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https://github.com/bevyengine/bevy
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49 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Joseph
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02688a99b8
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Fix safety invariants for WorldQuery::fetch and simplify cloning (#8246)
# Objective Cloning a `WorldQuery` type's "fetch" struct was made unsafe in #5593, by adding the `unsafe fn clone_fetch` to `WorldQuery`. However, as that method's documentation explains, it is not the right place to put the safety invariant: > While calling this method on its own cannot cause UB it is marked `unsafe` as the caller must ensure that the returned value is not used in any way that would cause two `QueryItem<Self>` for the same `archetype_index` or `table_row` to be alive at the same time. You can clone a fetch struct all you want and it will never cause undefined behavior -- in order for something to go wrong, you need to improperly call `WorldQuery::fetch` with it (which is marked unsafe). Additionally, making it unsafe to clone a fetch struct does not even prevent undefined behavior, since there are other ways to incorrectly use a fetch struct. For example, you could just call fetch more than once for the same entity, which is not currently forbidden by any documented invariants. ## Solution Document a safety invariant on `WorldQuery::fetch` that requires the caller to not create aliased `WorldQueryItem`s for mutable types. Remove the `clone_fetch` function, and add the bound `Fetch: Clone` instead. --- ## Changelog - Removed the associated function `WorldQuery::clone_fetch`, and added a `Clone` bound to `WorldQuery::Fetch`. ## Migration Guide ### `fetch` invariants The function `WorldQuery::fetch` has had the following safety invariant added: > If this type does not implement `ReadOnlyWorldQuery`, then the caller must ensure that it is impossible for more than one `Self::Item` to exist for the same entity at any given time. This invariant was always required for soundness, but was previously undocumented. If you called this function manually anywhere, you should check to make sure that this invariant is not violated. ### Removed `clone_fetch` The function `WorldQuery::clone_fetch` has been removed. The associated type `WorldQuery::Fetch` now has the bound `Clone`. Before: ```rust struct MyFetch<'w> { ... } unsafe impl WorldQuery for MyQuery { ... type Fetch<'w> = MyFetch<'w> unsafe fn clone_fetch<'w>(fetch: &Self::Fetch<'w>) -> Self::Fetch<'w> { MyFetch { field1: fetch.field1, field2: fetch.field2.clone(), ... } } } ``` After: ```rust #[derive(Clone)] struct MyFetch<'w> { ... } unsafe impl WorldQuery for MyQuery { ... type Fetch<'w> = MyFetch<'w>; } ``` --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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JoJoJet
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de1dcb986a
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Provide access to world storages via UnsafeWorldCell (#8987)
# Objective Title. This is necessary in order to update [`bevy-trait-query`](https://crates.io/crates/bevy-trait-query) to Bevy 0.11. --- ## Changelog Added the unsafe function `UnsafeWorldCell::storages`, which provides unchecked access to the internal data stores of a `World`. |
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JoJoJet
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db8d3651e0
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Migrate the rest of the engine to UnsafeWorldCell (#8833)
# Objective Follow-up to #6404 and #8292. Mutating the world through a shared reference is surprising, and it makes the meaning of `&World` unclear: sometimes it gives read-only access to the entire world, and sometimes it gives interior mutable access to only part of it. This is an up-to-date version of #6972. ## Solution Use `UnsafeWorldCell` for all interior mutability. Now, `&World` *always* gives you read-only access to the entire world. --- ## Changelog TODO - do we still care about changelogs? ## Migration Guide Mutating any world data using `&World` is now considered unsound -- the type `UnsafeWorldCell` must be used to achieve interior mutability. The following methods now accept `UnsafeWorldCell` instead of `&World`: - `QueryState`: `get_unchecked`, `iter_unchecked`, `iter_combinations_unchecked`, `for_each_unchecked`, `get_single_unchecked`, `get_single_unchecked_manual`. - `SystemState`: `get_unchecked_manual` ```rust let mut world = World::new(); let mut query = world.query::<&mut T>(); // Before: let t1 = query.get_unchecked(&world, entity_1); let t2 = query.get_unchecked(&world, entity_2); // After: let world_cell = world.as_unsafe_world_cell(); let t1 = query.get_unchecked(world_cell, entity_1); let t2 = query.get_unchecked(world_cell, entity_2); ``` The methods `QueryState::validate_world` and `SystemState::matches_world` now take a `WorldId` instead of `&World`: ```rust // Before: query_state.validate_world(&world); // After: query_state.validate_world(world.id()); ``` The methods `QueryState::update_archetypes` and `SystemState::update_archetypes` now take `UnsafeWorldCell` instead of `&World`: ```rust // Before: query_state.update_archetypes(&world); // After: query_state.update_archetypes(world.as_unsafe_world_cell_readonly()); ``` |
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JoJoJet
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2e7b915ba4
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Increase type safety and clarity for change detection (#7905) | ||
shuo
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002c9d8b7f |
fix whitespaces in comment (#7853)
fix double whitespaces in comments. (I know it's dumb commit, while reading code, double spaces hurts a little... :P) |
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James Liu
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a5b1c46d5b |
Extend EntityLocation with TableId and TableRow (#6681)
# Objective `Query::get` and other random access methods require looking up `EntityLocation` for every provided entity, then always looking up the `Archetype` to get the table ID and table row. This requires 4 total random fetches from memory: the `Entities` lookup, the `Archetype` lookup, the table row lookup, and the final fetch from table/sparse sets. If `EntityLocation` contains the table ID and table row, only the `Entities` lookup and the final storage fetch are required. ## Solution Add `TableId` and table row to `EntityLocation`. Ensure it's updated whenever entities are moved around. To ensure `EntityMeta` does not grow bigger, both `TableId` and `ArchetypeId` have been shrunk to u32, and the archetype index and table row are stored as u32s instead of as usizes. This should shrink `EntityMeta` by 4 bytes, from 24 to 20 bytes, as there is no padding anymore due to the change in alignment. This idea was partially concocted by @BoxyUwU. ## Performance This should restore the `Query::get` "gains" lost to #6625 that were introduced in #4800 without being unsound, and also incorporates some of the memory usage reductions seen in #3678. This also removes the same lookups during add/remove/spawn commands, so there may be a bit of a speedup in commands and `Entity{Ref,Mut}`. --- ## Changelog Added: `EntityLocation::table_id` Added: `EntityLocation::table_row`. Changed: `World`s can now only hold a maximum of 2<sup>32</sup>- 1 archetypes. Changed: `World`s can now only hold a maximum of 2<sup>32</sup> - 1 tables. ## Migration Guide A `World` can only hold a maximum of 2<sup>32</sup> - 1 archetypes and tables now. If your use case requires more than this, please file an issue explaining your use case. |
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James Liu
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530be10e72 |
Newtype ArchetypeRow and TableRow (#4878)
# Objective Prevent future unsoundness that was seen in #6623. ## Solution Newtype both indexes in `Archetype` and `Table` as `ArchetypeRow` and `TableRow`. This avoids weird numerical manipulation on the indices, and can be stored and treated opaquely. Also enforces the source and destination of where these indices at a type level. --- ## Changelog Changed: `Archetype` indices and `Table` rows have been newtyped as `ArchetypeRow` and `TableRow`. |
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James Liu
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d79888bdae |
Document and lock down types in bevy_ecs::archetype (#6742)
# Objective Document `bevy_ecs::archetype` and and declutter the public documentation for the module by making types non-`pub`. Addresses #3362 for `bevy_ecs::archetype`. ## Solution - Add module level documentation. - Add type and API level documentation for all public facing types. - Make `ArchetypeId`, `ArchetypeGeneration`, and `ArchetypeComponentId` truly opaque IDs that are not publicly constructable. - Make `AddBundle` non-pub, make `Edges::get_add_bundle` return a `Option<ArchetypeId>` and fork the existing function into `Edges::get_add_bundle_internal`. - Remove `pub(crate)` on fields that have a corresponding pub accessor function. - Removed the `Archetypes: Default` impl, opting for a `pub(crate) fn new` alternative instead. --- ## Changelog Added: `ArchetypeGeneration` now implements `Ord` and `PartialOrd`. Removed: `Archetypes`'s `Default` implementation. Removed: `Archetype::new` and `Archetype::is_empty`. Removed: `ArchetypeId::new` and `ArchetypeId::value`. Removed: `ArchetypeGeneration::value` Removed: `ArchetypeIdentity`. Removed: `ArchetypeComponentId::new` and `ArchetypeComponentId::value`. Removed: `AddBundle`. `Edges::get_add_bundle` now returns `Option<ArchetypeId>` |
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Nicola Papale
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15ea93a348 |
Fix size_hint for partially consumed QueryIter and QueryCombinationIter (#5214)
# Objective Fix #5149 ## Solution Instead of returning the **total count** of elements in the `QueryIter` in `size_hint`, we return the **count of remaining elements**. This Fixes #5149 even when #5148 gets merged. - https://github.com/bevyengine/bevy/issues/5149 - https://github.com/bevyengine/bevy/pull/5148 --- ## Changelog - Fix partially consumed `QueryIter` and `QueryCombinationIter` having invalid `size_hint` Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com> |
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James Liu
