Struct StreamStateContract 

pub struct StreamStateContract(/* private fields */);

The codec/schema/restartability contract a registered ItemStream carries, bound to the runtime at registration time.

Gate C requires the runtime to validate a registered stream’s expected schema and codec identity/version, apply declared migrations, and reject unknown-newer versions – all before the application’s open runs – without introspecting the stream’s opaque internal state. This is the small, explicit descriptor that makes that possible: it preserves the existing separation between the stream’s logical identity (crate::definition::ComponentStreamIdentity), its runtime implementation (ItemStream/BoxedStream), and its state contract (this type), which the stream’s own ComponentStateCodec already declares.

Implementations

impl StreamStateContract

pub fn new<T, C>(codec: C) -> StreamStateContract

where C: ComponentStateCodec<T> + Send + Sync + 'static, T: 'static,

Captures codec’s schema/codec identity, versions, and restartability declaration as a type-erased contract.

pub fn schema_id(&self) -> &StateSchemaId

Borrows the expected application schema identifier.

pub fn codec_id(&self) -> &CodecId

Borrows the expected codec identifier.

pub fn restartability(&self) -> RestartabilityDeclaration

Returns the declared restartability of the stream this contract belongs to.

pub fn validate_for_open( &self, envelope: &ComponentStateEnvelope, ) -> Result<ComponentStateEnvelope, ComponentStateError>

Validates and migrates envelope to this contract’s current schema and codec versions before the runtime may call open with it.

Errors

Returns the redacted identity, compatibility, or migration failure ComponentStateEnvelope::validated_for_open would.

Trait Implementations

impl Debug for StreamStateContract

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

Formats the value using the given formatter.