Method commitWithConstraint

db/journal/store.go:345–356

(ctx context.Context, key string, c Constraint, e Entry)

}

func (s *Store) commitWithConstraint(ctx context.Context, key string, c Constraint, e Entry) error {
	return s.commit(ctx, func() error {
		oldEntry, ok := s.table[key]
		if !ok {
			return ErrNoSuchKey
		}
		if c != nil && !c(oldEntry) {
			return ErrConstraint
		}
		return nil
	}, e)
}

func (s *Store) commit(ctx context.Context, fn func() error, entries ...Entry) error {
	serializer := bsupbytes.NewSerializer()