feat(jobs): introduce background job classes registry

Signed-off-by: Benjamin Gaussorgues <benjamin.gaussorgues@nextcloud.com>

core/Migrations/Version34000Date20260518163022.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Core\Migrations;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\Attributes\AddIndex;
+use OCP\Migration\Attributes\CreateTable;
+use OCP\Migration\Attributes\IndexType;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+use Override;
+
+#[CreateTable(table: 'job_classes_registry', columns: ['class_id', 'class_name'], description: 'New table to map job class name to an ID')]
+#[AddIndex(table: 'job_classes_registry', type: IndexType::PRIMARY)]
+#[AddIndex(table: 'job_classes_registry', type: IndexType::UNIQUE, description: 'Ensure each class is registered only once')]
+class Version34000Date20260518163022 extends SimpleMigrationStep {
+	#[Override]
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		if (!$schema->hasTable('job_classes_registry')) {
+			$table = $schema->createTable('job_classes_registry');
+			$table->addColumn('class_id', Types::BIGINT, [
+				'autoincrement' => true,
+				'notnull' => true,
+				'unsigned' => true,
+			]);
+			$table->addColumn('class_name', Types::STRING, ['notnull' => true, 'length' => 255]);
+			$table->setPrimaryKey(['class_id']);
+			$table->addUniqueConstraint(['class_name'], 'class_index');
+
+			return $schema;
+		}
+
+		return null;
+	}
+}

lib/composer/composer/autoload_classmap.php

@@ -1250,6 +1250,7 @@ return array(
     'OC\\Avatar\\GuestAvatar' => $baseDir . '/lib/private/Avatar/GuestAvatar.php',
     'OC\\Avatar\\PlaceholderAvatar' => $baseDir . '/lib/private/Avatar/PlaceholderAvatar.php',
     'OC\\Avatar\\UserAvatar' => $baseDir . '/lib/private/Avatar/UserAvatar.php',
+    'OC\\BackgroundJob\\JobClassesRegistry' => $baseDir . '/lib/private/BackgroundJob/JobClassesRegistry.php',
     'OC\\BackgroundJob\\JobList' => $baseDir . '/lib/private/BackgroundJob/JobList.php',
     'OC\\BinaryFinder' => $baseDir . '/lib/private/BinaryFinder.php',
     'OC\\Blurhash\\Listener\\GenerateBlurhashMetadata' => $baseDir . '/lib/private/Blurhash/Listener/GenerateBlurhashMetadata.php',
@@ -1611,6 +1612,7 @@ return array(
     'OC\\Core\\Migrations\\Version33000Date20260126120000' => $baseDir . '/core/Migrations/Version33000Date20260126120000.php',
     'OC\\Core\\Migrations\\Version34000Date20260318095645' => $baseDir . '/core/Migrations/Version34000Date20260318095645.php',
     'OC\\Core\\Migrations\\Version34000Date20260415161745' => $baseDir . '/core/Migrations/Version34000Date20260415161745.php',
+    'OC\\Core\\Migrations\\Version34000Date20260518163022' => $baseDir . '/core/Migrations/Version34000Date20260518163022.php',
     'OC\\Core\\Notification\\CoreNotifier' => $baseDir . '/core/Notification/CoreNotifier.php',
     'OC\\Core\\ResponseDefinitions' => $baseDir . '/core/ResponseDefinitions.php',
     'OC\\Core\\Service\\CronService' => $baseDir . '/core/Service/CronService.php',

lib/composer/composer/autoload_static.php

@@ -1291,6 +1291,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\Avatar\\GuestAvatar' => __DIR__ . '/../../..' . '/lib/private/Avatar/GuestAvatar.php',
         'OC\\Avatar\\PlaceholderAvatar' => __DIR__ . '/../../..' . '/lib/private/Avatar/PlaceholderAvatar.php',
         'OC\\Avatar\\UserAvatar' => __DIR__ . '/../../..' . '/lib/private/Avatar/UserAvatar.php',
+        'OC\\BackgroundJob\\JobClassesRegistry' => __DIR__ . '/../../..' . '/lib/private/BackgroundJob/JobClassesRegistry.php',
         'OC\\BackgroundJob\\JobList' => __DIR__ . '/../../..' . '/lib/private/BackgroundJob/JobList.php',
         'OC\\BinaryFinder' => __DIR__ . '/../../..' . '/lib/private/BinaryFinder.php',
         'OC\\Blurhash\\Listener\\GenerateBlurhashMetadata' => __DIR__ . '/../../..' . '/lib/private/Blurhash/Listener/GenerateBlurhashMetadata.php',
@@ -1652,6 +1653,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\Core\\Migrations\\Version33000Date20260126120000' => __DIR__ . '/../../..' . '/core/Migrations/Version33000Date20260126120000.php',
         'OC\\Core\\Migrations\\Version34000Date20260318095645' => __DIR__ . '/../../..' . '/core/Migrations/Version34000Date20260318095645.php',
         'OC\\Core\\Migrations\\Version34000Date20260415161745' => __DIR__ . '/../../..' . '/core/Migrations/Version34000Date20260415161745.php',
+        'OC\\Core\\Migrations\\Version34000Date20260518163022' => __DIR__ . '/../../..' . '/core/Migrations/Version34000Date20260518163022.php',
         'OC\\Core\\Notification\\CoreNotifier' => __DIR__ . '/../../..' . '/core/Notification/CoreNotifier.php',
         'OC\\Core\\ResponseDefinitions' => __DIR__ . '/../../..' . '/core/ResponseDefinitions.php',
         'OC\\Core\\Service\\CronService' => __DIR__ . '/../../..' . '/core/Service/CronService.php',

lib/private/BackgroundJob/JobClassesRegistry.php

@@ -0,0 +1,99 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\BackgroundJob;
+
+use Doctrine\DBAL\Exception\UniqueConstraintViolationException;
+use InvalidArgumentException;
+use OCP\BackgroundJob\IJob;
+use OCP\IDBConnection;
+use OCP\Snowflake\ISnowflakeGenerator;
+
+/**
+ * Map background job classes and their ID in database
+ */
+final class JobClassesRegistry {
+	/**
+	 * @var array<string,string>
+	 */
+	private array $registry = [];
+
+	private const TABLE = 'job_classes_registry';
+
+	public function __construct(
+		private readonly IDBConnection $connection,
+		private readonly ISnowflakeGenerator $snowflakeGenerator,
+	) {
+	}
+
+	private function loadRegistry(): void {
+		if ($this->registry !== []) {
+			return;
+		}
+		$qb = $this->connection->getQueryBuilder();
+		$result = $qb->select('class_id', 'class_name')->from(self::TABLE)->executeQuery();
+		foreach ($result->iterateAssociative() as $row) {
+			$this->registry[$row['class_name']] = (string)$row['class_id'];
+		}
+	}
+
+	/**
+	 * Resolve current ID or generates a new one
+	 */
+	public function getId(string $className): string {
+		$this->loadRegistry();
+		if (isset($this->registry[$className])) {
+			return $this->registry[$className];
+		}
+
+		if (!class_exists($className)) {
+			throw new InvalidArgumentException('Class ' . $className . ' doesn’t exists');
+		}
+		if (!is_a($className, IJob::class, true)) {
+			throw new InvalidArgumentException('Class ' . $className . ' isn’t an instance of ' . IJob::class);
+		}
+
+		$qb = $this->connection->getQueryBuilder();
+		try {
+			$classId = $this->snowflakeGenerator->nextId();
+			$qb
+				->insert(self::TABLE)
+				->values([
+					'class_id' => $qb->createNamedParameter($classId),
+					'class_name' => $qb->createNamedParameter($className),
+				])
+				->executeStatement();
+			$this->registry[$className] = $classId;
+
+			return $classId;
+		} catch (UniqueConstraintViolationException $e) {
+			// Class was probably added by a concurrent process
+			// Try to load it
+			$result = $qb->select('class_id')->from(self::TABLE)->where($qb->expr()->eq('class_name', $className))->executeQuery();
+			if ($classId = $result->fetchOne()) {
+				$classId = (string)$classId;
+				$this->registry[$className] = $classId;
+
+				return $classId;
+			}
+		}
+
+		throw new \Exception('Fail to retrieve ' . $className . ' ID', previous: $e);
+	}
+
+	public function getName(string|int $classId): string {
+		$this->loadRegistry();
+		$classId = (string)$classId;
+		$className = array_search($classId, $this->registry, true);
+		if ($className === false) {
+			throw new InvalidArgumentException('Class ID ' . $classId . ' doesn’t match any class name');
+		}
+
+		return $className;
+	}
+}

