/// <summary>
/// Получить части архивированного потока.
/// </summary>
/// <param name="sourceStream">Архивированный поток.</param>
/// <returns>Список частей архива.</returns>
private List <ArchivePart> GetArchiveParts(Stream sourceStream)
{
if (_archiveParts != null && _archiveParts.Any())
{
return(_archiveParts);
}
long offset = 0;
var portionSizeBufferLength = sizeof(long);
var portionSizeBuffer = new byte[portionSizeBufferLength];
var parts = new List <ArchivePart>();
while (offset + portionSizeBufferLength < sourceStream.Length)
{
sourceStream.Seek(offset, SeekOrigin.Begin);
sourceStream.Read(portionSizeBuffer, 0, portionSizeBufferLength);
var portionBufferLength = BitConverter.ToInt32(portionSizeBuffer, 0);
offset += portionSizeBufferLength;
var archivePart = new ArchivePart(offset, portionBufferLength);
parts.Add(archivePart);
offset += portionBufferLength;
}
return(parts);
}
/// <summary>
/// Выполнить архивацию файла.
/// </summary>
/// <param name="sourceStream">Исходный поток.</param>
/// <param name="targetStream">Архивированный поток.</param>
/// <param name="bufferSize">Размер буфера.</param>
private void CompressInternal(Stream sourceStream, Stream targetStream, long bufferSize)
{
var parts = Math.Ceiling((double)sourceStream.Length / bufferSize);
if (bufferSize > sourceStream.Length)
{
bufferSize = sourceStream.Length;
}
for (var portion = 0; portion < parts; portion++)
{
var currentPortion = portion;
var archivePart = new ArchivePart();
var size = bufferSize;
var offset = currentPortion * size;
if (offset + size > sourceStream.Length)
{
size = sourceStream.Length - offset;
}
archivePart.Offset = offset;
var compressingTask = new ProcessingTask(() =>
{
var portionArray = new byte[size];
lock (sourceStream)
{
sourceStream.Seek(archivePart.Offset, SeekOrigin.Begin);
sourceStream.Read(portionArray, 0, (int)size);
}
archivePart.Input = portionArray;
archivePart.Compress();
});
_queueManager.CompressQueue.Enqueue(compressingTask);
var writingTask = new ProcessingTask(() =>
{
while (true)
{
if (!archivePart.HasResult)
{
continue;
}
lock (targetStream)
archivePart.WriteResult(targetStream);
break;
}
});
_queueManager.WritingQueue.Enqueue(writingTask);
}
}
