public override void Write(byte[] buffer, int offset, int count)
{
if (!CanWrite)
{
throw new IOException("Attempt to write to read-only stream");
}
if (_position + count > _length)
{
throw new IOException("Attempt to write beyond end of stream");
}
int numWritten = 0;
while (numWritten < count)
{
long block = _position / _blockSize;
uint offsetInBlock = (uint)(_position % _blockSize);
int toWrite = count - numWritten;
// Need to read - we're not handling a full block
if (offsetInBlock != 0 || toWrite < _blockSize)
{
toWrite = (int)Math.Min(toWrite, _blockSize - offsetInBlock);
byte[] blockBuffer = new byte[_blockSize];
int numRead = _session.Read(_lun, block, 1, blockBuffer, 0);
if (numRead != _blockSize)
{
throw new IOException("Incomplete read, received " + numRead + " bytes from 1 block");
}
// Overlay as much data as we have for this block
Array.Copy(buffer, offset + numWritten, blockBuffer, offsetInBlock, toWrite);
// Write the block back
_session.Write(_lun, block, 1, _blockSize, blockBuffer, 0);
}
else
{
// Processing at least one whole block, just write (after making sure to trim any partial sectors from the end)...
short numBlocks = (short)(toWrite / _blockSize);
toWrite = numBlocks * _blockSize;
_session.Write(_lun, block, numBlocks, _blockSize, buffer, offset + numWritten);
}
numWritten += toWrite;
_position += toWrite;
}
}