move LDAP user attributes "sync" to background (except for ajax jobs)

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

11 files changed, 418 insertions, 35 deletions

diff --git a/apps/user_ldap/appinfo/info.xml b/apps/user_ldap/appinfo/info.xml
index 29d8b5df022..c303ef79283 100644
--- a/apps/user_ldap/appinfo/info.xml
+++ b/apps/user_ldap/appinfo/info.xml
@@ -10,7 +10,7 @@ A user logs into Nextcloud with their LDAP or AD credentials, and is granted acc
 	<licence>AGPL</licence>
 	<author>Dominik Schmidt</author>
 	<author>Arthur Schiwon</author>
-	<version>1.3.0</version>
+	<version>1.3.1</version>
 	<types>
 		<authentication/>
 	</types>
@@ -27,6 +27,7 @@ A user logs into Nextcloud with their LDAP or AD credentials, and is granted acc
 	<background-jobs>
 		<job>OCA\User_LDAP\Jobs\UpdateGroups</job>
 		<job>OCA\User_LDAP\Jobs\CleanUp</job>
+		<job>OCA\User_LDAP\Jobs\Sync</job>
 	</background-jobs>
 
 	<settings>
diff --git a/apps/user_ldap/composer/composer/autoload_classmap.php b/apps/user_ldap/composer/composer/autoload_classmap.php
index 0962fe2c4eb..7bade37d9f7 100644
--- a/apps/user_ldap/composer/composer/autoload_classmap.php
+++ b/apps/user_ldap/composer/composer/autoload_classmap.php
@@ -34,6 +34,7 @@ return array(
     'OCA\\User_LDAP\\ILDAPWrapper' => $baseDir . '/../lib/ILDAPWrapper.php',
     'OCA\\User_LDAP\\IUserLDAP' => $baseDir . '/../lib/IUserLDAP.php',
     'OCA\\User_LDAP\\Jobs\\CleanUp' => $baseDir . '/../lib/Jobs/CleanUp.php',
+    'OCA\\User_LDAP\\Jobs\\Sync' => $baseDir . '/../lib/Jobs/Sync.php',
     'OCA\\User_LDAP\\Jobs\\UpdateGroups' => $baseDir . '/../lib/Jobs/UpdateGroups.php',
     'OCA\\User_LDAP\\LDAP' => $baseDir . '/../lib/LDAP.php',
     'OCA\\User_LDAP\\LDAPProvider' => $baseDir . '/../lib/LDAPProvider.php',
diff --git a/apps/user_ldap/composer/composer/autoload_static.php b/apps/user_ldap/composer/composer/autoload_static.php
index ece7dd69d27..3a547577eca 100644
--- a/apps/user_ldap/composer/composer/autoload_static.php
+++ b/apps/user_ldap/composer/composer/autoload_static.php
@@ -49,6 +49,7 @@ class ComposerStaticInitUser_LDAP
         'OCA\\User_LDAP\\ILDAPWrapper' => __DIR__ . '/..' . '/../lib/ILDAPWrapper.php',
         'OCA\\User_LDAP\\IUserLDAP' => __DIR__ . '/..' . '/../lib/IUserLDAP.php',
         'OCA\\User_LDAP\\Jobs\\CleanUp' => __DIR__ . '/..' . '/../lib/Jobs/CleanUp.php',
+        'OCA\\User_LDAP\\Jobs\\Sync' => __DIR__ . '/..' . '/../lib/Jobs/Sync.php',
         'OCA\\User_LDAP\\Jobs\\UpdateGroups' => __DIR__ . '/..' . '/../lib/Jobs/UpdateGroups.php',
         'OCA\\User_LDAP\\LDAP' => __DIR__ . '/..' . '/../lib/LDAP.php',
         'OCA\\User_LDAP\\LDAPProvider' => __DIR__ . '/..' . '/../lib/LDAPProvider.php',
diff --git a/apps/user_ldap/lib/Access.php b/apps/user_ldap/lib/Access.php
index 012d9a47123..185d470abb7 100644
--- a/apps/user_ldap/lib/Access.php
+++ b/apps/user_ldap/lib/Access.php
@@ -58,6 +58,8 @@ use OCP\IServerContainer;
  * @package OCA\User_LDAP
  */
 class Access extends LDAPUtility implements IUserTools {
+	const UUID_ATTRIBUTES = ['entryuuid', 'nsuniqueid', 'objectguid', 'guid', 'ipauniqueid'];
+
 	/** @var \OCA\User_LDAP\Connection */
 	public $connection;
 	/** @var Manager */
@@ -518,13 +520,15 @@ class Access extends LDAPUtility implements IUserTools {
 
