internal static extern unsafe bool TransmitFile(
SafeHandle socket,
SafeHandle fileHandle,
int numberOfBytesToWrite,
int numberOfBytesPerSend,
SafeHandle overlapped,
TransmitFileBuffers* buffers,
TransmitFileOptions flags);
//
// SetUnmanagedStructures -
// Fills in Overlapped Structures used in an Async Overlapped Winsock call
// these calls are outside the runtime and are unmanaged code, so we need
// to prepare specific structures and ints that lie in unmanaged memory
// since the Overlapped calls can be Async
//
internal void SetUnmanagedStructures(byte[] preBuffer, byte[] postBuffer, FileStream fileStream, TransmitFileOptions flags, bool sync)
{
//
// fill in flags if we use it.
//
m_fileStream = fileStream;
m_flags = flags;
//
// Fill in Buffer Array structure that will be used for our send/recv Buffer
//
m_buffers = null;
int buffsNumber = 0;
if (preBuffer != null && preBuffer.Length > 0)
{
++buffsNumber;
}
if (postBuffer != null && postBuffer.Length > 0)
{
++buffsNumber;
}
object[] objectsToPin = null;
if (buffsNumber != 0)
{
++buffsNumber;
objectsToPin = new object[buffsNumber];
m_buffers = new TransmitFileBuffers();
objectsToPin[--buffsNumber] = m_buffers;
if (preBuffer != null && preBuffer.Length > 0)
{
m_buffers.preBufferLength = preBuffer.Length;
objectsToPin[--buffsNumber] = preBuffer;
}
if (postBuffer != null && postBuffer.Length > 0)
{
m_buffers.postBufferLength = postBuffer.Length;
objectsToPin[--buffsNumber] = postBuffer;
}
if (sync)
{
base.PinUnmanagedObjects(objectsToPin);
}
else
{
base.SetUnmanagedStructures(objectsToPin);
}
if (preBuffer != null && preBuffer.Length > 0)
{
m_buffers.preBuffer = Marshal.UnsafeAddrOfPinnedArrayElement(preBuffer, 0);
}
if (postBuffer != null && postBuffer.Length > 0)
{
m_buffers.postBuffer = Marshal.UnsafeAddrOfPinnedArrayElement(postBuffer, 0);
}
}
else if (!sync)
{
base.SetUnmanagedStructures(null);
}
} // SetUnmanagedStructures()