wp_check_comment_flood() WordPress Function

function wp_check_comment_flood( $is_flood, $ip, $email, $date, $avoid_die = false ) {

	global $wpdb;

	// Another callback has declared a flood. Trust it.
	if ( true === $is_flood ) {
		return $is_flood;
	}

	// Don't throttle admins or moderators.
	if ( current_user_can( 'manage_options' ) || current_user_can( 'moderate_comments' ) ) {
		return false;
	}

	$hour_ago = gmdate( 'Y-m-d H:i:s', time() - HOUR_IN_SECONDS );

	if ( is_user_logged_in() ) {
		$user         = get_current_user_id();
		$check_column = '`user_id`';
	} else {
		$user         = $ip;
		$check_column = '`comment_author_IP`';
	}

	$sql = $wpdb->prepare(
		"SELECT `comment_date_gmt` FROM `$wpdb->comments` WHERE `comment_date_gmt` >= %s AND ( $check_column = %s OR `comment_author_email` = %s ) ORDER BY `comment_date_gmt` DESC LIMIT 1",
		$hour_ago,
		$user,
		$email
	);

	$lasttime = $wpdb->get_var( $sql );

	if ( $lasttime ) {
		$time_lastcomment = mysql2date( 'U', $lasttime, false );
		$time_newcomment  = mysql2date( 'U', $date, false );

		/**
		 * Filters the comment flood status.
		 *
		 * @since 2.1.0
		 *
		 * @param bool $bool             Whether a comment flood is occurring. Default false.
		 * @param int  $time_lastcomment Timestamp of when the last comment was posted.
		 * @param int  $time_newcomment  Timestamp of when the new comment was posted.
		 */
		$flood_die = apply_filters( 'comment_flood_filter', false, $time_lastcomment, $time_newcomment );

		if ( $flood_die ) {
			/**
			 * Fires before the comment flood message is triggered.
			 *
			 * @since 1.5.0
			 *
			 * @param int $time_lastcomment Timestamp of when the last comment was posted.
			 * @param int $time_newcomment  Timestamp of when the new comment was posted.
			 */
			do_action( 'comment_flood_trigger', $time_lastcomment, $time_newcomment );

			if ( $avoid_die ) {
				return true;
			} else {
				/**
				 * Filters the comment flood error message.
				 *
				 * @since 5.2.0
				 *
				 * @param string $comment_flood_message Comment flood error message.
				 */
				$comment_flood_message = apply_filters( 'comment_flood_message', __( 'You are posting comments too quickly. Slow down.' ) );

				if ( wp_doing_ajax() ) {
					die( $comment_flood_message );
				}

				wp_die( $comment_flood_message, 429 );
			}
		}
	}

	return false;
}