bevy_ecs/storage/
sparse_set.rs

1use crate::{
2    change_detection::MaybeLocation,
3    component::{ComponentId, ComponentInfo, ComponentTicks, Tick, TickCells},
4    entity::Entity,
5    storage::{Column, TableRow},
6};
7use alloc::{boxed::Box, vec::Vec};
8use bevy_ptr::{OwningPtr, Ptr};
9use core::{cell::UnsafeCell, hash::Hash, marker::PhantomData, panic::Location};
10use nonmax::NonMaxUsize;
11
12type EntityIndex = u32;
13
14#[derive(Debug)]
15pub(crate) struct SparseArray<I, V = I> {
16    values: Vec<Option<V>>,
17    marker: PhantomData<I>,
18}
19
20/// A space-optimized version of [`SparseArray`] that cannot be changed
21/// after construction.
22#[derive(Debug)]
23pub(crate) struct ImmutableSparseArray<I, V = I> {
24    values: Box<[Option<V>]>,
25    marker: PhantomData<I>,
26}
27
28impl<I: SparseSetIndex, V> Default for SparseArray<I, V> {
29    fn default() -> Self {
30        Self::new()
31    }
32}
33
34impl<I, V> SparseArray<I, V> {
35    #[inline]
36    pub const fn new() -> Self {
37        Self {
38            values: Vec::new(),
39            marker: PhantomData,
40        }
41    }
42}
43
44macro_rules! impl_sparse_array {
45    ($ty:ident) => {
46        impl<I: SparseSetIndex, V> $ty<I, V> {
47            /// Returns `true` if the collection contains a value for the specified `index`.
48            #[inline]
49            pub fn contains(&self, index: I) -> bool {
50                let index = index.sparse_set_index();
51                self.values.get(index).is_some_and(Option::is_some)
52            }
53
54            /// Returns a reference to the value at `index`.
55            ///
56            /// Returns `None` if `index` does not have a value or if `index` is out of bounds.
57            #[inline]
58            pub fn get(&self, index: I) -> Option<&V> {
59                let index = index.sparse_set_index();
60                self.values.get(index).and_then(Option::as_ref)
61            }
62        }
63    };
64}
65
66impl_sparse_array!(SparseArray);
67impl_sparse_array!(ImmutableSparseArray);
68
69impl<I: SparseSetIndex, V> SparseArray<I, V> {
70    /// Inserts `value` at `index` in the array.
71    ///
72    /// If `index` is out-of-bounds, this will enlarge the buffer to accommodate it.
73    #[inline]
74    pub fn insert(&mut self, index: I, value: V) {
75        let index = index.sparse_set_index();
76        if index >= self.values.len() {
77            self.values.resize_with(index + 1, || None);
78        }
79        self.values[index] = Some(value);
80    }
81
82    /// Returns a mutable reference to the value at `index`.
83    ///
84    /// Returns `None` if `index` does not have a value or if `index` is out of bounds.
85    #[inline]
86    pub fn get_mut(&mut self, index: I) -> Option<&mut V> {
87        let index = index.sparse_set_index();
88        self.values.get_mut(index).and_then(Option::as_mut)
89    }
90
91    /// Removes and returns the value stored at `index`.
92    ///
93    /// Returns `None` if `index` did not have a value or if `index` is out of bounds.
94    #[inline]
95    pub fn remove(&mut self, index: I) -> Option<V> {
96        let index = index.sparse_set_index();
97        self.values.get_mut(index).and_then(Option::take)
98    }
99
100    /// Removes all of the values stored within.
101    pub fn clear(&mut self) {
102        self.values.clear();
103    }
104
105    /// Converts the [`SparseArray`] into an immutable variant.
106    pub(crate) fn into_immutable(self) -> ImmutableSparseArray<I, V> {
107        ImmutableSparseArray {
108            values: self.values.into_boxed_slice(),
109            marker: PhantomData,
110        }
111    }
112}
113
114/// A sparse data structure of [`Component`](crate::component::Component)s.
115///
116/// Designed for relatively fast insertions and deletions.
