Struct CacheSetter 

pub struct CacheSetter<T, Fn: FnOnce() -> T = fn() -> T>(Arc<SetOnce<T>>, Option<Fn>);

A value returned on cache misses. The owner of this struct should compute the value, then call CacheSetter::set to write the value into the cache.

If this struct is dropped before being written to (including due to panic), the value will remain empty and associated CacheFuts will never resolve. This can be avoided by calling CacheSetter::with_fallback which will specify a fallback closure in case it is prematurely dropped.

Tuple Fields

0: Arc<SetOnce<T>>

1: Option<Fn>

Implementations

impl<T, Fn: FnOnce() -> T> CacheSetter<T, Fn>

pub const fn new(arc: Arc<SetOnce<T>>) -> Self

Constructs a new CacheSetter writing into the given SetOnce.

By default, no fallback is configured.

pub fn with_fallback<F: FnOnce() -> T>(self, default: F) -> CacheSetter<T, F>

Returns a new CacheSetter with the configured fallback closure and writing into the same SetOnce.

pub fn set(self, value: T)

Writes the given value into the cache, consuming this CacheSetter.

pub fn dissociated() -> Self

Returns a new dissociated CacheSetter. That is, a setter which is not backed by any value within the cache. This can be useful to let uncacheable entities use the same cache-handling logic.

Trait Implementations

impl<T: Debug, Fn: Debug + FnOnce() -> T> Debug for CacheSetter<T, Fn>

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

Formats the value using the given formatter.

impl<T, Fn: FnOnce() -> T> Drop for CacheSetter<T, Fn>

Drop implementation that calls the stored CacheSetter::with_fallback closure, if it is configured and no value has been manually stored.

fn drop(&mut self)

Executes the destructor for this type.