Enum SessionError 

pub enum SessionError {
    MutationGap {
        client_id: String,
        expected: u64,
        got: u64,
    },
    ProducerGap {
        producer: String,
        expected: u64,
        got: u64,
    },
    PayloadTooLarge(String),
    RetryableConflict(String),
    Backend(String),
    CommitOutcomeExpired,
    CursorHistoryLost(String),
}

The engine’s error type — only the variants the state machine distinguishes and the wire renders. Each backend maps its native error in at the boundary (SessionBackend methods return these), keeping the engine monomorphic; MutationGap’s Display is byte-identical to rindle-server’s ServerError::MutationGap so the extraction changes no response body.

Variants

MutationGap

Fields

client_id: String

expected: u64

got: u64

ProducerGap

A foreign writer submitted a sequence beyond its watermark’s successor. The watermark model requires a per-producer total order (design 306 §4), so this is the producer’s protocol violation — the mid-gap rule, in the producer namespace.

Fields

producer: String

expected: u64

got: u64

PayloadTooLarge(String)

The backend rejected an otherwise valid transaction because its atomic payload exceeds the configured engine policy. This is a client-shape error (HTTP 413), not a retryable backend failure; callers must split the work into smaller transactions.

RetryableConflict(String)

Serializable OCC validation rejected the transaction at commit. The transaction has already been rolled back; a read-bearing mutator must re-run from its first statement so its reads are established against a fresh snapshot.

Backend(String)

Any backend-side failure, carrying the backend error’s display string. Statement errors, commit failures, capture errors — the engine treats them all as “poison the session” (rollback, advance nothing, surface the message).

CommitOutcomeExpired

The durable terminal record aged below the configured retention floor. The transaction may have committed, but the server can no longer prove either outcome and must never report a guaranteed negative.

CursorHistoryLost(String)

A session/strong read-only begin named a commit fence beyond the current master history.

Trait Implementations

impl Clone for SessionError

fn clone(&self) -> SessionError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SessionError

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

Formats the value using the given formatter.

impl Display for SessionError

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

Formats the value using the given formatter.

impl Error for SessionError

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 PartialEq for SessionError

fn eq(&self, other: &SessionError) -> 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 Eq for SessionError

impl StructuralPartialEq for SessionError