117#[derive(Debug)]
118pub struct ComponentSparseSet {
119    dense: Column,
120    // Internally this only relies on the Entity index to keep track of where the component data is
121    // stored for entities that are alive. The generation is not required, but is stored
122    // in debug builds to validate that access is correct.
123    #[cfg(not(debug_assertions))]
124    entities: Vec<EntityIndex>,
125    #[cfg(debug_assertions)]
126    entities: Vec<Entity>,
127    sparse: SparseArray<EntityIndex, TableRow>,
128}
129
130impl ComponentSparseSet {
131    /// Creates a new [`ComponentSparseSet`] with a given component type layout and
132    /// initial `capacity`.
133    pub(crate) fn new(component_info: &ComponentInfo, capacity: usize) -> Self {
134        Self {
135            dense: Column::with_capacity(component_info, capacity),
136            entities: Vec::with_capacity(capacity),
137            sparse: Default::default(),
138        }
139    }
140
141    /// Removes all of the values stored within.
142    pub(crate) fn clear(&mut self) {
143        self.dense.clear();
144        self.entities.clear();
145        self.sparse.clear();
146    }
147
148    /// Returns the number of component values in the sparse set.
149    #[inline]
150    pub fn len(&self) -> usize {
151        self.dense.len()
152    }
153
154    /// Returns `true` if the sparse set contains no component values.
155    #[inline]
156    pub fn is_empty(&self) -> bool {
157        self.dense.len() == 0
158    }
159
160    /// Inserts the `entity` key and component `value` pair into this sparse
161    /// set.
162    ///
163    /// # Safety
164    /// The `value` pointer must point to a valid address that matches the [`Layout`](std::alloc::Layout)
165    /// inside the [`ComponentInfo`] given when constructing this sparse set.
166    pub(crate) unsafe fn insert(
167        &mut self,
168        entity: Entity,
169        value: OwningPtr<'_>,
170        change_tick: Tick,
171        caller: MaybeLocation,
172    ) {
173        if let Some(&dense_index) = self.sparse.get(entity.index()) {
174            #[cfg(debug_assertions)]
175            assert_eq!(entity, self.entities[dense_index.as_usize()]);
176            self.dense.replace(dense_index, value, change_tick, caller);
177        } else {
178            let dense_index = self.dense.len();
179            self.dense
180                .push(value, ComponentTicks::new(change_tick), caller);
181            self.sparse
182                .insert(entity.index(), TableRow::from_usize(dense_index));
183            #[cfg(debug_assertions)]
184            assert_eq!(self.entities.len(), dense_index);
185            #[cfg(not(debug_assertions))]
186            self.entities.push(entity.index());
187            #[cfg(debug_assertions)]
188            self.entities.push(entity);
189        }
190    }
191
192    /// Returns `true` if the sparse set has a component value for the provided `entity`.
193    #[inline]
194    pub fn contains(&self, entity: Entity) -> bool {
195        #[cfg(debug_assertions)]
196        {
197            if let Some(&dense_index) = self.sparse.get(entity.index()) {
198                #[cfg(debug_assertions)]
199                assert_eq!(entity, self.entities[dense_index.as_usize()]);
200                true
201            } else {
202                false
203            }
204        }
205        #[cfg(not(debug_assertions))]
206        self.sparse.contains(entity.index())
207    }
208
209    /// Returns a reference to the entity's component value.
210    ///
211    /// Returns `None` if `entity` does not have a component in the sparse set.
212    #[inline]
213    pub fn get(&self, entity: Entity) -> Option<Ptr<'_>> {
214        self.sparse.get(entity.index()).map(|&dense_index| {
215            #[cfg(debug_assertions)]
216            assert_eq!(entity, self.entities[dense_index.as_usize()]);
217            // SAFETY: if the sparse index points to something in the dense vec, it exists
218            unsafe { self.dense.get_data_unchecked(dense_index) }
219        })
220    }
221
222    /// Returns references to the entity's component value and its added and changed ticks.
223    ///
224    /// Returns `None` if `entity` does not have a component in the sparse set.
