Struct PayloadSchema 

pub struct PayloadSchema { /* private fields */ }

A current schema version and optional migration from older stored JSON.

Migrations run only when versions differ. They must be deterministic, perform no external side effects, and avoid including secrets in errors. The runtime deserializes the returned JSON into the current Rust type; stored historical payloads remain unchanged.

Implementations

impl PayloadSchema

pub fn new(version: u32) -> Self

Uses version for newly serialized payloads. Legacy rows are version 1.

pub fn version(&self) -> u32

The version this application writes and expects to read.

pub fn migrate( self, migration: impl Fn(u32, Value) -> Result<Value, PayloadError> + Send + Sync + 'static, ) -> Self

Adds a migration receiving the stored version and JSON. Return an explicit error for versions the application cannot safely interpret.

pub fn decode(&self, stored: u32, value: Value) -> Result<Value, PayloadError>

Reads stored JSON, migrating it if needed. This does not update the record, its input fingerprint, or its authoritative effect status.

Errors

PayloadError::UnsupportedVersion when no migration is available, or an application migration error.

Trait Implementations

impl Clone for PayloadSchema

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for PayloadSchema

fn default() -> Self

Returns the “default value” for a type.