private void ProcessConcreteCompletedOperation(IAsyncOperationWithProgress <IBuffer, uint> completedOperation, out long bytesCompleted)
{
IBuffer resultBuffer = completedOperation.GetResults();
Debug.Assert(resultBuffer != null);
WinRtIOHelper.EnsureResultsInUserBuffer(_userBuffer, resultBuffer);
bytesCompleted = _userBuffer.Length;
}
// Moved it to the end while using Dev10 VS because it does not understand async and everything that follows looses intellisense.
// Should move this code into the Reading regios once using Dev11 VS becomes the norm.
private async Task <Int32> ReadAsyncInternal(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken)
{
Debug.Assert(buffer != null);
Debug.Assert(offset >= 0);
Debug.Assert(count >= 0);
Debug.Assert(buffer.Length - offset >= count);
Debug.Assert(_canRead);
IInputStream wrtStr = EnsureNotDisposed <IInputStream>();
#if DEBUG
AssertValidStream(wrtStr);
#endif // DEBUG
try
{
IBuffer userBuffer = buffer.AsBuffer(offset, count);
IAsyncOperationWithProgress <IBuffer, UInt32> asyncReadOperation = wrtStr.ReadAsync(userBuffer,
unchecked ((UInt32)count),
InputStreamOptions.Partial);
IBuffer resultBuffer = await asyncReadOperation.AsTask(cancellationToken).ConfigureAwait(continueOnCapturedContext: false);
// If cancellationToken was cancelled until now, then we are currently propagating the corresponding cancellation exception.
// (It will be correctly rethrown by the catch block below and overall we will return a cancelled task.)
// But if the underlying operation managed to complete before it was cancelled, we want
// the entire task to complete as well. This is ok as the continuation is very lightweight:
if (resultBuffer == null)
{
return(0);
}
WinRtIOHelper.EnsureResultsInUserBuffer(userBuffer, resultBuffer);
Debug.Assert(resultBuffer.Length <= unchecked ((UInt32)Int32.MaxValue));
return((Int32)resultBuffer.Length);
}
catch (Exception ex)
{
// If the interop layer gave us an Exception, we assume that it hit a general/unknown case and wrap it into
// an IOException as this is what Stream users expect.
WinRtIOHelper.NativeExceptionToIOExceptionInfo(ex).Throw();
return(0);
}
}