XmlMtomReader reading strategy

Question

Consider the following code:

Stream stream = GetStreamFromSomewhere(); 
XmlDictionaryReader mtomReader =XmlDictionaryReader.CreateMtomReader
(
 stream,
 Encoding.UTF8,
 XmlDictionaryReaderQuoatas.Max
);

/// ...

/// is there best way to read binary data from mtomReader's element??
string elementString = mtomReader.XmlReader.ReadElementString();
byte[] elementBytes = Covert.FromBase64String(elementString);
Stream elementFileStream = new FileStream(tempFileLocation);
elementFileStream.Write(elementBytes,0,elementBytes.Length);
elementFileStream.Close();

/// ...

mtomReader.Close();

The problem is that the size of the binary attachment supposed to be over 100Mb sometimes. Is there a way to read element's binary attachment block by block and then write it to the temporary file stream so i can escape from allocating memory for the hole stuff?

The second - even more specific issue - does mtomReader create any internal cache of the mime binary attachment before i read element's content, i.e. allocate memory for binary data? Or does it read bytes from the input stream directly?

Answer 1

For those who may be interested in the solution:

using (Stream stream = GetStreamFromSomewhere())
{
  using (
    XmlDictionaryReader mtomReader = XmlDictionaryReader.CreateMtomReader(
        stream, Encoding.UTF8, XmlDictionaryReaderQuotas.Max))
 {
    string elementString = mtomReader.ReadElementString();
    byte[] buffer = new byte[1024];
    using (
        Stream elementFileStream =
            new FileStream(tempFileLocation, FileMode.Create))
    {
        while(mtomReader.XmlReader.ReadElementContentAsBase64(buffer,0,buffer.Length)
        {
          elementFileStream.Write(buffer, 0, buffer.Length);
        }
    }

    /// ...

    mtomReader.Close();
 }
}

ReadElementContentAsBase64(...) helps read binary parts block by block. The second issue of my post was covered perfectly here: Does XmlMtomReader cache binary data from the input stream internally?