Enum BudgetError 

pub enum BudgetError<R, Q = u64>
where
    Q: Copy + Debug,
{
    LimitExceeded {
        resource: R,
        observed: Observation<Q>,
        maximum: Q,
    },
    Insufficient {
        resource: R,
        limit: Q,
        remaining: Q,
        requested: Q,
    },
}

Aggregate error for APIs that can perform both point and cumulative checks.

APIs with a single failure mode return LimitExceededError or InsufficientBudgetError directly. This type remains the common carrier for composite operations and measured-value errors. Releasable pool release failures use the separate crate::ResourceReleaseError type.

Type Parameters

• R - Caller-defined resource value retained for diagnostics.
• Q - Copyable measurement value used by the failed constraint.

Examples

use qubit_budget::BudgetError;
use qubit_budget::LimitExceededError;

let error = BudgetError::from(LimitExceededError::exact("depth", 3_u64, 2));
assert_eq!(error.configured_limit(), 2);
assert_eq!(error.exact_observed(), Some(3));

Variants

LimitExceeded

A point measurement exceeded its configured maximum.

Fields

resource: R

Resource associated with the failed point check.

observed: Observation<Q>

Observed point measurement or safe lower bound.

maximum: Q

Configured inclusive point maximum.

Insufficient

A cumulative consumption request exceeded the remaining capacity.

Fields

resource: R

Resource associated with the failed consumption request.

limit: Q

Configured finite limit.

remaining: Q

Capacity remaining before the failed request.

requested: Q

Quantity requested by the failed operation.

Implementations

impl<R, Q> BudgetError<R, Q>

where Q: Copy + Debug,

pub const fn resource(&self) -> &R

Returns the resource associated with this failure.

Returns

Returns the resource associated with this failure.

pub fn into_resource(self) -> R

Consumes this error and returns its associated resource.

Returns

Consumes this error and returns its associated resource.

pub const fn limit(&self) -> Option<Q>

Returns the cumulative limit for budget and pool failures.

Returns Some(limit) for Self::Insufficient, or None for a point-limit failure.

Returns

Returns the cumulative limit for budget and pool failures.

pub const fn observation(&self) -> Option<Observation<Q>>

Returns the observation for a point-limit failure.

Returns Some(observed) for Self::LimitExceeded, or None for a cumulative-budget or pool failure.

Returns

Returns the observation for a point-limit failure.

pub const fn exact_observed(&self) -> Option<Q>

Returns the exact point measurement when the observation is exact.

Returns

Returns the exact point measurement when the observation is exact.

None indicates that the observation is only a lower bound.

pub const fn observed_lower_bound(&self) -> Option<Q>

Returns the safe lower bound of a point measurement.

Returns

Returns the safe lower bound of a point measurement.

None indicates that this is a cumulative-budget failure rather than a point-limit failure.

pub const fn maximum(&self) -> Option<Q>

Returns the configured maximum for a point-limit failure.

Returns Some(maximum) for Self::LimitExceeded, or None for a cumulative-budget or pool failure.

Returns

Returns the configured maximum for a point-limit failure.

pub const fn remaining(&self) -> Option<Q>

Returns the remaining capacity for a cumulative-budget failure.

Returns Some(remaining) for Self::Insufficient, including failed pool acquisitions, or None for a point-limit failure.

Returns

Returns the remaining capacity for a cumulative-budget failure.

pub const fn requested(&self) -> Option<Q>

Returns the requested quantity for a cumulative budget failure.

Returns Some(requested) for Self::Insufficient, or None for a point-limit failure.

Returns

Returns the requested quantity for a cumulative budget failure.

impl<R, Q> BudgetError<R, Q>

where Q: ResourceQuantity,

pub const fn configured_limit(&self) -> Q

Returns the configured limit for either point or cumulative failures.

Returns

Returns the configured limit for either point or cumulative failures.

pub fn used(&self) -> Option<Q>

Returns cumulative usage before a failed request, when applicable.

Returns

Returns cumulative usage before a failed request, when applicable.

None indicates that this is a point-limit failure with no cumulative usage.

Trait Implementations

impl<R: Clone, Q> Clone for BudgetError<R, Q>

where Q: Copy + Debug + Clone,

fn clone(&self) -> BudgetError<R, Q>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

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

where Q: Copy + Debug + Debug,

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

Formats the value using the given formatter.

impl<R, Q> Display for BudgetError<R, Q>

where Q: Copy + Debug + Debug, R: Debug, Observation<Q>: Display,

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

Formats the value using the given formatter.

impl<R: Eq, Q> Eq for BudgetError<R, Q>

where Q: Copy + Debug + Eq,

impl<R, Q> Error for BudgetError<R, Q>

where Q: Copy + Debug, Self: Debug + Display,

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.

impl<R, Q> From<BudgetError<R, Q>> for MeasuredBudgetError<R, Q>

where Q: Copy + Debug,

fn from(source: BudgetError<R, Q>) -> Self

Converts to this type from the input type.

impl<R, Q> From<InsufficientBudgetError<R, Q>> for BudgetError<R, Q>

where Q: Copy + Debug,

fn from(error: InsufficientBudgetError<R, Q>) -> Self

Converts a precise cumulative-budget failure into an aggregate error.

Parameters

• error - Precise cumulative-budget failure to convert.

Returns

Converts a precise cumulative-budget failure into an aggregate error.

impl<R, Q> From<LimitExceededError<R, Q>> for BudgetError<R, Q>

where Q: Copy + Debug,

fn from(error: LimitExceededError<R, Q>) -> Self

Converts a precise point-limit failure into an aggregate error.

Parameters

• error - Precise point-limit failure to convert.

Returns

Converts a precise point-limit failure into an aggregate error.

impl<R: PartialEq, Q> PartialEq for BudgetError<R, Q>

where Q: Copy + Debug + PartialEq,

fn eq(&self, other: &BudgetError<R, Q>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<R: PartialEq, Q> StructuralPartialEq for BudgetError<R, Q>

where Q: Copy + Debug + PartialEq,