Function checkValidDest

protocol/validation/validation.go:388–444

(vs *validationState, vd *bc.ValueDestination)

}

func checkValidDest(vs *validationState, vd *bc.ValueDestination) error {
	if vd == nil {
		return errors.Wrap(errMissingField, "empty value destination")
	}
	if vd.Ref == nil {
		return errors.Wrap(errMissingField, "missing ref on value destination")
	}
	if vd.Value == nil || vd.Value.AssetId == nil {
		return errors.Wrap(errMissingField, "missing value on value source")
	}

	e, ok := vs.tx.Entries[*vd.Ref]
	if !ok {
		return errors.Wrapf(bc.ErrMissingEntry, "entry for value destination %x not found", vd.Ref.Bytes())
	}
	var src *bc.ValueSource
	switch ref := e.(type) {
	case *bc.Output:
		if vd.Position != 0 {
			return errors.Wrapf(errPosition, "invalid position %d for output destination", vd.Position)
		}
		src = ref.Source

	case *bc.Retirement:
		if vd.Position != 0 {
			return errors.Wrapf(errPosition, "invalid position %d for retirement destination", vd.Position)
		}
		src = ref.Source

	case *bc.Mux:
		if vd.Position >= uint64(len(ref.Sources)) {
			return errors.Wrapf(errPosition, "invalid position %d for %d-source mux destination", vd.Position, len(ref.Sources))
		}
		src = ref.Sources[vd.Position]

	default:
		return errors.Wrapf(bc.ErrEntryType, "value destination is %T, should be output, retirement, or mux", e)
	}

	if src.Ref == nil || *src.Ref != vs.entryID {
		return errors.Wrapf(errMismatchedReference, "value destination for %x has disagreeing source %x", vs.entryID.Bytes(), src.Ref.Bytes())
	}

	if src.Position != vs.destPos {
		return errors.Wrapf(errMismatchedPosition, "value destination position %d disagrees with %d", src.Position, vs.destPos)
	}

	eq, err := src.Value.Equal(vd.Value)
	if err != nil {
		return errors.Sub(errMissingField, err)
	}
	if !eq {
		return errors.Wrapf(errMismatchedValue, "destination value %v disagrees with %v", src.Value, vd.Value)
	}

	return nil
}