Struct Budget 

pub struct Budget { /* private fields */ }

A cloneable handle to one node in a hierarchical resource budget.

Implementations

impl Budget

pub fn builder() -> BudgetBuilder

Starts a root budget builder.

pub fn child(&self) -> BudgetBuilder

Starts a child builder whose operations will also count against this node.

pub fn id(&self) -> BudgetId

Returns this node’s process-local identifier.

pub fn consume( &self, resource: &Resource, amount: u64, ) -> Result<(), BudgetError>

Immediately and atomically consumes an amount across the entire lineage.

Errors

Returns an error when the request overflows, exceeds a limit, or begins after the effective deadline or cancellation request.

pub fn reserve( &self, resource: &Resource, amount: u64, ) -> Result<Reservation, BudgetError>

Atomically reserves capacity for one resource.

Errors

Returns an error when the request overflows, exceeds a limit, or begins after the effective deadline or cancellation request.

pub fn reserve_many<'a>( &self, resources: impl IntoIterator<Item = (&'a Resource, u64)>, ) -> Result<ReservationSet, BudgetError>

Atomically reserves several resources, combining duplicate entries.

The input is canonicalized by resource name. Overflow or exhaustion changes no accounting state.

Errors

Returns an error when canonicalization overflows, a request exceeds a limit, or the operation begins after the effective deadline or cancellation request.

pub fn remaining(&self, resource: &Resource) -> Remaining

Returns effective remaining capacity at one consistent instant.

The result is observational. Only Budget::consume, Budget::reserve, and Budget::reserve_many authorize work.

pub fn snapshot(&self) -> BudgetSnapshot

Captures a consistent snapshot across this node’s complete lineage.

impl Budget

pub fn cancel(&self)

Requests cancellation of this budget and all existing or future children.

pub fn is_cancelled(&self) -> bool

Returns whether cancellation has been requested for this node.

pub async fn run<F>(&self, future: F) -> Result<F::Output, BudgetError>

where F: Future,

Runs a future until it completes, cancellation is requested, or the effective deadline expires.

If several branches are ready simultaneously, cancellation wins over the deadline, which wins over future completion. Dropping the future is only safe when the future itself is cancellation-safe.

Errors

Returns BudgetError::Cancelled or BudgetError::DeadlineExceeded when the corresponding terminal condition wins.

Trait Implementations

impl Clone for Budget

fn clone(&self) -> Budget

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Budget

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

Formats the value using the given formatter.