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ec8c8fbc8a |
Remove unnecesary branches/panics from Query accesses (#6461)
# Objective Supercedes #6452. Upon inspection of the [generated assembly](https://gist.github.com/james7132/c2740c6941b80d7912f1e8888e223cbb#file-original-s) of a [simple Bevy binary](https://gist.github.com/james7132/c2740c6941b80d7912f1e8888e223cbb#file-source-rs) compiled with `cargo rustc --release -- --emit asm`, it's apparent that there are multiple unnecessary branches in the generated assembly: ```assembly .LBB5_5: cmpq %r10, %r11 je .LBB5_15 movq (%r11), %rcx movq 328(%r15), %rdx cmpq %rdx, %rcx jae .LBB5_14 movq 312(%r15), %rdi leaq (%rcx,%rcx,2), %rcx shlq $5, %rcx movq 336(%r12), %rdx movq 64(%rdi,%rcx), %rax cmpq %rdx, %rax jbe .LBB5_4 leaq (%rdi,%rcx), %rsi movq 48(%rsi), %rbp shlq $4, %rdx cmpq $0, (%rbp,%rdx) je .LBB5_4 movq 344(%r12), %rbx cmpq %rbx, %rax jbe .LBB5_4 shlq $4, %rbx cmpq $0, (%rbp,%rbx) je .LBB5_4 addq $8, %r11 movq 88(%rdi,%rcx), %rcx testq %rcx, %rcx je .LBB5_5 movq (%rsi), %rax movq 8(%rbp,%rdx), %rdx leaq (%rdx,%rdx,4), %rdi shlq $4, %rdi movq 32(%rax,%rdi), %rdx movq 56(%rax,%rdi), %r8 movq 8(%rbp,%rbx), %rbp leaq (%rbp,%rbp,4), %rbp shlq $4, %rbp movq 32(%rax,%rbp), %r9 xorl %ebp, %ebp jmp .LBB5_13 .p2align 4, 0x90 ``` Almost every one of the instructions starting with `j` is a potential branch, which can significantly slow down accesses. Of these, two labels are both common and never used: ```asm .LBB5_14: leaq __unnamed_2(%rip), %r8 callq _ZN4core9panicking18panic_bounds_check17h70367088e72af65aE ud2 .LBB5_4: callq _ZN8bevy_ecs5query25debug_checked_unreachable17h0855ff520ceaea77E ud2 .seh_endproc ``` These correpsond to subprocedure calls to panicking due to out of bounds from indexing `Tables` and `debug_checked_unreadable`. Both of which should be inlined and optimized out, but are not. ## Solution Make `debug_checked_unreachable` a macro to forcibly inline either `unreachable!()` in debug builds, and `std::hint::unreachable_unchecked()` in release mode. Replace the `Tables` and `Archetype` index access with `get(id).unwrap_or_else(|| debug_checked_unreachable!())` to assume that the table or archetype provided exists. This has no external breaking change of any kind. The equivalent section of code with these changes removes most of the conditional jump instructions: ```asm .LBB5_5: movss (%rbx,%rbp,4), %xmm0 movl %r14d, 4(%r8,%rbp,8) addss (%rdi,%rbp,4), %xmm0 movss %xmm0, (%rdi,%rbp,4) incq %rbp .LBB5_1: cmpq %rdx, %rbp jne .LBB5_5 .p2align 4, 0x90 .LBB5_2: cmpq %rcx, %rax je .LBB5_6 movq (%rax), %rdx addq $8, %rax movq 312(%rsi), %rbp leaq (%rdx,%rdx,2), %rbx shlq $5, %rbx movq 88(%rbp,%rbx), %rdx testq %rdx, %rdx je .LBB5_2 leaq (%rbx,%rbp), %r8 movq 336(%r15), %rdi movq 344(%r15), %r9 movq 48(%rbp,%rbx), %r10 shlq $4, %rdi movq (%r8), %rbx movq 8(%r10,%rdi), %rdi leaq (%rdi,%rdi,4), %rbp shlq $4, %rbp movq 32(%rbx,%rbp), %rdi movq 56(%rbx,%rbp), %r8 shlq $4, %r9 movq 8(%r10,%r9), %rbp leaq (%rbp,%rbp,4), %rbp shlq $4, %rbp movq 32(%rbx,%rbp), %rbx xorl %ebp, %ebp jmp .LBB5_5 .LBB5_6: addq $40, %rsp popq %rbx popq %rbp popq %rdi popq %rsi popq %r14 popq %r15 retq .seh_endproc ``` ## Performance Microbenchmarks results: <details> ``` group main no-panic-query ----- ---- -------------- busy_systems/01x_entities_03_systems 1.20 42.4±2.66µs ? ?/sec 1.00 35.3±1.68µs ? ?/sec busy_systems/01x_entities_06_systems 1.32 83.8±3.50µs ? ?/sec 1.00 63.6±1.72µs ? ?/sec busy_systems/01x_entities_09_systems 1.15 113.3±8.90µs ? ?/sec 1.00 98.2±6.15µs ? ?/sec busy_systems/01x_entities_12_systems 1.27 160.8±32.44µs ? ?/sec 1.00 126.6±4.70µs ? ?/sec busy_systems/01x_entities_15_systems 1.12 179.6±3.71µs ? ?/sec 1.00 160.3±11.03µs ? ?/sec busy_systems/02x_entities_03_systems 1.18 76.8±3.14µs ? ?/sec 1.00 65.2±3.17µs ? ?/sec busy_systems/02x_entities_06_systems 1.16 144.6±6.10µs ? ?/sec 1.00 124.5±5.14µs ? ?/sec busy_systems/02x_entities_09_systems 1.19 215.3±9.18µs ? ?/sec 1.00 181.5±5.67µs ? ?/sec busy_systems/02x_entities_12_systems 1.20 266.7±8.33µs ? ?/sec 1.00 222.0±9.53µs ? ?/sec busy_systems/02x_entities_15_systems 1.23 338.8±10.53µs ? ?/sec 1.00 276.3±6.94µs ? ?/sec busy_systems/03x_entities_03_systems 1.43 113.5±5.06µs ? ?/sec 1.00 79.6±1.49µs ? ?/sec busy_systems/03x_entities_06_systems 1.38 217.3±12.67µs ? ?/sec 1.00 157.5±3.07µs ? ?/sec busy_systems/03x_entities_09_systems 1.23 308.8±24.75µs ? ?/sec 1.00 251.6±8.93µs ? ?/sec busy_systems/03x_entities_12_systems 1.05 347.7±12.43µs ? ?/sec 1.00 330.6±11.43µs ? ?/sec busy_systems/03x_entities_15_systems 1.13 455.5±13.88µs ? ?/sec 1.00 401.7±17.29µs ? ?/sec busy_systems/04x_entities_03_systems 1.24 144.7±5.89µs ? ?/sec 1.00 116.9±6.29µs ? ?/sec busy_systems/04x_entities_06_systems 1.24 282.8±21.40µs ? ?/sec 1.00 228.6±21.31µs ? ?/sec busy_systems/04x_entities_09_systems 1.35 431.8±14.10µs ? ?/sec 1.00 319.6±9.83µs ? ?/sec busy_systems/04x_entities_12_systems 1.16 493.8±22.87µs ? ?/sec 1.00 424.9±15.24µs ? ?/sec busy_systems/04x_entities_15_systems 1.10 587.5±23.25µs ? ?/sec 1.00 531.7±16.32µs ? ?/sec busy_systems/05x_entities_03_systems 1.14 148.2±9.61µs ? ?/sec 1.00 129.5±4.32µs ? ?/sec busy_systems/05x_entities_06_systems 1.31 359.7±17.46µs ? ?/sec 1.00 273.6±10.55µs ? ?/sec busy_systems/05x_entities_09_systems 1.22 473.5±23.11µs ? ?/sec 1.00 389.3±13.62µs ? ?/sec busy_systems/05x_entities_12_systems 1.05 562.9±20.76µs ? ?/sec 1.00 536.5±24.35µs ? ?/sec busy_systems/05x_entities_15_systems 1.23 818.5±28.70µs ? ?/sec 1.00 666.6±45.87µs ? ?/sec contrived/01x_entities_03_systems 1.27 27.5±0.49µs ? ?/sec 1.00 21.6±1.71µs ? ?/sec contrived/01x_entities_06_systems 1.22 49.9±1.18µs ? ?/sec 1.00 40.7±2.62µs ? ?/sec contrived/01x_entities_09_systems 1.30 72.3±2.39µs ? ?/sec 1.00 55.4±2.60µs ? ?/sec contrived/01x_entities_12_systems 1.28 94.3±9.44µs ? ?/sec 1.00 73.7±3.62µs ? ?/sec contrived/01x_entities_15_systems 1.25 118.0±2.43µs ? ?/sec 1.00 94.1±3.99µs ? ?/sec contrived/02x_entities_03_systems 1.23 41.6±1.71µs ? ?/sec 1.00 33.7±2.30µs ? ?/sec contrived/02x_entities_06_systems 1.19 78.6±2.63µs ? ?/sec 1.00 65.9±2.35µs ? ?/sec contrived/02x_entities_09_systems 1.28 113.6±3.60µs ? ?/sec 1.00 88.6±3.60µs ? ?/sec contrived/02x_entities_12_systems 1.20 146.4±5.75µs ? ?/sec 1.00 121.7±3.35µs ? ?/sec contrived/02x_entities_15_systems 1.23 178.5±4.86µs ? ?/sec 1.00 145.7±4.00µs ? ?/sec contrived/03x_entities_03_systems 1.42 58.3±2.77µs ? ?/sec 1.00 41.1±1.54µs ? ?/sec contrived/03x_entities_06_systems 1.32 108.5±7.30µs ? ?/sec 1.00 82.4±4.86µs ? ?/sec contrived/03x_entities_09_systems 1.23 153.7±4.61µs ? ?/sec 1.00 125.0±4.76µs ? ?/sec contrived/03x_entities_12_systems 1.18 197.5±5.12µs ? ?/sec 1.00 166.8±8.14µs ? ?/sec contrived/03x_entities_15_systems 1.23 238.8±6.38µs ? ?/sec 1.00 194.6±4.55µs ? ?/sec contrived/04x_entities_03_systems 1.34 66.4±3.42µs ? ?/sec 1.00 49.5±1.98µs ? ?/sec contrived/04x_entities_06_systems 1.27 134.3±4.86µs ? ?/sec 1.00 105.8±3.58µs ? ?/sec contrived/04x_entities_09_systems 1.26 193.2±3.83µs ? ?/sec 1.00 153.0±5.60µs ? ?/sec contrived/04x_entities_12_systems 1.16 237.1±5.78µs ? ?/sec 1.00 204.9±18.77µs ? ?/sec contrived/04x_entities_15_systems 1.17 289.2±4.76µs ? ?/sec 1.00 246.3±8.57µs ? ?/sec contrived/05x_entities_03_systems 1.26 80.4±2.90µs ? ?/sec 1.00 63.7±3.07µs ? ?/sec contrived/05x_entities_06_systems 1.27 161.6±13.47µs ? ?/sec 1.00 127.2±5.59µs ? ?/sec contrived/05x_entities_09_systems 1.22 228.0±7.76µs ? ?/sec 1.00 186.2±7.68µs ? ?/sec contrived/05x_entities_12_systems 1.20 289.5±6.21µs ? ?/sec 1.00 241.8±7.52µs ? ?/sec contrived/05x_entities_15_systems 1.18 357.3±11.24µs ? ?/sec 1.00 302.7±7.21µs ? ?/sec heavy_compute/base 1.01 302.4±3.52µs ? ?/sec 1.00 300.2±3.40µs ? ?/sec iter_fragmented/base 1.00 348.1±7.51ns ? ?/sec 1.01 351.9±8.32ns ? ?/sec iter_fragmented/foreach 1.03 239.8±23.78ns ? ?/sec 1.00 233.8±18.12ns ? ?/sec iter_fragmented/foreach_wide 1.00 3.9±0.13µs ? ?/sec 1.02 4.0±0.22µs ? ?/sec iter_fragmented/wide 1.18 4.6±0.15µs ? ?/sec 1.00 3.9±0.10µs ? ?/sec iter_fragmented_sparse/base 1.02 8.1±0.15ns ? ?/sec 1.00 7.9±0.56ns ? ?/sec iter_fragmented_sparse/foreach 1.00 7.8±0.22ns ? ?/sec 1.01 7.9±0.62ns ? ?/sec iter_fragmented_sparse/foreach_wide 1.00 37.2±1.17ns ? ?/sec 1.10 40.9±0.95ns ? ?/sec iter_fragmented_sparse/wide 1.09 48.4±2.13ns ? ?/sec 1.00 44.5±18.34ns ? ?/sec iter_simple/base 1.02 8.4±0.10µs ? ?/sec 1.00 8.2±0.14µs ? ?/sec iter_simple/foreach 1.01 8.3±0.07µs ? ?/sec 1.00 8.2±0.09µs ? ?/sec iter_simple/foreach_sparse_set 1.00 25.3±0.32µs ? ?/sec 1.02 25.7±0.42µs ? ?/sec iter_simple/foreach_wide 1.03 41.1±0.94µs ? ?/sec 1.00 39.9±0.41µs ? ?/sec iter_simple/foreach_wide_sparse_set 1.05 123.6±2.05µs ? ?/sec 1.00 118.1±2.78µs ? ?/sec iter_simple/sparse_set 1.14 30.5±1.40µs ? ?/sec 1.00 26.9±0.64µs ? ?/sec iter_simple/system 1.01 8.4±0.25µs ? ?/sec 1.00 8.4±0.11µs ? ?/sec iter_simple/wide 1.18 48.2±0.62µs ? ?/sec 1.00 40.7±0.38µs ? ?/sec iter_simple/wide_sparse_set 1.12 140.8±21.56µs ? ?/sec 1.00 126.0±2.30µs ? ?/sec query_get/50000_entities_sparse 1.17 378.6±7.60µs ? ?/sec 1.00 324.1±23.17µs ? ?/sec query_get/50000_entities_table 1.08 330.9±10.90µs ? ?/sec 1.00 306.8±4.98µs ? ?/sec query_get_component/50000_entities_sparse 1.00 976.7±19.55µs ? ?/sec 1.00 979.8±35.87µs ? ?/sec query_get_component/50000_entities_table 1.00 1029.0±15.11µs ? ?/sec 1.05 1080.0±59.18µs ? ?/sec query_get_component_simple/system 1.13 839.7±14.18µs ? ?/sec 1.00 742.8±10.72µs ? ?/sec query_get_component_simple/unchecked 1.01 909.0±15.17µs ? ?/sec 1.00 898.0±13.56µs ? ?/sec query_get_many_10/50000_calls_sparse 1.04 5.5±0.54ms ? ?/sec 1.00 5.3±0.67ms ? ?/sec query_get_many_10/50000_calls_table 1.01 4.9±0.49ms ? ?/sec 1.00 4.8±0.45ms ? ?/sec query_get_many_2/50000_calls_sparse 1.28 848.4±210.89µs ? ?/sec 1.00 664.8±47.69µs ? ?/sec query_get_many_2/50000_calls_table 1.05 779.0±73.85µs ? ?/sec 1.00 739.2±83.02µs ? ?/sec query_get_many_5/50000_calls_sparse 1.05 2.4±0.37ms ? ?/sec 1.00 2.3±0.33ms ? ?/sec query_get_many_5/50000_calls_table 1.00 1939.9±75.22µs ? ?/sec 1.04 2.0±0.19ms ? ?/sec run_criteria/yes_using_query/001_systems 1.00 3.7±0.38µs ? ?/sec 1.30 4.9±0.14µs ? ?/sec run_criteria/yes_using_query/006_systems 1.00 8.9±0.40µs ? ?/sec 1.17 10.3±0.57µs ? ?