Struct smithay::wayland::compositor::MultiCache

pub struct MultiCache { /* fields omitted */ }

A typemap-like container for double-buffered values

All values inserted into this container must implement the Cacheable trait, which defines their buffering semantics. They furthermore must be Send as the surface state can be accessed from multiple threads (but Sync is not required, the surface internally synchronizes access to its state).

Consumers of surface state (like compositor applications using Smithay) will mostly be concerned with the MultiCache::current method, which gives access to the current state of the surface for a particular type.

Writers of protocol extensions logic will mostly be concerned with the MultiCache::pending method, which provides access to the pending state of the surface, in which new state from clients will be stored.

This contained has RefCell-like semantics: values of multiple stored types can be accessed at the same time. The stored values are initialized lazily the first time current() or pending() are invoked with this type as argument.

Implementations

impl MultiCache

pub fn pending<T: Cacheable + Send + 'static>(&self) -> RefMut<'_, T>

Access the pending state associated with type T

pub fn current<T: Cacheable + Send + 'static>(&self) -> RefMut<'_, T>

Access the current state associated with type T

pub fn has<T: Cacheable + Send + 'static>(&self) -> bool

Check if the container currently contains values for type T

Trait Implementations

impl Debug for MultiCache

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

Formats the value using the given formatter.