Add OCC command to reset rendered texts

The command is meant to be used when the fonts used to render texts
("core/fonts/NotoSans-Regular.ttf" and "core/fonts/NotoSans-Bold.ttf")
are changed (for example, to add support for other scripts). The avatar
and text file previews will be removed, so they will be generated again
with the updated font when needed.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

build/psalm-baseline.xml

@@ -2641,6 +2641,11 @@
       <code>section</code>
     </UndefinedInterfaceMethod>
   </file>
+  <file src="core/Command/Preview/ResetRenderedTexts.php">
+    <InvalidReturnStatement occurrences="1">
+      <code>[]</code>
+    </InvalidReturnStatement>
+  </file>
   <file src="core/Command/Upgrade.php">
     <InvalidScalarArgument occurrences="11">
       <code>0</code>

core/Command/Preview/ResetRenderedTexts.php

@@ -0,0 +1,202 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2021, Daniel Calviño Sánchez <danxuliu@gmail.com>
+ *
+ * @author Daniel Calviño Sánchez <danxuliu@gmail.com>
+ *
+ * @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 OC\Core\Command\Preview;
+
+use OC\Preview\Storage\Root;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\Files\IMimeTypeLoader;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
+use OCP\IAvatarManager;
+use OCP\IDBConnection;
+use OCP\IUserManager;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class ResetRenderedTexts extends Command {
+
+	/** @var IDBConnection */
+	protected $connection;
+
+	/** @var IUserManager */
+	protected $userManager;
+
+	/** @var IAvatarManager */
+	protected $avatarManager;
+
+	/** @var Root */
+	private $previewFolder;
+
+	/** @var IMimeTypeLoader */
+	private $mimeTypeLoader;
+
+	public function __construct(IDBConnection $connection,
+								IUserManager $userManager,
+								IAvatarManager $avatarManager,
+								Root $previewFolder,
+								IMimeTypeLoader $mimeTypeLoader) {
+		parent::__construct();
+
+		$this->connection = $connection;
+		$this->userManager = $userManager;
+		$this->avatarManager = $avatarManager;
+		$this->previewFolder = $previewFolder;
+		$this->mimeTypeLoader = $mimeTypeLoader;
+	}
+
+	protected function configure() {
+		$this
+			->setName('preview:reset-rendered-texts')
+			->setDescription('Deletes all generated avatars and previews of text and md files')
+			->addOption('dry', 'd', InputOption::VALUE_NONE, 'Dry mode - will not delete any files - in combination with the verbose mode one could check the operations.');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$dryMode = $input->getOption('dry');
+
+		if ($dryMode) {
+			$output->writeln('INFO: The command is run in dry mode and will not modify anything.');
+			$output->writeln('');
+		}
+
+		$this->deleteAvatars($output, $dryMode);
+		$this->deletePreviews($output, $dryMode);
+
+		return 0;
+	}
+
+	private function deleteAvatars(OutputInterface $output, bool $dryMode): void {
+		$avatarsToDeleteCount = 0;
+
+		foreach ($this->getAvatarsToDelete() as [$userId, $avatar]) {
+			$output->writeln('Deleting avatar for ' . $userId, OutputInterface::VERBOSITY_VERBOSE);
+
+			$avatarsToDeleteCount++;
+
+			if ($dryMode) {
+				continue;
+			}
+
+			try {
+				$avatar->remove();
+			} catch (NotFoundException $e) {
+				// continue
+			} catch (NotPermittedException $e) {
+				// continue
+			}
+		}
+
+		$output->writeln('Deleted ' . $avatarsToDeleteCount . ' avatars');
+		$output->writeln('');
+	}
+
+	private function getAvatarsToDelete(): \Iterator {
+		foreach ($this->userManager->search('') as $user) {
+			$avatar = $this->avatarManager->getAvatar($user->getUID());
+
+			if (!$avatar->isCustomAvatar()) {
+				yield [$user->getUID(), $avatar];
+			}
+		}
+	}
+
+	private function deletePreviews(OutputInterface $output, bool $dryMode): void {
+		$previewsToDeleteCount = 0;
+
+		foreach ($this->getPreviewsToDelete() as ['name' => $previewFileId, 'path' => $filePath]) {
+			$output->writeln('Deleting previews for ' . $filePath, OutputInterface::VERBOSITY_VERBOSE);
+
+			$previewsToDeleteCount++;
+
+			if ($dryMode) {
+				continue;
+			}
+
+			try {
+				$preview = $this->previewFolder->getFolder((string)$previewFileId);
+				$preview->delete();
+			} catch (NotFoundException $e) {
+				// continue
+			} catch (NotPermittedException $e) {
+				// continue
+			}
+		}
+
+		$output->writeln('Deleted ' . $previewsToDeleteCount . ' previews');
+	}
+
+	// Copy pasted and adjusted from
+	// "lib/private/Preview/BackgroundCleanupJob.php".
+	private function getPreviewsToDelete(): \Iterator {
+		$qb = $this->connection->getQueryBuilder();
+		$qb->select('path', 'mimetype')
+			->from('filecache')
+			->where($qb->expr()->eq('fileid', $qb->createNamedParameter($this->previewFolder->getId())));
+		$cursor = $qb->execute();
+		$data = $cursor->fetch();
+		$cursor->closeCursor();
+
+		if ($data === null) {
+			return [];
+		}
+
+		/*
+		 * This lovely like is the result of the way the new previews are stored
+		 * We take the md5 of the name (fileid) and split the first 7 chars. That way
+		 * there are not a gazillion files in the root of the preview appdata.
+		 */
+		$like = $this->connection->escapeLikeParameter($data['path']) . '/_/_/_/_/_/_/_/%';
+
+		$qb = $this->connection->getQueryBuilder();
+		$qb->select('a.name', 'b.path')
+			->from('filecache', 'a')
+			->leftJoin('a', 'filecache', 'b', $qb->expr()->eq(
+				$qb->expr()->castColumn('a.name', IQueryBuilder::PARAM_INT), 'b.fileid'
+			))
+			->where(
+				$qb->expr()->andX(
+					$qb->expr()->like('a.path', $qb->createNamedParameter($like)),
+					$qb->expr()->eq('a.mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('httpd/unix-directory'))),
+					$qb->expr()->orX(
+						$qb->expr()->eq('b.mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('text/plain'))),
+						$qb->expr()->eq('b.mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('text/markdown'))),
+						$qb->expr()->eq('b.mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('text/x-markdown')))
+					)
+				)
+			);
+
+		$cursor = $qb->execute();
+
+		while ($row = $cursor->fetch()) {
+			yield $row;
+		}
+
+		$cursor->closeCursor();
+	}
+}

