Exemple #1
0
        /// <summary>
        /// This method skips bytes of a single column value from the media. It supports NBCROW and handles all types of values, including PLP and long
        /// </summary>
        internal bool TrySkipValue(SqlMetaDataPriv md, int columnOrdinal, TdsParserStateObject stateObj)
        {
            if (stateObj.IsNullCompressionBitSet(columnOrdinal))
            {
                return true;
            }

            if (md.metaType.IsPlp)
            {
                ulong ignored;
                if (!TrySkipPlpValue(UInt64.MaxValue, stateObj, out ignored))
                {
                    return false;
                }
            }
            else if (md.metaType.IsLong)
            {
                Debug.Assert(!md.metaType.IsPlp, "Plp types must be handled using SkipPlpValue");

                byte textPtrLen;
                if (!stateObj.TryReadByte(out textPtrLen))
                {
                    return false;
                }

                if (0 != textPtrLen)
                {
                    if (!stateObj.TrySkipBytes(textPtrLen + TdsEnums.TEXT_TIME_STAMP_LEN))
                    {
                        return false;
                    }

                    int length;
                    if (!TryGetTokenLength(md.tdsType, stateObj, out length))
                    {
                        return false;
                    }
                    if (!stateObj.TrySkipBytes(length))
                    {
                        return false;
                    }
                }
            }
            else
            {
                int length;
                if (!TryGetTokenLength(md.tdsType, stateObj, out length))
                {
                    return false;
                }

                // if false, no value to skip - it's null
                if (!IsNull(md.metaType, (ulong)length))
                {
                    if (!stateObj.TrySkipBytes(length))
                    {
                        return false;
                    }
                }
            }

            return true;
        }
Exemple #2
0
        // takes care of any per data header information:
        // for long columns, reads off textptrs, reads length, check nullability
        // for other columns, reads length, checks nullability
        // returns length and nullability
        internal bool TryProcessColumnHeader(SqlMetaDataPriv col, TdsParserStateObject stateObj, int columnOrdinal, out bool isNull, out ulong length)
        {
            // query NBC row information first
            if (stateObj.IsNullCompressionBitSet(columnOrdinal))
            {
                isNull = true;
                // column information is not present in TDS if null compression bit is set, return now
                length = 0;
                return true;
            }

            return TryProcessColumnHeaderNoNBC(col, stateObj, out isNull, out length);
        }