/// <summary>
/// ContinueWith specified <see cref="Action{T}" /> on each <see cref="Task" /> on the GraphSet
/// </summary>
/// <typeparam name="T">Type of the elements</typeparam>
/// <param name="set">The set.</param>
/// <param name="action">The action.</param>
/// <returns><see cref="GraphSet{TaskPair}" /> with continuation tasks.</returns>
/// <exception cref="System.InvalidOperationException">Cannot process task on a cyclic graph</exception>
public static GraphSet <TaskPair <T> > ContinueWith <T>(this GraphSet <TaskPair <T> > set, Action <T> action)
{
if (set.IsCyclic())
{
throw new InvalidOperationException("Cannot process task on a cyclic graph");
}
var tasks = new Dictionary <GraphNode <TaskPair <T> >, Task>();
var taskSet = set.ToGraphSet(x => new TaskPair <T>(x.Value)
{
Task = x.Task
});
foreach (var node in taskSet.GetNodes())
{
tasks[node] = node.Value.Task;
node.Value.Task = null;
}
var nodes = taskSet.GetNodes().Where(n => n.Parents.Count == 0).ToArray();
foreach (var node in nodes)
{
node.Value.Task = tasks[node].ContinueWith(t => action(node.Value.Value));
}
var queue = new Queue <GraphNode <TaskPair <T> > >(nodes);
while (queue.Any())
{
var node = queue.Dequeue();
if (node.Value.Task == null)
{
var allParentsHaveTask = node.Parents.All(x => x.Value.Task != null);
if (allParentsHaveTask)
{
var list = node.Parents.Select(x => x.Value.Task).ToList();
list.Add(tasks[node]);
node.Value.Task = Task.Factory.ContinueWhenAll(
list.ToArray(),
x => action(node.Value.Value));
}
queue.Enqueue(node);
}
else
{
foreach (var child in node.Children)
{
if (child.Value.Task == null)
{
queue.Enqueue(child);
}
}
}
}
return(taskSet);
}
/// <summary>
/// ContinueWith specified <see cref="Action{T}" /> on the leaves of the GraphSet.
/// </summary>
/// <typeparam name="T">Type of the elements</typeparam>
/// <param name="set">The set.</param>
/// <param name="action">The action.</param>
/// <returns><see cref="GraphSet{TaskPair}" /> with continuation tasks.</returns>
/// <exception cref="System.InvalidOperationException">Cannot process task on a cyclic graph</exception>
public static GraphSet <TaskPair <T> > ContinueOnLeavesWith <T>(this GraphSet <TaskPair <T> > set, Action <T> action)
{
if (set.IsCyclic())
{
throw new InvalidOperationException("Cannot process task on a cyclic graph");
}
var taskSet = set.ToGraphSet(x => new TaskPair <T>(x.Value)
{
Task = x.Task
});
var graphNodes = taskSet.GetNodes().Where(x => x.Children.Count == 0);
foreach (var node in graphNodes)
{
node.Value.Task = node.Value.Task.ContinueWith(x => action(node.Value.Value));
}
return(taskSet);
}
/// <summary>
/// Transforms a <see cref="GraphSet{T}" /> to a GraphSet of Task executing the <see cref="Action{T}" /> on
/// each of the nodes while respecting the graph order.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="set">The set.</param>
/// <param name="action">The action.</param>
/// <returns>
/// <see cref="GraphSet{TaskPair}" />
/// </returns>
/// <exception cref="System.InvalidOperationException">Cannot process task on a cyclic graph</exception>
public static GraphSet <TaskPair <T> > ToTaskGraph <T>(this GraphSet <T> set, Action <T> action)
{
if (set.IsCyclic())
{
throw new InvalidOperationException("Cannot process task on a cyclic graph");
}
var taskSet = set.ToGraphSet(x => new TaskPair <T>(x));
var nodes = taskSet.GetNodes().Where(n => n.Parents.Count == 0).ToArray();
foreach (var node in nodes)
{
node.Value.Task = Task.Factory.StartNew(() => { action(node.Value.Value); });
}
var queue = new Queue <GraphNode <TaskPair <T> > >(nodes);
while (queue.Any())
{
var node = queue.Dequeue();
if (node.Value.Task == null)
{
var allParentsHaveTask = node.Parents.All(x => x.Value.Task != null);
if (allParentsHaveTask)
{
node.Value.Task = Task.Factory.ContinueWhenAll(
node.Parents.Select(x => x.Value.Task).ToArray(),
x => { action(node.Value.Value); });
}
queue.Enqueue(node);
}
else
{
foreach (var child in node.Children)
{
if (child.Value.Task == null)
{
queue.Enqueue(child);
}
}
}
}
return(taskSet);
}
