/// <summary>
/// Seeks to a position within the stream
/// </summary>
/// <param name="offset">offset to seek</param>
/// <param name="origin">seek origin</param>
/// <returns>Returns the new position</returns>
public override long Seek(long offset, SeekOrigin origin)
{
if (fileStream == null)
{
throw new ObjectDisposedException("fileStream", "storage stream no longer available");
}
long l = 0;
object local = l;
GCHandle gCHandle = new GCHandle();
try
{
gCHandle = GCHandle.Alloc(local, GCHandleType.Pinned);
IntPtr i = gCHandle.AddrOfPinnedObject();
fileStream.Seek(offset, (int)origin, i);
l = (long)local;
}
finally
{
if (gCHandle.IsAllocated)
{
gCHandle.Free();
}
}
return(l);
}
public override long Seek(long offset, SeekOrigin origin)
{
using (var buffer = new SafeStructureInOutBuffer <long>())
{
_stm.Seek(0, (int)origin, buffer.DangerousGetHandle());
return(buffer.Result);
}
}
public override long Seek(long offset, SeekOrigin origin)
{
IntPtr newPosPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(long)));
_baseStream.Seek(offset, (int)origin, newPosPtr);
long newPos = newPosPtr.ToInt64();
Marshal.FreeHGlobal(newPosPtr);
_currentPosition = newPos;
return(newPos);
}
/// <summary>
/// Move the current pointer in the strea relative to the seek origin
/// </summary>
/// <param name="offset">The number of bytes to move from origin</param>
/// <param name="origin">Move from begging, current cursor, or end of file</param>
/// <returns></returns>
public override long Seek(long offset, SeekOrigin origin)
{
int dwOrigin = 0;
switch (origin)
{
case SeekOrigin.Begin:
dwOrigin = 0;
break;
case SeekOrigin.Current:
dwOrigin = 1;
break;
case SeekOrigin.End:
dwOrigin = 2;
break;
default:
throw new ArgumentException("Invalid seek origin");
}
//ensure not seeking while reading
lock (this)
{
unsafe
{
// getting casting errors is unlikely as that would be millions of terrabytes for a single file
// This memory will be fixed due to it being declared in unsafe and allow taking the address
ulong ulongPosition = (ulong)m_position;
m_cachedIstream.Seek(offset, dwOrigin, new IntPtr(&ulongPosition));
m_position = (long)ulongPosition;
}
}
return(m_position);
}
/// <summary>
/// Create the optical disk image.
/// </summary>
/// <returns></returns>
public COMTypes.IStream CreateImageStream(IFileSystemImageResult fsres)
{
var ppos = IntPtr.Zero;
COMTypes.IStream imagestream = null;
try
{
_fsres = fsres;
imagestream = fsres.ImageStream;
ppos = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(long)));
imagestream.Seek(0, 0, ppos);
if (Marshal.ReadInt64(ppos) != 0)
{
throw new IOException("Can't reset the stream position");
}
//IDiscFormat2Data idf = this as IDiscFormat2Data;
//idf.Write(imagestream);
}
catch (Exception exc)
{
if (!string.IsNullOrEmpty(OutputFileName))
{
File.Delete(OutputFileName);
}
Debug.WriteLine(exc.ToString());
}
finally
{
if (ppos != IntPtr.Zero)
{
Marshal.FreeHGlobal(ppos);
}
}
return(imagestream);
}