public Future unschedule()

in server/src/main/java/org/apache/cassandra/sidecar/tasks/PeriodicTaskExecutor.java [177:225]
41 lines of code
6 McCabe index (conditional complexity)

    public Future<Void> unschedule(PeriodicTask task)
    {
        PeriodicTaskKey key = new PeriodicTaskKey(task);
        AtomicBoolean alreadyUnscheduled = new AtomicBoolean(false);
        Long timerId = timerIds.computeIfPresent(key, (k, tid) -> {
            alreadyUnscheduled.set(tid == UNSCHEDULED_STATE_TIMER_ID);
            if (tid > 0)
            {
                // Best-effort on cancelling the timer
                internalPool.cancelTimer(tid);
            }
            return UNSCHEDULED_STATE_TIMER_ID;
        });
        if (timerId == null)
        {
            LOGGER.debug("No such task to unschedule. task='{}'", key);
            return Future.failedFuture("No such task to unschedule");
        }

        if (alreadyUnscheduled.get())
        {
            LOGGER.debug("Task is already unscheduled. task='{}'", key);
            return Future.failedFuture("Task is already unscheduled");
        }

        LOGGER.debug("Unscheduling task. task='{}' timerId={}", key, timerId);

        // The current run might have started already.
        // If so, close the task once the run is completed; the task entry is removed on the next schedule.
        // Otherwise, the task entry should be removed here, as there are no more schedules.
        boolean removeEntry = !activeRuns.containsKey(key);
        return activeRuns
               .getOrDefault(key, Future.succeededFuture())
               .andThen(ignored -> {
                   try
                   {
                       task.close();
                   }
                   catch (Throwable cause)
                   {
                       // just log any error while closing and continue
                       LOGGER.warn("Failed to close task during unscheduling. task='{}'", key, cause);
                   }
                   if (removeEntry)
                   {
                       timerIds.remove(key);
                   }
               });
    }