@Override
public Void doInBackground(Void... args) {
  try (final AutoCloseOutputStream os = new AutoCloseOutputStream(mPfd);
      final SmbFile file = mClient.openFile(mUri, "r")) {
    int size;
    byte[] buf = new byte[mBuffer.capacity()];
    while ((size = file.read(mBuffer, Integer.MAX_VALUE)) > 0) {
      mBuffer.get(buf, 0, size);
      os.write(buf, 0, size);
      mBuffer.clear();
    }
  } catch (IOException e) {
    Log.e(TAG, "Failed to read file.", e);

    try {
      mPfd.closeWithError(e.getMessage());
    } catch (IOException exc) {
      Log.e(TAG, "Can't even close PFD with error.", exc);
    }
  }

  return null;
}
 

/**
 * {@inheritDoc}
 */
@Override
public ParcelFileDescriptor openFile(Uri uri, String mode)
  throws FileNotFoundException {
  if ("r".equals(mode)) {
    ParcelFileDescriptor[] pipe=null;

    try {
      pipe=ParcelFileDescriptor.createPipe();

      new TransferOutThread(getInputStream(uri),
                            new AutoCloseOutputStream(pipe[1])).start();
    }
    catch (IOException e) {
      Log.e(getClass().getSimpleName(), "Exception opening pipe", e);

      throw new FileNotFoundException("Could not open pipe for: "
          + uri.toString());
    }

    return(pipe[0]);
  }

  throw new IllegalArgumentException("Cannot support writing!");
}