/sec run_criteria/yes_using_query/011_systems 1.00 13.9±0.49µs ? ?/sec 1.08 15.0±0.89µs ? ?/sec run_criteria/yes_using_query/016_systems 1.00 18.8±0.74µs ? ?/sec 1.00 18.8±1.43µs ? ?/sec run_criteria/yes_using_query/021_systems 1.07 24.1±0.87µs ? ?/sec 1.00 22.6±1.58µs ? ?/sec run_criteria/yes_using_query/026_systems 1.04 27.9±0.62µs ? ?/sec 1.00 26.8±1.71µs ? ?/sec run_criteria/yes_using_query/031_systems 1.09 33.3±1.03µs ? ?/sec 1.00 30.5±2.18µs ? ?/sec run_criteria/yes_using_query/036_systems 1.14 38.7±0.80µs ? ?/sec 1.00 33.9±1.75µs ? ?/sec run_criteria/yes_using_query/041_systems 1.18 43.7±1.07µs ? ?/sec 1.00 37.0±2.39µs ? ?/sec run_criteria/yes_using_query/046_systems 1.14 47.6±1.16µs ? ?/sec 1.00 41.9±2.09µs ? ?/sec run_criteria/yes_using_query/051_systems 1.17 52.9±2.04µs ? ?/sec 1.00 45.3±1.75µs ? ?/sec run_criteria/yes_using_query/056_systems 1.25 59.2±2.38µs ? ?/sec 1.00 47.2±2.01µs ? ?/sec run_criteria/yes_using_query/061_systems 1.28 66.1±15.84µs ? ?/sec 1.00 51.5±2.47µs ? ?/sec run_criteria/yes_using_query/066_systems 1.28 70.2±2.57µs ? ?/sec 1.00 54.7±2.58µs ? ?/sec run_criteria/yes_using_query/071_systems 1.30 75.5±2.27µs ? ?/sec 1.00 58.2±3.31µs ? ?/sec run_criteria/yes_using_query/076_systems 1.26 81.5±2.66µs ? ?/sec 1.00 64.5±3.13µs ? ?/sec run_criteria/yes_using_query/081_systems 1.29 89.7±2.58µs ? ?/sec 1.00 69.3±3.47µs ? ?/sec run_criteria/yes_using_query/086_systems 1.33 95.6±3.39µs ? ?/sec 1.00 71.8±3.48µs ? ?/sec run_criteria/yes_using_query/091_systems 1.25 102.0±3.67µs ? ?/sec 1.00 81.4±4.82µs ? ?/sec run_criteria/yes_using_query/096_systems 1.33 111.7±3.29µs ? ?/sec 1.00 83.8±4.15µs ? ?/sec run_criteria/yes_using_query/101_systems 1.29 113.2±12.04µs ? ?/sec 1.00 87.7±5.15µs ? ?/sec world_query_for_each/50000_entities_sparse 1.00 47.4±0.51µs ? ?/sec 1.00 47.3±0.33µs ? ?/sec world_query_for_each/50000_entities_table 1.00 27.2±0.50µs ? ?/sec 1.00 27.2±0.17µs ? ?/sec world_query_get/50000_entities_sparse_wide 1.09 210.5±1.78µs ? ?/sec 1.00 192.5±2.61µs ? ?/sec world_query_get/50000_entities_table 1.00 127.7±2.09µs ? ?/sec 1.07 136.2±5.95µs ? ?/sec world_query_get/50000_entities_table_wide 1.00 209.8±2.37µs ? ?/sec 1.15 240.6±2.04µs ? ?/sec world_query_iter/50000_entities_sparse 1.00 54.2±0.36µs ? ?/sec 1.01 54.7±0.61µs ? ?/sec world_query_iter/50000_entities_table 1.00 27.2±0.31µs ? ?/sec 1.00 27.3±0.64µs ? ?/sec ``` </details> NOTE: This PR includes a change to enable LTO on our benchmarks to get a "fully optimized" baseline for our benchmarks. Both the main and the current PR's results were with LTO enabled. |
||
Boxy
|
30e35764a1 |
Replace WorldQueryGats trait with actual gats (#6319)
# Objective Replace `WorldQueryGats` trait with actual gats ## Solution Replace `WorldQueryGats` trait with actual gats --- ## Changelog - Replaced `WorldQueryGats` trait with actual gats ## Migration Guide - Replace usage of `WorldQueryGats` assoc types with the actual gats on `WorldQuery` trait |
||
|
James Liu
|
fe7ebd4326 |
Clean up Fetch code (#4800)
# Objective Clean up code surrounding fetch by pulling out the common parts into the iteration code. ## Solution Merge `Fetch::table_fetch` and `Fetch::archetype_fetch` into a single API: `Fetch::fetch(&mut self, entity: &Entity, table_row: &usize)`. This provides everything any fetch requires to internally decide which storage to read from and get the underlying data. All of these functions are marked as `#[inline(always)]` and the arguments are passed as references to attempt to optimize out the argument that isn't being used. External to `Fetch`, Query iteration has been changed to keep track of the table row and entity outside of fetch, which moves a lot of the expensive bookkeeping `Fetch` structs had previously done internally into the outer loop. ~~TODO: Benchmark, docs~~ Done. --- ## Changelog Changed: `Fetch::table_fetch` and `Fetch::archetype_fetch` have been merged into a single `Fetch::fetch` function. ## Migration Guide TODO Co-authored-by: Brian Merchant <bhmerchang@gmail.com> Co-authored-by: Saverio Miroddi <saverio.pub2@gmail.com> |
||
|
Boxy
|
54cf45c5b3 |
Avoid making Fetchs Clone (#5593)
# Objective - Do not implement `Copy` or `Clone` for `Fetch` types as this is kind of sus soundness wise (it feels like cloning an `IterMut` in safe code to me). Cloning a fetch seems important to think about soundness wise when doing it so I prefer this over adding a `Clone` bound to the assoc type definition (i.e. `type Fetch: Clone`) even though that would also solve the other listed things here. - Remove a bunch of `QueryFetch<'w, Q>: Clone` bounds from our API as now all fetches can be "cloned" for use in `iter_combinations`. This should also help avoid the type inference regression ptrification introduced where `for<'a> QueryFetch<'a, Q>: Trait` bounds misbehave since we no longer need any of those kind of higher ranked bounds (although in practice we had none anyway). - Stop being able to "forget" to implement clone for fetches, we've had a lot of issues where either `derive(Clone)` was used instead of a manual impl (so we ended up with too tight bounds on the impl) or flat out forgot to implement Clone at all. With this change all fetches are able to be cloned for `iter_combinations` so this will no longer be possible to mess up. On an unrelated note, while making this PR I realised we probably want safety invariants on `archetype/table_fetch` that nothing aliases the table_row/archetype_index according to the access we set. --- ## Changelog `Clone` and `Copy` were removed from all `Fetch` types. ## Migration Guide - Call `WorldQuery::clone_fetch` instead of `fetch.clone()`. Make sure to add safety comments :) |
||
Carter Weinberg
|
c6f27eb054 |
Add More Description to the Iter Combinations Documentation (#6260)
# Objective I was trying to implement a collision system for my game, and believed that the iter_combinations method might be what I need. But I couldn't find a simple explanation of what a combination was in Bevy and thought it could use some more explanation. ## Solution I added some description to the documentation that can hopefully further elaborate on what a combination is. I also changed up the docs for the method because a combination is a different thing than a permutation but the Bevy docs seemed to use them interchangeably. |
||
Theo Ottah
|
45e5eb1db3 |
Remove ExactSizeIterator from QueryCombinationIter (#5895)
# Objective - `QueryCombinationIter` can have sizes greater than `usize::MAX`. - Fixes #5846 ## Solution - Only the implementation of `ExactSizeIterator` has been removed. Instead of using `query_combination.len()`, you can use `query_combination.size_hint().0` to get the same value as before. --- ## Migration Guide - Switch to using other methods of getting the length. |
||
ira
|
e4af823b45 |
Clarify the behaviour of iter_many in the docs (#5973)
Add the following message: ``` Items are returned in the order of the list of entities. Entities that don't match the query are skipped. ``` Additionally, the docs in `iter.rs` and `state.rs` were updated to match those in `query.rs`. Co-authored-by: devil-ira <justthecooldude@gmail.com> |
||
|
JoJoJet
|
89c4b77bdd |
Add a method for accessing the width of a Table (#6249)
# Objective
There is currently no good way of getting the width (# of components) of a table outside of `bevy_ecs`.
# Solution
Added the methods `Table::{component_count, component_capacity}`
For consistency and clarity, renamed `Table::{len, capacity}` to `entity_count` and `entity_capacity`.
## Changelog
- Added the methods `Table::component_count` and `Table::component_capacity`
- Renamed `Table::len` and `Table::capacity` to `entity_count` and `entity_capacity`
## Migration Guide
Any use of `Table::len` should now be `Table::entity_count`. Any use of `Table::capacity` should now be `Table::entity_capacity`.
|
||
targrub
|
d0e294c86b |
Query filter types must be ReadOnlyWorldQuery (#6008)
# Objective Fixes Issue #6005. ## Solution Replaced WorldQuery with ReadOnlyWorldQuery on F generic in Query filters and QueryState to restrict its trait bound. ## Migration Guide Query filter (`F`) generics are now bound by `ReadOnlyWorldQuery`, rather than `WorldQuery`. If for some reason you were requesting `Query<&A, &mut B>`, please use `Query<&A, With<B>>` instead. |
||
Federico Rinaldi
|
5597fc54d2 |
Add documentation to QueryCombinationIter (#5739)
# Objective - Document `QueryCombinationIter` ## Solution - Describe the item, add usage and examples - Copy notes about the number of query items generated from the corresponding query methods (they will be removed in #5742 ([motivation])) ## Additional notes - Derived from #4989 [motivation]: https://github.com/bevyengine/bevy/pull/4989#issuecomment-1208421496 |
||
|
Boxy
|
eabcd27d93 |
make WorldQuery very flat (#5205)
# Objective Simplify the worldquery trait hierarchy as much as possible by putting it all in one trait. If/when gats are stabilised this can be trivially migrated over to use them, although that's not why I made this PR, those reasons are: - Moves all of the conceptually related unsafe code for a worldquery next to eachother - Removes now unnecessary traits simplifying the "type system magic" in bevy_ecs --- ## Changelog All methods/functions/types/consts on `FetchState` and `Fetch` traits have been moved to the `WorldQuery` trait and the other traits removed. `WorldQueryGats` now only contains an `Item` and `Fetch` assoc type. ## Migration Guide Implementors should move items in impls to the `WorldQuery/Gats` traits and remove any `Fetch`/`FetchState` impls Any use sites of items in the `Fetch`/`FetchState` traits should be updated to use the `WorldQuery` trait items instead Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
||
|
ira
|
83a9e16158 |
Replace many_for_each_mut with iter_many_mut. (#5402)
# Objective
Replace `many_for_each_mut` with `iter_many_mut` using the same tricks to avoid aliased mutability that `iter_combinations_mut` uses.
<sub>I tried rebasing the draft PR I made for this before and it died. F</sub>
## Why
`many_for_each_mut` is worse for a few reasons:
1. The closure prevents the use of `continue`, `break`, and `return` behaves like a limited `continue`.
2. rustfmt will crumple it and double the indentation when the line gets too long.
```rust
query.many_for_each_mut(
&entity_list,
|(mut transform, velocity, mut component_c)| {
// Double trouble.
