Struct specs::Storage

pub struct Storage<'e, T, D> { /* fields omitted */ }

A wrapper around the masked storage and the generations vector. Can be used for safe lookup of components, insertions and removes. This is what World::read/write fetches for the user.

Methods

impl<'st, T, D> Storage<'st, T, D> where
    T: Component,
    D: Deref<Target = MaskedStorage<T>>, 

pub fn restrict<'rf>(
    &'rf self
) -> RestrictedStorage<'rf, 'st, &BitSet, T, &T::Storage, ParallelRestriction>

Builds an immutable RestrictedStorage out of a Storage. Allows deferred unchecked access to the entity's component.

This is returned as a ParallelRestriction version since you can only get immutable components with this which is safe for parallel by default.

impl<'st, T, D> Storage<'st, T, D> where
    T: Component,
    D: DerefMut<Target = MaskedStorage<T>>, 

pub fn restrict_mut<'rf>(
    &'rf mut self
) -> RestrictedStorage<'rf, 'st, &BitSet, T, &mut T::Storage, NormalRestriction>

Builds a mutable RestrictedStorage out of a Storage. Allows restricted access to the inner components without allowing invalidating the bitset for iteration in Join.

pub fn par_restrict_mut<'rf>(
    &'rf mut self
) -> RestrictedStorage<'rf, 'st, &BitSet, T, &mut T::Storage, ParallelRestriction>

Builds a mutable, parallel RestrictedStorage, does not allow mutably getting other components aside from the current iteration.

impl<'e, T, D> Storage<'e, T, D> where
    T: Component + Deserialize<'e>,
    D: DerefMut<Target = MaskedStorage<T>>, 

pub fn merge<'a>(
    &'a mut self,
    entities: &'a [Entity],
    packed: PackedData<T>
) -> Result<(), MergeError>

Merges a list of components into the storage.

The list of entities will be used as the base for the offsets of the packed data.

e.g. rust,ignore let list = vec![Entity(0, 1), Entity(1, 1), Entity(2, 1)]; let packed = PackedData { offsets: [0, 2], components: [ ... ] }; storage.merge(&list, packed); Would merge the components at offset 0 and 2, which would be Entity(0, 1) and Entity(2, 1) while ignoring Entity(1, 1).

Note: The entity list should be at least the same size as the packed data. To make sure, you can call packed.pair_truncate(&entities). If the entity list is larger than the packed data then those entities are ignored.

Packed data should also be sorted in ascending order of offsets. If this is deserialized from data received from serializing a storage it will be in ascending order.

impl<'e, S, T, D> Storage<'e, T, D> where
    S: UnprotectedStorage<T> + Send + Sync + 'static,
    T: Component<Storage = TrackedStorage<T, S>> + Clone + Send + Sync,
    D: Deref<Target = MaskedStorage<T>>, 

pub fn change_events_tracked(&self) -> &[Change]

Returns the change events generated by the TrackedStorage. See Change for more explanations. The elements are mapped to entity indices, that means the Change for entity with id 5 will be the 6th element of this slice.

Examples

use specs::{Change, Component, TrackedStorage, World};

#[derive(Clone, PartialEq)] // `PartialEq` is only necessary for maintain
struct Comp(u8);

impl Component for Comp {
    // Will use `DenseVecStorage` by default.
    type Storage = TrackedStorage<Self>;
}

let mut w = World::new();
w.register::<Comp>();

let a = w.create_entity().with(Comp(1)).build();

let change = w.read::<Comp>().change_events_tracked()[a.id() as usize];
assert_eq!(change, Change::Inserted);

impl<'e, S, T, D> Storage<'e, T, D> where
    S: UnprotectedStorage<T> + Send + Sync + 'static,
    T: Component<Storage = TrackedStorage<T, S>> + Clone + Send + Sync,
    D: DerefMut<Target = MaskedStorage<T>>, 

pub fn maintain_tracked(&mut self) where
    T: PartialEq, 

Maintains the TrackedStorage.

You can only call this in case your component implements PartialEq. This will compare the cache with the current storage and generate change events in case the PartialEq implementation says that two components are different.

If you don't care about Change::Modified events, you don't have to call this method.

When should I call this method?

