {
+            for (v, p) in velocity.iter().zip(position.iter_mut()) {
+                p.0 += v.0;
+            }
+        }
+    }
+}

benches/benches/bevy_ecs/iteration/mod.rs

@@ -8,11 +8,16 @@ mod iter_frag_sparse;
 mod iter_frag_wide;
 mod iter_frag_wide_sparse;
 mod iter_simple;
+mod iter_simple_contiguous;
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+mod iter_simple_contiguous_avx2;
 mod iter_simple_foreach;
 mod iter_simple_foreach_hybrid;
 mod iter_simple_foreach_sparse_set;
 mod iter_simple_foreach_wide;
 mod iter_simple_foreach_wide_sparse_set;
+mod iter_simple_no_detection;
+mod iter_simple_no_detection_contiguous;
 mod iter_simple_sparse_set;
 mod iter_simple_system;
 mod iter_simple_wide;
@@ -40,6 +45,27 @@ fn iter_simple(c: &mut Criterion) {
         let mut bench = iter_simple::Benchmark::new();
         b.iter(move || bench.run());
     });
+    group.bench_function("base_contiguous", |b| {
+        let mut bench = iter_simple_contiguous::Benchmark::new();
+        b.iter(move || bench.run());
+    });
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    {
+        if iter_simple_contiguous_avx2::Benchmark::supported() {
+            group.bench_function("base_contiguous_avx2", |b| {
+                let mut bench = iter_simple_contiguous_avx2::Benchmark::new().unwrap();
+                b.iter(move || bench.run());
+            });
+        }
+    }
+    group.bench_function("base_no_detection", |b| {
+        let mut bench = iter_simple_no_detection::Benchmark::new();
+        b.iter(move || bench.run());
+    });
+    group.bench_function("base_no_detection_contiguous", |b| {
+        let mut bench = iter_simple_no_detection_contiguous::Benchmark::new();
+        b.iter(move || bench.run());
+    });
     group.bench_function("wide", |b| {
         let mut bench = iter_simple_wide::Benchmark::new();
         b.iter(move || bench.run());

crates/bevy_ecs/compile_fail/tests/ui/world_query_derive.rs

@@ -12,7 +12,7 @@ struct MutableUnmarked {
 
 #[derive(QueryData)]
 #[query_data(mut)]
-//~^ ERROR: invalid attribute, expected `mutable` or `derive`
+//~^ ERROR: invalid attribute, expected `mutable`, `derive` or `contiguous`
 struct MutableInvalidAttribute {
     a: &'static mut Foo,
 }

crates/bevy_ecs/compile_fail/tests/ui/world_query_derive.stderr

@@ -1,4 +1,4 @@
-error: invalid attribute, expected `mutable` or `derive`
+error: invalid attribute, expected `mutable`, `derive` or `contiguous`
   --> tests/ui/world_query_derive.rs:14:14
    |
 14 | #[query_data(mut)]