wp_check_comment_flood

/**
 * Checks whether comment flooding is occurring.
 *
 * Won't run, if current user can manage options, so to not block
 * administrators.
 *
 * @since 4.7.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param bool   $is_flood  Is a comment flooding occurring?
 * @param string $ip        Comment author's IP address.
 * @param string $email     Comment author's email address.
 * @param string $date      MySQL time string.
 * @param bool   $avoid_die When true, a disallowed comment will result in the function
 *                          returning without executing wp_die() or die(). Default false.
 * @return bool Whether comment flooding is occurring.
 */
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 );