Struct EntityTree 

pub struct EntityTree {
    pub path: EntityPath,
    pub children: BTreeMap<EntityPathPart, EntityTree>,
}

A recursive, manually updated ChunkStoreSubscriber that maintains the entity hierarchy.

The tree contains a list of subtrees, and so on recursively.

Fields

path: EntityPath

Full path prefix to the root of this (sub)tree.

children: BTreeMap<EntityPathPart, EntityTree>

Direct descendants of this (sub)tree.

Implementations

impl EntityTree

pub fn root() -> EntityTree

pub fn new(path: EntityPath) -> EntityTree

pub fn is_leaf(&self) -> bool

Has no child entities.

pub fn check_is_empty(&self, engine: &StorageEngineReadGuard<'_>) -> bool

Returns true if this entity has no children and no data.

Checking for the absence of data is neither costly nor totally free: do it a few hundreds or thousands times a frame and it will absolutely kill framerate. Don’t blindly call this on every existing entity every frame: use ChunkStoreEvents to make sure anything changed at all first.

pub fn on_store_additions(&mut self, events: &[ChunkStoreEvent])

Updates the EntityTree by applying a batch of ChunkStoreEvents, adding any new entities to the tree.

Only reacts to additions (event.kind == StoreDiffKind::Addition).

pub fn on_new_entity(&mut self, entity_path: &EntityPath)

pub fn on_store_deletions( &mut self, engine: &StorageEngineReadGuard<'_>, entity_paths_with_deletions: &HashSet<EntityPath, BuildHasherDefault<NoHashHasher<EntityPath>>>, events: &[ChunkStoreEvent], )

Updates the EntityTree by removing any entities which have no data and no children.

pub fn subtree(&self, path: &EntityPath) -> Option<&EntityTree>

pub fn visit_children_recursively(&self, visitor: impl FnMut(&EntityPath))

Invokes visitor for self and all children recursively.

pub fn find_first_child_recursive( &self, predicate: impl FnMut(&EntityPath) -> bool, ) -> Option<&EntityTree>

Invokes the predicate for self and all children recursively, returning the first entity for which the predicate returns true.

Note that this function has early return semantics, meaning if multiple entities would return true, only the first is returned. The entities are yielded in order of their entity paths.

Trait Implementations

impl ChunkStoreSubscriber for EntityTree

fn name(&self) -> String

Arbitrary name for the subscriber.

fn as_any(&self) -> &(dyn Any + 'static)

Workaround for downcasting support, simply return self:

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Workaround for downcasting support, simply return self:

fn on_events(&mut self, _events: &[ChunkStoreEvent])

The core of this trait: get notified of changes happening in all ChunkStores.

fn on_drop(&mut self, store_id: &StoreId)

Notifies a subscriber that an entire store was dropped.

impl Clone for EntityTree

fn clone(&self) -> EntityTree

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for EntityTree

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for EntityTree

fn default() -> EntityTree

Returns the “default value” for a type.