 	/**
 	 * returns an internal Nextcloud name for the given LDAP DN, false on DN outside of search DN
+	 *
 	 * @param string $fdn the dn of the user object
 	 * @param string $ldapName optional, the display name of the object
 	 * @param bool $isUser optional, whether it is a user object (otherwise group assumed)
 	 * @param bool|null $newlyMapped
-	 * @return string|false with with the name to use in Nextcloud
+	 * @param array|null $record
+	 * @return false|string with with the name to use in Nextcloud
 	 */
-	public function dn2ocname($fdn, $ldapName = null, $isUser = true, &$newlyMapped = null) {
+	public function dn2ocname($fdn, $ldapName = null, $isUser = true, &$newlyMapped = null, array $record = null) {
 		$newlyMapped = false;
 		if($isUser) {
 			$mapper = $this->getUserMapper();
@@ -541,7 +545,7 @@ class Access extends LDAPUtility implements IUserTools {
 		}
 
 		//second try: get the UUID and check if it is known. Then, update the DN and return the name.
-		$uuid = $this->getUUID($fdn, $isUser);
+		$uuid = $this->getUUID($fdn, $isUser, $record);
 		if(is_string($uuid)) {
 			$ncName = $mapper->getNameByUUID($uuid);
 			if(is_string($ncName)) {
@@ -800,7 +804,7 @@ class Access extends LDAPUtility implements IUserTools {
 	 * utilizing the login filter.
 	 *
 	 * @param string $loginName
-	 * @return array
+	 * @return int
 	 */
 	public function countUsersByLoginName($loginName) {
 		$loginName = $this->escapeFilterPart($loginName);
@@ -814,11 +818,22 @@ class Access extends LDAPUtility implements IUserTools {
 	 * @param string|string[] $attr
 	 * @param int $limit
 	 * @param int $offset
+	 * @param bool $forceApplyAttributes
 	 * @return array
 	 */
-	public function fetchListOfUsers($filter, $attr, $limit = null, $offset = null) {
+	public function fetchListOfUsers($filter, $attr, $limit = null, $offset = null, $forceApplyAttributes = false) {
 		$ldapRecords = $this->searchUsers($filter, $attr, $limit, $offset);
-		$this->batchApplyUserAttributes($ldapRecords);
+		$recordsToUpdate = $ldapRecords;
+		if(!$forceApplyAttributes) {
+			$isBackgroundJobModeAjax = $this->c->getConfig()
+					->getAppValue('core', 'backgroundjobs_mode', 'ajax') === 'ajax';
+			$recordsToUpdate = array_filter($ldapRecords, function($record) use ($isBackgroundJobModeAjax) {
+				$newlyMapped = false;
+				$uid = $this->dn2ocname($record['dn'][0], null, true, $newlyMapped, $record);
+				return ($uid !== false) && ($newlyMapped || $isBackgroundJobModeAjax);
+			});
+		}
+		$this->batchApplyUserAttributes($recordsToUpdate);
 		return $this->fetchList($ldapRecords, (count($attr) > 1));
 	}
 