},
);
```
3. It is more surprising to have `many_for_each_mut` as a mutable counterpart to `iter_many` than `iter_many_mut`.
4. It required a separate unsafe fn; more unsafe code to maintain.
5. The `iter_many_mut` API matches the existing `iter_combinations_mut` API.
Co-authored-by: devil-ira <justthecooldude@gmail.com>
|
||
|
Boxy
|
be19c696bd |
Add missing ReadOnly = Self bound (#5462)
# Objective `ReadOnlyWorldQuery` should have required `Self::ReadOnly = Self` so that calling `.iter()` on a readonly query is equivelent to calling `iter_mut()`. ## Solution add `ReadOnly = Self` to the definition of `ReadOnlyWorldQuery` --- ## Changelog ReadOnlyWorldQuery's `ReadOnly` assoc type is now always equal to `Self` ## Migration Guide Make `Self::ReadOnly = Self` hold |
||
|
Boxy
|
1ac8a476cf |
remove QF generics from all Query/State methods and types (#5170)
# Objective remove `QF` generics from a bunch of types and methods on query related items. this has a few benefits: - simplifies type signatures `fn iter(&self) -> QueryIter<'_, 's, Q::ReadOnly, F::ReadOnly>` is (imo) conceptually simpler than `fn iter(&self) -> QueryIter<'_, 's, Q, ROQueryFetch<'_, Q>, F>` - `Fetch` is mostly an implementation detail but previously we had to expose it on every `iter` `get` etc method - Allows us to potentially in the future simplify the `WorldQuery` trait hierarchy by removing the `Fetch` trait ## Solution remove the `QF` generic and add a way to (unsafely) turn `&QueryState<Q1, F1>` into `&QueryState<Q2, F2>` --- ## Changelog/Migration Guide The `QF` generic was removed from various `Query` iterator types and some methods, you should update your code to use the type of the corresponding worldquery of the fetch type that was being used, or call `as_readonly`/`as_nop` to convert a querystate to the appropriate type. For example: `.get_single_unchecked_manual::<ROQueryFetch<Q>>(..)` -> `.as_readonly().get_single_unchecked_manual(..)` `my_field: QueryIter<'w, 's, Q, ROQueryFetch<'w, Q>, F>` -> `my_field: QueryIter<'w, 's, Q::ReadOnly, F::ReadOnly>` |
||
|
Nicola Papale
|
6c06fc5b7c |
Add ExactSizeIterator implementation for QueryCombinatonIter (#5148)
Following https://github.com/bevyengine/bevy/pull/5124 I decided to add the `ExactSizeIterator` impl for `QueryCombinationIter`. Also: - Clean up the tests for `size_hint` and `len` for both the normal `QueryIter` and `QueryCombinationIter`. - Add tests to `QueryCombinationIter` when it shouldn't be `ExactSizeIterator` --- ## Changelog - Added `ExactSizeIterator` implementation for `QueryCombinatonIter` |
||
Jakob Hellermann
|
d38a8dfdd7 |
add more SAFETY comments and lint for missing ones in bevy_ecs (#4835)
# Objective `SAFETY` comments are meant to be placed before `unsafe` blocks and should contain the reasoning of why in this case the usage of unsafe is okay. This is useful when reading the code because it makes it clear which assumptions are required for safety, and makes it easier to spot possible unsoundness holes. It also forces the code writer to think of something to write and maybe look at the safety contracts of any called unsafe methods again to double-check their correct usage. There's a clippy lint called `undocumented_unsafe_blocks` which warns when using a block without such a comment. ## Solution - since clippy expects `SAFETY` instead of `SAFE`, rename those - add `SAFETY` comments in more places - for the last remaining 3 places, add an `#[allow()]` and `// TODO` since I wasn't comfortable enough with the code to justify their safety - add ` #![warn(clippy::undocumented_unsafe_blocks)]` to `bevy_ecs` ### Note for reviewers The first commit only renames `SAFETY` to `SAFE` so it doesn't need a thorough review. |
||
Carter Anderson
|
96f0ebb9af |
Fix rust 1.62 changes (#5154)
# Objective CI is now failing with some changes that landed in 1.62. ## Solution * Fix an unused lifetime by using it (we double-used the `w` lifetime). * Update compile_fail error messages * temporarily disable check-unused-dependencies |
||
harudagondi
|
6e50b249a4 |
Update ExactSizeIterator impl to support archetypal filters (With, Without) (#5124)
# Objective - Fixes #3142 ## Solution - Done according to #3142 - Created new marker trait `ArchetypeFilter` - Implement said trait to: - `With<T>` - `Without<T>` - tuples containing only types that implement `ArchetypeFilter`, from 0 to 15 elements - `Or<T>` where T is a tuple as described previously - Changed `ExactSizeIterator` impl to include a new generic that must implement `WorldQuery` and `ArchetypeFilter` - Added new tests --- ## Changelog ### Added - `Query`s with archetypal filters can now use `.iter().len()` to get the exact size of the iterator. |
||
|
Boxy
|
407c080e59 |
Replace ReadOnlyFetch with ReadOnlyWorldQuery (#4626)
# Objective - Fix a type inference regression introduced by #3001 - Make read only bounds on world queries more user friendly ptrification required you to write `Q::Fetch: ReadOnlyFetch` as `for<'w> QueryFetch<'w, Q>: ReadOnlyFetch` which has the same type inference problem as `for<'w> QueryFetch<'w, Q>: FilterFetch<'w>` had, i.e. the following code would error: ```rust #[derive(Component)] struct Foo; fn bar(a: Query<(&Foo, Without<Foo>)>) { foo(a); } fn foo<Q: WorldQuery>(a: Query<Q, ()>) where for<'w> QueryFetch<'w, Q>: ReadOnlyFetch, { } ``` `for<..>` bounds are also rather user unfriendly.. ## Solution Remove the `ReadOnlyFetch` trait in favour of a `ReadOnlyWorldQuery` trait, and remove `WorldQueryGats::ReadOnlyFetch` in favor of `WorldQuery::ReadOnly` allowing the previous code snippet to be written as: ```rust #[derive(Component)] struct Foo; fn bar(a: Query<(&Foo, Without<Foo>)>) { foo(a); } fn foo<Q: ReadOnlyWorldQuery>(a: Query<Q, ()>) {} ``` This avoids the `for<...>` bound which makes the code simpler and also fixes the type inference issue. The reason for moving the two functions out of `FetchState` and into `WorldQuery` is to allow the world query `&mut T` to share a `State` with the `&T` world query so that it can have `type ReadOnly = &T`. Presumably it would be possible to instead have a `ReadOnlyRefMut<T>` world query and then do `type ReadOnly = ReadOnlyRefMut<T>` much like how (before this PR) we had a `ReadOnlyWriteFetch<T>`. A side benefit of the current solution in this PR is that it will likely make it easier in the future to support an API such as `Query<&mut T> -> Query<&T>`. The primary benefit IMO is just that `ReadOnlyRefMut<T>` and its associated fetch would have to reimplement all of the logic that the `&T` world query impl does but this solution avoids that :) --- ## Changelog/Migration Guide The trait `ReadOnlyFetch` has been replaced with `ReadOnlyWorldQuery` along with the `WorldQueryGats::ReadOnlyFetch` assoc type which has been replaced with `<WorldQuery::ReadOnly as WorldQueryGats>::Fetch` - Any where clauses such as `QueryFetch<Q>: ReadOnlyFetch` should be replaced with `Q: ReadOnlyWorldQuery`. - Any custom world query impls should implement `ReadOnlyWorldQuery` insead of `ReadOnlyFetch` Functions `update_component_access` and `update_archetype_component_access` have been moved from the `FetchState` trait to `WorldQuery` - Any callers should now call `Q::update_component_access(state` instead of `state.update_component_access` (and `update_archetype_component_access` respectively) - Any custom world query impls should move the functions from the `FetchState` impl to `WorldQuery` impl `WorldQuery` has been made an `unsafe trait`, `FetchState` has been made a safe `trait`. (I think this is how it should have always been, but regardless this is _definitely_ necessary now that the two functions have been moved to `WorldQuery`) - If you have a custom `FetchState` impl make it a normal `impl` instead of `unsafe impl` - If you have a custom `WorldQuery` impl make it an `unsafe impl`, if your code was sound before it is going to still be sound |
||
|
James Liu
|
f2b545049c |
Implement FusedIterator for eligible Iterator types (#4942)
# Objective Most of our `Iterator` impls satisfy the requirements of `std::iter::FusedIterator`, which has internal specialization that optimizes `Interator::fuse`. The std lib iterator combinators do have a few that rely on `fuse`, so this could optimize those use cases. I don't think we're using any of them in the engine itself, but beyond a light increase in compile time, it doesn't hurt to implement the trait. ## Solution Implement the trait for all eligible iterators in first party crates. Also add a missing `ExactSizeIterator` on an iterator that could use it. |
||
|
ira
|
92ddfe8ad4 |
Add methods for querying lists of entities. (#4879)
# Objective
Improve querying ergonomics around collections and iterators of entities.
Example how queries over Children might be done currently.
```rust
fn system(foo_query: Query<(&Foo, &Children)>, bar_query: Query<(&Bar, &Children)>) {
for (foo, children) in &foo_query {
for child in children.iter() {
if let Ok((bar, children)) = bar_query.get(*child) {
for child in children.iter() {
if let Ok((foo, children)) = foo_query.get(*child) {
// D:
}
}
}
}
}
}
```
Answers #4868
Partially addresses #4864
Fixes #1470
## Solution
Based on the great work by @deontologician in #2563
Added `iter_many` and `many_for_each_mut` to `Query`.
These take a list of entities (Anything that implements `IntoIterator<Item: Borrow<Entity>>`).
`iter_many` returns a `QueryManyIter` iterator over immutable results of a query (mutable data will be cast to an immutable form).
`many_for_each_mut` calls a closure for every result of the query, ensuring not aliased mutability.
This iterator goes over the list of entities in order and returns the result from the query for it. Skipping over any entities that don't match the query.
Also added `unsafe fn iter_many_unsafe`.
### Examples
```rust
#[derive(Component)]
struct Counter {
value: i32
}
#[derive(Component)]
struct Friends {
list: Vec<Entity>,
}
fn system(
friends_query: Query<&Friends>,
mut counter_query: Query<&mut Counter>,
) {
for friends in &friends_query {
for counter in counter_query.iter_many(&friends.list) {
println!("Friend's counter: {:?}", counter.value);
}
counter_query.many_for_each_mut(&friends.list, |mut counter| {
counter.value += 1;
println!("Friend's counter: {:?}", counter.value);
});
}
}
```
Here's how example in the Objective section can be written with this PR.
```rust
fn system(foo_query: Query<(&Foo, &Children)>, bar_query: Query<(&Bar, &Children)>) {
for (foo, children) in &foo_query {
for (bar, children) in bar_query.iter_many(children) {
for (foo, children) in foo_query.iter_many(children) {
// :D
}
}
}
}
```
## Additional changes
Implemented `IntoIterator` for `&Children` because why not.
## Todo
- Bikeshed!
