System.Net.Sockets.TransmitFileOverlappedAsyncResult.SetUnmanagedStructures C# (CSharp) Method

        internal void SetUnmanagedStructures(byte[] preBuffer, byte[] postBuffer, FileStream fileStream, TransmitFileOptions flags, ref OverlappedCache overlappedCache)
        {
            SetupCache(ref overlappedCache);
            SetUnmanagedStructures(preBuffer, postBuffer, fileStream, flags, false);
        }

        private void DoBeginSendFile(
            string fileName,
            byte[] preBuffer,
            byte[] postBuffer,
            TransmitFileOptions flags,
            TransmitFileOverlappedAsyncResult asyncResult)
        {
            if(s_LoggingEnabled)Logging.Enter(Logging.Sockets, this, "BeginSendFile", "");

            if (CleanedUp) {
                throw new ObjectDisposedException(this.GetType().FullName);
            }

            if (CleanedUp) {
                throw new ObjectDisposedException(this.GetType().FullName);
            }

#if FEATURE_PAL
            throw new PlatformNotSupportedException(SR.GetString(SR.WinNTRequired));
#endif // FEATURE_PAL


            if (!Connected) {
                throw new NotSupportedException(SR.GetString(SR.net_notconnected));
            }

            GlobalLog.Print("Socket#" + ValidationHelper.HashString(this) + "::DoBeginSendFile() SRC:" + ValidationHelper.ToString(LocalEndPoint) + " DST:" + ValidationHelper.ToString(RemoteEndPoint) + " fileName:" + fileName);

            FileStream fileStream = null;
            if (fileName != null && fileName.Length>0) {
                fileStream = new FileStream(fileName,FileMode.Open,FileAccess.Read,FileShare.Read);
            }

            SafeHandle fileHandle = null;

            if (fileStream != null) {
                ExceptionHelper.UnmanagedPermission.Assert();
                try {
                    fileHandle = fileStream.SafeFileHandle;
                }
                finally {
                    SecurityPermission.RevertAssert();
                }
            }

            // Guarantee to call CheckAsyncCallOverlappedResult if we call SetUnamangedStructures with a cache in order to
            // avoid a Socket leak in case of error.
            SocketError errorCode = SocketError.SocketError;
            try
            {
                asyncResult.SetUnmanagedStructures(preBuffer, postBuffer, fileStream, flags, ref Caches.SendOverlappedCache);
                bool result = false;

                // This can throw ObjectDisposedException.
                if (fileHandle != null){
                    result = UnsafeNclNativeMethods.OSSOCK.TransmitFile(m_Handle,fileHandle,0,0,asyncResult.OverlappedHandle,asyncResult.TransmitFileBuffers,flags);
                }
                else{
                    result = UnsafeNclNativeMethods.OSSOCK.TransmitFile2(m_Handle,IntPtr.Zero,0,0,asyncResult.OverlappedHandle,asyncResult.TransmitFileBuffers,flags);
                }
                if(!result)
                {
                    errorCode =  (SocketError)Marshal.GetLastWin32Error();
                }
                else
                {
                    errorCode = SocketError.Success;
                }
            }
            finally
            {
                errorCode = asyncResult.CheckAsyncCallOverlappedResult(errorCode);
            }

            //
            // if the native call fails we'll throw a SocketException
            //
            if (errorCode!=SocketError.Success) {
                //
                // update our internal state after this socket error and throw
                //
                asyncResult.ExtractCache(ref Caches.SendOverlappedCache);
                SocketException socketException = new SocketException(errorCode);
                UpdateStatusAfterSocketError(socketException);

                if(s_LoggingEnabled)Logging.Exception(Logging.Sockets, this, "BeginSendFile", socketException);
                throw socketException;
            }

            GlobalLog.Print("Socket#" + ValidationHelper.HashString(this) + "::DoBeginSendFile() UnsafeNclNativeMethods.OSSOCK.send returns:" + errorCode.ToString());

            if(s_LoggingEnabled)Logging.Exit(Logging.Sockets, this, "BeginSendFile", errorCode);
        }