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

        internal bool TryReadSqlValue(SqlBuffer value, SqlMetaDataPriv md, int length, TdsParserStateObject stateObj)
        {
            bool isPlp = md.metaType.IsPlp;
            byte tdsType = md.tdsType;

            Debug.Assert(isPlp || !IsNull(md.metaType, (ulong)length), "null value should not get here!");
            if (isPlp)
            {
                // We must read the column value completely, no matter what length is passed in
                length = Int32.MaxValue;
            }
            switch (tdsType)
            {
                case TdsEnums.SQLDECIMALN:
                case TdsEnums.SQLNUMERICN:
                    if (!TryReadSqlDecimal(value, length, md.precision, md.scale, stateObj))
                    {
                        return false;
                    }
                    break;

                case TdsEnums.SQLUDT:
                case TdsEnums.SQLBINARY:
                case TdsEnums.SQLBIGBINARY:
                case TdsEnums.SQLBIGVARBINARY:
                case TdsEnums.SQLVARBINARY:
                case TdsEnums.SQLIMAGE:
                    byte[] b = null;

                    // If varbinary(max), we only read the first chunk here, expecting the caller to read the rest
                    if (isPlp)
                    {
                        // If we are given -1 for length, then we read the entire value,
                        // otherwise only the requested amount, usually first chunk.
                        int ignored;
                        if (!stateObj.TryReadPlpBytes(ref b, 0, length, out ignored))
                        {
                            return false;
                        }
                    }
                    else
                    {
                        //Debug.Assert(length > 0 && length < (long)(Int32.MaxValue), "Bad length for column");
                        b = new byte[length];
                        if (!stateObj.TryReadByteArray(b, 0, length))
                        {
                            return false;
                        }
                    }

                    value.SqlBinary = SqlTypeWorkarounds.SqlBinaryCtor(b, true);

                    break;

                case TdsEnums.SQLCHAR:
                case TdsEnums.SQLBIGCHAR:
                case TdsEnums.SQLVARCHAR:
                case TdsEnums.SQLBIGVARCHAR:
                case TdsEnums.SQLTEXT:
                case TdsEnums.SQLNCHAR:
                case TdsEnums.SQLNVARCHAR:
                case TdsEnums.SQLNTEXT:
                    if (!TryReadSqlStringValue(value, tdsType, length, md.encoding, isPlp, stateObj))
                    {
                        return false;
                    }
                    break;

                case TdsEnums.SQLXMLTYPE:
                    // We store SqlCachedBuffer here, so that we can return either SqlBinary, SqlString or SqlXmlReader.
                    SqlCachedBuffer sqlBuf;
                    if (!SqlCachedBuffer.TryCreate(md, this, stateObj, out sqlBuf))
                    {
                        return false;
                    }

                    value.SqlCachedBuffer = sqlBuf;
                    break;

                case TdsEnums.SQLDATE:
                case TdsEnums.SQLTIME:
                case TdsEnums.SQLDATETIME2:
                case TdsEnums.SQLDATETIMEOFFSET:
                    if (!TryReadSqlDateTime(value, tdsType, length, md.scale, stateObj))
                    {
                        return false;
                    }
                    break;

                default:
                    Debug.Assert(!isPlp, "ReadSqlValue calling ReadSqlValueInternal with plp data");
                    if (!TryReadSqlValueInternal(value, tdsType, length, stateObj))
                    {
                        return false;
                    }
                    break;
            }

            Debug.Assert((stateObj._longlen == 0) && (stateObj._longlenleft == 0), "ReadSqlValue did not read plp field completely, longlen =" + stateObj._longlen.ToString((IFormatProvider)null) + ",longlenleft=" + stateObj._longlenleft.ToString((IFormatProvider)null));
            return true;
        }