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

        internal static int CalcBufferSize(Stream input)
        {
            // determine the size of byte buffer
            int bufferSize = DefaultBufferSize;
            if (input.CanSeek)
            {
                long len = input.Length;
                if (len < bufferSize)
                {
                    bufferSize = checked((int)len);
                }
                else if (len > MaxStreamLengthForDefaultBufferSize)
                {
                    bufferSize = BiggerBufferSize;
                }
            }

            // return the byte buffer size
            return bufferSize;
        }