private NodeTask BuildDependencyTree(string rootTask)
{
Queue<NodeTask> notProcessedNodes = new Queue<NodeTask>();
NodeTask rootNode = new NodeTask(rootTask);
taskToNode.Add(rootTask, rootNode);
notProcessedNodes.Enqueue(rootNode);
while (notProcessedNodes.Count > 0)
{
NodeTask currentNode = notProcessedNodes.Dequeue();
if (!taskToDescription.ContainsKey(currentNode.Name))
{
throw new BuildSystemException(String.Format("No declaration for task \"{0}\" found.", rootTask));
}
IList<string> dependencies = taskToDescription[currentNode.Name].Dependencies;
IList<NodeTask> children = new List<NodeTask>(dependencies.Count);
foreach (var child in dependencies)
{
if (taskToNode.ContainsKey(child))
{
children.Add(taskToNode[child]);
}
else
{
NodeTask childNode = new NodeTask(child);
taskToNode.Add(child, childNode);
children.Add(childNode);
notProcessedNodes.Enqueue(childNode);
}
}
currentNode.Children = children;
}
return rootNode;
}
private void SatisfyNodeTask(NodeTask node)
{
Stack<NodeTask> notSatisfiedTasks = new Stack<NodeTask>();
Console.WriteLine("\"{0}\" task is started.", node.Name);
notSatisfiedTasks.Push(node);
while (notSatisfiedTasks.Count > 0)
{
bool continueFlag = false;
NodeTask current = notSatisfiedTasks.Peek();
foreach (var child in current.Children)
{
if (!child.Satisfied)
{
Console.WriteLine("\"{0}\" task is started.", child.Name);
notSatisfiedTasks.Push(child);
continueFlag = true;
break;
}
}
if (continueFlag)
{
continue;
}
ExecuteActions(taskToDescription[current.Name].Actions);
current.Satisfied = true;
Console.WriteLine("\"{0}\" task is finished.", current.Name);
notSatisfiedTasks.Pop();
}
}
private void SatisfyInitialTask()
{
if (!File.Exists(makefileName))
{
throw new BuildSystemException(String.Format("File \"{0}\" doesn't exist.", makefileName));
}
// first pass through file
ReadDependeciesForAllTasks();
initialTaskDependencyTree = BuildDependencyTree(initialTask);
if (!NoCycles(initialTaskDependencyTree))
{
throw new BuildSystemException("Cannot determine the order of execution: circular dependency found.");
}
// second pass through file
ReadActionsForTasksFromDependencyTree();
SatisfyNodeTask(initialTaskDependencyTree);
}
private bool NoCycles(NodeTask node)
{
Stack<NodeTask> notProcessedNodes = new Stack<NodeTask>();
node.State = 1;
notProcessedNodes.Push(node);
while (notProcessedNodes.Count > 0)
{
bool continueFlag = false;
NodeTask current = notProcessedNodes.Peek();
foreach (var child in current.Children)
{
if (child.State == 1)
{
return false;
}
if (child.State == 0)
{
child.State = 1;
notProcessedNodes.Push(child);
continueFlag = true;
break;
}
}
if (continueFlag)
{
continue;
}
// all children are black =)
current.State = 2;
notProcessedNodes.Pop();
}
return true;
}