System.Xml.XmlReader.CreateSqlReader C# (CSharp) Method

        internal static XmlReader CreateSqlReader(Stream input, XmlReaderSettings settings, XmlParserContext inputContext)
        {
            if (input == null)
            {
                throw new ArgumentNullException(nameof(input));
            }
            if (settings == null)
            {
                settings = new XmlReaderSettings();
            }

            XmlReader reader;

            // allocate byte buffer
            byte[] bytes = new byte[CalcBufferSize(input)];

            int byteCount = 0;
            int read;
            do
            {
                read = input.Read(bytes, byteCount, bytes.Length - byteCount);
                byteCount += read;
            } while (read > 0 && byteCount < 2);

            // create text or binary XML reader depenting on the stream first 2 bytes
            if (byteCount >= 2 && (bytes[0] == 0xdf && bytes[1] == 0xff))
            {
                if (inputContext != null)
                    throw new ArgumentException(SR.XmlBinary_NoParserContext, nameof(inputContext));
                reader = new XmlSqlBinaryReader(input, bytes, byteCount, string.Empty, settings.CloseInput, settings);
            }
            else
            {
                reader = new XmlTextReaderImpl(input, bytes, byteCount, settings, null, string.Empty, inputContext, settings.CloseInput);
            }

            // wrap with validating reader
            if (settings.ValidationType != ValidationType.None)
            {
                reader = settings.AddValidation(reader);
            }

            if (settings.Async)
            {
                reader = XmlAsyncCheckReader.CreateAsyncCheckWrapper(reader);
            }

            return reader;
        }