woothemes/woocommerce

<?php
/**
 * Provide basic rate limiting functionality via WP Options API.
 *
 * Currently only provides a simple limit by delaying action by X seconds.
 *
 * Example usage:
 *
 * When an action runs, call set_rate_limit, e.g.:
 *
 * WC_Rate_Limiter::set_rate_limit( "{$my_action_name}_{$user_id}", $delay );
 *
 * This sets a timestamp for future timestamp after which action can run again.
 *
 *
 * Then before running the action again, check if the action is allowed to run, e.g.:
 *
 * if ( WC_Rate_Limiter::retried_too_soon( "{$my_action_name}_{$user_id}" ) ) {
 *     add_notice( 'Sorry, too soon!' );
 * }
 *
 * @package WooCommerce\Classes
 * @version 3.9.0
 * @since   3.9.0
 */

defined( 'ABSPATH' ) || exit;

/**
 * Rate limit class.
 */
class WC_Rate_Limiter {

    /**
     * Constructs Option name from action identifier.
     *
     * @param string $action_id Identifier of the action.
     * @return string
     */
    public static function storage_id( $action_id ) {
        return 'woocommerce_rate_limit_' . $action_id;
    }

    /**
     * Returns true if the action is not allowed to be run by the rate limiter yet, false otherwise.
     *
     * @param string $action_id Identifier of the action.
     * @return bool
     */
    public static function retried_too_soon( $action_id ) {
        $next_try_allowed_at = get_option( self::storage_id( $action_id ) );

        // No record of action running, so action is allowed to run.
        if ( false === $next_try_allowed_at ) {
            return false;
        }

        // Before the next run is allowed, retry forbidden.
        if ( time() <= $next_try_allowed_at ) {
            return true;
        }

        // After the next run is allowed, retry allowed.
        return false;
    }

    /**
     * Sets the rate limit delay in seconds for action with identifier $id.
     *
     * @param string $action_id Identifier of the action.
     * @param int    $delay Delay in seconds.
     * @return bool True if the option setting was successful, false otherwise.
     */
    public static function set_rate_limit( $action_id, $delay ) {
        $option_name         = self::storage_id( $action_id );
        $next_try_allowed_at = time() + $delay;
        return update_option( $option_name, $next_try_allowed_at );
    }
}