System.Xml.XmlUTF8TextReader.BreakText C# (CSharp) Méthode

        private int BreakText(byte[] buffer, int offset, int length)
        {
            // See if we might be breaking a utf8 sequence
            if (length > 0 && (buffer[offset + length - 1] & 0x80) == 0x80)
            {
                // Find the lead char of the utf8 sequence (0x11xxxxxx)
                int originalLength = length;
                do
                {
                    length--;
                }
                while (length > 0 && (buffer[offset + length] & 0xC0) != 0xC0);
                // Couldn't find the lead char
                if (length == 0)
                    return originalLength; // Invalid utf8 sequence - can't break
                // Count how many bytes follow the lead char
                byte b = (byte)(buffer[offset + length] << 2);
                int byteCount = 2;
                while ((b & 0x80) == 0x80)
                {
                    b = (byte)(b << 1);
                    byteCount++;
                    // There shouldn't be more than 3 bytes following the lead char
                    if (byteCount > 4)
                        return originalLength; // Invalid utf8 sequence - can't break
                }
                if (length + byteCount == originalLength)
                    return originalLength; // sequence fits exactly
            }
            return length;
        }