Struct SceneCache 

pub struct SceneCache { /* private fields */ }

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

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.