Limit View Content Hook to once per post

/**
 * View Content Hook Adjustment
 * Force the View Content hook to only award points once per post.
 * @version 1.1.2
 */
add_filter( 'mycred_add', 'mycred_pro_view_once_per_post', 10, 3 );
function mycred_pro_view_once_per_post( $reply, $request, $mycred ) {

    if ( ! in_array( $request['ref'], array( 'view_content', 'view_content_author' ) ) || $reply === false ) return $reply;

    extract( $request );

    if ( $mycred->has_entry( $ref, $ref_id, $user_id, $data, $type ) )
        return false;

    return $reply;

}