void Enqueue(FilePacketArray filePacket)
{
filePacket.CopyTo(packetQueue[nextBufIndexToProduce]);
nextBufIndexToProduce++;
if (nextBufIndexToProduce == queueDepth)
{
nextBufIndexToProduce = 0;
}
queueFilledCount++;
}
ReaderCompressorSharedState(int queueDepth, int packetSize)
{
this.queueDepth = queueDepth;
this.packetSize = packetSize;
packetQueue = new FilePacketArray[queueDepth];
for (var i = 0; i < queueDepth; i++)
{
packetQueue[i] = new FilePacketArray(0, packetSize);
}
eventsForProducer[(int)EventsForProducer.SpaceAppeared] = eventForNewSpaceInQueue;
eventsForProducer[(int)EventsForProducer.Cancel] = eventForWorkCancellation;
eventsForConsumer[(int)EventsForConsumer.PacketAppeared] = eventForFirstPacketInQueue;
eventsForConsumer[(int)EventsForConsumer.ReadCompleted] = eventForInputCompletion;
eventsForConsumer[(int)EventsForConsumer.Cancel] = eventForWorkCancellation;
}
/// <summary>
/// Thread's execution body
/// </summary>
void RunThread()
{
try
{
using (var fileStream = File.OpenRead(file))
{
int bytesRead;
var packet = new FilePacketArray(0, bufSize);
var count = 0;
while ((bytesRead = fileStream.Read(packet.Buffer, 0, bufSize)) > 0)
{
packet.FilledLength = bytesRead;
outputState.Produce(packet, out var cancel);
if (cancel)
{
return;
}
packet.IncIndex();
count++;
}
if (count == 0) // If file is empty
{
packet.FilledLength = 0;
outputState.Produce(packet, out var cancel);
}
outputState.ReadCompleted();
}
}
catch (IOException)
{
SafeCancel();
Console.WriteLine("Could not read the file.");
}
catch (Exception ex)
{
SafeCancel();
Console.WriteLine("Error in file reading thread: " + ex.ToString());
}
}
/// <summary>
/// Saving "packet" of file
/// </summary>
/// <param name="filePacket">Piece of source file</param>
/// <param name="cancel">Cancellation flag</param>
public void Produce(FilePacketArray filePacket, out bool cancel)
{
Debug.Assert(filePacket != null, $"{nameof(filePacket)} is null");
Debug.Assert(filePacket.Index >= 0, $"{nameof(filePacket)}.{nameof(filePacket.Index)} must be not negative zero-based index");
var taken = true;
mutex.WaitOne();
try
{
cancel = cancelled;
if (cancelled)
{
return;
}
var eventType = EventsForProducer.SpaceExists;
// If queue is full, start awaiting for free space
while (queueFilledCount == queueDepth)
{
taken = false;
mutex.ReleaseMutex();
eventType = (EventsForProducer)WaitHandle.WaitAny(eventsForProducer);
mutex.WaitOne();
taken = true;
if ((eventType == EventsForProducer.SpaceAppeared && queueFilledCount != queueDepth) ||
eventType == EventsForProducer.Cancel)
{
break;
}
}
switch (eventType)
{
case EventsForProducer.SpaceExists:
case EventsForProducer.SpaceAppeared:
Enqueue(filePacket);
if (queueFilledCount == 1) // If it is a first packet in queue, setting signal for consumers
{
eventForFirstPacketInQueue.Set();
}
if (eventType == EventsForProducer.SpaceAppeared && queueFilledCount == queueDepth)
{
eventForNewSpaceInQueue.Reset(); // Resetting our signal about appearing of free space
}
break;
case EventsForProducer.Cancel:
cancel = true;
break;
default:
Debug.Write($"Unsupported event type for producer: {Enum.GetName(typeof(EventsForProducer), eventType)}");
break;
}
}
finally
{
if (taken)
{
mutex.ReleaseMutex();
}
}
}
