1 files changed, 253 insertions, 0 deletions
diff --git a/apps/files_external/lib/Command/Notify.php b/apps/files_external/lib/Command/Notify.php
new file mode 100644
index 00000000000..0982aa5598b
--- /dev/null
+++ b/apps/files_external/lib/Command/Notify.php
@@ -0,0 +1,253 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\Files_External\Command;
+
+use Doctrine\DBAL\Exception\DriverException;
+use OCA\Files_External\Service\GlobalStoragesService;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\Files\Notify\IChange;
+use OCP\Files\Notify\INotifyHandler;
+use OCP\Files\Notify\IRenameChange;
+use OCP\Files\Storage\INotifyStorage;
+use OCP\Files\Storage\IStorage;
+use OCP\IDBConnection;
+use OCP\IUserManager;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class Notify extends StorageAuthBase {
+	public function __construct(
+		private IDBConnection $connection,
+		private LoggerInterface $logger,
+		GlobalStoragesService $globalService,
+		IUserManager $userManager,
+	) {
+		parent::__construct($globalService, $userManager);
+	}
+
+	protected function configure(): void {
+		$this
+			->setName('files_external:notify')
+			->setDescription('Listen for active update notifications for a configured external mount')
+			->addArgument(
+				'mount_id',
+				InputArgument::REQUIRED,
+				'the mount id of the mount to listen to'
+			)->addOption(
+				'user',
+				'u',
+				InputOption::VALUE_REQUIRED,
+				'The username for the remote mount (required only for some mount configuration that don\'t store credentials)'
+			)->addOption(
+				'password',
+				'p',
+				InputOption::VALUE_REQUIRED,
+				'The password for the remote mount (required only for some mount configuration that don\'t store credentials)'
+			)->addOption(
+				'path',
+				'',
+				InputOption::VALUE_REQUIRED,
+				'The directory in the storage to listen for updates in',
+				'/'
+			)->addOption(
+				'no-self-check',
+				'',
+				InputOption::VALUE_NONE,
+				'Disable self check on startup'
+			)->addOption(
+				'dry-run',
+				'',
+				InputOption::VALUE_NONE,
+				'Don\'t make any changes, only log detected changes'
+			);
+		parent::configure();
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		[$mount, $storage] = $this->createStorage($input, $output);
+		if ($storage === null) {
+			return self::FAILURE;
+		}
+
+		if (!$storage instanceof INotifyStorage) {
+			$output->writeln('<error>Mount of type "' . $mount->getBackend()->getText() . '" does not support active update notifications</error>');
+			return self::FAILURE;
+		}
+
+		$dryRun = $input->getOption('dry-run');
+		if ($dryRun && $output->getVerbosity() < OutputInterface::VERBOSITY_VERBOSE) {
+			$output->setVerbosity(OutputInterface::VERBOSITY_VERBOSE);
+		}
+
+		$path = trim($input->getOption('path'), '/');
+		$notifyHandler = $storage->notify($path);
+
+		if (!$input->getOption('no-self-check')) {
+			$this->selfTest($storage, $notifyHandler, $output);
+		}
+
+		$notifyHandler->listen(function (IChange $change) use ($mount, $output, $dryRun): void {
+			$this->logUpdate($change, $output);
+			if ($change instanceof IRenameChange) {
+				$this->markParentAsOutdated($mount->getId(), $change->getTargetPath(), $output, $dryRun);
+			}
+			$this->markParentAsOutdated($mount->getId(), $change->getPath(), $output, $dryRun);
+		});
+		return self::SUCCESS;
+	}
+
+	private function markParentAsOutdated($mountId, $path, OutputInterface $output, bool $dryRun): void {
+		$parent = ltrim(dirname($path), '/');
+		if ($parent === '.') {
+			$parent = '';
+		}
+
+		try {
+			$storages = $this->getStorageIds($mountId, $parent);
+		} catch (DriverException $ex) {
+			$this->logger->warning('Error while trying to find correct storage ids.', ['exception' => $ex]);
+			$this->connection = $this->reconnectToDatabase($this->connection, $output);
+			$output->writeln('<info>Needed to reconnect to the database</info>');
+			$storages = $this->getStorageIds($mountId, $path);
+		}
+		if (count($storages) === 0) {
+			$output->writeln("  no users found with access to '$parent', skipping", OutputInterface::VERBOSITY_VERBOSE);
+			return;
+		}
+
+		$users = array_map(function (array $storage) {
+			return $storage['user_id'];
+		}, $storages);
+
+		$output->writeln("  marking '$parent' as outdated for " . implode(', ', $users), OutputInterface::VERBOSITY_VERBOSE);
+
+		$storageIds = array_map(function (array $storage) {
+			return intval($storage['storage_id']);
+		}, $storages);
+		$storageIds = array_values(array_unique($storageIds));
+
+		if ($dryRun) {
+			$output->writeln('  dry-run: skipping database write');
+		} else {
+			$result = $this->updateParent($storageIds, $parent);
+			if ($result === 0) {
+				//TODO: Find existing parent further up the tree in the database and register that folder instead.
