private static List handleSignal()

in flux/src/main/java/software/amazon/aws/clients/swf/flux/poller/DecisionTaskPoller.java [775:839]
52 lines of code
8 McCabe index (conditional complexity)

    private static List<Decision> handleSignal(WorkflowState state, BaseSignalData signal,
                                               String partitionId, String activityName, MetricRecorder metrics)
            throws JsonProcessingException {
        List<Decision> decisions = new LinkedList<>();
        switch (signal.getSignalType()) {
            case DELAY_RETRY:
                // cancel the timer...
                decisions.add(buildCancelTimerDecision(signal.getActivityId()));

                // ... then schedule it to be recreated with the specified delay.
                SignalExternalWorkflowExecutionDecisionAttributes signalAttrs
                        = buildScheduleRetrySignalAttrs(state, (DelayRetrySignalData)signal);
                Decision scheduleRetry = Decision.builder().decisionType(DecisionType.SIGNAL_EXTERNAL_WORKFLOW_EXECUTION)
                                                           .signalExternalWorkflowExecutionDecisionAttributes(signalAttrs)
                                                           .build();
                decisions.add(scheduleRetry);

                log.debug("Signaling for activity {} to be re-scheduled due to a {} signal.",
                          signal.getActivityId(), signal.getSignalType().getFriendlyName());

                metrics.addCount(formatSignalProcessedForActivityMetricName(activityName, signal.getSignalType()), 1);
                break;
            case SCHEDULE_DELAYED_RETRY:
                if (!state.getOpenTimers().containsKey(signal.getActivityId())) {
                    int delay = ((ScheduleDelayedRetrySignalData) signal).getDelayInSeconds();

                    // then re-create it with the new delay.
                    StartTimerDecisionAttributes timerAttrs = buildStartTimerDecisionAttrs(signal.getActivityId(), delay,
                                                                                           partitionId);
                    Decision startTimer = Decision.builder().decisionType(DecisionType.START_TIMER)
                                                            .startTimerDecisionAttributes(timerAttrs)
                                                            .build();
                    decisions.add(startTimer);
                    log.debug("Setting retry timer for activity {} due to a {} signal, with new delay of {} second{}",
                              signal.getActivityId(), signal.getSignalType().getFriendlyName(), delay,
                              (delay != 1 ? "s." : "."));

                    metrics.addCount(formatSignalProcessedForActivityMetricName(activityName, signal.getSignalType()), 1);
                } else {
                    log.debug("Ignoring signal {} because the timer is still open.", signal.getSignalType().getFriendlyName());
                }
                break;
            case RETRY_NOW:
                decisions.add(buildCancelTimerDecision(signal.getActivityId()));

                // Simply canceling the timer won't cause a new decision task to be scheduled, meaning the step retry would never
                // be scheduled; to solve this, we need to force a new decision task.
                decisions.add(decisionToForceNewDecision());

                log.debug("Immediately retrying activity {} due to {} signal.",
                          signal.getActivityId(), signal.getSignalType().getFriendlyName());

                metrics.addCount(formatSignalProcessedForActivityMetricName(activityName, signal.getSignalType()), 1);
                break;
            case FORCE_RESULT:
                if (state.getOpenTimers().containsKey(signal.getActivityId())) {
                    decisions.add(buildCancelTimerDecision(signal.getActivityId()));
                }
                break;
            default:
                log.warn("Ignoring signal with unknown type: {}", signal.getSignalType());
                break;
        }
        return decisions;
    }