Method ValidateSideEffectTask

chasm/tree.go:3332–3435

ValidateSideEffectTask checks whether a side effect task should still be executed. Intended for use by standby handlers. It returns two booleans: - isTaskInTree: true if the task's logical counterpart still exists in the replicated tree state (node found, InitialVersionedTransition matches, and log

(
	ctx context.Context,
	chasmTask *tasks.ChasmTask,
)

//
// If an error is returned both booleans are false.
func (n *Node) ValidateSideEffectTask(
	ctx context.Context,
	chasmTask *tasks.ChasmTask,
) (isTaskInTree bool, isValidByComponent bool, retErr error) {

	taskInfo := chasmTask.Info
	taskTypeID := taskInfo.TypeId
	registrableTask, ok := n.registry.TaskByID(taskTypeID)
	if !ok {
		return false, false, softassert.UnexpectedInternalErr(
			n.logger,
			"unknown task type id",
			fmt.Errorf("%d", taskTypeID))
	}

	if registrableTask.isPureTask {
		return false, false, softassert.UnexpectedInternalErr(
			n.logger,
			"ValidateSideEffectTask called on a Pure task, task type: ",
			fmt.Errorf("%s", registrableTask.fqType()))
	}

	node, ok := n.findNode(taskInfo.Path)
	if !ok {
		return false, false, nil
	}

	// node.serializedNode should always be available when running a side effect task.
	if transitionhistory.Compare(
		taskInfo.ComponentInitialVersionedTransition,
		node.serializedNode.Metadata.InitialVersionedTransition,
	) != 0 {
		return false, false, nil
	}

	// Verify the logical task this physical task was generated from still exists,
	// and capture it so we can use its Data pointer for the deserialization cache.
	//
	// A logical task can be dropped mid-flight (e.g. component paused then unpaused)
	// without the physical task being cancelled. Checking existence here prevents
	// stale physical tasks from executing after their logical counterpart is gone.
	//
	// TaskVersionedTransition is unset on physical tasks created before this field
	// was added; skip the check in that case to preserve backward compatibility.
	var logicalTask *persistencespb.ChasmComponentAttributes_Task
	if taskInfo.TaskVersionedTransition != nil {
		componentAttr := node.serializedNode.Metadata.GetComponentAttributes()
		for _, t := range componentAttr.GetSideEffectTasks() {
			if transitionhistory.Compare(t.VersionedTransition, taskInfo.TaskVersionedTransition) == 0 &&
				t.VersionedTransitionOffset == taskInfo.TaskVersionedTransitionOffset {
				logicalTask = t
				break
			}
		}
		if logicalTask == nil {
			return false, false, nil
		}
	}