225    #[inline]
226    pub fn get_with_ticks(
227        &self,
228        entity: Entity,
229    ) -> Option<(
230        Ptr<'_>,
231        TickCells<'_>,
232        MaybeLocation<&UnsafeCell<&'static Location<'static>>>,
233    )> {
234        let dense_index = *self.sparse.get(entity.index())?;
235        #[cfg(debug_assertions)]
236        assert_eq!(entity, self.entities[dense_index.as_usize()]);
237        // SAFETY: if the sparse index points to something in the dense vec, it exists
238        unsafe {
239            Some((
240                self.dense.get_data_unchecked(dense_index),
241                TickCells {
242                    added: self.dense.get_added_tick_unchecked(dense_index),
243                    changed: self.dense.get_changed_tick_unchecked(dense_index),
244                },
245                self.dense.get_changed_by_unchecked(dense_index),
246            ))
247        }
248    }
249
250    /// Returns a reference to the "added" tick of the entity's component value.
251    ///
252    /// Returns `None` if `entity` does not have a component in the sparse set.
253    #[inline]
254    pub fn get_added_tick(&self, entity: Entity) -> Option<&UnsafeCell<Tick>> {
255        let dense_index = *self.sparse.get(entity.index())?;
256        #[cfg(debug_assertions)]
257        assert_eq!(entity, self.entities[dense_index.as_usize()]);
258        // SAFETY: if the sparse index points to something in the dense vec, it exists
259        unsafe { Some(self.dense.get_added_tick_unchecked(dense_index)) }
260    }
261
262    /// Returns a reference to the "changed" tick of the entity's component value.
263    ///
264    /// Returns `None` if `entity` does not have a component in the sparse set.
265    #[inline]
266    pub fn get_changed_tick(&self, entity: Entity) -> Option<&UnsafeCell<Tick>> {
267        let dense_index = *self.sparse.get(entity.index())?;
268        #[cfg(debug_assertions)]
269        assert_eq!(entity, self.entities[dense_index.as_usize()]);
270        // SAFETY: if the sparse index points to something in the dense vec, it exists
271        unsafe { Some(self.dense.get_changed_tick_unchecked(dense_index)) }
272    }
273
274    /// Returns a reference to the "added" and "changed" ticks of the entity's component value.
275    ///
276    /// Returns `None` if `entity` does not have a component in the sparse set.
277    #[inline]
278    pub fn get_ticks(&self, entity: Entity) -> Option<ComponentTicks> {
279        let dense_index = *self.sparse.get(entity.index())?;
280        #[cfg(debug_assertions)]
281        assert_eq!(entity, self.entities[dense_index.as_usize()]);
282        // SAFETY: if the sparse index points to something in the dense vec, it exists
283        unsafe { Some(self.dense.get_ticks_unchecked(dense_index)) }
284    }
285
286    /// Returns a reference to the calling location that last changed the entity's component value.
287    ///
288    /// Returns `None` if `entity` does not have a component in the sparse set.
289    #[inline]
290    pub fn get_changed_by(
291        &self,
292        entity: Entity,
293    ) -> MaybeLocation<Option<&UnsafeCell<&'static Location<'static>>>> {
294        MaybeLocation::new_with_flattened(|| {
295            let dense_index = *self.sparse.get(entity.index())?;
296            #[cfg(debug_assertions)]
297            assert_eq!(entity, self.entities[dense_index.as_usize()]);
298            // SAFETY: if the sparse index points to something in the dense vec, it exists
299            unsafe { Some(self.dense.get_changed_by_unchecked(dense_index)) }
300        })
301    }
302
303    /// Removes the `entity` from this sparse set and returns a pointer to the associated value (if
304    /// it exists).
305    #[must_use = "The returned pointer must be used to drop the removed component."]
306    pub(crate) fn remove_and_forget(&mut self, entity: Entity) -> Option<OwningPtr<'_>> {
307        self.sparse.remove(entity.index()).map(|dense_index| {
308            #[cfg(debug_assertions)]
309            assert_eq!(entity, self.entities[dense_index.as_usize()]);
310            self.entities.swap_remove(dense_index.as_usize());
311            let is_last = dense_index.as_usize() == self.dense.len() - 1;
312            // SAFETY: dense_index was just removed from `sparse`, which ensures that it is valid
313            let (value, _, _) = unsafe { self.dense.swap_remove_and_forget_unchecked(dense_index) };
314            if !is_last {
315                let swapped_entity = self.entities[dense_index.as_usize()];
316                #[cfg(not(debug_assertions))]
317                let index = swapped_entity;
318                #[cfg(debug_assertions)]
319                let index = swapped_entity.index();
320                *self.sparse.get_mut(index).unwrap() = dense_index;
321            }
322            value
323        })
324    }
325
326    /// Removes (and drops) the entity's component value from the sparse set.
