Struct Migration 

pub struct Migration {
    pub from_schema: String,
    pub from_hash: u64,
    pub to_schema: String,
    pub to_hash: u64,
    pub from_version: SchemaVersion,
    pub to_version: SchemaVersion,
    pub transform: MigrationFn,
    pub description: String,
}

A registered migration between schema versions.

Fields

from_schema: String

Source schema name with version (e.g., “OrderInput@v1”).

from_hash: u64

Source schema hash.

to_schema: String

Target schema name with version (e.g., “OrderInput@v2”).

to_hash: u64

Target schema hash.

from_version: SchemaVersion

Source version.

to_version: SchemaVersion

Target version.

transform: MigrationFn

The transform function.

description: String

Human-readable description of what this migration does.

Implementations

impl Migration

pub fn new<F>( from_schema: impl Into<String>, from_hash: u64, to_schema: impl Into<String>, to_hash: u64, transform: F, ) -> Self

where F: Fn(&Arena, ArenaOffset) -> Result<ArenaOffset> + Send + Sync + 'static,

Create a new migration.

pub fn with_description(self, description: impl Into<String>) -> Self

Add a description to this migration.

pub fn apply(&self, arena: &Arena, offset: ArenaOffset) -> Result<ArenaOffset>

Apply this migration to data at the given offset.

Trait Implementations

impl Clone for Migration

fn clone(&self) -> Migration

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Migration

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

Formats the value using the given formatter.