Merge pull request #32047 from nextcloud/performance/cache-display-name

3 files changed, 79 insertions, 0 deletions

diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 685fae9bef1..831f5229d4a 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -1540,6 +1540,7 @@ return array(
     'OC\\UserStatus\\Manager' => $baseDir . '/lib/private/UserStatus/Manager.php',
     'OC\\User\\Backend' => $baseDir . '/lib/private/User/Backend.php',
     'OC\\User\\Database' => $baseDir . '/lib/private/User/Database.php',
+    'OC\\User\\DisplayNameCache' => $baseDir . '/lib/private/User/DisplayNameCache.php',
     'OC\\User\\LoginException' => $baseDir . '/lib/private/User/LoginException.php',
     'OC\\User\\Manager' => $baseDir . '/lib/private/User/Manager.php',
     'OC\\User\\NoUserException' => $baseDir . '/lib/private/User/NoUserException.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 7e778d73b83..94719344013 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -1569,6 +1569,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\UserStatus\\Manager' => __DIR__ . '/../../..' . '/lib/private/UserStatus/Manager.php',
         'OC\\User\\Backend' => __DIR__ . '/../../..' . '/lib/private/User/Backend.php',
         'OC\\User\\Database' => __DIR__ . '/../../..' . '/lib/private/User/Database.php',
+        'OC\\User\\DisplayNameCache' => __DIR__ . '/../../..' . '/lib/private/User/DisplayNameCache.php',
         'OC\\User\\LoginException' => __DIR__ . '/../../..' . '/lib/private/User/LoginException.php',
         'OC\\User\\Manager' => __DIR__ . '/../../..' . '/lib/private/User/Manager.php',
         'OC\\User\\NoUserException' => __DIR__ . '/../../..' . '/lib/private/User/NoUserException.php',
diff --git a/lib/private/User/DisplayNameCache.php b/lib/private/User/DisplayNameCache.php
new file mode 100644
index 00000000000..ed0c723ef37
--- /dev/null
+++ b/lib/private/User/DisplayNameCache.php
@@ -0,0 +1,77 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright 2022 Carl Schwan <carl@carlschwan.eu>
+ * @license AGPL-3.0-or-later
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+
+namespace OC\User;
+
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\ICache;
+use OCP\ICacheFactory;
+use OCP\IUserManager;
+use OCP\User\Events\UserChangedEvent;
+
+/**
+ * Class that cache the relation UserId -> Display name
+ *
+ * This saves fetching the user from a user backend and later on fetching
+ * their preferences. It's generally not an issue if this data is slightly
+ * outdated.
+ */
+class DisplayNameCache implements IEventListener {
+	private ICache $internalCache;
+	private IUserManager $userManager;
+
+	public function __construct(ICacheFactory $cacheFactory, IUserManager $userManager) {
+		$this->internalCache = $cacheFactory->createDistributed('displayNameMappingCache');
+		$this->userManager = $userManager;
+	}
+
+	public function getDisplayName(string $userId) {
+		$displayName = $this->internalCache->get($userId);
+		if ($displayName) {
+			return $displayName;
+		}
+
+		$user = $this->userManager->get($userId);
+		if ($user) {
+			$displayName = $user->getDisplayName();
+		} else {
+			$displayName = $userId;
+		}
+		$this->internalCache->set($userId, $displayName, 60 * 10); // 10 minutes
+
+		return $displayName;
+	}
+
+	public function clear(): void {
+		$this->internalCache->clear();
+	}
+
+	public function handle(Event $event): void {
+		if ($event instanceof UserChangedEvent && $event->getFeature() === 'displayName') {
+			$userId = $event->getUser()->getUID();
+			$newDisplayName = $event->getValue();
+			$this->internalCache->set($userId, $newDisplayName, 60 * 10); // 10 minutes
+		}
+	}
+}