Struct ManagedResourcePermit 

pub struct ManagedResourcePermit<R, Q = u64>
where
    Q: ResourceQuantity,
{ /* private fields */ }

Owns acquired capacity and returns it to its pool when dropped.

A permit may move across threads when its resource and quantity types allow that movement. Calling Self::release returns capacity early; otherwise normal Drop, early returns, ?, and panic unwinding all return it.

Type Parameters

• R - Caller-defined resource value retained by the owning pool.
• Q - Exact unsigned quantity owned by this permit.

Examples

use qubit_budget::ManagedResourcePool;

let pool = ManagedResourcePool::new("connections", 1_u64);
let permit = pool.try_acquire(1).expect("one connection should fit");
assert_eq!(permit.amount(), 1);
permit.release();
assert_eq!(pool.available(), 1);

Implementations

impl<R, Q> ManagedResourcePermit<R, Q>

where Q: ResourceQuantity,

pub fn resource(&self) -> &R

Returns the resource whose capacity this permit owns.

Panics

Panics only if an internal invariant is violated and a live permit no longer retains its owning pool.

pub const fn amount(&self) -> Q

Returns the quantity owned by this permit.

pub fn release(self)

Returns this permit’s capacity before the end of its lexical scope.

Consuming self prevents callers from releasing the same permit twice.

Trait Implementations

impl<R: Debug, Q> Debug for ManagedResourcePermit<R, Q>

where Q: ResourceQuantity + Debug,

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

Formats the value using the given formatter.

impl<R, Q> Drop for ManagedResourcePermit<R, Q>

where Q: ResourceQuantity,

fn drop(&mut self)

Returns owned capacity without panicking during unwinding.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.