@@ -830,16 +845,13 @@ class Access extends LDAPUtility implements IUserTools {
 	 */
 	public function batchApplyUserAttributes(array $ldapRecords){
 		$displayNameAttribute = strtolower($this->connection->ldapUserDisplayName);
-		$config = $this->c->getConfig();
-		$isBackgroundJobModeAjax = $config->getAppValue('core', 'backgroundjobs_mode', 'ajax') === 'ajax';
 		foreach($ldapRecords as $userRecord) {
 			if(!isset($userRecord[$displayNameAttribute])) {
 				// displayName is obligatory
 				continue;
 			}
-			$newlyMapped = false;
-			$ocName  = $this->dn2ocname($userRecord['dn'][0], null, true, $newlyMapped);
-			if($ocName === false || ($newlyMapped === false && !$isBackgroundJobModeAjax)) {
+			$ocName  = $this->dn2ocname($userRecord['dn'][0], null, true);
+			if($ocName === false) {
 				continue;
 			}
 			$this->cacheUserExists($ocName);
@@ -1235,7 +1247,9 @@ class Access extends LDAPUtility implements IUserTools {
 						if($key !== 'dn') {
 							$selection[$i][$key] = $this->resemblesDN($key) ?
 								$this->helper->sanitizeDN($item[$key])
-								: $item[$key];
+								: $key === 'objectguid' || $key === 'guid' ?
+									$selection[$i][$key] = $this->convertObjectGUID2Str($item[$key])
+									: $item[$key];
 						} else {
 							$selection[$i][$key] = [$this->helper->sanitizeDN($item[$key])];
 						}
@@ -1527,12 +1541,14 @@ class Access extends LDAPUtility implements IUserTools {
 
 	/**
 	 * auto-detects the directory's UUID attribute
+	 *
 	 * @param string $dn a known DN used to check against
 	 * @param bool $isUser
 	 * @param bool $force the detection should be run, even if it is not set to auto
+	 * @param array|null $ldapRecord
 	 * @return bool true on success, false otherwise
 	 */
-	private function detectUuidAttribute($dn, $isUser = true, $force = false) {
+	private function detectUuidAttribute($dn, $isUser = true, $force = false, array $ldapRecord = null) {
 		if($isUser) {
 			$uuidAttr     = 'ldapUuidUserAttribute';
 			$uuidOverride = $this->connection->ldapExpertUUIDUserAttr;
@@ -1550,10 +1566,17 @@ class Access extends LDAPUtility implements IUserTools {
 			return true;
 		}
 
-		// for now, supported attributes are entryUUID, nsuniqueid, objectGUID, ipaUniqueID
-		$testAttributes = array('entryuuid', 'nsuniqueid', 'objectguid', 'guid', 'ipauniqueid');
+		foreach(self::UUID_ATTRIBUTES as $attribute) {
+			if($ldapRecord !== null) {
+				// we have the info from LDAP already, we don't need to talk to the server again
+				if(isset($ldapRecord[$attribute])) {
+					$this->connection->$uuidAttr = $attribute;
+					return true;
+				} else {
+					continue;
+				}
+			}
 
-		foreach($testAttributes as $attribute) {
 			$value = $this->readAttribute($dn, $attribute);
 			if(is_array($value) && isset($value[0]) && !empty($value[0])) {
 				\OCP\Util::writeLog('user_ldap',
@@ -1573,9 +1596,10 @@ class Access extends LDAPUtility implements IUserTools {
 	/**
 	 * @param string $dn
 	 * @param bool $isUser
-	 * @return string|bool
+	 * @param null $ldapRecord
+	 * @return bool|string
 	 */
-	public function getUUID($dn, $isUser = true) {
+	public function getUUID($dn, $isUser = true, $ldapRecord = null) {
 		if($isUser) {
 			$uuidAttr     = 'ldapUuidUserAttribute';
 			$uuidOverride = $this->connection->ldapExpertUUIDUserAttr;
@@ -1585,14 +1609,16 @@ class Access extends LDAPUtility implements IUserTools {
 		}
 
 		$uuid = false;
-		if($this->detectUuidAttribute($dn, $isUser)) {
+		if($this->detectUuidAttribute($dn, $isUser, false, $ldapRecord)) {
 			$attr = $this->connection->$uuidAttr;
-			$uuid = $this->readAttribute($dn, $attr);
+			$uuid = isset($ldapRecord[$attr]) ? $ldapRecord[$attr] : $this->readAttribute($dn, $attr);
 			if( !is_array($uuid)
 				&& $uuidOverride !== ''
-				&& $this->detectUuidAttribute($dn, $isUser, true)) {
-					$uuid = $this->readAttribute($dn,
-												 $this->connection->$uuidAttr);
+				&& $this->detectUuidAttribute($dn, $isUser, true, $ldapRecord))
+			{
+				$uuid = isset($ldapRecord[$this->connection->$uuidAttr])
+					? $ldapRecord[$this->connection->$uuidAttr]
+					: $this->readAttribute($dn, $this->connection->$uuidAttr);
 			}
 			if(is_array($uuid) && isset($uuid[0]) && !empty($uuid[0])) {
 				$uuid = $uuid[0];
diff --git a/apps/user_ldap/lib/Configuration.php b/apps/user_ldap/lib/Configuration.php
index d971f2ffefd..8522962172b 100644
--- a/apps/user_ldap/lib/Configuration.php
+++ b/apps/user_ldap/lib/Configuration.php
@@ -282,6 +282,7 @@ class Configuration {
 			}
 			$this->saveValue($cta[$key], $value);
 		}
+		$this->saveValue('_lastChange', time());
 		$this->unsavedChanges = [];
 	}
 