core/register_command.php

@@ -168,6 +168,7 @@
 	));
 
 	$application->add(\OC::$server->query(\OC\Core\Command\Preview\Repair::class));
+	$application->add(\OC::$server->query(\OC\Core\Command\Preview\ResetRenderedTexts::class));
 
 	$application->add(new OC\Core\Command\User\Add(\OC::$server->getUserManager(), \OC::$server->getGroupManager()));
 	$application->add(new OC\Core\Command\User\Delete(\OC::$server->getUserManager()));

lib/composer/composer/autoload_classmap.php

@@ -854,6 +854,7 @@
     'OC\\Core\\Command\\Maintenance\\UpdateHtaccess' => $baseDir . '/core/Command/Maintenance/UpdateHtaccess.php',
     'OC\\Core\\Command\\Maintenance\\UpdateTheme' => $baseDir . '/core/Command/Maintenance/UpdateTheme.php',
     'OC\\Core\\Command\\Preview\\Repair' => $baseDir . '/core/Command/Preview/Repair.php',
+    'OC\\Core\\Command\\Preview\\ResetRenderedTexts' => $baseDir . '/core/Command/Preview/ResetRenderedTexts.php',
     'OC\\Core\\Command\\Security\\ImportCertificate' => $baseDir . '/core/Command/Security/ImportCertificate.php',
     'OC\\Core\\Command\\Security\\ListCertificates' => $baseDir . '/core/Command/Security/ListCertificates.php',
     'OC\\Core\\Command\\Security\\RemoveCertificate' => $baseDir . '/core/Command/Security/RemoveCertificate.php',

lib/composer/composer/autoload_static.php

@@ -883,6 +883,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Core\\Command\\Maintenance\\UpdateHtaccess' => __DIR__ . '/../../..' . '/core/Command/Maintenance/UpdateHtaccess.php',
         'OC\\Core\\Command\\Maintenance\\UpdateTheme' => __DIR__ . '/../../..' . '/core/Command/Maintenance/UpdateTheme.php',
         'OC\\Core\\Command\\Preview\\Repair' => __DIR__ . '/../../..' . '/core/Command/Preview/Repair.php',
+        'OC\\Core\\Command\\Preview\\ResetRenderedTexts' => __DIR__ . '/../../..' . '/core/Command/Preview/ResetRenderedTexts.php',
         'OC\\Core\\Command\\Security\\ImportCertificate' => __DIR__ . '/../../..' . '/core/Command/Security/ImportCertificate.php',
         'OC\\Core\\Command\\Security\\ListCertificates' => __DIR__ . '/../../..' . '/core/Command/Security/ListCertificates.php',
         'OC\\Core\\Command\\Security\\RemoveCertificate' => __DIR__ . '/../../..' . '/core/Command/Security/RemoveCertificate.php',