def migrate_archiver_dirs():
    from ckan import model
    from ckan.logic import get_action

    site_user = get_action('get_site_user')(
        {'model': model, 'ignore_auth': True, 'defer_commit': True}, {}
    )

    site_url_base = config['ckanext-archiver.cache_url_root'].rstrip('/')
    old_dir_regex = re.compile(r'(.*)/([a-f0-9\-]+)/([^/]*)$')
    new_dir_regex = re.compile(r'(.*)/[a-f0-9]{2}/[a-f0-9\-]{36}/[^/]*$')
    for resource in model.Session.query(model.Resource). \
            filter(model.Resource.state != model.State.DELETED):
        if not resource.cache_url or resource.cache_url == 'None':
            continue
        if new_dir_regex.match(resource.cache_url):
            print('Resource with new url already: %s' % resource.cache_url)
            continue
        match = old_dir_regex.match(resource.cache_url)
        if not match:
            print('ERROR Could not match url: %s' % resource.cache_url)
            continue
        url_base, res_id, filename = match.groups()
        # check the package isn't deleted
        # Need to refresh the resource's session
        resource = model.Session.query(model.Resource).get(resource.id)
        if p.toolkit.check_ckan_version(max_version='2.2.99'):
            package = None
            if resource.resource_group:
                package = resource.resource_group.package
        else:
            package = resource.package

        if package and package.state == model.State.DELETED:
            print('Package is deleted')
            continue

        if url_base != site_url_base:
            print('ERROR Base URL is incorrect: %r != %r' % (url_base, site_url_base))
            continue

        # move the file
        filepath_base = config['ckanext-archiver.archive_dir']
        old_path = os.path.join(filepath_base, resource.id)
        new_dir = os.path.join(filepath_base, resource.id[:2])
        new_path = os.path.join(filepath_base, resource.id[:2], resource.id)
        new_filepath = os.path.join(new_path, filename)
        if not os.path.exists(new_dir):
            os.mkdir(new_dir)
        if os.path.exists(new_path) and not os.path.exists(old_path):
            print('File already moved: %s' % new_path)
        else:
            print('File: "%s" -> "%s"' % (old_path, new_path))
            try:
                shutil.move(old_path, new_path)
            except IOError as e:
                print('ERROR moving resource: %s' % e)
                continue

        # change the cache_url and cache_filepath
        new_cache_url = '/'.join((url_base, res_id[:2], res_id, filename))
        print('cache_filepath: "%s" -> "%s"' % (resource.extras.get('cache_filepath'), new_filepath))
        print('cache_url: "%s" -> "%s"' % (resource.cache_url, new_cache_url))
        context = {'model': model, 'user': site_user['name'], 'ignore_auth': True, 'session': model.Session}
        data_dict = {'id': resource.id}
        res_dict = get_action('resource_show')(context, data_dict)
        res_dict['cache_filepath'] = new_filepath
        res_dict['cache_url'] = new_cache_url
        data_dict = res_dict
        result = get_action('resource_update')(context, data_dict)
        if result.get('id') == res_id:
            print('Successfully updated resource')
        else:
            print('ERROR updating resource: %r' % result)