Enum A2aStorageError 

#[non_exhaustive]
pub enum A2aStorageError {
    TaskNotFound(String),
    InvalidTransition {
        current: TaskState,
        requested: TaskState,
    },
    TerminalState(TaskState),
    TerminalStateAlreadySet {
        task_id: String,
        current_state: String,
    },
    OwnerMismatch {
        task_id: String,
    },
    TenantMismatch {
        task_id: String,
    },
    ConcurrentModification(String),
    PushConfigNotFound(String),
    ClaimAlreadyHeld {
        tenant: String,
        task_id: String,
        event_sequence: u64,
        config_id: String,
    },
    StaleDeliveryClaim {
        tenant: String,
        task_id: String,
        event_sequence: u64,
        config_id: String,
    },
    CreateConfigCasTimeout {
        tenant: String,
        task_id: String,
    },
    DatabaseError(String),
    SerializationError(String),
    TypeError(A2aTypeError),
    Generic(String),
}

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.

TaskNotFound(String)

InvalidTransition

Fields

current: TaskState

requested: TaskState

TerminalState(TaskState)

TerminalStateAlreadySet

The atomic store’s single-terminal-writer invariant rejected a terminal write because the task was already in a terminal state at the time of the CAS. Distinct from Self::TerminalState which is the raw state-machine signal: TerminalStateAlreadySet is specifically the “you lost the race” signal emitted by crate::storage::A2aAtomicStore::update_task_status_with_events. Callers typically translate this to HTTP 409 TaskNotCancelable / JSON-RPC -32002 on the wire, and to EventSink::closed semantics when the caller is an executor sink.

The current_state field carries the wire enum name (e.g. "TASK_STATE_COMPLETED") so log/telemetry consumers can see exactly which terminal won the race.

Fields

task_id: String

current_state: String

OwnerMismatch

Fields

task_id: String

TenantMismatch

Fields

task_id: String

ConcurrentModification(String)

PushConfigNotFound(String)

ClaimAlreadyHeld

The push delivery claim for a (tenant, task_id, event_sequence, config_id) tuple is already held by another instance whose claim has not yet expired, OR the tuple has already reached a terminal outcome (Succeeded, GaveUp, Abandoned) and cannot be re-claimed regardless of expiry.

Returned only by crate::push::A2aPushDeliveryStore::claim_delivery. Callers treat this as “skip delivery on this instance” — the event is already being (or has already been) handled.

Fields

tenant: String

task_id: String

event_sequence: u64

config_id: String

StaleDeliveryClaim

The claim identity passed to crate::push::A2aPushDeliveryStore::record_delivery_outcome does not match the currently-stored claim for this tuple. Two causes: the claim expired and another instance re-claimed (generation advanced), or the same instance’s prior process died and the restarted process holds a different claimant identifier. Either way, the stale caller’s outcome is dropped so it cannot overwrite a terminal state committed by the current claimant.

Workers that receive this error MUST abort their retry loop for the affected tuple — the current claimant (or whoever re-claims next) owns the remaining lifecycle.

Fields

tenant: String

task_id: String

event_sequence: u64

config_id: String

CreateConfigCasTimeout

/ §6.4: create_config exhausted its bounded retry budget (default 5 attempts with 10/50/250/1000 ms backoff) while its CAS against a2a_tasks.latest_event_sequence kept losing to concurrent event commits. The operator should retry the create from the handler; in practice this surfaces only under pathological event-burst workloads against a single task.

Fields

tenant: String

task_id: String

DatabaseError(String)

SerializationError(String)

TypeError(A2aTypeError)

Generic(String)

Trait Implementations

impl Debug for A2aStorageError

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

Formats the value using the given formatter.

impl Display for A2aStorageError

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

Formats the value using the given formatter.

impl Error for A2aStorageError

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<A2aStorageError> for A2aError

fn from(err: A2aStorageError) -> Self

Converts to this type from the input type.

impl From<A2aTypeError> for A2aStorageError

fn from(source: A2aTypeError) -> Self

Converts to this type from the input type.