Enum BackendError 

#[non_exhaustive]
pub enum BackendError {
    NotFound,
    Serialization(String),
    WireFormat(WireFormatError),
    Network(String),
    Other(Box<dyn Error + Send + Sync>),
}

Errors from the CacheBackend trait surface.

Backends choose the variant that best matches the underlying failure; consumers pattern-match on the variant rather than parsing the message.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

NotFound

The backend reports the entry is absent — distinct from a transport failure. Surfaces as a None to the caller in most flows; the dedicated variant exists so backends with strict existence semantics can be unambiguous.

Serialization(String)

The backend could not serialize or deserialize a payload. The inner string is backend-supplied (e.g., serde error rendering).

WireFormat(WireFormatError)

The backend encountered a Sassi wire-envelope error.

Network(String)

Network / IO transport error. Inner string is backend-supplied.

Other(Box<dyn Error + Send + Sync>)

Anything that doesn’t fit the variants above. Boxed so the variant size stays small.

Trait Implementations

impl Debug for BackendError

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

Formats the value using the given formatter.

impl Display for BackendError

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

Formats the value using the given formatter.

impl Error for BackendError

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<BackendError> for FetchError

fn from(source: BackendError) -> Self

Converts to this type from the input type.

impl From<BackendError> for InsertError

fn from(source: BackendError) -> Self

Converts to this type from the input type.

impl From<Error> for BackendError

Available on crate feature serde only.

fn from(err: Error) -> Self

Converts to this type from the input type.

impl From<WireFormatError> for BackendError

fn from(source: WireFormatError) -> Self

Converts to this type from the input type.