327    ///
328    /// Returns `true` if `entity` had a component value in the sparse set.
329    pub(crate) fn remove(&mut self, entity: Entity) -> bool {
330        if let Some(dense_index) = self.sparse.remove(entity.index()) {
331            #[cfg(debug_assertions)]
332            assert_eq!(entity, self.entities[dense_index.as_usize()]);
333            self.entities.swap_remove(dense_index.as_usize());
334            let is_last = dense_index.as_usize() == self.dense.len() - 1;
335            // SAFETY: if the sparse index points to something in the dense vec, it exists
336            unsafe {
337                self.dense.swap_remove_unchecked(dense_index);
338            }
339            if !is_last {
340                let swapped_entity = self.entities[dense_index.as_usize()];
341                #[cfg(not(debug_assertions))]
342                let index = swapped_entity;
343                #[cfg(debug_assertions)]
344                let index = swapped_entity.index();
345                *self.sparse.get_mut(index).unwrap() = dense_index;
346            }
347            true
348        } else {
349            false
350        }
351    }
352
353    pub(crate) fn check_change_ticks(&mut self, change_tick: Tick) {
354        self.dense.check_change_ticks(change_tick);
355    }
356}
357
358/// A data structure that blends dense and sparse storage
359///
360/// `I` is the type of the indices, while `V` is the type of data stored in the dense storage.
361#[derive(Debug)]
362pub struct SparseSet<I, V: 'static> {
363    dense: Vec<V>,
364    indices: Vec<I>,
365    sparse: SparseArray<I, NonMaxUsize>,
366}
367
368/// A space-optimized version of [`SparseSet`] that cannot be changed
369/// after construction.
370#[derive(Debug)]
371pub(crate) struct ImmutableSparseSet<I, V: 'static> {
372    dense: Box<[V]>,
373    indices: Box<[I]>,
374    sparse: ImmutableSparseArray<I, NonMaxUsize>,
375}
376
377macro_rules! impl_sparse_set {
378    ($ty:ident) => {
379        impl<I: SparseSetIndex, V> $ty<I, V> {
380            /// Returns the number of elements in the sparse set.
381            #[inline]
382            pub fn len(&self) -> usize {
383                self.dense.len()
384            }
385
386            /// Returns `true` if the sparse set contains a value for `index`.
387            #[inline]
388            pub fn contains(&self, index: I) -> bool {
389                self.sparse.contains(index)
390            }
391
392            /// Returns a reference to the value for `index`.
393            ///
394            /// Returns `None` if `index` does not have a value in the sparse set.
395            pub fn get(&self, index: I) -> Option<&V> {
396                self.sparse.get(index).map(|dense_index| {
397                    // SAFETY: if the sparse index points to something in the dense vec, it exists
398                    unsafe { self.dense.get_unchecked(dense_index.get()) }
399                })
400            }
401
402            /// Returns a mutable reference to the value for `index`.
403            ///
404            /// Returns `None` if `index` does not have a value in the sparse set.
405            pub fn get_mut(&mut self, index: I) -> Option<&mut V> {
406                let dense = &mut self.dense;
407                self.sparse.get(index).map(move |dense_index| {
408                    // SAFETY: if the sparse index points to something in the dense vec, it exists
409                    unsafe { dense.get_unchecked_mut(dense_index.get()) }
410                })
411            }
412
413            /// Returns an iterator visiting all keys (indices) in arbitrary order.
414            pub fn indices(&self) -> impl Iterator<Item = I> + Clone + '_ {
415                self.indices.iter().cloned()
416            }
417
418            /// Returns an iterator visiting all values in arbitrary order.
