public void determineExecutionPlan() {
List<TaskInfo> nodeQueue =
CollectionUtils.collect(
new ArrayList<Task>(entryTasks),
new Transformer<TaskInfo, Task>() {
public TaskInfo transform(Task original) {
return graph.getNode(original);
}
});
Set<TaskInfo> visitingNodes = new HashSet<TaskInfo>();
while (!nodeQueue.isEmpty()) {
TaskInfo taskNode = nodeQueue.get(0);
boolean filtered = !filter.isSatisfiedBy(taskNode.getTask());
if (filtered) {
taskNode.setRequired(false);
}
if (!taskNode.getRequired() || executionPlan.containsKey(taskNode.getTask())) {
nodeQueue.remove(0);
continue;
}
if (visitingNodes.add(taskNode)) {
// Have not seen this task before - add its dependencies to the head of the queue and leave
// this
// task in the queue
ArrayList<TaskInfo> dependsOnTasks = new ArrayList<TaskInfo>();
addAllReversed(dependsOnTasks, taskNode.getHardSuccessors());
addAllReversed(dependsOnTasks, taskNode.getSoftSuccessors());
for (TaskInfo dependsOnTask : dependsOnTasks) {
if (visitingNodes.contains(dependsOnTask)) {
throw new CircularReferenceException(
String.format(
"Circular dependency between tasks. Cycle includes [%s, %s].",
taskNode.getTask(), dependsOnTask.getTask()));
}
nodeQueue.add(0, dependsOnTask);
}
} else {
// Have visited this task's dependencies - add it to the end of the plan
nodeQueue.remove(0);
visitingNodes.remove(taskNode);
executionPlan.put(taskNode.getTask(), taskNode);
}
}
}