diff --git a/apps/user_ldap/lib/Connection.php b/apps/user_ldap/lib/Connection.php
index 79d66189c27..1dcf9b72d7c 100644
--- a/apps/user_ldap/lib/Connection.php
+++ b/apps/user_ldap/lib/Connection.php
@@ -54,6 +54,8 @@ use OC\ServerNotAvailableException;
  * @property bool|mixed|void ldapGroupMemberAssocAttr
  * @property string ldapUuidUserAttribute
  * @property string ldapUuidGroupAttribute
+ * @property string ldapExpertUUIDUserAttr
+ * @property string ldapExpertUUIDGroupAttr
  */
 class Connection extends LDAPUtility {
 	private $ldapConnectionRes = null;
@@ -350,8 +352,8 @@ class Connection extends LDAPUtility {
 			if(!empty($uuidOverride)) {
 				$this->configuration->$effectiveSetting = $uuidOverride;
 			} else {
-				$uuidAttributes = array('auto', 'entryuuid', 'nsuniqueid',
-										'objectguid', 'guid', 'ipauniqueid');
+				$uuidAttributes = Access::UUID_ATTRIBUTES;
+				array_unshift($uuidAttributes, 'auto');
 				if(!in_array($this->configuration->$effectiveSetting,
 							$uuidAttributes)
 					&& (!is_null($this->configID))) {
diff --git a/apps/user_ldap/lib/Jobs/Sync.php b/apps/user_ldap/lib/Jobs/Sync.php
new file mode 100644
index 00000000000..179ba923123
--- /dev/null
+++ b/apps/user_ldap/lib/Jobs/Sync.php
@@ -0,0 +1,332 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\User_LDAP\Jobs;
+
+use OC\BackgroundJob\TimedJob;
+use OC\ServerNotAvailableException;
+use OCA\User_LDAP\Access;
+use OCA\User_LDAP\Configuration;
+use OCA\User_LDAP\Connection;
+use OCA\User_LDAP\FilesystemHelper;
+use OCA\User_LDAP\Helper;
+use OCA\User_LDAP\LDAP;
+use OCA\User_LDAP\LogWrapper;
+use OCA\User_LDAP\Mapping\UserMapping;
+use OCA\User_LDAP\User\Manager;
+use OCA\User_LDAP\User_LDAP;
+use OCP\Image;
+use OCP\IServerContainer;
+
+class Sync extends TimedJob {
+	/** @var IServerContainer */
+	protected $c;
+	/** @var  Helper */
+	protected $ldapHelper;
+	/** @var  LDAP */
+	protected $ldap;
+	/** @var  Manager */
+	protected $userManager;
+	/** @var UserMapping */
+	protected $mapper;
+	/** @var int */
+	protected $maxInterval = 12 * 60 * 60; // 12h
+	/** @var int */
+	protected $minInterval = 30 * 60; // 30min
+
+	public function __construct() {
+		$this->setInterval(
+			\OC::$server->getConfig()->getAppValue(
+				'user_ldap',
+				'background_sync_interval',
+				$this->minInterval
+			)
+		);
+	}
+
+	/**
+	 * updates the interval
+	 *
+	 * the idea is to adjust the interval depending on the amount of known users
+	 * and the attempt to update each user one day. At most it would run every
+	 * 30 minutes, and at least every 12 hours.
+	 */
+	public function updateInterval() {
+		$minPagingSize = $this->getMinPagingSize();
+		$mappedUsers = $this->mapper->count();
+
+		$runsPerDay = ($minPagingSize === 0) ? $this->maxInterval : $mappedUsers / $minPagingSize;
+		$interval = floor(24 * 60 * 60 / $runsPerDay);
+		$interval = min(max($interval, $this->minInterval), $this->maxInterval);
+
+		$this->c->getConfig()->setAppValue('user_ldap', 'background_sync_interval', $interval);
+	}
+
+	/**
+	 * returns the smallest configured paging size
+	 * @return int
+	 */
+	protected function getMinPagingSize() {
+		$config = $this->c->getConfig();
+		$configKeys = $config->getAppKeys('user_ldap');
+		$configKeys = array_filter($configKeys, function($key) {
+			return strpos($key, 'ldap_paging_size') !== false;
+		});
+		$minPagingSize = null;
+		foreach ($configKeys as $configKey) {
+			$pagingSize = $config->getAppValue('user_ldap', $configKey, $minPagingSize);
+			$minPagingSize = $minPagingSize === null ? $pagingSize : min($minPagingSize, $pagingSize);
+		}
+		return (int)$minPagingSize;
+	}
+
+	/**
+	 * @param array $argument
+	 */
+	protected function run($argument) {
+		$this->setArgument($argument);
+
+		$isBackgroundJobModeAjax = $this->c->getConfig()
+				->getAppValue('core', 'backgroundjobs_mode', 'ajax') === 'ajax';
+		if($isBackgroundJobModeAjax) {
+			return;
+		}
+
+		$cycleData = $this->getCycle();
+		if($cycleData === null) {
+			$cycleData = $this->determineNextCycle();
+			if($cycleData === null) {
+				$this->updateInterval();
+				return;
+			}
+		}
+
+		if(!$this->qualifiesToRun($cycleData)) {
+			$this->updateInterval();
+			return;
+		}
+
+		try {
+			$expectMoreResults = $this->runCycle($cycleData);
+			if ($expectMoreResults) {
+				$this->increaseOffset($cycleData);
+			} else {
+				$this->determineNextCycle();
+			}
+			$this->updateInterval();
+		} catch (ServerNotAvailableException $e) {
+			$this->determineNextCycle();
+		}
+	}
+
+	/**
+	 * @param array $cycleData
+	 * @return bool whether more results are expected from the same configuration
+	 */
+	public function runCycle($cycleData) {
+		$connection = new Connection($this->ldap, $cycleData['prefix']);
+		$access = new Access($connection, $this->ldap, $this->userManager, $this->ldapHelper, $this->c);
+		$access->setUserMapper($this->mapper);
+
+		$filter = $access->combineFilterWithAnd(array(
+			$access->connection->ldapUserFilter,
+			$access->connection->ldapUserDisplayName . '=*',
+			$access->getFilterPartForUserSearch('')
+		));
+		$results = $access->fetchListOfUsers(
+			$filter,
+			$access->userManager->getAttributes(),
+			$connection->ldapPagingSize,
+			$cycleData['offset'],
+			true
+		);
+
+		if($connection->ldapPagingSize === 0) {
+			return true;
+		}