419            pub fn values(&self) -> impl Iterator<Item = &V> {
420                self.dense.iter()
421            }
422
423            /// Returns an iterator visiting all values mutably in arbitrary order.
424            pub fn values_mut(&mut self) -> impl Iterator<Item = &mut V> {
425                self.dense.iter_mut()
426            }
427
428            /// Returns an iterator visiting all key-value pairs in arbitrary order, with references to the values.
429            pub fn iter(&self) -> impl Iterator<Item = (&I, &V)> {
430                self.indices.iter().zip(self.dense.iter())
431            }
432
433            /// Returns an iterator visiting all key-value pairs in arbitrary order, with mutable references to the values.
434            pub fn iter_mut(&mut self) -> impl Iterator<Item = (&I, &mut V)> {
435                self.indices.iter().zip(self.dense.iter_mut())
436            }
437        }
438    };
439}
440
441impl_sparse_set!(SparseSet);
442impl_sparse_set!(ImmutableSparseSet);
443
444impl<I: SparseSetIndex, V> Default for SparseSet<I, V> {
445    fn default() -> Self {
446        Self::new()
447    }
448}
449
450impl<I, V> SparseSet<I, V> {
451    /// Creates a new [`SparseSet`].
452    pub const fn new() -> Self {
453        Self {
454            dense: Vec::new(),
455            indices: Vec::new(),
456            sparse: SparseArray::new(),
457        }
458    }
459}
460
461impl<I: SparseSetIndex, V> SparseSet<I, V> {
462    /// Creates a new [`SparseSet`] with a specified initial capacity.
463    pub fn with_capacity(capacity: usize) -> Self {
464        Self {
465            dense: Vec::with_capacity(capacity),
466            indices: Vec::with_capacity(capacity),
467            sparse: Default::default(),
468        }
469    }
470
471    /// Returns the total number of elements the [`SparseSet`] can hold without needing to reallocate.
472    #[inline]
473    pub fn capacity(&self) -> usize {
474        self.dense.capacity()
475    }
476
477    /// Inserts `value` at `index`.
478    ///
479    /// If a value was already present at `index`, it will be overwritten.
480    pub fn insert(&mut self, index: I, value: V) {
481        if let Some(dense_index) = self.sparse.get(index.clone()).cloned() {
482            // SAFETY: dense indices stored in self.sparse always exist
483            unsafe {
484                *self.dense.get_unchecked_mut(dense_index.get()) = value;
485            }
486        } else {
487            self.sparse
488                .insert(index.clone(), NonMaxUsize::new(self.dense.len()).unwrap());
489            self.indices.push(index);
490            self.dense.push(value);
491        }
492    }
493
494    /// Returns a reference to the value for `index`, inserting one computed from `func`
495    /// if not already present.
496    pub fn get_or_insert_with(&mut self, index: I, func: impl FnOnce() -> V) -> &mut V {
497        if let Some(dense_index) = self.sparse.get(index.clone()).cloned() {
498            // SAFETY: dense indices stored in self.sparse always exist
499            unsafe { self.dense.get_unchecked_mut(dense_index.get()) }
500        } else {
501            let value = func();
502            let dense_index = self.dense.len();
503            self.sparse
504                .insert(index.clone(), NonMaxUsize::new(dense_index).unwrap());
505            self.indices.push(index);
506            self.dense.push(value);
507            // SAFETY: dense index was just populated above
508            unsafe { self.dense.get_unchecked_mut(dense_index) }
509        }
510    }
511
512    /// Returns `true` if the sparse set contains no elements.
513    #[inline]
514    pub fn is_empty(&self) -> bool {
515        self.dense.len() == 0
516    }
517
518    /// Removes and returns the value for `index`.
519    ///
520    /// Returns `None` if `index` does not have a value in the sparse set.
521    pub fn remove(&mut self, index: I) -> Option<V> {
522        self.sparse.remove(index).map(|dense_index| {
523            let index = dense_index.get();
524            let is_last = index == self.dense.len() - 1;
525            let value = self.dense.swap_remove(index);
526            self.indices.swap_remove(index);
527            if !is_last {
528                let swapped_index = self.indices[index].clone();
529                *self.sparse.get_mut(swapped_index).unwrap() = dense_index;
530            }
531            value
532        })
533    }
534
535    /// Clears all of the elements from the sparse set.
