perf(cron): Delay (re)checking timed jobs

lib/private/BackgroundJob/JobList.php

@@ -20,6 +20,7 @@
 use Psr\Log\LoggerInterface;
 use function get_class;
 use function json_encode;
+use function min;
 use function strlen;
 
 class JobList implements IJobList {
@@ -209,6 +210,26 @@ public function getNext(bool $onlyTimeSensitive = false, ?array $jobClasses = nu
 				return $this->getNext($onlyTimeSensitive);
 			}
 
+			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()))

lib/public/BackgroundJob/TimedJob.php

@@ -32,6 +32,15 @@ public function setInterval(int $seconds) {
 		$this->interval = $seconds;
 	}
 
+	/**
+	 * Get the interval [seconds] for the job
+	 *
+	 * @since 32.0.0
+	 */
+	public function getInterval(): int {
+		return $this->interval;
+	}
+
 	/**
 	 * Whether the background job is time sensitive and needs to run soon after
 	 * the scheduled interval, of if it is okay to be delayed until a later time.