Co-authored-by: deontologician <deontologician@gmail.com>
Co-authored-by: devil-ira <justthecooldude@gmail.com>
|
||
Félix Lescaudey de Maneville
|
f000c2b951 |
Clippy improvements (#4665)
# Objective Follow up to my previous MR #3718 to add new clippy warnings to bevy: - [x] [~~option_if_let_else~~](https://rust-lang.github.io/rust-clippy/master/#option_if_let_else) (reverted) - [x] [redundant_else](https://rust-lang.github.io/rust-clippy/master/#redundant_else) - [x] [match_same_arms](https://rust-lang.github.io/rust-clippy/master/#match_same_arms) - [x] [semicolon_if_nothing_returned](https://rust-lang.github.io/rust-clippy/master/#semicolon_if_nothing_returned) - [x] [explicit_iter_loop](https://rust-lang.github.io/rust-clippy/master/#explicit_iter_loop) - [x] [map_flatten](https://rust-lang.github.io/rust-clippy/master/#map_flatten) There is one commit per clippy warning, and the matching flags are added to the CI execution. To test the CI execution you may run `cargo run -p ci -- clippy` at the root. I choose the add the flags in the `ci` tool crate to avoid having them in every `lib.rs` but I guess it could become an issue with suprise warnings coming up after a commit/push Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
||
Hennadii Chernyshchyk
|
c02beabe22 |
Add QueryState::get_single_unchecked_manual and its family (#4841)
# Objective - Rebase of #3159. - Fixes https://github.com/bevyengine/bevy/issues/3156 - add #[inline] to single related functions so that they matches with other function defs ## Solution * added functions to QueryState * get_single_unchecked_manual * get_single_unchecked * get_single * get_single_mut * single * single_mut * make Query::get_single use QueryState::get_single_unchecked_manual * added #[inline] --- ## Changelog ### Added Functions `QueryState::single`, `QueryState::get_single`, `QueryState::single_mut`, `QueryState::get_single_mut`, `QueryState::get_single_unchecked`, `QueryState::get_single_unchecked_manual`. ### Changed `QuerySingleError` is now in the `state` module. ## Migration Guide Change `query::QuerySingleError` to `state::QuerySingleError` Co-authored-by: 2ne1ugly <chattermin@gmail.com> Co-authored-by: 2ne1ugly <47616772+2ne1ugly@users.noreply.github.com> |
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|
James Liu
|
2c93b5cf73 |
Reduce code duplication by using QueryIterationCursor in QueryIter (#4733)
# Objective We have duplicated code between `QueryIter` and `QueryIterationCursor`. Reuse that code. ## Solution - Reuse `QueryIterationCursor` inside `QueryIter`. - Slim down `QueryIter` by removing the `&'w World`. It was only being used by the `size_hint` and `ExactSizeIterator` impls, which can use the QueryState and &Archetypes in the type already. - Benchmark to make sure there is no significant regression. Relevant benchmark results seem to show that there is no tangible difference between the two. Everything seems to be either identical or within a workable margin of error here. ``` group embed-cursor main ----- ------------ ---- fragmented_iter/base 1.00 387.4±19.70ns ? ?/sec 1.07 413.1±27.95ns ? ?/sec many_maps_iter 1.00 27.3±0.22ms ? ?/sec 1.00 27.4±0.10ms ? ?/sec simple_iter/base 1.00 13.8±0.07µs ? ?/sec 1.00 13.7±0.17µs ? ?/sec simple_iter/sparse 1.00 61.9±0.37µs ? ?/sec 1.00 62.2±0.64µs ? ?/sec simple_iter/system 1.00 13.7±0.34µs ? ?/sec 1.00 13.7±0.10µs ? ?/sec sparse_fragmented_iter/base 1.00 11.0±0.54ns ? ?/sec 1.03 11.3±0.48ns ? ?/sec world_query_iter/50000_entities_sparse 1.08 105.0±2.68µs ? ?/sec 1.00 97.5±2.18µs ? ?/sec world_query_iter/50000_entities_table 1.00 27.3±0.13µs ? ?/sec 1.00 27.3±0.37µs ? ?/sec ``` |
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|
Boxy
|
96b4956126 | Fix CI (#4675) | ||
TheRawMeatball
|
73c78c3667 |
Use lifetimed, type erased pointers in bevy_ecs (#3001)
# Objective
`bevy_ecs` has large amounts of unsafe code which is hard to get right and makes it difficult to audit for soundness.
## Solution
Introduce lifetimed, type-erased pointers: `Ptr<'a>` `PtrMut<'a>` `OwningPtr<'a>'` and `ThinSlicePtr<'a, T>` which are newtypes around a raw pointer with a lifetime and conceptually representing strong invariants about the pointee and validity of the pointer.
The process of converting bevy_ecs to use these has already caught multiple cases of unsound behavior.
## Changelog
TL;DR for release notes: `bevy_ecs` now uses lifetimed, type-erased pointers internally, significantly improving safety and legibility without sacrificing performance. This should have approximately no end user impact, unless you were meddling with the (unfortunately public) internals of `bevy_ecs`.
- `Fetch`, `FilterFetch` and `ReadOnlyFetch` trait no longer have a `'state` lifetime
- this was unneeded
- `ReadOnly/Fetch` associated types on `WorldQuery` are now on a new `WorldQueryGats<'world>` trait
- was required to work around lack of Generic Associated Types (we wish to express `type Fetch<'a>: Fetch<'a>`)
- `derive(WorldQuery)` no longer requires `'w` lifetime on struct
- this was unneeded, and improves the end user experience
- `EntityMut::get_unchecked_mut` returns `&'_ mut T` not `&'w mut T`
- allows easier use of unsafe API with less footguns, and can be worked around via lifetime transmutery as a user
- `Bundle::from_components` now takes a `ctx` parameter to pass to the `FnMut` closure
- required because closure return types can't borrow from captures
- `Fetch::init` takes `&'world World`, `Fetch::set_archetype` takes `&'world Archetype` and `&'world Tables`, `Fetch::set_table` takes `&'world Table`
- allows types implementing `Fetch` to store borrows into world
- `WorldQuery` trait now has a `shrink` fn to shorten the lifetime in `Fetch::<'a>::Item`
- this works around lack of subtyping of assoc types, rust doesnt allow you to turn `<T as Fetch<'static>>::Item'` into `<T as Fetch<'a>>::Item'`
- `QueryCombinationsIter` requires this
- Most types implementing `Fetch` now have a lifetime `'w`
- allows the fetches to store borrows of world data instead of using raw pointers
## Migration guide
- `EntityMut::get_unchecked_mut` returns a more restricted lifetime, there is no general way to migrate this as it depends on your code
- `Bundle::from_components` implementations must pass the `ctx` arg to `func`
- `Bundle::from_components` callers have to use a fn arg instead of closure captures for borrowing from world
- Remove lifetime args on `derive(WorldQuery)` structs as it is nonsensical
- `<Q as WorldQuery>::ReadOnly/Fetch` should be changed to either `RO/QueryFetch<'world>` or `<Q as WorldQueryGats<'world>>::ReadOnly/Fetch`
- `<F as Fetch<'w, 's>>` should be changed to `<F as Fetch<'w>>`
- Change the fn sigs of `Fetch::init/set_archetype/set_table` to match respective trait fn sigs
- Implement the required `fn shrink` on any `WorldQuery` implementations
- Move assoc types `Fetch` and `ReadOnlyFetch` on `WorldQuery` impls to `WorldQueryGats` impls
- Pass an appropriate `'world` lifetime to whatever fetch struct you are for some reason using
### Type inference regression
in some cases rustc may give spurrious errors when attempting to infer the `F` parameter on a query/querystate this can be fixed by manually specifying the type, i.e. `QueryState:🆕:<_, ()>(world)`. The error is rather confusing:
```rust=
error[E0271]: type mismatch resolving `<() as Fetch<'_>>::Item == bool`
--> crates/bevy_pbr/src/render/light.rs:1413:30
|
1413 | main_view_query: QueryState::new(world),
| ^^^^^^^^^^^^^^^ expected `bool`, found `()`
|
= note: required because of the requirements on the impl of `for<'x> FilterFetch<'x>` for `<() as WorldQueryGats<'x>>::Fetch`
note: required by a bound in `bevy_ecs::query::QueryState::<Q, F>::new`
--> crates/bevy_ecs/src/query/state.rs:49:32
|
49 | for<'x> QueryFetch<'x, F>: FilterFetch<'x>,
| ^^^^^^^^^^^^^^^ required by this bound in `bevy_ecs::query::QueryState::<Q, F>::new`
```
---
Made with help from @BoxyUwU and @alice-i-cecile
Co-authored-by: Boxy <supbscripter@gmail.com>
|
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Nicola Papale
|
71a246ce9e |
Improve QueryIter size_hint hints (#4244)
## Objective This fixes #1686. `size_hint` can be useful even if a little niche. For example, `collect::<Vec<_>>()` uses the `size_hint` of Iterator it collects from to pre-allocate a memory slice large enough to not require re-allocating when pushing all the elements of the iterator. ## Solution To this effect I made the following changes: * Add a `IS_ARCHETYPAL` associated constant to the `Fetch` trait, this constant tells us when it is safe to assume that the `Fetch` relies exclusively on archetypes to filter queried entities * Add `IS_ARCHETYPAL` to all the implementations of `Fetch` * Use that constant in `QueryIter::size_hint` to provide a more useful ## Migration guide The new associated constant is an API breaking change. For the user, if they implemented a custom `Fetch`, it means they have to add this associated constant to their implementation. Either `true` if it doesn't limit the number of entities returned in a query beyond that of archetypes, or `false` for when it does. |
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KDecay
|
506642744c |
docs: Fix private doc links and enable CI test (#3743)
# Objective Fixes #3566 ## Solution - [x] Fix broken links in private docs. - [x] Add the `--document-private-items` flag to the CI. ## Note The following was said by @killercup in #3566: > I don't have time to confirm this but I assume that linking to private items throws an error/warning when just running cargo doc, and --document-private-item might actually hide that warning. So to test this, you'd have to run it twice. I tested this and this is thankfully not the case. If you are linking to a private item you will get a warning no matter if you run `cargo doc` or `cargo doc --document-private-items`. ### Example I added `struct Test;` to `bevy_core/src/name.rs` and linked to it inside of a doc comment using ``[`Test`]``. After that I ran `cargo doc -p bevy_core --document-private-items` using `RUSTDOCFLAGS="-D warnings"` and got the following output (note the last sentence): ```rust error: public documentation for `Name` links to private item `Test` --> crates/bevy_core/src/name.rs:11:82 | 11 | /// Component used to identify an entity. Stores a hash for faster comparisons [`Test`] | ^^^^ this item is private | = note: `-D rustdoc::private-intra-doc-links` implied by `-D warnings` = note: this link resolves only because you passed `--document-private-items`, but will break without ``` |
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Michael Dorst
|
507441d96f |
Fix doc_markdown lints in bevy_ecs (#3473)
#3457 adds the `doc_markdown` clippy lint, which checks doc comments to make sure code identifiers are escaped with backticks. This causes a lot of lint errors, so this is one of a number of PR's that will fix those lint errors one crate at a time. This PR fixes lints in the `bevy_ecs` crate. |
||
Joshua Chapman
|
274ace790b |
Implement iter() for mutable Queries (#2305)
A sample implementation of how to have `iter()` work on mutable queries without breaking aliasing rules. # Objective - Fixes #753 ## Solution - Added a ReadOnlyFetch to WorldQuery that is the `&T` version of `&mut T` that is used to specify the return type for read only operations like `iter()`. - ~~As the comment suggests specifying the bound doesn't work due to restrictions on defining recursive implementations (like `Or`). However bounds on the functions are fine~~ Never mind I misread how `Or` was constructed, bounds now exist. - Note that the only mutable one has a new `Fetch` for readonly as the `State` has to be the same for any of this to work Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
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Paweł Grabarz
|
07ed1d053e |
Implement and require #[derive(Component)] on all component structs (#2254)
This implements the most minimal variant of #1843 - a derive for marker trait. This is a prerequisite to more complicated features like statically defined storage type or opt-out component reflection. In order to make component struct's purpose explicit and avoid misuse, it must be annotated with `#[derive(Component)]` (manual impl is discouraged for compatibility). Right now this is just a marker trait, but in the future it might be expanded. Making this change early allows us to make further changes later without breaking backward compatibility for derive macro users. This already prevents a lot of issues, like using bundles in `insert` calls. Primitive types are no longer valid components as well. This can be easily worked around by adding newtype wrappers and deriving `Component` for them. One funny example of prevented bad code (from our own tests) is when an newtype struct or enum variant is used. Previously, it was possible to write `insert(Newtype)` instead of `insert(Newtype(value))`. That code compiled, because function pointers (in this case newtype struct constructor) implement `Send + Sync + 'static`, so we allowed them to be used as components. This is no longer the case and such invalid code will trigger a compile error. Co-authored-by: = <=> Co-authored-by: TheRawMeatball <therawmeatball@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
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Boxy
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155068a090 |
Add 's (state) lifetime to Fetch (#2515)
Allows iterators to return things that borrow data from `QueryState`, needed this in my relations PR figure might be worth landing separately maybe |
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Boxy
|
5ffff03b33 |
Fix some nightly clippy lints (#2522)
on nightly these two clippy lints fail: - [needless_borrow](https://rust-lang.github.io/rust-clippy/master/#needless_borrow) - [unused_unit](https://rust-lang.github.io/rust-clippy/master/#unused_unit) |
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Nathan Ward
|
19db1e402b |
[ecs] implement is_empty for queries (#2271)
## Problem - The `Query` struct does not provide an easy way to check if it is empty. - Specifically, users have to use `.iter().peekable()` or `.iter().next().is_none()` which is not very ergonomic. - Fixes: #2270 ## Solution - Implement an `is_empty` function for queries to more easily check if the query is empty. |
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Paweł Grabarz