You should make sure that it gets called before you need the information which component has been modified. E.g. in case you have several systems writing to the component, then several reading from it, you can just call maintain_tracked once in between.

pub fn reset_tracked(&mut self)

Resets the tracked storage. This clears all change events. You most likely want to do this at the end of every frame.

impl<'e, T, D> Storage<'e, T, D>

pub fn new(entities: Fetch<'e, EntitiesRes>, data: D) -> Storage<'e, T, D>

Create a new Storage

impl<'e, T, D> Storage<'e, T, D> where
    T: Component,
    D: Deref<Target = MaskedStorage<T>>, 

pub fn get(&self, e: Entity) -> Option<&T>

Tries to read the data associated with an Entity.

pub fn check(&self) -> BitSet

Returns a copy of the BitSet of the storage. This allows you to do some methods on the actual storage without worrying about borrowing semantics.

This bitset can be invalidated here if insertion or removal methods are used after the call to get the BitSet, so there is no guarantee that the storage will have a component for a specific entity.

impl<'e, T, D> Storage<'e, T, D> where
    T: Component,
    D: DerefMut<Target = MaskedStorage<T>>, 

pub fn get_mut(&mut self, e: Entity) -> Option<&mut T>

Tries to mutate the data associated with an Entity.

pub fn entry<'a>(
    &'a mut self,
    e: Entity
) -> Result<StorageEntry<'a, 'e, T, D>, WrongGeneration> where
    'e: 'a, 

Returns an entry to the component associated to the entity.

Behaves somewhat similarly to std::collections::HashMap's entry api.

Example

 if let Ok(entry) = storage.entry(entity) {
     entry.or_insert(Comp { field: 55 });
 }

pub fn insert(&mut self, e: Entity, v: T) -> InsertResult<T>

Inserts new data for a given Entity. Returns the result of the operation as a InsertResult<T>

pub fn remove(&mut self, e: Entity) -> Option<T>

Removes the data associated with an Entity.

pub fn clear(&mut self)

Clears the contents of the storage.

pub fn drain(&mut self) -> Drain<T>

Creates a draining storage wrapper which can be .joined to get a draining iterator.

Trait Implementations

impl<'e, T, D> Serialize for Storage<'e, T, D> where
    T: Component + Serialize,
    D: Deref<Target = MaskedStorage<T>>, 

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl<'a, T: Component, D> DistinctStorage for Storage<'a, T, D> where
    T::Storage: DistinctStorage, 

impl<'a, 'e, T, D> Join for &'a Storage<'e, T, D> where
    T: Component,
    D: Deref<Target = MaskedStorage<T>>, 

type Type = &'a T

Type of joined components.

type Value = &'a T::Storage

Type of joined storages.

type Mask = &'a BitSet

Type of joined bit mask.

fn open(self) -> (Self::Mask, Self::Value)

Open this join by returning the mask and the storages.

unsafe fn get(v: &mut Self::Value, i: Index) -> &'a T

Get a joined component value by a given index.

fn join(self) -> JoinIter<Self> where
    Self: Sized, 

Create a joined iterator over the contents.

impl<'a, 'e, T, D> Not for &'a Storage<'e, T, D> where
    T: Component,
    D: Deref<Target = MaskedStorage<T>>, 

type Output = AntiStorage<'a>

The resulting type after applying the ! operator.

fn not(self) -> Self::Output

Performs the unary ! operation.

impl<'a, 'e, T, D> ParJoin for &'a Storage<'e, T, D> where
    T: Component,
    D: Deref<Target = MaskedStorage<T>>,
    T::Storage: Sync, 

fn par_join(self) -> JoinParIter<Self> where
    Self: Sized, 

Create a joined parallel iterator over the contents.

impl<'a, 'e, T, D> Join for &'a mut Storage<'e, T, D> where
    T: Component,
    D: DerefMut<Target = MaskedStorage<T>>, 

type Type = &'a mut T

Type of joined components.

type Value = &'a mut T::Storage

Type of joined storages.

type Mask = &'a BitSet

Type of joined bit mask.

fn open(self) -> (Self::Mask, Self::Value)

Open this join by returning the mask and the storages.

unsafe fn get(v: &mut Self::Value, i: Index) -> &'a mut T

Get a joined component value by a given index.

fn join(self) -> JoinIter<Self> where
    Self: Sized, 

Create a joined iterator over the contents.

impl<'a, 'e, T, D> ParJoin for &'a mut Storage<'e, T, D> where
    T: Component,
    D: DerefMut<Target = MaskedStorage<T>>,
    T::Storage: Sync + DistinctStorage, 

fn par_join(self) -> JoinParIter<Self> where
    Self: Sized, 

Create a joined parallel iterator over the contents.