private void runCurrentStepInstanceApproved()

in core/src/main/java/org/apache/brooklyn/core/workflow/WorkflowExecutionContext.java [1468:1584]
94 lines of code
26 McCabe index (conditional complexity)

        private void runCurrentStepInstanceApproved(WorkflowStepDefinition step) {
            stepsRun++;

            Task<?> t;
            if (continuationInstructions!=null) {
                t = step.newTaskContinuing(currentStepInstance, continuationInstructions);
                continuationInstructions = null;
            } else {
                t = step.newTask(currentStepInstance);
            }

            updateOldNextStepOnThisStepStarting();

            // about to run -- checkpoint noting current and previous steps, and updating replayable from info
            OldStepRecord currentStepRecord = oldStepInfo.compute(currentStepIndex, (index, old) -> {
                if (old == null) old = new OldStepRecord();
                old.countStarted++;

                old.workflowScratchUpdates = null;

                old.previous = MutableSet.<Integer>of(previousStepIndex == null ? STEP_INDEX_FOR_START : previousStepIndex).putAll(old.previous);
                old.previousTaskId = previousStepTaskId;
                old.nextTaskId = null;
                return old;
            });
            WorkflowReplayUtils.updateReplayableFromStep(WorkflowExecutionContext.this, step);
            oldStepInfo.compute(previousStepIndex==null ? STEP_INDEX_FOR_START : previousStepIndex, (index, old) -> {
                if (old==null) old = new OldStepRecord();
                if (previousStepIndex==null && workflowScratchVariables!=null && !workflowScratchVariables.isEmpty()) {
                    // if workflow scratch vars were initialized prior to run, we nee to save those
                    old.workflowScratch = MutableMap.copyOf(workflowScratchVariables);
                }
                old.next = MutableSet.<Integer>of(currentStepIndex).putAll(old.next);
                old.nextTaskId = t.getId();
                return old;
            });

            errorHandlerContext = null;
            errorHandlerTaskId = null;
            currentStepInstance.next = null;  // clear, eg if was set from a previous run; will be reset from step definition
            // but don't clear output, in case a step is returning to itself and wants to reference previous_step.output

            persist();

            BiConsumer<Object,Object> onFinish = (stepOutputDefinition,overrideNext) -> {
                currentStepInstance.next = WorkflowReplayUtils.getNext(overrideNext, currentStepInstance, step);
                if (stepOutputDefinition!=null) {
                    Object outputResolved = resolve(WorkflowExpressionResolution.WorkflowExpressionStage.STEP_FINISHING_POST_OUTPUT, stepOutputDefinition, Object.class);
                    currentStepInstance.setOutput(outputResolved);
                }
                if (currentStepInstance.output != null) {
                    Pair<Object, Set<Integer>> prev = getStepOutputAndBacktrackedSteps(null);
                    if (prev != null && Objects.equals(prev.getLeft(), currentStepInstance.output) && lastErrorHandlerOutput==null) {
                        // optimization, clear the value here if we can simply take it from the previous step
                        currentStepInstance.output = null;
                    }
                }
                if (workflowScratchVariablesUpdatedThisStep!=null && !workflowScratchVariablesUpdatedThisStep.isEmpty()) {
                    currentStepRecord.workflowScratchUpdates = workflowScratchVariablesUpdatedThisStep;
                }
                if (currentStepRecord.workflowScratch != null) {
                    // if we are repeating, check if we need to keep what we were repeating
                    Pair<Map<String, Object>, Set<Integer>> prev = getStepWorkflowScratchAndBacktrackedSteps(null);
                    if (prev!=null && !prev.getRight().contains(currentStepIndex) && Objects.equals(prev.getLeft(), currentStepRecord.workflowScratch)){
                        currentStepRecord.workflowScratch = null;
                    }
                }

                workflowScratchVariablesUpdatedThisStep = null;
            };

            // now run the step
            try {
                Duration duration = step.getTimeout();
                Object newOutput;
                if (duration!=null) {
                    boolean isEnded = DynamicTasks.queue(t).blockUntilEnded(duration);
                    if (isEnded) {
                        newOutput = t.getUnchecked();
                    } else {
                        t.cancel(true);
                        throw new TimeoutException("Timeout after "+duration+": "+t.getDisplayName());
                    }
                } else {
                    newOutput = DynamicTasks.queue(t).getUnchecked();
                }
                currentStepInstance.setOutput(newOutput);

                // allow output to be customized / overridden
                onFinish.accept(step.output, null);

            } catch (Exception e) {
                try {
                    handleErrorAtStep(step, t, onFinish, e);
                } catch (Exception e2) {
                    currentStepInstance.setError(e2);
                    throw e2;
                }
            } finally {
                // do this whether or not error
                oldStepInfo.compute(currentStepIndex, (index, old) -> {
                    if (old == null) {
                        log.warn("Lost old step info for " + this + ", step " + index);
                        old = new OldStepRecord();
                    }
                    if (currentStepInstance.getError()==null) old.countCompleted++;
                    // okay if this gets picked up by accident because we will check the stepIndex it records against the currentStepIndex,
                    // and ignore it if different
                    old.context = currentStepInstance;
                    return old;
                });
            }

            previousStepTaskId = currentStepInstance.taskId;
            previousStepIndex = currentStepIndex;
            moveToNextStep("Completed step "+ workflowStepReference(currentStepIndex), false);
        }