+		return count($results) !== $connection->ldapPagingSize;
+	}
+
+	/**
+	 * returns the info about the current cycle that should be run, if any,
+	 * otherwise null
+	 *
+	 * @return array|null
+	 */
+	public function getCycle() {
+		$prefixes = $this->ldapHelper->getServerConfigurationPrefixes(true);
+		if(count($prefixes) === 0) {
+			return null;
+		}
+
+		$config = $this->c->getConfig();
+		$cycleData = [
+			'prefix' => $config->getAppValue('user_ldap', 'background_sync_prefix', null),
+			'offset' => (int)$config->getAppValue('user_ldap', 'background_sync_offset', 0),
+		];
+
+		if(
+			$cycleData['prefix'] !== null
+			&& in_array($cycleData['prefix'], $prefixes)
+		) {
+			return $cycleData;
+		}
+
+		return null;
+	}
+
+	/**
+	 * Save the provided cycle information in the DB
+	 *
+	 * @param array $cycleData
+	 */
+	public function setCycle(array $cycleData) {
+		$config = $this->c->getConfig();
+		$config->setAppValue('user_ldap', 'background_sync_prefix', $cycleData['prefix']);
+		$config->setAppValue('user_ldap', 'background_sync_offset', $cycleData['offset']);
+	}
+
+	/**
+	 * returns data about the next cycle that should run, if any, otherwise
+	 * null. It also always goes for the next LDAP configuration!
+	 *
+	 * @param array|null $cycleData the old cycle
+	 * @return array|null
+	 */
+	public function determineNextCycle(array $cycleData = null) {
+		$prefixes = $this->ldapHelper->getServerConfigurationPrefixes(true);
+		if(count($prefixes) === 0) {
+			return null;
+		}
+
+		// get the next prefix in line and remember it
+		$oldPrefix = $cycleData === null ? null : $cycleData['prefix'];
+		$prefix = $this->getNextPrefix($oldPrefix);
+		if($prefix === null) {
+			return null;
+		}
+		$cycleData['prefix'] = $prefix;
+		$cycleData['offset'] = 0;
+		$this->setCycle(['prefix' => $prefix, 'offset' => 0]);
+
+		return $cycleData;
+	}
+
+	/**
+	 * Checks whether the provided cycle should be run. Currently only the
+	 * last configuration change goes into account (at least one hour).
+	 *
+	 * @param $cycleData
+	 * @return bool
+	 */
+	protected function qualifiesToRun($cycleData) {
+		$config = $this->c->getConfig();
+		$lastChange = $config->getAppValue('user_ldap', $cycleData['prefix'] . '_lastChange', 0);
+		if((time() - $lastChange) > 60 * 30) {
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * increases the offset of the current cycle for the next run
+	 *
+	 * @param $cycleData
+	 */
+	protected function increaseOffset($cycleData) {
+		$ldapConfig = new Configuration($cycleData['prefix']);
+		$cycleData['offset'] += (int)$ldapConfig->ldapPagingSize;
+		$this->setCycle($cycleData);
+	}
+
+	/**
+	 * determines the next configuration prefix based on the last one (if any)
+	 *
+	 * @param string|null $lastPrefix
+	 * @return string|null
+	 */
+	protected function getNextPrefix($lastPrefix) {
+		$prefixes = $this->ldapHelper->getServerConfigurationPrefixes(true);
+		$noOfPrefixes = count($prefixes);
+		if($noOfPrefixes === 0) {
+			return null;
+		}
+		$i = $lastPrefix === null ? false : array_search($lastPrefix, $prefixes, true);
+		if($i === false) {
+			$i = -1;
+		} else {
+			$i++;
+		}
+
+		if(!isset($prefixes[$i])) {
+			$i = 0;
+		}
+		return $prefixes[$i];
+	}
+
+	/**
+	 * "fixes" DI
+	 *
+	 * @param array $argument
+	 */
+	public function setArgument($argument) {
+		if(isset($argument['c'])) {
+			$this->c = $argument['c'];
+		} else {
+			$this->c = \OC::$server;
+		}
+
+		if(isset($argument['helper'])) {
+			$this->ldapHelper = $argument['helper'];
+		} else {
+			$this->ldapHelper = new Helper($this->c->getConfig());
+		}
+
+		if(isset($argument['ldapWrapper'])) {
+			$this->ldap = $argument['ldapWrapper'];
+		} else {
+			$this->ldap = new LDAP();
+		}
+
+		if(isset($argument['userManager'])) {
+			$this->userManager = $argument['userManager'];
+		} else {
+			$this->userManager = new Manager(
+				$this->c->getConfig(),
+				new FilesystemHelper(),
+				new LogWrapper(),
+				$this->c->getAvatarManager(),
+				new Image(),
+				$this->c->getDatabaseConnection(),
+				$this->c->getUserManager(),
+				$this->c->getNotificationManager()
+			);
+		}
+
+		if(isset($argument['mapper'])) {
+			$this->mapper = $argument['mapper'];
+		} else {
+			$this->mapper = new UserMapping($this->c->getDatabaseConnection());
+		}
+	}
+}
diff --git a/apps/user_ldap/lib/Mapping/AbstractMapping.php b/apps/user_ldap/lib/Mapping/AbstractMapping.php
index 755cfadbccd..f5f56ce03d6 100644
--- a/apps/user_ldap/lib/Mapping/AbstractMapping.php
+++ b/apps/user_ldap/lib/Mapping/AbstractMapping.php
@@ -277,4 +277,19 @@ abstract class AbstractMapping {
 			->getTruncateTableSQL('`' . $this->getTableName() . '`');
 		return $this->dbc->prepare($sql)->execute();
 	}
+
+	/**
+	 * returns the number of entries in the mappings table
+	 *
+	 * @return int
+	 */
+	public function count() {
+		$qb = $this->dbc->getQueryBuilder();
+		$query = $qb->select($qb->createFunction('COUNT(`ldap_dn`)'))
+			->from($this->getTableName());
+		$res = $query->execute();
+		$count = $res->fetchColumn();
+		$res->closeCursor();
+		return (int)$count;
+	}
 }
diff --git a/apps/user_ldap/lib/User/Manager.php b/apps/user_ldap/lib/User/Manager.php
index f04106b7fbf..b04a321652c 100644
--- a/apps/user_ldap/lib/User/Manager.php
+++ b/apps/user_ldap/lib/User/Manager.php
@@ -28,6 +28,7 @@
 namespace OCA\User_LDAP\User;
 