536    pub fn clear(&mut self) {
537        self.dense.clear();
538        self.indices.clear();
539        self.sparse.clear();
540    }
541
542    /// Converts the sparse set into its immutable variant.
543    pub(crate) fn into_immutable(self) -> ImmutableSparseSet<I, V> {
544        ImmutableSparseSet {
545            dense: self.dense.into_boxed_slice(),
546            indices: self.indices.into_boxed_slice(),
547            sparse: self.sparse.into_immutable(),
548        }
549    }
550}
551
552/// Represents something that can be stored in a [`SparseSet`] as an integer.
553///
554/// Ideally, the `usize` values should be very small (ie: incremented starting from
555/// zero), as the number of bits needed to represent a `SparseSetIndex` in a `FixedBitSet`
556/// is proportional to the **value** of those `usize`.
557pub trait SparseSetIndex: Clone + PartialEq + Eq + Hash {
558    /// Gets the sparse set index corresponding to this instance.
559    fn sparse_set_index(&self) -> usize;
560    /// Creates a new instance of this type with the specified index.
561    fn get_sparse_set_index(value: usize) -> Self;
562}
563
564macro_rules! impl_sparse_set_index {
565    ($($ty:ty),+) => {
566        $(impl SparseSetIndex for $ty {
567            #[inline]
568            fn sparse_set_index(&self) -> usize {
569                *self as usize
570            }
571
572            #[inline]
573            fn get_sparse_set_index(value: usize) -> Self {
574                value as $ty
575            }
576        })*
577    };
578}
579
580impl_sparse_set_index!(u8, u16, u32, u64, usize);
581
582/// A collection of [`ComponentSparseSet`] storages, indexed by [`ComponentId`]
583///
584/// Can be accessed via [`Storages`](crate::storage::Storages)
585#[derive(Default)]
586pub struct SparseSets {
587    sets: SparseSet<ComponentId, ComponentSparseSet>,
588}
589
590impl SparseSets {
591    /// Returns the number of [`ComponentSparseSet`]s this collection contains.
592    #[inline]
593    pub fn len(&self) -> usize {
594        self.sets.len()
595    }
596
597    /// Returns true if this collection contains no [`ComponentSparseSet`]s.
598    #[inline]
599    pub fn is_empty(&self) -> bool {
600        self.sets.is_empty()
601    }
602
603    /// An Iterator visiting all ([`ComponentId`], [`ComponentSparseSet`]) pairs.
604    /// NOTE: Order is not guaranteed.
605    pub fn iter(&self) -> impl Iterator<Item = (ComponentId, &ComponentSparseSet)> {
606        self.sets.iter().map(|(id, data)| (*id, data))
607    }
608
609    /// Gets a reference to the [`ComponentSparseSet`] of a [`ComponentId`]. This may be `None` if the component has never been spawned.
610    #[inline]
611    pub fn get(&self, component_id: ComponentId) -> Option<&ComponentSparseSet> {
612        self.sets.get(component_id)
613    }
614
615    /// Gets a mutable reference of [`ComponentSparseSet`] of a [`ComponentInfo`].
616    /// Create a new [`ComponentSparseSet`] if not exists.
617    pub(crate) fn get_or_insert(
618        &mut self,
619        component_info: &ComponentInfo,
620    ) -> &mut ComponentSparseSet {
621        if !self.sets.contains(component_info.id()) {
622            self.sets.insert(
623                component_info.id(),
624                ComponentSparseSet::new(component_info, 64),
625            );
626        }
627
628        self.sets.get_mut(component_info.id()).unwrap()
629    }
630
631    /// Gets a mutable reference to the [`ComponentSparseSet`] of a [`ComponentId`]. This may be `None` if the component has never been spawned.
