LatchedActionsQueue.cs

LatchedActionsQueue.cs

public class LatchedActionsQueue {

	private List<KeyValuePair<object, Action>> actionsQueue = new List<KeyValuePair<object, Action>>();

	public void Enlist(Action action) {
		enlist(action, action);
	}

	public void Enlist<T1>(Action<T1> action, T1 p1) {
		enlist(action, () => action(p1));
	}

	public void Enlist<T1, T2>(Action<T1, T2> action, T1 p1, T2 p2) {
		enlist(action, () => action(p1, p2));
	}
	public void Enlist(object key, Action action) {
		enlist(key, action);
	}

	public void Enlist<T1>(object key, Action<T1> action, T1 p1) {
		enlist(key, () => action(p1));
	}

	public void Enlist<T1, T2>(object key, Action<T1, T2> action, T1 p1, T2 p2) {
		enlist(key, () => action(p1, p2));
	}

	void enlist(object key, Action action) {
		actionsQueue.Add(new KeyValuePair<object, Action>(key, action));
	}

	public void DequeueActions() {
		var alreadyPerformedActions = new HashSet<object>();
		foreach (var entry in actionsQueue.AsEnumerable().Reverse()) {
			if (alreadyPerformedActions.Contains(entry.Key)) {
				continue;
			}
			alreadyPerformedActions.Add(entry.Key);
			entry.Value();
		}
		actionsQueue.Clear();
	}
}
[TestFixture]
public class LatchedActionsQueueTestFixture {
	[Test]
	public void issuing_several_calls_only_executes_last_key_based_on_action() {
		var queue = new LatchedActionsQueue();

		bool doneTodo1 = false;
		bool doneTodo2 = false;
		int lastTodo1Result = default(int);
		int lastTodo2Result = default(int);

		Action<int> toDo1 = (value) =>
		{
			Assert.IsFalse(doneTodo1);
			lastTodo1Result = value;
			doneTodo1 = true;
		};

		Action<int, int> toDo2 = (value1, value2) =>
		{
			Assert.IsFalse(doneTodo2);
			lastTodo2Result = value1 + value2;
			doneTodo2 = true;
		};

		queue.Enlist(toDo1, 1);
		queue.Enlist(toDo1, 42);
		queue.Enlist(toDo2, 42, 0);
		queue.Enlist(toDo2, 42, 42);

		queue.DequeueActions();

		Assert.AreEqual(42, lastTodo1Result);
		Assert.AreEqual(84, lastTodo2Result);

	}

	[Test]
	public void issuing_several_calls_only_executes_last_arbitrary_key() {
		var queue = new LatchedActionsQueue();

		bool doneTodo2 = false;
		int lastTodo2Result = default(int);

		Action<int> toDo1 = (value) =>
		{
			Assert.Fail();
		};

		Action<int, int> toDo2 = (value1, value2) =>
		{
			Assert.IsFalse(doneTodo2);
			lastTodo2Result = value1 + value2;
			doneTodo2 = true;
		};

		queue.Enlist(1, toDo1, 1);
		queue.Enlist(1, toDo1, 42);
		queue.Enlist(1, toDo2, 42, 0);
		queue.Enlist(1, toDo2, 42, 42);

		queue.DequeueActions();

		Assert.AreEqual(84, lastTodo2Result);

	}
}