Trait VersionedStateCodec 

pub trait VersionedStateCodec<T>: Send + Sync {
    // Required methods
    fn schema_id(&self) -> &StateSchemaId;
    fn current_version(&self) -> StateSchemaVersion;
    fn encode(&self, value: &T) -> Result<Vec<u8>, StateCodecError>;
    fn decode(&self, payload: &[u8]) -> Result<T, StateCodecError>;

    // Provided method
    fn upgrades(&self) -> &[StateSchemaUpgrade] { ... }
}

Serializer-neutral application codec for one durable-state schema.

Payloads are JSON objects represented as bytes so the public contract does not expose a particular serializer’s types. A codec may use Serde, manual JSON handling, or another implementation internally.

A codec declares its current version and the directed upgrades it can apply. The framework accepts an equal or older recorded version, walks one bounded deterministic chain of declared upgrades up to the current version, and only then calls decode. A codec therefore parses exactly one shape, and a recorded version newer than the current one is rejected rather than truncated, defaulted, or reinterpreted.

Required Methods

fn schema_id(&self) -> &StateSchemaId

Returns the stable schema identifier.

fn current_version(&self) -> StateSchemaVersion

Returns the version emitted by encode.

fn encode(&self, value: &T) -> Result<Vec<u8>, StateCodecError>

Encodes the current typed value as one JSON object.

Errors

Returns a value-redacted codec classification.

fn decode(&self, payload: &[u8]) -> Result<T, StateCodecError>

Decodes one JSON-object payload already at current_version.

Errors

Returns StateCodecError::InvalidPayload when the payload does not satisfy the current schema.

Provided Methods

fn upgrades(&self) -> &[StateSchemaUpgrade]

Declares the directed upgrades this codec can apply.

The default suits a codec whose schema has only ever had one version. A codec that has published an older version returns the edges that reach the current one; a recorded version with no path to the current version is rejected rather than guessed at.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors