1 files changed, 454 insertions, 0 deletions
diff --git a/lib/private/BackgroundJob/JobList.php b/lib/private/BackgroundJob/JobList.php
new file mode 100644
index 00000000000..c00a51e3851
--- /dev/null
+++ b/lib/private/BackgroundJob/JobList.php
@@ -0,0 +1,454 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\BackgroundJob;
+
+use OCP\AppFramework\QueryException;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\AutoloadNotAllowedException;
+use OCP\BackgroundJob\IJob;
+use OCP\BackgroundJob\IJobList;
+use OCP\BackgroundJob\IParallelAwareJob;
+use OCP\DB\Exception;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\IConfig;
+use OCP\IDBConnection;
+use Psr\Log\LoggerInterface;
+use function get_class;
+use function json_encode;
+use function min;
+use function strlen;
+
+class JobList implements IJobList {
+	/** @var array<string, int> */
+	protected array $alreadyVisitedParallelBlocked = [];
+
+	public function __construct(
+		protected IDBConnection $connection,
+		protected IConfig $config,
+		protected ITimeFactory $timeFactory,
+		protected LoggerInterface $logger,
+	) {
+	}
+
+	public function add($job, $argument = null, ?int $firstCheck = null): void {
+		if ($firstCheck === null) {
+			$firstCheck = $this->timeFactory->getTime();
+		}
+
+		$class = ($job instanceof IJob) ? get_class($job) : $job;
+
+		$argumentJson = json_encode($argument);
+		if (strlen($argumentJson) > 4000) {
+			throw new \InvalidArgumentException('Background job arguments can\'t exceed 4000 characters (json encoded)');
+		}
+
+		$query = $this->connection->getQueryBuilder();
+		if (!$this->has($job, $argument)) {
+			$query->insert('jobs')
+				->values([
+					'class' => $query->createNamedParameter($class),
+					'argument' => $query->createNamedParameter($argumentJson),
+					'argument_hash' => $query->createNamedParameter(hash('sha256', $argumentJson)),
+					'last_run' => $query->createNamedParameter(0, IQueryBuilder::PARAM_INT),
+					'last_checked' => $query->createNamedParameter($firstCheck, IQueryBuilder::PARAM_INT),
+				]);
+		} else {
+			$query->update('jobs')
+				->set('reserved_at', $query->expr()->literal(0, IQueryBuilder::PARAM_INT))
+				->set('last_checked', $query->createNamedParameter($firstCheck, IQueryBuilder::PARAM_INT))
+				->set('last_run', $query->createNamedParameter(0, IQueryBuilder::PARAM_INT))
+				->where($query->expr()->eq('class', $query->createNamedParameter($class)))
+				->andWhere($query->expr()->eq('argument_hash', $query->createNamedParameter(hash('sha256', $argumentJson))));
+		}
+		$query->executeStatement();
+	}
+
+	public function scheduleAfter(string $job, int $runAfter, $argument = null): void {
+		$this->add($job, $argument, $runAfter);
+	}
+
+	/**
+	 * @param IJob|string $job
+	 * @param mixed $argument
+	 */
+	public function remove($job, $argument = null): void {
+		$class = ($job instanceof IJob) ? get_class($job) : $job;
+
+		$query = $this->connection->getQueryBuilder();
+		$query->delete('jobs')
+			->where($query->expr()->eq('class', $query->createNamedParameter($class)));
+		if (!is_null($argument)) {
+			$argumentJson = json_encode($argument);
+			$query->andWhere($query->expr()->eq('argument_hash', $query->createNamedParameter(hash('sha256', $argumentJson))));
+		}
+
+		// Add galera safe delete chunking if using mysql
+		// Stops us hitting wsrep_max_ws_rows when large row counts are deleted
+		if ($this->connection->getDatabaseProvider() === IDBConnection::PLATFORM_MYSQL) {
+			// Then use chunked delete
+			$max = IQueryBuilder::MAX_ROW_DELETION;
+
+			$query->setMaxResults($max);
+
+			do {
+				$deleted = $query->executeStatement();
+			} while ($deleted === $max);
+		} else {
+			// Dont use chunked delete - let the DB handle the large row count natively
+			$query->executeStatement();
+		}
+	}
+
+	public function removeById(int $id): void {
+		$query = $this->connection->getQueryBuilder();
+		$query->delete('jobs')
+			->where($query->expr()->eq('id', $query->createNamedParameter($id, IQueryBuilder::PARAM_INT)));
+		$query->executeStatement();
+	}
+
+	/**
+	 * check if a job is in the list
+	 *
+	 * @param IJob|class-string<IJob> $job
+	 * @param mixed $argument
+	 */
+	public function has($job, $argument): bool {
+		$class = ($job instanceof IJob) ? get_class($job) : $job;
+		$argument = json_encode($argument);
+
+		$query = $this->connection->getQueryBuilder();
+		$query->select('id')
+			->from('jobs')
+			->where($query->expr()->eq('class', $query->createNamedParameter($class)))
+			->andWhere($query->expr()->eq('argument_hash', $query->createNamedParameter(hash('sha256', $argument))))
+			->setMaxResults(1);
+
+		$result = $query->executeQuery();
+		$row = $result->fetch();
+		$result->closeCursor();
+
+		return (bool)$row;
+	}
+
+	public function getJobs($job, ?int $limit, int $offset): array {
+		$iterable = $this->getJobsIterator($job, $limit, $offset);
+		return (is_array($iterable))
+			? $iterable
+			: iterator_to_array($iterable);
+	}
+
+	/**
+	 * @param IJob|class-string<IJob>|null $job
+	 * @return iterable<IJob> Avoid to store these objects as they may share a Singleton instance. You should instead use these IJobs instances while looping on the iterable.
+	 */
+	public function getJobsIterator($job, ?int $limit, int $offset): iterable {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('*')
+			->from('jobs')
+			->setMaxResults($limit)
+			->setFirstResult($offset);
+
+		if ($job !== null) {
+			$class = ($job instanceof IJob) ? get_class($job) : $job;
+			$query->where($query->expr()->eq('class', $query->createNamedParameter($class)));
+		}
+
+		$result = $query->executeQuery();
+
+		while ($row = $result->fetch()) {
+			$job = $this->buildJob($row);
+			if ($job) {
+				yield $job;
+			}
+		}
+		$result->closeCursor();
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getNext(bool $onlyTimeSensitive = false, ?array $jobClasses = null): ?IJob {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('*')
+			->from('jobs')
+			->where($query->expr()->lte('reserved_at', $query->createNamedParameter($this->timeFactory->getTime() - 12 * 3600, IQueryBuilder::PARAM_INT)))
+			->andWhere($query->expr()->lte('last_checked', $query->createNamedParameter($this->timeFactory->getTime(), IQueryBuilder::PARAM_INT)))
+			->orderBy('last_checked', 'ASC')
+			->setMaxResults(1);
+
+		if ($onlyTimeSensitive) {
+			$query->andWhere($query->expr()->eq('time_sensitive', $query->createNamedParameter(IJob::TIME_SENSITIVE, IQueryBuilder::PARAM_INT)));
+		}
+
+		if (!empty($jobClasses)) {
+			$orClasses = [];
+			foreach ($jobClasses as $jobClass) {
+				$orClasses[] = $query->expr()->eq('class', $query->createNamedParameter($jobClass, IQueryBuilder::PARAM_STR));
+			}
+			$query->andWhere($query->expr()->orX(...$orClasses));
+		}
+
+		$result = $query->executeQuery();
+		$row = $result->fetch();
+		$result->closeCursor();
+
+		if ($row) {
+			$job = $this->buildJob($row);
+
+			if ($job instanceof IParallelAwareJob && !$job->getAllowParallelRuns() && $this->hasReservedJob(get_class($job))) {
+				if (!isset($this->alreadyVisitedParallelBlocked[get_class($job)])) {
+					$this->alreadyVisitedParallelBlocked[get_class($job)] = $job->getId();
+				} elseif ($this->alreadyVisitedParallelBlocked[get_class($job)] === $job->getId()) {
+					$this->logger->info('Skipped through all jobs and revisited a IParallelAwareJob blocked job again, giving up.', ['app' => 'cron']);
+					return null;
+				}
+				$this->logger->info('Skipping ' . get_class($job) . ' job with ID ' . $job->getId() . ' because another job with the same class is already running', ['app' => 'cron']);
+
+				$update = $this->connection->getQueryBuilder();
+				$update->update('jobs')
+					->set('last_checked', $update->createNamedParameter($this->timeFactory->getTime() + 1))
+					->where($update->expr()->eq('id', $update->createParameter('jobid')));
+				$update->setParameter('jobid', $row['id']);
+				$update->executeStatement();
+
+				return $this->getNext($onlyTimeSensitive, $jobClasses);
+			}
+
+			if ($job !== null && isset($this->alreadyVisitedParallelBlocked[get_class($job)])) {
+				unset($this->alreadyVisitedParallelBlocked[get_class($job)]);
+			}
+
+			if ($job instanceof \OCP\BackgroundJob\TimedJob) {
+				$now = $this->timeFactory->getTime();
+				$nextPossibleRun = $job->getLastRun() + $job->getInterval();
+				if ($now < $nextPossibleRun) {
+					// This job is not ready for execution yet. Set timestamps to the future to avoid
+					// re-checking with every cron run.
+					// To avoid bugs that lead to jobs never executing again, the future timestamp is
+					// capped at two days.
+					$nextCheck = min($nextPossibleRun, $now + 48 * 3600);
+					$updateTimedJob = $this->connection->getQueryBuilder();
+					$updateTimedJob->update('jobs')
+						->set('last_checked', $updateTimedJob->createNamedParameter($nextCheck, IQueryBuilder::PARAM_INT))
+						->where($updateTimedJob->expr()->eq('id', $updateTimedJob->createParameter('jobid')));
+					$updateTimedJob->setParameter('jobid', $row['id']);
+					$updateTimedJob->executeStatement();
+
+					return $this->getNext($onlyTimeSensitive, $jobClasses);
+				}
+			}
+
+			$update = $this->connection->getQueryBuilder();
+			$update->update('jobs')
+				->set('reserved_at', $update->createNamedParameter($this->timeFactory->getTime()))
+				->set('last_checked', $update->createNamedParameter($this->timeFactory->getTime()))
+				->where($update->expr()->eq('id', $update->createParameter('jobid')))
+				->andWhere($update->expr()->eq('reserved_at', $update->createParameter('reserved_at')))
+				->andWhere($update->expr()->eq('last_checked', $update->createParameter('last_checked')));
+			$update->setParameter('jobid', $row['id']);
+			$update->setParameter('reserved_at', $row['reserved_at']);
+			$update->setParameter('last_checked', $row['last_checked']);
+			$count = $update->executeStatement();
+
+			if ($count === 0) {
+				// Background job already executed elsewhere, try again.
+				return $this->getNext($onlyTimeSensitive, $jobClasses);
+			}
+
+			if ($job === null) {
+				// set the last_checked to 12h in the future to not check failing jobs all over again
+				$reset = $this->connection->getQueryBuilder();
+				$reset->update('jobs')
+					->set('reserved_at', $reset->expr()->literal(0, IQueryBuilder::PARAM_INT))
+					->set('last_checked', $reset->createNamedParameter($this->timeFactory->getTime() + 12 * 3600, IQueryBuilder::PARAM_INT))
+					->where($reset->expr()->eq('id', $reset->createNamedParameter($row['id'], IQueryBuilder::PARAM_INT)));
+				$reset->executeStatement();
+
+				// Background job from disabled app, try again.
+				return $this->getNext($onlyTimeSensitive, $jobClasses);
+			}
+
+			return $job;
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * @return ?IJob The job matching the id. Beware that this object may be a singleton and may be modified by the next call to buildJob.
+	 */
+	public function getById(int $id): ?IJob {
+		$row = $this->getDetailsById($id);
+
+		if ($row) {
+			return $this->buildJob($row);
+		}
+
+		return null;
+	}
+
+	public function getDetailsById(int $id): ?array {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('*')
+			->from('jobs')
+			->where($query->expr()->eq('id', $query->createNamedParameter($id, IQueryBuilder::PARAM_INT)));
+		$result = $query->executeQuery();
+		$row = $result->fetch();
+		$result->closeCursor();
+
+		if ($row) {
+			return $row;
+		}
+
+		return null;
+	}
+
+	/**
+	 * get the job object from a row in the db
+	 *
+	 * @param array{class:class-string<IJob>, id:mixed, last_run:mixed, argument:string} $row
+	 * @return ?IJob the next job to run. Beware that this object may be a singleton and may be modified by the next call to buildJob.
+	 */
+	private function buildJob(array $row): ?IJob {
+		try {
+			try {
+				// Try to load the job as a service
+				/** @var IJob $job */
+				$job = \OCP\Server::get($row['class']);
+			} catch (QueryException $e) {
+				if (class_exists($row['class'])) {
+					$class = $row['class'];
+					$job = new $class();
+				} else {
+					$this->logger->warning('failed to create instance of background job: ' . $row['class'], ['app' => 'cron', 'exception' => $e]);
+					// Remove job from disabled app or old version of an app
+					$this->removeById($row['id']);
+					return null;
+				}
+			}
+
+			if (!($job instanceof IJob)) {
+				// This most likely means an invalid job was enqueued. We can ignore it.
