class-wp-redis-user-session-storage.php

<?php
/**
 * Offload session storage to Redis.
 *
 * @package WP_Redis_User_Session_Storage
 */

/**
 * Don't load in contexts that lack the WP_Session_Tokens class
 */
if ( ! class_exists( 'WP_Session_Tokens' ) ) {
	return;
}

/**
 * Redis-based user sessions token manager.
 *
 * @since 0.1
 */
class WP_Redis_User_Session_Storage extends WP_Session_Tokens {
	/**
	 * Holds the Redis client.
	 *
	 * @var
	 */
	private $redis;

	/**
	 * Track if Redis is available
	 *
	 * @var bool
	 */
	private $redis_connected = false;

	/**
	 * Prefix used to namespace keys
	 *
	 * @var string
	 */
	public $prefix = 'wpruss';

	/**
	 * Create Redis connection using the Redis PECL extension
	 */
	public function __construct( $user_id ) {
		// General Redis settings
		$redis = array(
			'host'       => '127.0.0.1',
			'port'       => 6379,
			'socket'     => null,
			'serializer' => Redis::SERIALIZER_PHP,
		);

		if ( defined( 'WP_REDIS_USER_SESSION_HOST' ) && WP_REDIS_USER_SESSION_HOST ) {
			$redis['host'] = WP_REDIS_USER_SESSION_HOST;
		}
		if ( defined( 'WP_REDIS_USER_SESSION_PORT' ) && WP_REDIS_USER_SESSION_PORT ) {
			$redis['port'] = WP_REDIS_USER_SESSION_PORT;
		}
		if ( defined( 'WP_REDIS_USER_SESSION_SOCKET' ) && WP_REDIS_USER_SESSION_SOCKET ) {
			$redis['socket'] = WP_REDIS_USER_SESSION_SOCKET;
		}
		if ( defined( 'WP_REDIS_USER_SESSION_AUTH' ) && WP_REDIS_USER_SESSION_AUTH ) {
			$redis['auth'] = WP_REDIS_USER_SESSION_AUTH;
		}
		if ( defined( 'WP_REDIS_USER_SESSION_DB' ) && WP_REDIS_USER_SESSION_DB ) {
			$redis['database'] = WP_REDIS_USER_SESSION_DB;
		}
		if ( defined( 'WP_REDIS_USER_SESSION_SERIALIZER' ) && WP_REDIS_USER_SESSION_SERIALIZER ) {
			$redis['serializer'] =  WP_REDIS_USER_SESSION_SERIALIZER;