 use OC\Cache\CappedMemoryCache;
+use OCA\User_LDAP\Access;
 use OCA\User_LDAP\LogWrapper;
 use OCA\User_LDAP\FilesystemHelper;
 use OCP\IAvatarManager;
@@ -167,8 +168,9 @@ class Manager {
 	 * @return string[]
 	 */
 	public function getAttributes($minimal = false) {
-		$attributes = array('dn', 'uid', 'samaccountname', 'memberof');
+		$attributes = array_merge(Access::UUID_ATTRIBUTES, ['dn', 'uid', 'samaccountname', 'memberof']);
 		$possible = array(
+			$this->access->getConnection()->ldapExpertUUIDUserAttr,
 			$this->access->getConnection()->ldapQuotaAttribute,
 			$this->access->getConnection()->ldapEmailAttribute,
 			$this->access->getConnection()->ldapUserDisplayName,
diff --git a/apps/user_ldap/lib/User/User.php b/apps/user_ldap/lib/User/User.php
index ed3ecedf227..afd43999c7f 100644
--- a/apps/user_ldap/lib/User/User.php
+++ b/apps/user_ldap/lib/User/User.php
@@ -190,13 +190,6 @@ class User {
 		}
 		unset($attr);
 
-		//Email
-		$attr = strtolower($this->connection->ldapEmailAttribute);
-		if(isset($ldapEntry[$attr])) {
-			$this->updateEmail($ldapEntry[$attr][0]);
-		}
-		unset($attr);
-
 		//displayName
 		$displayName = $displayName2 = '';
 		$attr = strtolower($this->connection->ldapUserDisplayName);
@@ -217,6 +210,15 @@ class User {
 		}
 		unset($attr);
 