632    pub(crate) fn get_mut(&mut self, component_id: ComponentId) -> Option<&mut ComponentSparseSet> {
633        self.sets.get_mut(component_id)
634    }
635
636    /// Clear entities stored in each [`ComponentSparseSet`]
637    pub(crate) fn clear_entities(&mut self) {
638        for set in self.sets.values_mut() {
639            set.clear();
640        }
641    }
642
643    pub(crate) fn check_change_ticks(&mut self, change_tick: Tick) {
644        for set in self.sets.values_mut() {
645            set.check_change_ticks(change_tick);
646        }
647    }
648}
649
650#[cfg(test)]
651mod tests {
652    use super::SparseSets;
653    use crate::{
654        component::{Component, ComponentDescriptor, ComponentId, ComponentInfo},
655        entity::Entity,
656        storage::SparseSet,
657    };
658    use alloc::{vec, vec::Vec};
659
660    #[derive(Debug, Eq, PartialEq)]
661    struct Foo(usize);
662
663    #[test]
664    fn sparse_set() {
665        let mut set = SparseSet::<Entity, Foo>::default();
666        let e0 = Entity::from_raw(0);
667        let e1 = Entity::from_raw(1);
668        let e2 = Entity::from_raw(2);
669        let e3 = Entity::from_raw(3);
670        let e4 = Entity::from_raw(4);
671
672        set.insert(e1, Foo(1));
673        set.insert(e2, Foo(2));
674        set.insert(e3, Foo(3));
675
676        assert_eq!(set.get(e0), None);
677        assert_eq!(set.get(e1), Some(&Foo(1)));
678        assert_eq!(set.get(e2), Some(&Foo(2)));
679        assert_eq!(set.get(e3), Some(&Foo(3)));
680        assert_eq!(set.get(e4), None);
681
682        {
683            let iter_results = set.values().collect::<Vec<_>>();
684            assert_eq!(iter_results, vec![&Foo(1), &Foo(2), &Foo(3)]);
685        }
686
687        assert_eq!(set.remove(e2), Some(Foo(2)));
688        assert_eq!(set.remove(e2), None);
689
690        assert_eq!(set.get(e0), None);
691        assert_eq!(set.get(e1), Some(&Foo(1)));
692        assert_eq!(set.get(e2), None);
693        assert_eq!(set.get(e3), Some(&Foo(3)));
694        assert_eq!(set.get(e4), None);
695
696        assert_eq!(set.remove(e1), Some(Foo(1)));
697
698        assert_eq!(set.get(e0), None);
699        assert_eq!(set.get(e1), None);
700        assert_eq!(set.get(e2), None);
701        assert_eq!(set.get(e3), Some(&Foo(3)));
702        assert_eq!(set.get(e4), None);
703
704        set.insert(e1, Foo(10));
705
706        assert_eq!(set.get(e1), Some(&Foo(10)));
707
708        *set.get_mut(e1).unwrap() = Foo(11);
709        assert_eq!(set.get(e1), Some(&Foo(11)));
710    }
711
712    #[test]
713    fn sparse_sets() {
714        let mut sets = SparseSets::default();
715
716        #[derive(Component, Default, Debug)]
717        struct TestComponent1;
718
719        #[derive(Component, Default, Debug)]
720        struct TestComponent2;
721
722        assert_eq!(sets.len(), 0);
723        assert!(sets.is_empty());
724
725        register_component::<TestComponent1>(&mut sets, 1);
726        assert_eq!(sets.len(), 1);
727
728        register_component::<TestComponent2>(&mut sets, 2);
729        assert_eq!(sets.len(), 2);
730
731        // check its shape by iter
732        let mut collected_sets = sets
733            .iter()
734            .map(|(id, set)| (id, set.len()))
735            .collect::<Vec<_>>();
736        collected_sets.sort();
737        assert_eq!(
738            collected_sets,
739            vec![(ComponentId::new(1), 0), (ComponentId::new(2), 0),]
740        );
741
742        fn register_component<T: Component>(sets: &mut SparseSets, id: usize) {
743            let descriptor = ComponentDescriptor::new::<T>();
744            let id = ComponentId::new(id);
745            let info = ComponentInfo::new(id, descriptor);
746            sets.get_or_insert(&info);
747        }
748    }
749}
bevy_ecs/storage/sparse_set.rs

bevy_ecs/storage/
sparse_set.rs
