System.Data.SqlClient.TdsParser.TryGetTokenLength C# (CSharp) Method

        internal bool TryGetTokenLength(byte token, TdsParserStateObject stateObj, out int tokenLength)
        {
            Debug.Assert(token != 0, "0 length token!");

            switch (token)
            { // rules about SQLLenMask no longer apply to new tokens (as of 7.4)
                case TdsEnums.SQLFEATUREEXTACK:
                    tokenLength = -1;
                    return true;
                case TdsEnums.SQLSESSIONSTATE:
                    return stateObj.TryReadInt32(out tokenLength);
            }

            {
                if (token == TdsEnums.SQLUDT)
                { // special case for UDTs
                    tokenLength = -1; // Should we return -1 or not call GetTokenLength for UDTs?
                    return true;
                }
                else if (token == TdsEnums.SQLRETURNVALUE)
                {
                    tokenLength = -1; // In Yukon, the RETURNVALUE token stream no longer has length
                    return true;
                }
                else if (token == TdsEnums.SQLXMLTYPE)
                {
                    ushort value;
                    if (!stateObj.TryReadUInt16(out value))
                    {
                        tokenLength = 0;
                        return false;
                    }
                    tokenLength = (int)value;
                    Debug.Assert(tokenLength == TdsEnums.SQL_USHORTVARMAXLEN, "Invalid token stream for xml datatype");
                    return true;
                }
            }

            switch (token & TdsEnums.SQLLenMask)
            {
                case TdsEnums.SQLFixedLen:
                    tokenLength = ((0x01 << ((token & 0x0c) >> 2))) & 0xff;
                    return true;
                case TdsEnums.SQLZeroLen:
                    tokenLength = 0;
                    return true;
                case TdsEnums.SQLVarLen:
                case TdsEnums.SQLVarCnt:
                    if (0 != (token & 0x80))
                    {
                        ushort value;
                        if (!stateObj.TryReadUInt16(out value))
                        {
                            tokenLength = 0;
                            return false;
                        }
                        tokenLength = value;
                        return true;
                    }
                    else if (0 == (token & 0x0c))
                    {
                        if (!stateObj.TryReadInt32(out tokenLength))
                        {
                            return false;
                        }
                        return true;
                    }
                    else
                    {
                        byte value;
                        if (!stateObj.TryReadByte(out value))
                        {
                            tokenLength = 0;
                            return false;
                        }
                        tokenLength = value;
                        return true;
                    }
                default:
                    Debug.Assert(false, "Unknown token length!");
                    tokenLength = 0;
                    return true;
            }
        }