+		//Email
+		//email must be stored after displayname, because it would cause a user
+		//change event that will trigger fetching the display name again
+		$attr = strtolower($this->connection->ldapEmailAttribute);
+		if(isset($ldapEntry[$attr])) {
+			$this->updateEmail($ldapEntry[$attr][0]);
+		}
+		unset($attr);
+
 		// LDAP Username, needed for s2s sharing
 		if(isset($ldapEntry['uid'])) {
 			$this->storeLDAPUserName($ldapEntry['uid'][0]);
diff --git a/apps/user_ldap/lib/User_LDAP.php b/apps/user_ldap/lib/User_LDAP.php
index ca157f69538..506ea36c529 100644
--- a/apps/user_ldap/lib/User_LDAP.php
+++ b/apps/user_ldap/lib/User_LDAP.php
@@ -278,7 +278,7 @@ class User_LDAP extends BackendUtility implements \OCP\IUserBackend, \OCP\UserIn
 		Util::writeLog('user_ldap',
 			'getUsers: Options: search '.$search.' limit '.$limit.' offset '.$offset.' Filter: '.$filter,
 			Util::DEBUG);
-		//do the search and translate results to owncloud names
+		//do the search and translate results to Nextcloud names
 		$ldap_users = $this->access->fetchListOfUsers(
 			$filter,
 			$this->access->userManager->getAttributes(true),