lib/public/BackgroundJob/JobStatus.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\BackgroundJob;
+
+/**
+ * Background job statuses
+ *
+ * @since 34.0.0
+ */
+enum JobStatus: int {
+	/**
+	 * Background job is still running
+	 *
+	 * @since 34.0.0
+	 */
+	case RUNNING = 0;
+
+	/**
+	 * Background job completed sucessfully
+	 *
+	 * @since 34.0.0
+	 */
+	case SUCCEEDED = 1;
+
+	/**
+	 * Background job failed
+	 *
+	 * @since 34.0.0
+	 */
+	case FAILED = 2;
+
+	/**
+	 * Background job crashed the PHP process
+	 *
+	 * @since 34.0.0
+	 */
+	case CRASHED = 3;
+}

tests/lib/BackgroundJob/DummyJob.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace Test\BackgroundJob;
+
+use OCP\BackgroundJob\IJob;
+use OCP\BackgroundJob\IJobList;
+
+/**
+ * Dummy Job fo tests only
+ */
+class DummyJob implements IJob {
+	public function start(IJobList $jobList): void {
+	}
+
+	public function setId(string $id): void {
+	}
+
+	public function setLastRun(int $lastRun): void {
+	}
+
+	public function setArgument(mixed $argument): void {
+	}
+
+	public function getId(): string {
+	}
+
+	public function getLastRun(): int {
+	}
+
+	public function getArgument(): mixed {
+	}
+}

tests/lib/BackgroundJob/JobClassesRegistryTest.php

@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace Test\BackgroundJob;
+
+use InvalidArgumentException;
+use OC\BackgroundJob\JobClassesRegistry;
+use OCP\IDBConnection;
+use OCP\Server;
+use OCP\Snowflake\ISnowflakeGenerator;
+use Override;
+use Test\TestCase;
+
+/**
+ * @package Test\BackgroundJob
+ */
+#[\PHPUnit\Framework\Attributes\Group('DB')]
+class JobClassesRegistryTest extends TestCase {
+	private readonly IDBConnection $connection;
+	private readonly ISnowflakeGenerator $snowflakeGenerator;
+	private JobClassesRegistry $registry;
+
+	#[Override]
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->connection = Server::get(IDBConnection::class);
+		$this->snowflakeGenerator = Server::get(ISnowflakeGenerator::class);
+		$this->registry = new JobClassesRegistry($this->connection, $this->snowflakeGenerator);
+	}
+
+	public function testResolveNonExistingClass() {
+		$className = 'invalid_class_name_122278';
+
+		$this->expectException(InvalidArgumentException::class);
+		$this->expectExceptionMessage('Class ' . $className . ' doesn’t exists');
+		$this->registry->getId($className);
+	}
+
+	public function testResolveInvalidClass() {
+		$className = self::class;
+
+		$this->expectException(InvalidArgumentException::class);
+		$this->expectExceptionMessage('Class ' . $className . ' isn’t an instance of OCP\BackgroundJob\IJob');
+		$this->registry->getId($className);
+	}
+
+	public function testResolveValidClass() {
+		$className = DummyJob::class;
+
+		$classId = $this->registry->getId($className);
+		$this->assertIsString($classId);
+		$this->assertGreaterThan(0, $classId);
+
+		// Renew register. ID should stay the same
+		$this->registry = new JobClassesRegistry($this->connection, $this->snowflakeGenerator);
+		$newId = $this->registry->getId($className);
+		$this->assertEquals($classId, $newId);
+	}
+
+	public function testResolveValidId() {
+		$className = DummyJob::class;
+
+		$classId = $this->registry->getId($className);
+		$resolvedClass = $this->registry->getName($classId);
+
+		$this->assertEquals($className, $resolvedClass);
+	}
+
+	public function testResolveInvalidId() {
+		$classId = PHP_INT_MAX;
+		$this->expectException(InvalidArgumentException::class);
+		$this->expectExceptionMessage('Class ID ' . $classId . ' doesn’t match any class name');
+		$this->registry->getName($classId);
+	}
+}