diff --git a/composer.json b/composer.json
index d4169af995e569c16014e6a95f02b4816150c1f7..9bb13dcfe93e6719852863c1854563d3627574c1 100644
--- a/composer.json
+++ b/composer.json
@@ -12,6 +12,7 @@
"php": ">=7.1",
"ahand/mobileesp": "dev-master",
"cap60552/php-sip2": "1.0.0",
+ "colinmollenhour/credis": "1.10.1",
"endroid/qr-code": "3.5.8",
"ghislainf/zf2-whoops": "dev-master#2649cf7caf400409942ddc3f8fe15b89381fc74e",
"jasig/phpcas": "1.3.7",
diff --git a/config/vufind/config.ini b/config/vufind/config.ini
index 93b31fcee24479db1d9ea5cf5cd9af595769075f..256e3d17577fde772b707e4a1df778fa0b809448 100644
--- a/config/vufind/config.ini
+++ b/config/vufind/config.ini
@@ -151,7 +151,7 @@ nonJavascriptSupportEnabled = false
generator = "VuFind 6.0"
; This section allows you to configure the mechanism used for storing user
-; sessions. Available types: File, Memcache, Database.
+; sessions. Available types: File, Memcache, Database, Redis.
; Some of the settings below only apply to specific session handlers;
; such settings are named with an obvious prefix. Non-prefixed settings
; are global to all handlers.
@@ -169,6 +169,15 @@ secure = false
;memcache_host = localhost
;memcache_port = 11211
;memcache_connection_timeout = 1
+;
+; Settings related to Redis-based sessions; default values are listed below
+;redis_host = localhost
+;redis_port = 6379
+;redis_connection_timeout = 0.5
+;redis_db = 0
+;redis_auth = some_secret_password
+;redis_version = 3
+;redis_standalone = true
; This section controls how VuFind creates cookies (to store session IDs, bookbag
; contents, theme/language settings, etc.)
diff --git a/module/VuFind/src/VuFind/Session/PluginManager.php b/module/VuFind/src/VuFind/Session/PluginManager.php
index 456afc02709d1b3ea83ce37eec083f82aa5ae5be..6927865aa57f51412950e035a6fea0e604784f0d 100644
--- a/module/VuFind/src/VuFind/Session/PluginManager.php
+++ b/module/VuFind/src/VuFind/Session/PluginManager.php
@@ -52,6 +52,7 @@ class PluginManager extends \VuFind\ServiceManager\AbstractPluginManager
'database' => Database::class,
'file' => File::class,
'memcache' => Memcache::class,
+ 'redis' => Redis::class,
// for legacy 1.x compatibility
'filesession' => File::class,
'memcachesession' => Memcache::class,
@@ -67,6 +68,7 @@ class PluginManager extends \VuFind\ServiceManager\AbstractPluginManager
Database::class => InvokableFactory::class,
File::class => InvokableFactory::class,
Memcache::class => InvokableFactory::class,
+ Redis::class => InvokableFactory::class,
];
/**
@@ -78,6 +80,7 @@ class PluginManager extends \VuFind\ServiceManager\AbstractPluginManager
Database::class => [SecureDelegatorFactory::class],
File::class => [SecureDelegatorFactory::class],
Memcache::class => [SecureDelegatorFactory::class],
+ Redis::class => [SecureDelegatorFactory::class],
];
/**
diff --git a/module/VuFind/src/VuFind/Session/Redis.php b/module/VuFind/src/VuFind/Session/Redis.php
new file mode 100644
index 0000000000000000000000000000000000000000..3a1f36f37efb6a9751aed4e913abc799b69c7396
--- /dev/null
+++ b/module/VuFind/src/VuFind/Session/Redis.php
@@ -0,0 +1,138 @@
+<?php
+/**
+ * Redis session handler
+ *
+ * Note: Using phpredis extension (see https://github.com/phpredis/phpredis) is
+ * optional, this class use Credis in standalone mode by default
+ *
+ * PHP version 7
+ *
+ * Coypright (C) Moravian Library 2019.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * @category VuFind
+ * @package Session_Handlers
+ * @author Veros Kaplan <cpk-dev@mzk.cz>
+ * @author Josef Moravec <moravec@mzk.cz>
+ * @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License
+ * @link http://vufind.org/wiki/vufind2:session_handlers Wiki
+ */
+namespace VuFind\Session;
+
+/**
+ * Redis session handler
+ *
+ * @category VuFind
+ * @package Session_Handlers
+ * @author Veros Kaplan <cpk-dev@mzk.cz>
+ * @author Josef Moravec <moravec@mzk.cz>
+ * @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License
+ * @link http://vufind.org/wiki/vufind2:session_handlers Wiki
+ */
+class Redis extends AbstractBase
+{
+ /**
+ * Redis connection
+ *
+ * @var \Credis_Client
+ */
+ protected $connection = false;
+
+ /**
+ * Redis version
+ *
+ * @var int
+ */
+ protected $redisVersion = 3;
+
+ /**
+ * Get connection to Redis
+ *
+ * @throws \Exception
+ * @return \Credis_Client
+ */
+ protected function getConnection()
+ {
+ if (!$this->connection) {
+ // Set defaults if nothing set in config file.
+ $host = $this->config->redis_host ?? 'localhost';
+ $port = $this->config->redis_port ?? 6379;
+ $timeout = $this->config->redis_connection_timeout ?? 0.5;
+ $auth = $this->config->redis_auth ?? false;
+ $redis_db = $this->config->redis_db ?? 0;
+ $this->redisVersion = int($this->config->redis_version ?? 3);
+ $standalone = bool($this->config->redis_standalone ?? true);
+
+ // Create Credis client, the connection is established lazily
+ $this->connection = new \Credis_Client(
+ $host, $port, $timeout, '', $redis_db, $auth
+ );
+ if ($standalone) {
+ $this->connection->forceStandalone();
+ }
+ }
+ return $this->connection;
+ }
+
+ /**
+ * Read function must return string value always to make save handler work as
+ * expected. Return empty string if there is no data to read.
+ *
+ * @param string $sess_id The session ID to read
+ *
+ * @return string
+ */
+ public function read($sess_id)
+ {
+ $session = $this->getConnection()->get("vufind_sessions/{$sess_id}");
+ return $session !== false ? $session : '';
+ }
+
+ /**
+ * Write function that is called when session data is to be saved.
+ *
+ * @param string $sess_id The current session ID
+ * @param string $data The session data to write
+ *
+ * @return bool
+ */
+ public function write($sess_id, $data)
+ {
+ return $this->getConnection()->setex(
+ "vufind_sessions/{$sess_id}", $this->lifetime, $data
+ );
+ }
+
+ /**
+ * The destroy handler, this is executed when a session is destroyed with
+ * session_destroy() and takes the session id as its only parameter.
+ *
+ * @param string $sess_id The session ID to destroy
+ *
+ * @return void
+ */
+ public function destroy($sess_id)
+ {
+ // Perform standard actions required by all session methods:
+ parent::destroy($sess_id);
+
+ // Perform Redis-specific cleanup
+ if ($this->redisVersion >= 4) {
+ $this->getConnection()->unlink("vufind_sessions/{$sess_id}");
+ } else {
+ $this->getConnection()->del("vufind_sessions/{$sess_id}");
+ }
+ }
+}