Enum MemoryError 

pub enum MemoryError {
    TierExhausted {
        tier: &'static str,
        requested: u64,
        used: u64,
        limit: u64,
        available: u64,
        role: MemoryRole,
    },
    InvalidRequest {
        tier: &'static str,
        requested: u64,
        reason: &'static str,
    },
    AllocationFailed {
        tier: &'static str,
        requested: u64,
        reason: String,
    },
    CapacityUnavailable {
        tier: &'static str,
        requested: u64,
        available: u64,
        role: MemoryRole,
        detail: String,
        source: Option<Box<dyn Error + Send + Sync>>,
    },
}

Shared error vocabulary for mechanism and governance operations.

Not Clone/PartialEq: a refusal that carries the cause underneath it cannot be meaningfully duplicated or compared, and keeping the cause is worth more than either. Match on the variant instead.

Variants

TierExhausted

The tier does not have room, and no holder released enough.

Fields

tier: &'static str

Which tier ran out.

requested: u64

What the caller asked for.

used: u64

Bytes leased before this request.

limit: u64

The tier ceiling.

available: u64

limit - used.

role: MemoryRole

The role that was refused.

InvalidRequest

The request itself is not representable.

Fields

tier: &'static str

Which tier was addressed.

requested: u64

What the caller asked for.

reason: &'static str

What is wrong with it.

AllocationFailed

The request was well formed and within budget, but the allocator behind the tier refused it for a reason of its own.

Distinct from MemoryError::TierExhausted, which means we declined, and from MemoryError::InvalidRequest, which means the caller asked for something impossible. This one carries the backing allocator’s own account of the failure, which is usually the only thing that identifies it: a driver that is out of memory and a driver that has no context both fail an allocation, and calling them both “out of memory” sends the next person to read the log in the wrong direction.

Fields

tier: &'static str

Which tier was addressed.

requested: u64

What the caller asked for.

reason: String

What the backing allocator said.

CapacityUnavailable

A well-formed capacity transfer or backing claim could not make enough governed bytes available.

Fields

tier: &'static str

requested: u64

available: u64

role: MemoryRole

detail: String

What this layer can say about the shortfall on its own.

Names the operation that came up short; the refusal underneath it, when there was one, belongs in source rather than being folded in here, so that a caller can still match on it and a reader is not shown the same sentence twice.

source: Option<Box<dyn Error + Send + Sync>>

The refusal this one is reporting, when it is reporting one.

None when this layer decided on its own, as when a reclaim target simply was not reached. Typed as dyn Error rather than a boxed MemoryError both because the layer underneath is not always a governor and because #[source] on a Box<ConcreteError> hands callers a chain node whose concrete type is the box, so downcast_ref::<MemoryError>() would miss it – which is the whole thing this field exists to make possible.

Trait Implementations

impl Debug for MemoryError

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

Formats the value using the given formatter.

impl Display for MemoryError

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

Formats the value using the given formatter.

impl Error for MemoryError

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 From<MemoryError> for BindingError

fn from(source: MemoryError) -> Self

Converts to this type from the input type.