C# TdsParserStateObject.TryReadUInt16方法代码示例

        internal bool TryProcessAltMetaData(int cColumns, TdsParserStateObject stateObj, out _SqlMetaDataSet metaData)
        {
            Debug.Assert(cColumns > 0, "should have at least 1 column in altMetaData!");

            metaData = null;

            _SqlMetaDataSet altMetaDataSet = new _SqlMetaDataSet(cColumns);
            int[] indexMap = new int[cColumns];

            if (!stateObj.TryReadUInt16(out altMetaDataSet.id))
            {
                return false;
            }

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

            while (byCols > 0)
            {
                if (!stateObj.TrySkipBytes(2))
                { // ignore ColNum ...
                    return false;
                }
                byCols--;
            }

            // pass 1, read the meta data off the wire
            for (int i = 0; i < cColumns; i++)
            {
                // internal meta data class
                _SqlMetaData col = altMetaDataSet[i];

                byte op;
                if (!stateObj.TryReadByte(out op))
                {
                    return false;
                }
                ushort operand;
                if (!stateObj.TryReadUInt16(out operand))
                {
                    return false;
                }

                if (!TryCommonProcessMetaData(stateObj, col))
                {
                    return false;
                }

                indexMap[i] = i;
            }

            altMetaDataSet.indexMap = indexMap;
            altMetaDataSet.visibleColumns = cColumns;

            metaData = altMetaDataSet;
            return true;
        }

        private bool TryProcessOneTable(TdsParserStateObject stateObj, ref int length, out MultiPartTableName multiPartTableName)
        {
            ushort tableLen;
            MultiPartTableName mpt;
            string value;

            multiPartTableName = default(MultiPartTableName);

            mpt = new MultiPartTableName();
            byte nParts;

            // Find out how many parts in the TDS stream
            if (!stateObj.TryReadByte(out nParts))
            {
                return false;
            }
            length--;
            if (nParts == 4)
            {
                if (!stateObj.TryReadUInt16(out tableLen))
                {
                    return false;
                }
                length -= 2;
                if (!stateObj.TryReadString(tableLen, out value))
                {
                    return false;
                }
                mpt.ServerName = value;
                nParts--;
                length -= (tableLen * 2); // wide bytes
            }
            if (nParts == 3)
            {
                if (!stateObj.TryReadUInt16(out tableLen))
                {
                    return false;
                }
                length -= 2;
                if (!stateObj.TryReadString(tableLen, out value))
                {
                    return false;
                }
                mpt.CatalogName = value;
                length -= (tableLen * 2); // wide bytes
                nParts--;
            }
            if (nParts == 2)
            {
                if (!stateObj.TryReadUInt16(out tableLen))
                {
                    return false;
                }
                length -= 2;
                if (!stateObj.TryReadString(tableLen, out value))
                {
                    return false;
                }
                mpt.SchemaName = value;
                length -= (tableLen * 2); // wide bytes
                nParts--;
            }
            if (nParts == 1)
            {
                if (!stateObj.TryReadUInt16(out tableLen))
                {
                    return false;
                }
                length -= 2;
                if (!stateObj.TryReadString(tableLen, out value))
                {
                    return false;
                }
                mpt.TableName = value;
                length -= (tableLen * 2); // wide bytes
                nParts--;
            }
            Debug.Assert(nParts == 0, "ProcessTableName:Unidentified parts in the table name token stream!");

            multiPartTableName = mpt;
            return true;
        }

        internal bool TryProcessError(byte token, TdsParserStateObject stateObj, out SqlError error)
        {
            ushort shortLen;
            byte byteLen;
            int number;
            byte state;
            byte errorClass;

            error = null;

            if (!stateObj.TryReadInt32(out number))
            {
                return false;
            }
            if (!stateObj.TryReadByte(out state))
            {
                return false;
            }
            if (!stateObj.TryReadByte(out errorClass))
            {
                return false;
            }

            Debug.Assert(((errorClass >= TdsEnums.MIN_ERROR_CLASS) && token == TdsEnums.SQLERROR) ||
                          ((errorClass < TdsEnums.MIN_ERROR_CLASS) && token == TdsEnums.SQLINFO), "class and token don't match!");

            if (!stateObj.TryReadUInt16(out shortLen))
            {
                return false;
            }
            string message;
            if (!stateObj.TryReadString(shortLen, out message))
            {
                return false;
            }

