Enum BackendErrorKind 

#[non_exhaustive]
pub enum BackendErrorKind {
    Transport,
    Protocol,
    Timeout,
    Auth,
    Cluster,
    BusyLoading,
    ScriptNotLoaded,
    Other,
}

Classified backend transport errors, kept backend-agnostic on purpose (#88). Each variant maps a family of native backend error kinds into a stable, consumer-matchable shape.

Consumers requiring the exact native kind for a Valkey backend must go through ff_backend_valkey explicitly; ff-sdk/ff-server’s public surface will only ever hand out BackendErrorKind.

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.

Transport

Network / I/O failure: the request may or may not have been processed. Typically retryable with backoff.

Protocol

Backend rejected the request on protocol / parse grounds. Not retryable without a fix.

Timeout

Backend timed out responding to the request. Retryable.

Auth

Authentication / authorization failure. Not retryable.

Cluster

Cluster topology churn (MOVED, ASK, CLUSTERDOWN, MasterDown, CrossSlot, ConnectionNotFoundForRoute, AllConnectionsUnavailable). Retryable after topology settles.

BusyLoading

Backend is temporarily busy loading state (e.g. Valkey LOADING). Retryable.

ScriptNotLoaded

Backend indicates the referenced script/function does not exist. Typically handled by the caller via re-load.

Other

Any other classified error from the backend. Fallback bucket for native kinds outside the curated set above.

Implementations

impl BackendErrorKind

pub fn as_stable_str(&self) -> &'static str

Stable, lowercase-kebab label suitable for log fields / HTTP kind body slots. Guaranteed not to change across releases for the existing variants.

pub fn is_retryable(&self) -> bool

Whether a caller should consider this kind retryable with backoff. Conservative — auth + protocol + other are terminal.

Trait Implementations

impl Clone for BackendErrorKind

fn clone(&self) -> BackendErrorKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BackendErrorKind

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

Formats the value using the given formatter.

impl PartialEq for BackendErrorKind

fn eq(&self, other: &BackendErrorKind) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for BackendErrorKind

impl Eq for BackendErrorKind

impl StructuralPartialEq for BackendErrorKind