/**
* Instantiate the Redis class.
*
* Instantiates the Redis class.
*
* @param null $persistent_id To create an instance that persists between requests, use persistent_id to specify a unique ID for the instance.
*/
public function __construct()
{
global $blog_id, $table_prefix;
// General Redis settings
$redis = array('host' => '127.0.0.1', 'port' => 6379);
if (defined('WP_REDIS_BACKEND_HOST') && WP_REDIS_BACKEND_HOST) {
$redis['host'] = WP_REDIS_BACKEND_HOST;
}
if (defined('WP_REDIS_BACKEND_PORT') && WP_REDIS_BACKEND_PORT) {
$redis['port'] = WP_REDIS_BACKEND_PORT;
}
if (defined('WP_REDIS_BACKEND_AUTH') && WP_REDIS_BACKEND_AUTH) {
$redis['auth'] = WP_REDIS_BACKEND_AUTH;
}
if (defined('WP_REDIS_BACKEND_DB') && WP_REDIS_BACKEND_DB) {
$redis['database'] = WP_REDIS_BACKEND_DB;
}
if (defined('WP_REDIS_SERIALIZER')) {
$redis['serializer'] = WP_REDIS_SERIALIZER;
} else {
$redis['serializer'] = Redis::SERIALIZER_PHP;
}
// Use Redis PECL library.
try {
$this->redis = new Redis();
$this->redis->connect($redis['host'], $redis['port']);
$this->redis->setOption(Redis::OPT_SERIALIZER, $redis['serializer']);
if (isset($redis['auth'])) {
$this->redis->auth($redis['auth']);
}
if (isset($redis['database'])) {
$this->redis->select($redis['database']);
}
$this->redis_connected = true;
} catch (RedisException $e) {
// When Redis is unavailable, fall back to the internal back by forcing all groups to be "no redis" groups
$this->no_redis_groups = array_unique(array_merge($this->no_redis_groups, $this->global_groups));
$this->redis_connected = false;
}
/**
* This approach is borrowed from Sivel and Boren. Use the salt for easy cache invalidation and for
* multi single WP installs on the same server.
*/
if (!defined('WP_CACHE_KEY_SALT')) {
define('WP_CACHE_KEY_SALT', '');
}
// Assign global and blog prefixes for use with keys
if (function_exists('is_multisite')) {
$this->global_prefix = is_multisite() || defined('CUSTOM_USER_TABLE') && defined('CUSTOM_USER_META_TABLE') ? '' : $table_prefix;
$this->blog_prefix = (is_multisite() ? $blog_id : $table_prefix) . ':';
}
}