+				$this->logger->info('Failed updating parent for "' . $path . '" while trying to register change. It may not exist in the filecache.');
+			}
+		}
+	}
+
+	private function logUpdate(IChange $change, OutputInterface $output): void {
+		$text = match ($change->getType()) {
+			INotifyStorage::NOTIFY_ADDED => 'added',
+			INotifyStorage::NOTIFY_MODIFIED => 'modified',
+			INotifyStorage::NOTIFY_REMOVED => 'removed',
+			INotifyStorage::NOTIFY_RENAMED => 'renamed',
+			default => '',
+		};
+
+		if ($text === '') {
+			return;
+		}
+
+		$text .= ' ' . $change->getPath();
+		if ($change instanceof IRenameChange) {
+			$text .= ' to ' . $change->getTargetPath();
+		}
+
+		$output->writeln($text, OutputInterface::VERBOSITY_VERBOSE);
+	}
+
+	private function getStorageIds(int $mountId, string $path): array {
+		$pathHash = md5(trim(\OC_Util::normalizeUnicode($path), '/'));
+		$qb = $this->connection->getQueryBuilder();
+		return $qb
+			->select('storage_id', 'user_id')
+			->from('mounts', 'm')
+			->innerJoin('m', 'filecache', 'f', $qb->expr()->eq('m.storage_id', 'f.storage'))
+			->where($qb->expr()->eq('mount_id', $qb->createNamedParameter($mountId, IQueryBuilder::PARAM_INT)))
+			->andWhere($qb->expr()->eq('path_hash', $qb->createNamedParameter($pathHash, IQueryBuilder::PARAM_STR)))
+			->execute()
+			->fetchAll();
+	}
+
+	private function updateParent(array $storageIds, string $parent): int {
+		$pathHash = md5(trim(\OC_Util::normalizeUnicode($parent), '/'));
+		$qb = $this->connection->getQueryBuilder();
+		return $qb
+			->update('filecache')
+			->set('size', $qb->createNamedParameter(-1, IQueryBuilder::PARAM_INT))
+			->where($qb->expr()->in('storage', $qb->createNamedParameter($storageIds, IQueryBuilder::PARAM_INT_ARRAY, ':storage_ids')))
+			->andWhere($qb->expr()->eq('path_hash', $qb->createNamedParameter($pathHash, IQueryBuilder::PARAM_STR)))
+			->executeStatement();
+	}
+
+	private function reconnectToDatabase(IDBConnection $connection, OutputInterface $output): IDBConnection {
+		try {
+			$connection->close();
+		} catch (\Exception $ex) {
+			$this->logger->warning('Error while disconnecting from DB', ['exception' => $ex]);
+			$output->writeln("<info>Error while disconnecting from database: {$ex->getMessage()}</info>");
+		}
+		$connected = false;
+		while (!$connected) {
+			try {
+				$connected = $connection->connect();
+			} catch (\Exception $ex) {
+				$this->logger->warning('Error while re-connecting to database', ['exception' => $ex]);
+				$output->writeln("<info>Error while re-connecting to database: {$ex->getMessage()}</info>");
+				sleep(60);
+			}
+		}
+		return $connection;
+	}
+
+
+	private function selfTest(IStorage $storage, INotifyHandler $notifyHandler, OutputInterface $output): void {
+		usleep(100 * 1000); //give time for the notify to start
+		if (!$storage->file_put_contents('/.nc_test_file.txt', 'test content')) {
+			$output->writeln('Failed to create test file for self-test');
+			return;
+		}
+		$storage->mkdir('/.nc_test_folder');
+		$storage->file_put_contents('/.nc_test_folder/subfile.txt', 'test content');
+
+		usleep(100 * 1000); //time for all changes to be processed
+		$changes = $notifyHandler->getChanges();
+
+		$storage->unlink('/.nc_test_file.txt');
+		$storage->unlink('/.nc_test_folder/subfile.txt');
+		$storage->rmdir('/.nc_test_folder');
+
+		usleep(100 * 1000); //time for all changes to be processed
+		$notifyHandler->getChanges(); // flush
+
+		$foundRootChange = false;
+		$foundSubfolderChange = false;
+
+		foreach ($changes as $change) {
+			if ($change->getPath() === '/.nc_test_file.txt' || $change->getPath() === '.nc_test_file.txt') {
+				$foundRootChange = true;
+			} elseif ($change->getPath() === '/.nc_test_folder/subfile.txt' || $change->getPath() === '.nc_test_folder/subfile.txt') {
+				$foundSubfolderChange = true;
+			}
+		}
+
+		if ($foundRootChange && $foundSubfolderChange) {
+			$output->writeln('<info>Self-test successful</info>', OutputInterface::VERBOSITY_VERBOSE);
+		} elseif ($foundRootChange) {
+			$output->writeln('<error>Error while running self-test, change is subfolder not detected</error>');
+		} else {
+			$output->writeln('<error>Error while running self-test, no changes detected</error>');
+		}
+	}
+}