|
a81fb7aa7e |
Add a method iter_combinations on query to iterate over combinations of query results (#1763)
Related to [discussion on discord](https://discord.com/channels/691052431525675048/742569353878437978/824731187724681289) With const generics, it is now possible to write generic iterator over multiple entities at once. This enables patterns of query iterations like ```rust for [e1, e2, e3] in query.iter_combinations() { // do something with relation of all three entities } ``` The compiler is able to infer the correct iterator for given size of array, so either of those work ```rust for [e1, e2] in query.iter_combinations() { ... } for [e1, e2, e3] in query.iter_combinations() { ... } ``` This feature can be very useful for systems like collision detection. When you ask for permutations of size K of N entities: - if K == N, you get one result of all entities - if K < N, you get all possible subsets of N with size K, without repetition - if K > N, the result set is empty (no permutation of size K exist) Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
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Lukas Wirth
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7c274e5a44 |
Improve bevy_ecs query docs (#1935)
Mainly documents Query, WorldQuery and the various Query Filter types as well as some smaller doc changes. |
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MinerSebas
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c78b76bba8 |
Provide better size_hint for QueryIter (#1697)
This PR overrides the default size_hint for QueryIter. This is mainly done to provide inline documentation of Issue #1686. |
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Alice Cecile
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6121e5f933 |
Reliable change detection (#1471)
# Problem Definition The current change tracking (via flags for both components and resources) fails to detect changes made by systems that are scheduled to run earlier in the frame than they are. This issue is discussed at length in [#68](https://github.com/bevyengine/bevy/issues/68) and [#54](https://github.com/bevyengine/bevy/issues/54). This is very much a draft PR, and contributions are welcome and needed. # Criteria 1. Each change is detected at least once, no matter the ordering. 2. Each change is detected at most once, no matter the ordering. 3. Changes should be detected the same frame that they are made. 4. Competitive ergonomics. Ideally does not require opting-in. 5. Low CPU overhead of computation. 6. Memory efficient. This must not increase over time, except where the number of entities / resources does. 7. Changes should not be lost for systems that don't run. 8. A frame needs to act as a pure function. Given the same set of entities / components it needs to produce the same end state without side-effects. **Exact** change-tracking proposals satisfy criteria 1 and 2. **Conservative** change-tracking proposals satisfy criteria 1 but not 2. **Flaky** change tracking proposals satisfy criteria 2 but not 1. # Code Base Navigation There are three types of flags: - `Added`: A piece of data was added to an entity / `Resources`. - `Mutated`: A piece of data was able to be modified, because its `DerefMut` was accessed - `Changed`: The bitwise OR of `Added` and `Changed` The special behavior of `ChangedRes`, with respect to the scheduler is being removed in [#1313](https://github.com/bevyengine/bevy/pull/1313) and does not need to be reproduced. `ChangedRes` and friends can be found in "bevy_ecs/core/resources/resource_query.rs". The `Flags` trait for Components can be found in "bevy_ecs/core/query.rs". `ComponentFlags` are stored in "bevy_ecs/core/archetypes.rs", defined on line 446. # Proposals **Proposal 5 was selected for implementation.** ## Proposal 0: No Change Detection The baseline, where computations are performed on everything regardless of whether it changed. **Type:** Conservative **Pros:** - already implemented - will never miss events - no overhead **Cons:** - tons of repeated work - doesn't allow users to avoid repeating work (or monitoring for other changes) ## Proposal 1: Earlier-This-Tick Change Detection The current approach as of Bevy 0.4. Flags are set, and then flushed at the end of each frame. **Type:** Flaky **Pros:** - already implemented - simple to understand - low memory overhead (2 bits per component) - low time overhead (clear every flag once per frame) **Cons:** - misses systems based on ordering - systems that don't run every frame miss changes - duplicates detection when looping - can lead to unresolvable circular dependencies ## Proposal 2: Two-Tick Change Detection Flags persist for two frames, using a double-buffer system identical to that used in events. A change is observed if it is found in either the current frame's list of changes or the previous frame's. **Type:** Conservative **Pros:** - easy to understand - easy to implement - low memory overhead (4 bits per component) - low time overhead (bit mask and shift every flag once per frame) **Cons:** - can result in a great deal of duplicated work - systems that don't run every frame miss changes - duplicates detection when looping ## Proposal 3: Last-Tick Change Detection Flags persist for two frames, using a double-buffer system identical to that used in events. A change is observed if it is found in the previous frame's list of changes. **Type:** Exact **Pros:** - exact - easy to understand - easy to implement - low memory overhead (4 bits per component) - low time overhead (bit mask and shift every flag once per frame) **Cons:** - change detection is always delayed, possibly causing painful chained delays - systems that don't run every frame miss changes - duplicates detection when looping ## Proposal 4: Flag-Doubling Change Detection Combine Proposal 2 and Proposal 3. Differentiate between `JustChanged` (current behavior) and `Changed` (Proposal 3). Pack this data into the flags according to [this implementation proposal](https://github.com/bevyengine/bevy/issues/68#issuecomment-769174804). **Type:** Flaky + Exact **Pros:** - allows users to acc - easy to implement - low memory overhead (4 bits per component) - low time overhead (bit mask and shift every flag once per frame) **Cons:** - users must specify the type of change detection required - still quite fragile to system ordering effects when using the flaky `JustChanged` form - cannot get immediate + exact results - systems that don't run every frame miss changes - duplicates detection when looping ## [SELECTED] Proposal 5: Generation-Counter Change Detection A global counter is increased after each system is run. Each component saves the time of last mutation, and each system saves the time of last execution. Mutation is detected when the component's counter is greater than the system's counter. Discussed [here](https://github.com/bevyengine/bevy/issues/68#issuecomment-769174804). How to handle addition detection is unsolved; the current proposal is to use the highest bit of the counter as in proposal 1. **Type:** Exact (for mutations), flaky (for additions) **Pros:** - low time overhead (set component counter on access, set system counter after execution) - robust to systems that don't run every frame - robust to systems that loop **Cons:** - moderately complex implementation - must be modified as systems are inserted dynamically - medium memory overhead (4 bytes per component + system) - unsolved addition detection ## Proposal 6: System-Data Change Detection For each system, track which system's changes it has seen. This approach is only worth fully designing and implementing if Proposal 5 fails in some way. **Type:** Exact **Pros:** - exact - conceptually simple **Cons:** - requires storing data on each system - implementation is complex - must be modified as systems are inserted dynamically ## Proposal 7: Total-Order Change Detection Discussed [here](https://github.com/bevyengine/bevy/issues/68#issuecomment-754326523). This proposal is somewhat complicated by the new scheduler, but I believe it should still be conceptually feasible. This approach is only worth fully designing and implementing if Proposal 5 fails in some way. **Type:** Exact **Pros:** - exact - efficient data storage relative to other exact proposals **Cons:** - requires access to the scheduler - complex implementation and difficulty grokking - must be modified as systems are inserted dynamically # Tests - We will need to verify properties 1, 2, 3, 7 and 8. Priority: 1 > 2 = 3 > 8 > 7 - Ideally we can use identical user-facing syntax for all proposals, allowing us to re-use the same syntax for each. - When writing tests, we need to carefully specify order using explicit dependencies. - These tests will need to be duplicated for both components and resources. - We need to be sure to handle cases where ambiguous system orders exist. `changing_system` is always the system that makes the changes, and `detecting_system` always detects the changes. The component / resource changed will be simple boolean wrapper structs. ## Basic Added / Mutated / Changed 2 x 3 design: - Resources vs. Components - Added vs. Changed vs. Mutated - `changing_system` runs before `detecting_system` - verify at the end of tick 2 ## At Least Once 2 x 3 design: - Resources vs. Components - Added vs. Changed vs. Mutated - `changing_system` runs after `detecting_system` - verify at the end of tick 2 ## At Most Once 2 x 3 design: - Resources vs. Components - Added vs. Changed vs. Mutated - `changing_system` runs once before `detecting_system` - increment a counter based on the number of changes detected - verify at the end of tick 2 ## Fast Detection 2 x 3 design: - Resources vs. Components - Added vs. Changed vs. Mutated - `changing_system` runs before `detecting_system` - verify at the end of tick 1 ## Ambiguous System Ordering Robustness 2 x 3 x 2 design: - Resources vs. Components - Added vs. Changed vs. Mutated - `changing_system` runs [before/after] `detecting_system` in tick 1 - `changing_system` runs [after/before] `detecting_system` in tick 2 ## System Pausing 2 x 3 design: - Resources vs. Components - Added vs. Changed vs. Mutated - `changing_system` runs in tick 1, then is disabled by run criteria - `detecting_system` is disabled by run criteria until it is run once during tick 3 - verify at the end of tick 3 ## Addition Causes Mutation 2 design: - Resources vs. Components - `adding_system_1` adds a component / resource - `adding system_2` adds the same component / resource - verify the `Mutated` flag at the end of the tick - verify the `Added` flag at the end of the tick First check tests for: https://github.com/bevyengine/bevy/issues/333 Second check tests for: https://github.com/bevyengine/bevy/issues/1443 ## Changes Made By Commands - `adding_system` runs in Update in tick 1, and sends a command to add a component - `detecting_system` runs in Update in tick 1 and 2, after `adding_system` - We can't detect the changes in tick 1, since they haven't been processed yet - If we were to track these changes as being emitted by `adding_system`, we can't detect the changes in tick 2 either, since `detecting_system` has already run once after `adding_system` :( # Benchmarks See: [general advice](https://github.com/bevyengine/bevy/blob/master/docs/profiling.md), [Criterion crate](https://github.com/bheisler/criterion.rs) There are several critical parameters to vary: 1. entity count (1 to 10^9) 2. fraction of entities that are changed (0% to 100%) 3. cost to perform work on changed entities, i.e. workload (1 ns to 1s) 1 and 2 should be varied between benchmark runs. 3 can be added on computationally. We want to measure: - memory cost - run time We should collect these measurements across several frames (100?) to reduce bootup effects and accurately measure the mean, variance and drift. Entity-component change detection is much more important to benchmark than resource change detection, due to the orders of magnitude higher number of pieces of data. No change detection at all should be included in benchmarks as a second control for cases where missing changes is unacceptable. ## Graphs 1. y: performance, x: log_10(entity count), color: proposal, facet: performance metric. Set cost to perform work to 0. 2. y: run time, x: cost to perform work, color: proposal, facet: fraction changed. Set number of entities to 10^6 3. y: memory, x: frames, color: proposal # Conclusions 1. Is the theoretical categorization of the proposals correct according to our tests? 2. How does the performance of the proposals compare without any load? 3. How does the performance of the proposals compare with realistic loads? 4. At what workload does more exact change tracking become worth the (presumably) higher overhead? 5. When does adding change-detection to save on work become worthwhile? 6. Is there enough divergence in performance between the best solutions in each class to ship more than one change-tracking solution? # Implementation Plan 1. Write a test suite. 2. Verify that tests fail for existing approach. 3. Write a benchmark suite. 4. Get performance numbers for existing approach. 5. Implement, test and benchmark various solutions using a Git branch per proposal. 6. Create a draft PR with all solutions and present results to team. 7. Select a solution and replace existing change detection. Co-authored-by: Brice DAVIER <bricedavier@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
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Carter Anderson
|
68606934e3 |
remove unsafe get_unchecked (and mut variant) from Tables and Archetypes (#1614)