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

            string server;

            // If the server field is not recieved use the locally cached value.
            if (byteLen == 0)
            {
                server = _server;
            }
            else
            {
                if (!stateObj.TryReadString(byteLen, out server))
                {
                    return false;
                }
            }

            if (!stateObj.TryReadByte(out byteLen))
            {
                return false;
            }
            string procedure;
            if (!stateObj.TryReadString(byteLen, out procedure))
            {
                return false;
            }

            int line;
            if (!stateObj.TryReadInt32(out line))
            {
                return false;
            }

            error = new SqlError(number, state, errorClass, _server, message, procedure, line);
            return true;
        }

        internal bool TryProcessReturnValue(int length, TdsParserStateObject stateObj, out SqlReturnValue returnValue)
        {
            returnValue = null;
            SqlReturnValue rec = new SqlReturnValue();
            rec.length = length;        // In Yukon this length is -1
            ushort parameterIndex;
            if (!stateObj.TryReadUInt16(out parameterIndex))
            {
                return false;
            }
            byte len;
            if (!stateObj.TryReadByte(out len))
            { // Length of parameter name
                return false;
            }

            if (len > 0)
            {
                if (!stateObj.TryReadString(len, out rec.parameter))
                {
                    return false;
                }
            }

            // read status and ignore
            byte ignored;
            if (!stateObj.TryReadByte(out ignored))
            {
                return false;
            }

            UInt32 userType;

            // read user type - 4 bytes Yukon, 2 backwards
            if (!stateObj.TryReadUInt32(out userType))
            {
                return false;
            }

            // read off the flags
            ushort ignoredFlags;
            if (!stateObj.TryReadUInt16(out ignoredFlags))
            {
                return false;
            }

            // read the type
            byte tdsType;
            if (!stateObj.TryReadByte(out tdsType))
            {
                return false;
            }

            // read the MaxLen
            // For xml datatpyes, there is no tokenLength
            int tdsLen;

            if (tdsType == TdsEnums.SQLXMLTYPE)
            {
                tdsLen = TdsEnums.SQL_USHORTVARMAXLEN;
            }
            else if (IsVarTimeTds(tdsType))
                tdsLen = 0;  // placeholder until we read the scale, just make sure it's not SQL_USHORTVARMAXLEN
            else if (tdsType == TdsEnums.SQLDATE)
            {
                tdsLen = 3;
            }
            else
            {
                if (!TryGetTokenLength(tdsType, stateObj, out tdsLen))
                {
                    return false;
                }
            }

            rec.metaType = MetaType.GetSqlDataType(tdsType, userType, tdsLen);
            rec.type = rec.metaType.SqlDbType;

            // always use the nullable type for parameters if Shiloh or later
            // Sphinx sometimes sends fixed length return values
            rec.tdsType = rec.metaType.NullableType;
            rec.isNullable = true;
            if (tdsLen == TdsEnums.SQL_USHORTVARMAXLEN)
            {
                rec.metaType = MetaType.GetMaxMetaTypeFromMetaType(rec.metaType);
            }

            if (rec.type == SqlDbType.Decimal)
            {
                if (!stateObj.TryReadByte(out rec.precision))
                {
                    return false;
                }
                if (!stateObj.TryReadByte(out rec.scale))
                {
                    return false;
                }
            }

            if (rec.metaType.IsVarTime)
//.........这里部分代码省略.........

        internal bool TryProcessReturnValue(int length,
                                            TdsParserStateObject stateObj,
                                            out SqlReturnValue returnValue,
                                            SqlCommandColumnEncryptionSetting columnEncryptionSetting) {
            returnValue = null;
            SqlReturnValue rec = new SqlReturnValue();
            rec.length = length;        // In Yukon this length is -1
            if (_isYukon) {
                if (!stateObj.TryReadUInt16(out rec.parmIndex)) {
                    return false;
                }
            }
            byte len;
            if (!stateObj.TryReadByte(out len)) { // Length of parameter name
                return false;
            }

            rec.parameter = null;
            if (len > 0) {
                if (!stateObj.TryReadString(len, out rec.parameter)) {
                    return false;
                }
            }

