private void RunSparse()
{
SparseStream inStream = InputStream as SparseStream;
if (inStream == null)
{
inStream = SparseStream.FromStream(InputStream, Ownership.None);
}
if (BufferSize > SparseChunkSize && (BufferSize % SparseChunkSize) != 0)
{
throw new InvalidOperationException("Buffer size is not a multiple of the sparse chunk size");
}
byte[] copyBuffer = new byte[Math.Max(BufferSize, SparseChunkSize)];
BytesRead = 0;
BytesWritten = 0;
foreach (var extent in inStream.Extents)
{
inStream.Position = extent.Start;
long extentOffset = 0;
while (extentOffset < extent.Length)
{
int toRead = (int)Math.Min(copyBuffer.Length, extent.Length - extentOffset);
int numRead = Utilities.ReadFully(inStream, copyBuffer, 0, toRead);
BytesRead += numRead;
int copyBufferOffset = 0;
for (int i = 0; i < numRead; i += SparseChunkSize)
{
if (IsAllZeros(copyBuffer, i, Math.Min(SparseChunkSize, numRead - i)))
{
if (copyBufferOffset < i)
{
OutputStream.Position = extent.Start + extentOffset + copyBufferOffset;
OutputStream.Write(copyBuffer, copyBufferOffset, i - copyBufferOffset);
BytesWritten += i - copyBufferOffset;
}
copyBufferOffset = i + SparseChunkSize;
}
}
if (copyBufferOffset < numRead)
{
OutputStream.Position = extent.Start + extentOffset + copyBufferOffset;
OutputStream.Write(copyBuffer, copyBufferOffset, numRead - copyBufferOffset);
BytesWritten += numRead - copyBufferOffset;
}
extentOffset += numRead;
RaiseProgressEvent();
}
}
// Ensure the output stream is at least as long as the input stream. This uses
// read/write, rather than SetLength, to avoid failing on streams that can't be
// explicitly resized. Side-effect of this, is that if outStream is an NTFS
// file stream, then actual clusters will be allocated out to at least the
// length of the input stream.
if (OutputStream.Length < inStream.Length)
{
inStream.Position = inStream.Length - 1;
int b = inStream.ReadByte();
if (b >= 0)
{
OutputStream.Position = inStream.Length - 1;
OutputStream.WriteByte((byte)b);
}
}
}
