Struct SceneCache 

pub struct SceneCache { /* private fields */ }

Shared LRU compute cache for pure authoring computations, with optional byte accounting.

Entries can be dropped and recomputed at any time; decoded resources that must keep their identity live in a crate::ResourceStore instead.

Values must depend only on their keys and immutable resources. Resource revisions belong in the key. The default retains 256 entries without a byte cap. with_limits adds a caller-declared logical byte allowance for cache_with_cost. Ordinary cache() is entry-bounded only and reports no retained-byte charge. Outstanding Arc pins and allocator overhead are not bounded. Concurrent misses may compute more than once; builders and cost callbacks run outside the lock. Zero entries disable retention; zero bytes disable costed values. Original keys are retained and compared by type and equality after hashing.

Implementations

impl SceneCache

pub fn new(capacity: usize) -> Self

Creates a cache with at most this many retained entries; zero disables it.

pub fn with_limits(limits: CacheLimits) -> Self

Bounds entries and caller-declared retained payload bytes. Heap-owning keys and values need SceneContext::cache_with_cost for payload charges. Neither allocator overhead nor externally pinned Arc values are bounded.

pub fn max_bytes(&self) -> usize

Logical payload allowance; usize::MAX means no configured byte bound.

pub fn retained_bytes(&self) -> usize

Sum of the declared charges for currently retained entries.

pub fn capacity(&self) -> usize

Maximum number of retained entries, not a byte budget.

pub fn len(&self) -> usize

Number of currently retained entries.

pub fn is_empty(&self) -> bool

Whether no computed values are currently retained.

pub fn clear(&self)

Removes retained entries without invalidating existing returned handles.

pub fn get_with_cost<Key: Eq + Hash + Send + Sync + 'static, Value: Send + Sync + 'static>( &self, key: Key, build: impl FnOnce() -> Value, cost: impl FnOnce(&Value) -> usize, ) -> Arc<Value>

Gets a pure computed value with a caller-declared retained payload charge.

pub fn lookup<Key: Eq + Hash + Send + Sync + 'static, Value: Send + Sync + 'static>( &self, key: &Key, ) -> Option<Arc<Value>>

Looks up a renderer content key independently of the caller’s source location.

pub fn insert_with_cost<Key: Eq + Hash + Send + Sync + 'static, Value: Send + Sync + 'static>( &self, key: Key, value: Value, cost: impl FnOnce(&Value) -> usize, ) -> Arc<Value>

Inserts checked pure content, converging concurrent inserts to the retained value.

Trait Implementations

impl Debug for SceneCache

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

Formats the value using the given formatter.

impl Default for SceneCache

fn default() -> Self

Returns the “default value” for a type.