Removes `get_unchecked` and `get_unchecked_mut` from `Tables` and `Archetypes` collections in favor of safe Index implementations. This fixes a safety error in `Archetypes::get_id_or_insert()` (which previously relied on TableId being valid to be safe ... the alternative was to make that method unsafe too). It also cuts down on a lot of unsafe and makes the code easier to look at. I'm not sure what changed since the last benchmark, but these numbers are more favorable than my last tests of similar changes. I didn't include the Components collection as those severely killed perf last time I tried. But this does inspire me to try again (just in a separate pr)! Note that the `simple_insert/bevy_unbatched` benchmark fluctuates a lot on both branches (this was also true for prior versions of bevy). It seems like the allocator has more variance for many small allocations. And `sparse_frag_iter/bevy` operates on such a small scale that 10% fluctuations are common. Some benches do take a small hit here, but I personally think its worth it. This also fixes a safety error in Query::for_each_mut, which needed to mutably borrow Query (aaahh!).   |
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Carter Anderson
|
3a2a68852c |
Bevy ECS V2 (#1525)
# Bevy ECS V2
This is a rewrite of Bevy ECS (basically everything but the new executor/schedule, which are already awesome). The overall goal was to improve the performance and versatility of Bevy ECS. Here is a quick bulleted list of changes before we dive into the details:
* Complete World rewrite
* Multiple component storage types:
* Tables: fast cache friendly iteration, slower add/removes (previously called Archetypes)
* Sparse Sets: fast add/remove, slower iteration
* Stateful Queries (caches query results for faster iteration. fragmented iteration is _fast_ now)
* Stateful System Params (caches expensive operations. inspired by @DJMcNab's work in #1364)
* Configurable System Params (users can set configuration when they construct their systems. once again inspired by @DJMcNab's work)
* Archetypes are now "just metadata", component storage is separate
* Archetype Graph (for faster archetype changes)
* Component Metadata
* Configure component storage type
* Retrieve information about component size/type/name/layout/send-ness/etc
* Components are uniquely identified by a densely packed ComponentId
* TypeIds are now totally optional (which should make implementing scripting easier)
* Super fast "for_each" query iterators
* Merged Resources into World. Resources are now just a special type of component
* EntityRef/EntityMut builder apis (more efficient and more ergonomic)
* Fast bitset-backed `Access<T>` replaces old hashmap-based approach everywhere
* Query conflicts are determined by component access instead of archetype component access (to avoid random failures at runtime)
* With/Without are still taken into account for conflicts, so this should still be comfy to use
* Much simpler `IntoSystem` impl
* Significantly reduced the amount of hashing throughout the ecs in favor of Sparse Sets (indexed by densely packed ArchetypeId, ComponentId, BundleId, and TableId)
* Safety Improvements
* Entity reservation uses a normal world reference instead of unsafe transmute
* QuerySets no longer transmute lifetimes
* Made traits "unsafe" where relevant
* More thorough safety docs
* WorldCell
* Exposes safe mutable access to multiple resources at a time in a World
* Replaced "catch all" `System::update_archetypes(world: &World)` with `System::new_archetype(archetype: &Archetype)`
* Simpler Bundle implementation
* Replaced slow "remove_bundle_one_by_one" used as fallback for Commands::remove_bundle with fast "remove_bundle_intersection"
* Removed `Mut<T>` query impl. it is better to only support one way: `&mut T`
* Removed with() from `Flags<T>` in favor of `Option<Flags<T>>`, which allows querying for flags to be "filtered" by default
* Components now have is_send property (currently only resources support non-send)
* More granular module organization
* New `RemovedComponents<T>` SystemParam that replaces `query.removed::<T>()`
* `world.resource_scope()` for mutable access to resources and world at the same time
* WorldQuery and QueryFilter traits unified. FilterFetch trait added to enable "short circuit" filtering. Auto impled for cases that don't need it
* Significantly slimmed down SystemState in favor of individual SystemParam state
* System Commands changed from `commands: &mut Commands` back to `mut commands: Commands` (to allow Commands to have a World reference)
Fixes #1320
## `World` Rewrite
This is a from-scratch rewrite of `World` that fills the niche that `hecs` used to. Yes, this means Bevy ECS is no longer a "fork" of hecs. We're going out our own!
(the only shared code between the projects is the entity id allocator, which is already basically ideal)
A huge shout out to @SanderMertens (author of [flecs](https://github.com/SanderMertens/flecs)) for sharing some great ideas with me (specifically hybrid ecs storage and archetype graphs). He also helped advise on a number of implementation details.
## Component Storage (The Problem)
Two ECS storage paradigms have gained a lot of traction over the years:
* **Archetypal ECS**:
* Stores components in "tables" with static schemas. Each "column" stores components of a given type. Each "row" is an entity.
* Each "archetype" has its own table. Adding/removing an entity's component changes the archetype.
* Enables super-fast Query iteration due to its cache-friendly data layout
* Comes at the cost of more expensive add/remove operations for an Entity's components, because all components need to be copied to the new archetype's "table"
* **Sparse Set ECS**:
* Stores components of the same type in densely packed arrays, which are sparsely indexed by densely packed unsigned integers (Entity ids)
* Query iteration is slower than Archetypal ECS because each entity's component could be at any position in the sparse set. This "random access" pattern isn't cache friendly. Additionally, there is an extra layer of indirection because you must first map the entity id to an index in the component array.
* Adding/removing components is a cheap, constant time operation
Bevy ECS V1, hecs, legion, flec, and Unity DOTS are all "archetypal ecs-es". I personally think "archetypal" storage is a good default for game engines. An entity's archetype doesn't need to change frequently in general, and it creates "fast by default" query iteration (which is a much more common operation). It is also "self optimizing". Users don't need to think about optimizing component layouts for iteration performance. It "just works" without any extra boilerplate.
Shipyard and EnTT are "sparse set ecs-es". They employ "packing" as a way to work around the "suboptimal by default" iteration performance for specific sets of components. This helps, but I didn't think this was a good choice for a general purpose engine like Bevy because:
1. "packs" conflict with each other. If bevy decides to internally pack the Transform and GlobalTransform components, users are then blocked if they want to pack some custom component with Transform.
2. users need to take manual action to optimize
Developers selecting an ECS framework are stuck with a hard choice. Select an "archetypal" framework with "fast iteration everywhere" but without the ability to cheaply add/remove components, or select a "sparse set" framework to cheaply add/remove components but with slower iteration performance.
## Hybrid Component Storage (The Solution)
In Bevy ECS V2, we get to have our cake and eat it too. It now has _both_ of the component storage types above (and more can be added later if needed):
* **Tables** (aka "archetypal" storage)
* The default storage. If you don't configure anything, this is what you get
* Fast iteration by default
* Slower add/remove operations
* **Sparse Sets**
* Opt-in
* Slower iteration
* Faster add/remove operations
These storage types complement each other perfectly. By default Query iteration is fast. If developers know that they want to add/remove a component at high frequencies, they can set the storage to "sparse set":
```rust
world.register_component(
ComponentDescriptor:🆕:<MyComponent>(StorageType::SparseSet)
).unwrap();
```
## Archetypes
Archetypes are now "just metadata" ... they no longer store components directly. They do store:
* The `ComponentId`s of each of the Archetype's components (and that component's storage type)
* Archetypes are uniquely defined by their component layouts
* For example: entities with "table" components `[A, B, C]` _and_ "sparse set" components `[D, E]` will always be in the same archetype.
* The `TableId` associated with the archetype
* For now each archetype has exactly one table (which can have no components),
* There is a 1->Many relationship from Tables->Archetypes. A given table could have any number of archetype components stored in it:
* Ex: an entity with "table storage" components `[A, B, C]` and "sparse set" components `[D, E]` will share the same `[A, B, C]` table as an entity with `[A, B, C]` table component and `[F]` sparse set components.
* This 1->Many relationship is how we preserve fast "cache friendly" iteration performance when possible (more on this later)
* A list of entities that are in the archetype and the row id of the table they are in
* ArchetypeComponentIds
* unique densely packed identifiers for (ArchetypeId, ComponentId) pairs
* used by the schedule executor for cheap system access control
* "Archetype Graph Edges" (see the next section)
## The "Archetype Graph"
Archetype changes in Bevy (and a number of other archetypal ecs-es) have historically been expensive to compute. First, you need to allocate a new vector of the entity's current component ids, add or remove components based on the operation performed, sort it (to ensure it is order-independent), then hash it to find the archetype (if it exists). And thats all before we get to the _already_ expensive full copy of all components to the new table storage.
The solution is to build a "graph" of archetypes to cache these results. @SanderMertens first exposed me to the idea (and he got it from @gjroelofs, who came up with it). They propose adding directed edges between archetypes for add/remove component operations. If `ComponentId`s are densely packed, you can use sparse sets to cheaply jump between archetypes.
Bevy takes this one step further by using add/remove `Bundle` edges instead of `Component` edges. Bevy encourages the use of `Bundles` to group add/remove operations. This is largely for "clearer game logic" reasons, but it also helps cut down on the number of archetype changes required. `Bundles` now also have densely-packed `BundleId`s. This allows us to use a _single_ edge for each bundle operation (rather than needing to traverse N edges ... one for each component). Single component operations are also bundles, so this is strictly an improvement over a "component only" graph.
As a result, an operation that used to be _heavy_ (both for allocations and compute) is now two dirt-cheap array lookups and zero allocations.
## Stateful Queries
World queries are now stateful. This allows us to:
1. Cache archetype (and table) matches
* This resolves another issue with (naive) archetypal ECS: query performance getting worse as the number of archetypes goes up (and fragmentation occurs).
2. Cache Fetch and Filter state
* The expensive parts of fetch/filter operations (such as hashing the TypeId to find the ComponentId) now only happen once when the Query is first constructed
3. Incrementally build up state
* When new archetypes are added, we only process the new archetypes (no need to rebuild state for old archetypes)
As a result, the direct `World` query api now looks like this:
```rust
let mut query = world.query::<(&A, &mut B)>();
for (a, mut b) in query.iter_mut(&mut world) {
}
```
Requiring `World` to generate stateful queries (rather than letting the `QueryState` type be constructed separately) allows us to ensure that _all_ queries are properly initialized (and the relevant world state, such as ComponentIds). This enables QueryState to remove branches from its operations that check for initialization status (and also enables query.iter() to take an immutable world reference because it doesn't need to initialize anything in world).
However in systems, this is a non-breaking change. State management is done internally by the relevant SystemParam.
## Stateful SystemParams
Like Queries, `SystemParams` now also cache state. For example, `Query` system params store the "stateful query" state mentioned above. Commands store their internal `CommandQueue`. This means you can now safely use as many separate `Commands` parameters in your system as you want. `Local<T>` system params store their `T` value in their state (instead of in Resources).
SystemParam state also enabled a significant slim-down of SystemState. It is much nicer to look at now.
Per-SystemParam state naturally insulates us from an "aliased mut" class of errors we have hit in the past (ex: using multiple `Commands` system params).
(credit goes to @DJMcNab for the initial idea and draft pr here #1364)
## Configurable SystemParams
@DJMcNab also had the great idea to make SystemParams configurable. This allows users to provide some initial configuration / values for system parameters (when possible). Most SystemParams have no config (the config type is `()`), but the `Local<T>` param now supports user-provided parameters:
```rust
fn foo(value: Local<usize>) {
}
app.add_system(foo.system().config(|c| c.0 = Some(10)));
```
## Uber Fast "for_each" Query Iterators
Developers now have the choice to use a fast "for_each" iterator, which yields ~1.5-3x iteration speed improvements for "fragmented iteration", and minor ~1.2x iteration speed improvements for unfragmented iteration.
```rust
fn system(query: Query<(&A, &mut B)>) {
// you now have the option to do this for a speed boost
query.for_each_mut(|(a, mut b)| {
});
// however normal iterators are still available
for (a, mut b) in query.iter_mut() {
}
}
```
I think in most cases we should continue to encourage "normal" iterators as they are more flexible and more "rust idiomatic". But when that extra "oomf" is needed, it makes sense to use `for_each`.
We should also consider using `for_each` for internal bevy systems to give our users a nice speed boost (but that should be a separate pr).
## Component Metadata
`World` now has a `Components` collection, which is accessible via `world.components()`. This stores mappings from `ComponentId` to `ComponentInfo`, as well as `TypeId` to `ComponentId` mappings (where relevant). `ComponentInfo` stores information about the component, such as ComponentId, TypeId, memory layout, send-ness (currently limited to resources), and storage type.