            // read status and ignore
            byte ignored;
            if (!stateObj.TryReadByte(out ignored)) {
                return false;
            }

            UInt32 userType;

            // read user type - 4 bytes Yukon, 2 backwards
            if (IsYukonOrNewer) {
                if (!stateObj.TryReadUInt32(out userType)) {
                    return false;
                }
            }
            else {
                ushort userTypeShort;
                if (!stateObj.TryReadUInt16(out userTypeShort)) {
                    return false;
                }
                userType = userTypeShort;
            }

            // Read off the flags.
            // The first byte is ignored since it doesn't contain any interesting information.
            byte flags;
            if (!stateObj.TryReadByte(out flags)) {
                return false;
            }

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

            // Check if the column is encrypted.
            if (_serverSupportsColumnEncryption) {
                rec.isEncrypted = (TdsEnums.IsEncrypted == (flags & TdsEnums.IsEncrypted));
            }

            // read the type
            byte tdsType;
            if (!stateObj.TryReadByte(out tdsType)) {
                return false;
            }

            // read the MaxLen
            // For xml datatpyes, there is no tokenLength
            int tdsLen;

            if (tdsType == TdsEnums.SQLXMLTYPE) {
                tdsLen = TdsEnums.SQL_USHORTVARMAXLEN;
            }
            else if (IsVarTimeTds(tdsType))
                tdsLen = 0;  // placeholder until we read the scale, just make sure it's not SQL_USHORTVARMAXLEN
            else if (tdsType == TdsEnums.SQLDATE) {
                tdsLen = 3;
            }
            else {
                if (!TryGetTokenLength(tdsType, stateObj, out tdsLen)) {
                    return false;
                }
            }

            rec.metaType = MetaType.GetSqlDataType(tdsType, userType, tdsLen);
            rec.type = rec.metaType.SqlDbType;

            // always use the nullable type for parameters if Shiloh or later
            // Sphinx sometimes sends fixed length return values
            if (_isShiloh) {
                rec.tdsType = rec.metaType.NullableType;
                rec.isNullable = true;
                if (tdsLen == TdsEnums.SQL_USHORTVARMAXLEN) {
                    Debug.Assert(_isYukon, "plp data from pre-Yukon server");
                    rec.metaType = MetaType.GetMaxMetaTypeFromMetaType(rec.metaType);
                }
            }
            else {      // For sphinx, keep the fixed type if that is what is returned
//.........这里部分代码省略.........

        private bool TryProcessDone(SqlCommand cmd, SqlDataReader reader, ref RunBehavior run, TdsParserStateObject stateObj)
        {
            ushort curCmd;
            ushort status;
            int count;

            // Can't retry TryProcessDone
            stateObj._syncOverAsync = true;

            // status
            // command
            // rowcount (valid only if DONE_COUNT bit is set)

            if (!stateObj.TryReadUInt16(out status))
            {
                return false;
            }
            if (!stateObj.TryReadUInt16(out curCmd))
            {
                return false;
            }

            long longCount;
            if (!stateObj.TryReadInt64(out longCount))
            {
                return false;
            }
            count = (int)longCount;

            // We get a done token with the attention bit set
            if (TdsEnums.DONE_ATTN == (status & TdsEnums.DONE_ATTN))
            {
                Debug.Assert(TdsEnums.DONE_MORE != (status & TdsEnums.DONE_MORE), "Not expecting DONE_MORE when receiving DONE_ATTN");
                Debug.Assert(stateObj._attentionSent, "Received attention done without sending one!");
                stateObj._attentionReceived = true;
                Debug.Assert(stateObj._inBytesUsed == stateObj._inBytesRead && stateObj._inBytesPacket == 0, "DONE_ATTN received with more data left on wire");
            }
            if ((null != cmd) && (TdsEnums.DONE_COUNT == (status & TdsEnums.DONE_COUNT)))
            {
                if (curCmd != TdsEnums.SELECT)
                {
                    cmd.InternalRecordsAffected = count;
                }
                // Skip the bogus DONE counts sent by the server
                if (stateObj._receivedColMetaData || (curCmd != TdsEnums.SELECT))
                {
                    cmd.OnStatementCompleted(count);
                }
            }

            stateObj._receivedColMetaData = false;

