migrations

type Backfill func(context.Context, Batch) (BatchResult, error)

type Batch struct {
	Tx     *sql.Tx
	Cursor string
	Limit  int
	// Rebind converts ? placeholders to the dialect's own form. It is never
	// nil; the runner substitutes an identity function for dialects that take
	// ? directly.
	Rebind func(string) string
}

type BatchResult struct {
	Cursor string
	Rows   int64
	Done   bool
}

type Locker interface {
	Acquire(context.Context, *sql.Conn) (func() error, error)
}

type Migration struct {
	Version          int
	Name             string
	BackfillRevision string
	SQL              map[string]SQL
	Backfill         Backfill
	BatchSize        int
}

type Phase string

type Runner struct {
	DB       *sql.DB
	Dialect  string
	Registry []Migration
	Locker   Locker
	Logger   *slog.Logger
	Now      func() time.Time
	// Rebind converts ? placeholders to the dialect's own form for data-driven
	// backfills. Leave nil to use the runner's own Dialect-derived rebinder;
	// an identity default would feed ? straight to a dialect that rejects it.
	Rebind func(string) string
}

type SQL struct {
	Expand   []string
	Contract []string
}

type UpgradeError struct {
	Version int
	Name    string
	Phase   Phase
	Err     error
}