Struct sierra::ResourceCache

pub struct ResourceCache<T> { /* private fields */ }

General purpose cache for sierra resources. This cache evicts resources based on their last used epoch. Each time a resource is used, its last used epoch is updated to the current. The cache evicts all resources that have not been used for a certain amount of epochs.

This strategy works best for resources that may become obsolete and require substantial amount of memory while only few resources are in use so cache size is always low.

Implementations

impl<T> ResourceCache<T>

pub const fn new() -> Self

Creates a new empty cache.

pub fn with_capacity(cap: usize) -> Self

Creates a new cache with preallocated resource capacity.

pub fn fetch<F>(&mut self, eq: F) -> Option<&T>where
    F: Fn(&T) -> bool,

Fetches resource from cache. Resource last used epoch is updated to the current epoch. Returns None if resource is not in cache. Returns Some if resource is in cache.

pub fn get<Q>(&mut self, key: &Q) -> Option<&T>where
    T: Borrow<Q>,
    Q: ?Sized + Hash + Eq,

Fetches resource from cache. Resource last used epoch is updated to the current epoch. Returns None if resource is not in cache. Returns Some if resource is in cache.

pub fn fetch_no_update<F>(&self, eq: F) -> Option<&T>where
    F: Fn(&T) -> bool,

Fetches resource from cache. Resource last used epoch is not updated. This is useful when only shared reference to cache is available. Returns None if resource is not in cache. Returns Some if resource is in cache.

pub fn get_no_update<Q>(&self, key: &Q) -> Option<&T>where
    T: Borrow<Q>,
    Q: ?Sized + Hash + Eq,

Fetches resource from cache. Resource last used epoch is not updated. This is useful when only shared reference to cache is available. Returns None if resource is not in cache. Returns Some if resource is in cache.

pub fn try_fetch_or_create<K, F, E>(&mut self, eq: K, create: F) -> Result<&T, E>where
    K: Fn(&T) -> bool,
    F: FnOnce() -> Result<T, E>,

Fetches resource from cache. Resource last used epoch is updated to the current epoch. If resource is not in cache, it is created and added to the cache. Returns a reference to the resource. Returns error if resource is not in cache and create function fails.

pub fn fetch_or_create<E, F>(&mut self, eq: E, create: F) -> &Twhere
    E: Fn(&T) -> bool,
    F: FnOnce() -> T,

Fetches resource from cache. Resource last used epoch is updated to the current epoch. If resource is not in cache, it is created and added to the cache. Returns a reference to the resource.

pub fn try_get_or_create<Q, F, E>(&mut self, key: &Q, create: F) -> Result<&T, E>where
    T: Borrow<Q>,
    Q: ?Sized + Hash + Eq,
    F: FnOnce() -> Result<T, E>,

Fetches resource from cache. Resource last used epoch is updated to the current epoch. If resource is not in cache, it is created and added to the cache. Returns a reference to the resource.

pub fn get_or_create<Q, F>(&mut self, key: &Q, create: F) -> &Twhere
    T: Borrow<Q>,
    Q: ?Sized + Hash + Eq,
    F: FnOnce() -> T,

Fetches resource from cache. Resource last used epoch is updated to the current epoch. If resource is not in cache, it is created and added to the cache. Returns a reference to the resource.

pub fn next_epoch(&mut self)

Moves to the next epoch.

pub fn evict(&mut self, epoch: u64)

Evicts resources that have not been used since specified epoch.

Trait Implementations

impl<T: Debug> Debug for ResourceCache<T>

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

Formats the value using the given formatter.