            // Surface exception for DONE_ERROR in the case we did not receive an error token
            // in the stream, but an error occurred.  In these cases, we throw a general server error.  The
            // situations where this can occur are: an invalid buffer received from client, login error
            // and the server refused our connection, and the case where we are trying to log in but
            // the server has reached its max connection limit.  Bottom line, we need to throw general
            // error in the cases where we did not receive a error token along with the DONE_ERROR.
            if ((TdsEnums.DONE_ERROR == (TdsEnums.DONE_ERROR & status)) && stateObj.ErrorCount == 0 &&
                  stateObj._errorTokenReceived == false && (RunBehavior.Clean != (RunBehavior.Clean & run)))
            {
                stateObj.AddError(new SqlError(0, 0, TdsEnums.MIN_ERROR_CLASS, _server, SQLMessage.SevereError(), "", 0));

                if (null != reader)
                {
                    if (!reader.IsInitialized)
                    {
                        run = RunBehavior.UntilDone;
                    }
                }
            }

            // Similar to above, only with a more severe error.  In this case, if we received
            // the done_srverror, this exception will be added to the collection regardless.
            // The server will always break the connection in this case.
            if ((TdsEnums.DONE_SRVERROR == (TdsEnums.DONE_SRVERROR & status)) && (RunBehavior.Clean != (RunBehavior.Clean & run)))
            {
                stateObj.AddError(new SqlError(0, 0, TdsEnums.FATAL_ERROR_CLASS, _server, SQLMessage.SevereError(), "", 0));

                if (null != reader)
                {
                    if (!reader.IsInitialized)
                    {
                        run = RunBehavior.UntilDone;
                    }
                }
            }

            ProcessSqlStatistics(curCmd, status, count);

            // stop if the DONE_MORE bit isn't set (see above for attention handling)
            if (TdsEnums.DONE_MORE != (status & TdsEnums.DONE_MORE))
            {
                stateObj._errorTokenReceived = false;
                if (stateObj._inBytesUsed >= stateObj._inBytesRead)
                {
                    stateObj._pendingData = false;
                }
            }

//.........这里部分代码省略.........

        internal bool TryProcessError(byte token, TdsParserStateObject stateObj, out SqlError error)
        {
            ushort shortLen;
            byte byteLen;
            int number;
            byte state;
            byte errorClass;

            error = null;

            if (!stateObj.TryReadInt32(out number))
            {
                return false;
            }
            if (!stateObj.TryReadByte(out state))
            {
                return false;
            }
            if (!stateObj.TryReadByte(out errorClass))
            {
                return false;
            }

            Debug.Assert(((errorClass >= TdsEnums.MIN_ERROR_CLASS) && token == TdsEnums.SQLERROR) ||
                          ((errorClass < TdsEnums.MIN_ERROR_CLASS) && token == TdsEnums.SQLINFO), "class and token don't match!");

            if (!stateObj.TryReadUInt16(out shortLen))
            {
                return false;
            }
            string message;
            if (!stateObj.TryReadString(shortLen, out message))
            {
                return false;
            }

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

            string server;

            // If the server field is not received use the locally cached value.
            if (byteLen == 0)
            {
                server = _server;
            }
            else
            {
                if (!stateObj.TryReadString(byteLen, out server))
                {
                    return false;
                }
            }

            if (!stateObj.TryReadByte(out byteLen))
            {
                return false;
            }
            string procedure;
            if (!stateObj.TryReadString(byteLen, out procedure))
            {
                return false;
            }

            int line;
            if (_isYukon)
            {
                if (!stateObj.TryReadInt32(out line))
                {
                    return false;
                }
            }
            else
            {
                ushort shortLine;
                if (!stateObj.TryReadUInt16(out shortLine))
                {
                    return false;
                }
                line = shortLine;
                // If we haven't yet completed processing login token stream yet, we may be talking to a Yukon server
                // In that case we still have to read another 2 bytes
                if (_state == TdsParserState.OpenNotLoggedIn)
                {
                    // Login incomplete
                    byte b;
                    if (!stateObj.TryPeekByte(out b))
                    {
                        return false;
                    }
                    if (b == 0)
                    {
                        // This is an invalid token value
                        ushort value;
                        if (!stateObj.TryReadUInt16(out value))
                        {
                            return false;
                        }
//.........这里部分代码省略.........