+				return null;
+			}
+			$job->setId((int)$row['id']);
+			$job->setLastRun((int)$row['last_run']);
+			$job->setArgument(json_decode($row['argument'], true));
+			return $job;
+		} catch (AutoloadNotAllowedException $e) {
+			// job is from a disabled app, ignore
+			return null;
+		}
+	}
+
+	/**
+	 * set the job that was last ran
+	 */
+	public function setLastJob(IJob $job): void {
+		$this->unlockJob($job);
+		$this->config->setAppValue('backgroundjob', 'lastjob', (string)$job->getId());
+	}
+
+	/**
+	 * Remove the reservation for a job
+	 */
+	public function unlockJob(IJob $job): void {
+		$query = $this->connection->getQueryBuilder();
+		$query->update('jobs')
+			->set('reserved_at', $query->expr()->literal(0, IQueryBuilder::PARAM_INT))
+			->where($query->expr()->eq('id', $query->createNamedParameter($job->getId(), IQueryBuilder::PARAM_INT)));
+		$query->executeStatement();
+	}
+
+	/**
+	 * set the lastRun of $job to now
+	 */
+	public function setLastRun(IJob $job): void {
+		$query = $this->connection->getQueryBuilder();
+		$query->update('jobs')
+			->set('last_run', $query->createNamedParameter(time(), IQueryBuilder::PARAM_INT))
+			->where($query->expr()->eq('id', $query->createNamedParameter($job->getId(), IQueryBuilder::PARAM_INT)));
+
+		if ($job instanceof \OCP\BackgroundJob\TimedJob
+			&& !$job->isTimeSensitive()) {
+			$query->set('time_sensitive', $query->createNamedParameter(IJob::TIME_INSENSITIVE));
+		}
+
+		$query->executeStatement();
+	}
+
+	/**
+	 * @param int $timeTaken
+	 */
+	public function setExecutionTime(IJob $job, $timeTaken): void {
+		$query = $this->connection->getQueryBuilder();
+		$query->update('jobs')
+			->set('execution_duration', $query->createNamedParameter($timeTaken, IQueryBuilder::PARAM_INT))
+			->set('reserved_at', $query->createNamedParameter(0, IQueryBuilder::PARAM_INT))
+			->where($query->expr()->eq('id', $query->createNamedParameter($job->getId(), IQueryBuilder::PARAM_INT)));
+		$query->executeStatement();
+	}
+
+	/**
+	 * Reset the $job so it executes on the next trigger
+	 *
+	 * @since 23.0.0
+	 */
+	public function resetBackgroundJob(IJob $job): void {
+		$query = $this->connection->getQueryBuilder();
+		$query->update('jobs')
+			->set('last_run', $query->createNamedParameter(0, IQueryBuilder::PARAM_INT))
+			->set('reserved_at', $query->createNamedParameter(0, IQueryBuilder::PARAM_INT))
+			->where($query->expr()->eq('id', $query->createNamedParameter($job->getId()), IQueryBuilder::PARAM_INT));
+		$query->executeStatement();
+	}
+
+	public function hasReservedJob(?string $className = null): bool {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('*')
+			->from('jobs')
+			->where($query->expr()->gt('reserved_at', $query->createNamedParameter($this->timeFactory->getTime() - 6 * 3600, IQueryBuilder::PARAM_INT)))
+			->setMaxResults(1);
+
+		if ($className !== null) {
+			$query->andWhere($query->expr()->eq('class', $query->createNamedParameter($className)));
+		}
+
+		try {
+			$result = $query->executeQuery();
+			$hasReservedJobs = $result->fetch() !== false;
+			$result->closeCursor();
+			return $hasReservedJobs;
+		} catch (Exception $e) {
+			$this->logger->debug('Querying reserved jobs failed', ['exception' => $e]);
+			return false;
+		}
+	}
+
+	public function countByClass(): array {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('class')
+			->selectAlias($query->func()->count('id'), 'count')
+			->from('jobs')
+			->orderBy('count')
+			->groupBy('class');
+
+		$result = $query->executeQuery();
+
+		$jobs = [];
+
+		while (($row = $result->fetch()) !== false) {
+			/**
+			 * @var array{count:int, class:class-string} $row
+			 */
+			$jobs[] = $row;
+		}
+
+		return $jobs;
+	}
+}