## Significantly Cheaper `Access<T>`
We used to use `TypeAccess<TypeId>` to manage read/write component/archetype-component access. This was expensive because TypeIds must be hashed and compared individually. The parallel executor got around this by "condensing" type ids into bitset-backed access types. This worked, but it had to be re-generated from the `TypeAccess<TypeId>`sources every time archetypes changed.
This pr removes TypeAccess in favor of faster bitset access everywhere. We can do this thanks to the move to densely packed `ComponentId`s and `ArchetypeComponentId`s.
## Merged Resources into World
Resources had a lot of redundant functionality with Components. They stored typed data, they had access control, they had unique ids, they were queryable via SystemParams, etc. In fact the _only_ major difference between them was that they were unique (and didn't correlate to an entity).
Separate resources also had the downside of requiring a separate set of access controls, which meant the parallel executor needed to compare more bitsets per system and manage more state.
I initially got the "separate resources" idea from `legion`. I think that design was motivated by the fact that it made the direct world query/resource lifetime interactions more manageable. It certainly made our lives easier when using Resources alongside hecs/bevy_ecs. However we already have a construct for safely and ergonomically managing in-world lifetimes: systems (which use `Access<T>` internally).
This pr merges Resources into World:
```rust
world.insert_resource(1);
world.insert_resource(2.0);
let a = world.get_resource::<i32>().unwrap();
let mut b = world.get_resource_mut::<f64>().unwrap();
*b = 3.0;
```
Resources are now just a special kind of component. They have their own ComponentIds (and their own resource TypeId->ComponentId scope, so they don't conflict wit components of the same type). They are stored in a special "resource archetype", which stores components inside the archetype using a new `unique_components` sparse set (note that this sparse set could later be used to implement Tags). This allows us to keep the code size small by reusing existing datastructures (namely Column, Archetype, ComponentFlags, and ComponentInfo). This allows us the executor to use a single `Access<ArchetypeComponentId>` per system. It should also make scripting language integration easier.
_But_ this merge did create problems for people directly interacting with `World`. What if you need mutable access to multiple resources at the same time? `world.get_resource_mut()` borrows World mutably!
## WorldCell
WorldCell applies the `Access<ArchetypeComponentId>` concept to direct world access:
```rust
let world_cell = world.cell();
let a = world_cell.get_resource_mut::<i32>().unwrap();
let b = world_cell.get_resource_mut::<f64>().unwrap();
```
This adds cheap runtime checks (a sparse set lookup of `ArchetypeComponentId` and a counter) to ensure that world accesses do not conflict with each other. Each operation returns a `WorldBorrow<'w, T>` or `WorldBorrowMut<'w, T>` wrapper type, which will release the relevant ArchetypeComponentId resources when dropped.
World caches the access sparse set (and only one cell can exist at a time), so `world.cell()` is a cheap operation.
WorldCell does _not_ use atomic operations. It is non-send, does a mutable borrow of world to prevent other accesses, and uses a simple `Rc<RefCell<ArchetypeComponentAccess>>` wrapper in each WorldBorrow pointer.
The api is currently limited to resource access, but it can and should be extended to queries / entity component access.
## Resource Scopes
WorldCell does not yet support component queries, and even when it does there are sometimes legitimate reasons to want a mutable world ref _and_ a mutable resource ref (ex: bevy_render and bevy_scene both need this). In these cases we could always drop down to the unsafe `world.get_resource_unchecked_mut()`, but that is not ideal!
Instead developers can use a "resource scope"
```rust
world.resource_scope(|world: &mut World, a: &mut A| {
})
```
This temporarily removes the `A` resource from `World`, provides mutable pointers to both, and re-adds A to World when finished. Thanks to the move to ComponentIds/sparse sets, this is a cheap operation.
If multiple resources are required, scopes can be nested. We could also consider adding a "resource tuple" to the api if this pattern becomes common and the boilerplate gets nasty.
## Query Conflicts Use ComponentId Instead of ArchetypeComponentId
For safety reasons, systems cannot contain queries that conflict with each other without wrapping them in a QuerySet. On bevy `main`, we use ArchetypeComponentIds to determine conflicts. This is nice because it can take into account filters:
```rust
// these queries will never conflict due to their filters
fn filter_system(a: Query<&mut A, With<B>>, b: Query<&mut B, Without<B>>) {
}
```
But it also has a significant downside:
```rust
// these queries will not conflict _until_ an entity with A, B, and C is spawned
fn maybe_conflicts_system(a: Query<(&mut A, &C)>, b: Query<(&mut A, &B)>) {
}
```
The system above will panic at runtime if an entity with A, B, and C is spawned. This makes it hard to trust that your game logic will run without crashing.
In this pr, I switched to using `ComponentId` instead. This _is_ more constraining. `maybe_conflicts_system` will now always fail, but it will do it consistently at startup. Naively, it would also _disallow_ `filter_system`, which would be a significant downgrade in usability. Bevy has a number of internal systems that rely on disjoint queries and I expect it to be a common pattern in userspace.
To resolve this, I added a new `FilteredAccess<T>` type, which wraps `Access<T>` and adds with/without filters. If two `FilteredAccess` have with/without values that prove they are disjoint, they will no longer conflict.
## EntityRef / EntityMut
World entity operations on `main` require that the user passes in an `entity` id to each operation:
```rust
let entity = world.spawn((A, )); // create a new entity with A
world.get::<A>(entity);
world.insert(entity, (B, C));
world.insert_one(entity, D);
```
This means that each operation needs to look up the entity location / verify its validity. The initial spawn operation also requires a Bundle as input. This can be awkward when no components are required (or one component is required).
These operations have been replaced by `EntityRef` and `EntityMut`, which are "builder-style" wrappers around world that provide read and read/write operations on a single, pre-validated entity:
```rust
// spawn now takes no inputs and returns an EntityMut
let entity = world.spawn()
.insert(A) // insert a single component into the entity
.insert_bundle((B, C)) // insert a bundle of components into the entity
.id() // id returns the Entity id
// Returns EntityMut (or panics if the entity does not exist)
world.entity_mut(entity)
.insert(D)
.insert_bundle(SomeBundle::default());
{
// returns EntityRef (or panics if the entity does not exist)
let d = world.entity(entity)
.get::<D>() // gets the D component
.unwrap();
// world.get still exists for ergonomics
let d = world.get::<D>(entity).unwrap();
}
// These variants return Options if you want to check existence instead of panicing
world.get_entity_mut(entity)
.unwrap()
.insert(E);
if let Some(entity_ref) = world.get_entity(entity) {
let d = entity_ref.get::<D>().unwrap();
}
```
This _does not_ affect the current Commands api or terminology. I think that should be a separate conversation as that is a much larger breaking change.
## Safety Improvements
* Entity reservation in Commands uses a normal world borrow instead of an unsafe transmute
* QuerySets no longer transmutes lifetimes
* Made traits "unsafe" when implementing a trait incorrectly could cause unsafety
* More thorough safety docs
## RemovedComponents SystemParam
The old approach to querying removed components: `query.removed:<T>()` was confusing because it had no connection to the query itself. I replaced it with the following, which is both clearer and allows us to cache the ComponentId mapping in the SystemParamState:
```rust
fn system(removed: RemovedComponents<T>) {
for entity in removed.iter() {
}
}
```
## Simpler Bundle implementation
Bundles are no longer responsible for sorting (or deduping) TypeInfo. They are just a simple ordered list of component types / data. This makes the implementation smaller and opens the door to an easy "nested bundle" implementation in the future (which i might even add in this pr). Duplicate detection is now done once per bundle type by World the first time a bundle is used.
## Unified WorldQuery and QueryFilter types
(don't worry they are still separate type _parameters_ in Queries .. this is a non-breaking change)
WorldQuery and QueryFilter were already basically identical apis. With the addition of `FetchState` and more storage-specific fetch methods, the overlap was even clearer (and the redundancy more painful).
QueryFilters are now just `F: WorldQuery where F::Fetch: FilterFetch`. FilterFetch requires `Fetch<Item = bool>` and adds new "short circuit" variants of fetch methods. This enables a filter tuple like `(With<A>, Without<B>, Changed<C>)` to stop evaluating the filter after the first mismatch is encountered. FilterFetch is automatically implemented for `Fetch` implementations that return bool.
This forces fetch implementations that return things like `(bool, bool, bool)` (such as the filter above) to manually implement FilterFetch and decide whether or not to short-circuit.
## More Granular Modules
World no longer globs all of the internal modules together. It now exports `core`, `system`, and `schedule` separately. I'm also considering exporting `core` submodules directly as that is still pretty "glob-ey" and unorganized (feedback welcome here).
## Remaining Draft Work (to be done in this pr)
* ~~panic on conflicting WorldQuery fetches (&A, &mut A)~~
* ~~bevy `main` and hecs both currently allow this, but we should protect against it if possible~~
* ~~batch_iter / par_iter (currently stubbed out)~~
* ~~ChangedRes~~
* ~~I skipped this while we sort out #1313. This pr should be adapted to account for whatever we land on there~~.
* ~~The `Archetypes` and `Tables` collections use hashes of sorted lists of component ids to uniquely identify each archetype/table. This hash is then used as the key in a HashMap to look up the relevant ArchetypeId or TableId. (which doesn't handle hash collisions properly)~~
* ~~It is currently unsafe to generate a Query from "World A", then use it on "World B" (despite the api claiming it is safe). We should probably close this gap. This could be done by adding a randomly generated WorldId to each world, then storing that id in each Query. They could then be compared to each other on each `query.do_thing(&world)` operation. This _does_ add an extra branch to each query operation, so I'm open to other suggestions if people have them.~~
* ~~Nested Bundles (if i find time)~~
## Potential Future Work
* Expand WorldCell to support queries.
* Consider not allocating in the empty archetype on `world.spawn()`
* ex: return something like EntityMutUninit, which turns into EntityMut after an `insert` or `insert_bundle` op
* this actually regressed performance last time i tried it, but in theory it should be faster
* Optimize SparseSet::insert (see `PERF` comment on insert)
* Replace SparseArray `Option<T>` with T::MAX to cut down on branching
* would enable cheaper get_unchecked() operations
* upstream fixedbitset optimizations
* fixedbitset could be allocation free for small block counts (store blocks in a SmallVec)
* fixedbitset could have a const constructor
* Consider implementing Tags (archetype-specific by-value data that affects archetype identity)
* ex: ArchetypeA could have `[A, B, C]` table components and `[D(1)]` "tag" component. ArchetypeB could have `[A, B, C]` table components and a `[D(2)]` tag component. The archetypes are different, despite both having D tags because the value inside D is different.
* this could potentially build on top of the `archetype.unique_components` added in this pr for resource storage.
* Consider reverting `all_tuples` proc macro in favor of the old `macro_rules` implementation
* all_tuples is more flexible and produces cleaner documentation (the macro_rules version produces weird type parameter orders due to parser constraints)
* but unfortunately all_tuples also appears to make Rust Analyzer sad/slow when working inside of `bevy_ecs` (does not affect user code)
* Consider "resource queries" and/or "mixed resource and entity component queries" as an alternative to WorldCell
* this is basically just "systems" so maybe it's not worth it
* Add more world ops
* `world.clear()`
* `world.reserve<T: Bundle>(count: usize)`
* Try using the old archetype allocation strategy (allocate new memory on resize and copy everything over). I expect this to improve batch insertion performance at the cost of unbatched performance. But thats just a guess. I'm not an allocation perf pro :)
* Adapt Commands apis for consistency with new World apis
## Benchmarks
key:
* `bevy_old`: bevy `main` branch
* `bevy`: this branch
* `_foreach`: uses an optimized for_each iterator
* ` _sparse`: uses sparse set storage (if unspecified assume table storage)
* `_system`: runs inside a system (if unspecified assume test happens via direct world ops)
### Simple Insert (from ecs_bench_suite)
### Simpler Iter (from ecs_bench_suite)
### Fragment Iter (from ecs_bench_suite)
### Sparse Fragmented Iter
Iterate a query that matches 5 entities from a single matching archetype, but there are 100 unmatching archetypes
### Schedule (from ecs_bench_suite)
### Add Remove Component (from ecs_bench_suite)
### Add Remove Component Big
Same as the test above, but each entity has 5 "large" matrix components and 1 "large" matrix component is added and removed
### Get Component
Looks up a single component value a large number of times
|