        //
        // Read in a SQLVariant
        //
        // SQLVariant looks like:
        // struct
        // {
        //      BYTE TypeTag
        //      BYTE cbPropBytes
        //      BYTE[] Properties
        //      BYTE[] DataVal
        // }
        internal bool TryReadSqlVariant(SqlBuffer value, int lenTotal, TdsParserStateObject stateObj)
        {
            // get the SQLVariant type
            byte type;
            if (!stateObj.TryReadByte(out type))
            {
                return false;
            }
            ushort lenMax = 0; // maximum lenData of value inside variant

            // read cbPropBytes
            byte cbPropsActual;
            if (!stateObj.TryReadByte(out cbPropsActual))
            {
                return false;
            }
            MetaType mt = MetaType.GetSqlDataType(type, 0 /*no user datatype*/, 0 /* no lenData, non-nullable type */);
            byte cbPropsExpected = mt.PropBytes;

            int lenConsumed = TdsEnums.SQLVARIANT_SIZE + cbPropsActual; // type, count of propBytes, and actual propBytes
            int lenData = lenTotal - lenConsumed; // length of actual data

            // read known properties and skip unknown properties
            Debug.Assert(cbPropsActual >= cbPropsExpected, "cbPropsActual is less that cbPropsExpected!");

            //
            // now read the value
            //
            switch (type)
            {
                case TdsEnums.SQLBIT:
                case TdsEnums.SQLINT1:
                case TdsEnums.SQLINT2:
                case TdsEnums.SQLINT4:
                case TdsEnums.SQLINT8:
                case TdsEnums.SQLFLT4:
                case TdsEnums.SQLFLT8:
                case TdsEnums.SQLMONEY:
                case TdsEnums.SQLMONEY4:
                case TdsEnums.SQLDATETIME:
                case TdsEnums.SQLDATETIM4:
                case TdsEnums.SQLUNIQUEID:
                    if (!TryReadSqlValueInternal(value, type, lenData, stateObj))
                    {
                        return false;
                    }
                    break;

                case TdsEnums.SQLDECIMALN:
                case TdsEnums.SQLNUMERICN:
                    {
                        Debug.Assert(cbPropsExpected == 2, "SqlVariant: invalid PropBytes for decimal/numeric type!");

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

                        // skip over unknown properties
                        if (cbPropsActual > cbPropsExpected)
                        {
                            if (!stateObj.TrySkipBytes(cbPropsActual - cbPropsExpected))
                            {
                                return false;
                            }
                        }

                        if (!TryReadSqlDecimal(value, TdsEnums.MAX_NUMERIC_LEN, precision, scale, stateObj))
                        {
                            return false;
                        }
                        break;
                    }

                case TdsEnums.SQLBIGBINARY:
                case TdsEnums.SQLBIGVARBINARY:
                    //Debug.Assert(TdsEnums.VARNULL == lenData, "SqlVariant: data length for Binary indicates null?");
                    Debug.Assert(cbPropsExpected == 2, "SqlVariant: invalid PropBytes for binary type!");

                    if (!stateObj.TryReadUInt16(out lenMax))
                    {
                        return false;
                    }
//.........这里部分代码省略.........

        private bool TryCommonProcessMetaData(TdsParserStateObject stateObj, _SqlMetaData col, SqlTceCipherInfoTable? cipherTable, bool fColMD, SqlCommandColumnEncryptionSetting columnEncryptionSetting) {
            byte byteLen;
            UInt32 userType;

            // read user type - 4 bytes Yukon, 2 backwards
            if (IsYukonOrNewer) {
                if (!stateObj.TryReadUInt32(out userType)) {
                    return false;
                }
            }
            else {
                ushort userTypeShort;
                if (!stateObj.TryReadUInt16(out userTypeShort)) {
                    return false;
                }
                userType = userTypeShort;
            }

            // read flags and set appropriate flags in structure
            byte flags;
            if (!stateObj.TryReadByte(out flags)) {
                return false;
            }

            col.updatability = (byte)((flags & TdsEnums.Updatability) >> 2);
            col.isNullable = (TdsEnums.Nullable == (flags & TdsEnums.Nullable));
            col.isIdentity = (TdsEnums.Identity == (flags & TdsEnums.Identity));

