Struct LazySubsystem 

pub struct LazySubsystem<T: Send + Sync + 'static> { /* private fields */ }

A lazily-initialized subsystem value.

The inner T is initialized on the first call to LazySubsystem::get or LazySubsystem::get_or_try_init. Subsequent calls return the cached value without re-running the initializer.

This is a thin, ergonomic wrapper around tokio::sync::OnceCell that adds logging and a human-readable subsystem name.

Implementations

impl<T: Send + Sync + 'static> LazySubsystem<T>

pub fn new(name: &'static str) -> Self

Create a new lazy subsystem with the given human-readable name.

pub async fn get<F, Fut>(&self, init: F) -> &T

where F: FnOnce() -> Fut, Fut: Future<Output = T>,

Get the value, initializing it with init if necessary.

The init future runs at most once, even under concurrent access.

pub async fn get_or_try_init<F, Fut, E>(&self, init: F) -> Result<&T, E>

where F: FnOnce() -> Fut, Fut: Future<Output = Result<T, E>>,

Get the value, initializing with a fallible init if necessary.

If init returns an error, the cell remains uninitialized and future calls will retry.

pub fn is_initialized(&self) -> bool

Check whether the subsystem has been initialized.

pub fn try_get(&self) -> Option<&T>

Return the value if already initialized, without triggering init.

pub fn name(&self) -> &'static str

The human-readable name of this subsystem.

Trait Implementations

impl<T: Send + Sync + 'static> Clone for LazySubsystem<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Send + Sync + Debug + 'static> Debug for LazySubsystem<T>

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

Formats the value using the given formatter.