public void OrderedQueueTest()
{
var q = new OrderingQueue<string>();
q.Enqueue(0, "Zero");
Assert.True(q.CanDequeue);
Assert.AreEqual("Zero",q.Dequeue());
q.Enqueue(2, "Two");
Assert.False(q.CanDequeue);
q.Enqueue(3, "Three");
Assert.False(q.CanDequeue);
q.Enqueue(1, "One");
Assert.True(q.CanDequeue);
Assert.AreEqual("One",q.Dequeue());
Assert.True(q.CanDequeue);
Assert.AreEqual("Two",q.Dequeue());
Assert.True(q.CanDequeue);
Assert.AreEqual("Three",q.Dequeue());
Assert.False(q.CanDequeue);
}
/// <summary>
/// Get the next piece of the compressed file
/// </summary>
/// <returns>Packet containing part of the compressed file, or null, if file is ended</returns>
/// <param name="cancel">Cancellation flag</param>
public FilePacketMemoryStream Consume(out bool cancel)
{
FilePacketMemoryStream result = null;
var taken = true;
mutex.WaitOne();
try
{
cancel = cancelled;
if (cancel)
{
return(result); // Пустой результат.
}
var eventType = EventsForConsumer.PacketsExists;
// If queue is empty, begin to await when it's filled
while (queue.CountContiguous == 0 && activeCompressorThreads != 0)
{
taken = false;
mutex.ReleaseMutex();
eventType = (EventsForConsumer)WaitHandle.WaitAny(eventsForConsumer);
mutex.WaitOne();
taken = true;
if ((eventType == EventsForConsumer.PacketAppeared && queue.CountContiguous != 0) ||
eventType == EventsForConsumer.ProductionCompleted ||
eventType == EventsForConsumer.Cancel)
{
break;
}
}
// If queue is empty and all compressor threads finished their work, we are finishing our work too
if (queue.CountContiguous == 0 && activeCompressorThreads == 0)
{
return(result); // Empty result
}
switch (eventType)
{
case EventsForConsumer.PacketsExists:
case EventsForConsumer.PacketAppeared:
var hasSpace = queue.HaveSpace();
result = queue.Dequeue();
if (!hasSpace && queue.HaveSpace()) // If one new free space appeared in the queue, send signal to the producer
{
eventForNewSpaceInQueue.Set();
}
if (eventType == EventsForConsumer.PacketAppeared && queue.CountContiguous == 0)
{
eventForFirstPacketInQueue.Reset(); // Resetting our signal about packet appearing
}
break;
case EventsForConsumer.ProductionCompleted:
// Do nothing, just returning the pre-initialized empty result below
break;
case EventsForConsumer.Cancel:
cancel = true;
break;
default:
Debug.Write($"Unsupported event type for consumer: {Enum.GetName(typeof(EventsForConsumer), eventType)}");
break;
}
}
finally
{
if (taken)
{
mutex.ReleaseMutex();
}
}
return(result);
}