            // read second byte of column metadata flags
            if (!stateObj.TryReadByte(out flags)) {
                return false;
            }
            
            col.isColumnSet = (TdsEnums.IsColumnSet == (flags & TdsEnums.IsColumnSet));
            if (fColMD && _serverSupportsColumnEncryption) {
                col.isEncrypted = (TdsEnums.IsEncrypted == (flags & TdsEnums.IsEncrypted));
            }

            // Read TypeInfo
            if (!TryProcessTypeInfo (stateObj, col, userType)) {
                return false;
            }

            // Read tablename if present
            if (col.metaType.IsLong && !col.metaType.IsPlp) {
                if (_isYukon) {
                    int  unusedLen = 0xFFFF;      //We ignore this value
                    if (!TryProcessOneTable(stateObj, ref unusedLen, out col.multiPartTableName)) {
                        return false;
                    }
                } else {
                    ushort shortLen;
                    if (!stateObj.TryReadUInt16(out shortLen)) {
                        return false;
                    }
                    string tableName;
                    if (!stateObj.TryReadString(shortLen, out tableName)) {
                        return false;
                    }
                    // with Sql2000 this is returned as an unquoted mix of catalog.owner.table
                    // all of which may contain "." and unable to parse correctly from the string alone
                    // example "select * from pubs..[A.B.C.D.E]" AND only when * will contain a image/text/ntext column
                    // by delay parsing from execute to SqlDataReader.GetSchemaTable to enable more scenarios
                    col.multiPartTableName = new MultiPartTableName(tableName);
                }
            }

            // Read the TCE column cryptoinfo
            if (fColMD && _serverSupportsColumnEncryption && col.isEncrypted) {
                // If the column is encrypted, we should have a valid cipherTable
                if (cipherTable.HasValue && !TryProcessTceCryptoMetadata (stateObj, col, cipherTable.Value, columnEncryptionSetting, isReturnValue: false)) {
                    return false;
                }
            }

            // Read the column name 
            if (!stateObj.TryReadByte(out byteLen)) {
                return false;
            }
            if (!stateObj.TryReadString(byteLen, out col.column)) {
                return false;
            }

            // We get too many DONE COUNTs from the server, causing too meany StatementCompleted event firings.
            // We only need to fire this event when we actually have a meta data stream with 0 or more rows.
            stateObj._receivedColMetaData = true;
            return true;
        }

         private bool TryProcessUDTMetaData(SqlMetaDataPriv metaData, TdsParserStateObject stateObj) {

            ushort shortLength;
            byte byteLength;

            if (!stateObj.TryReadUInt16(out shortLength)) { // max byte size
                return false;
            }
            metaData.length = shortLength;

            // database name
            if (!stateObj.TryReadByte(out byteLength)) {
                return false;
            }
            if (byteLength != 0) {
                if (!stateObj.TryReadString(byteLength, out metaData.udtDatabaseName)) {
                    return false;
                }
            }

            // schema name
            if (!stateObj.TryReadByte(out byteLength)) {
                return false;
            }
            if (byteLength != 0) {
                if (!stateObj.TryReadString(byteLength, out metaData.udtSchemaName)) {
                    return false;
                }
            }

            // type name
            if (!stateObj.TryReadByte(out byteLength)) {
                return false;
            }
            if (byteLength != 0) {
                if (!stateObj.TryReadString(byteLength, out metaData.udtTypeName)) {
                    return false;
                }
            }

            if (!stateObj.TryReadUInt16(out shortLength)) {
                return false;
            }
            if (shortLength != 0) {
                if (!stateObj.TryReadString(shortLength, out metaData.udtAssemblyQualifiedName)) {
                    return false;
                }
            }

            return true;
        }       

        /// <summary>
        /// <para> Parses the TDS message to read single CIPHER_INFO entry.</para>
        /// </summary>
        internal bool TryReadCipherInfoEntry (TdsParserStateObject stateObj, out SqlTceCipherInfoEntry entry) {
            byte cekValueCount = 0;
            entry = new SqlTceCipherInfoEntry(ordinal: 0);

            // Read the DB ID
            int dbId;
            if (!stateObj.TryReadInt32(out dbId)) {
                return false;
            }

            // Read the keyID
            int keyId;
            if (!stateObj.TryReadInt32(out keyId)) {
                return false;
            }

            // Read the key version
            int keyVersion;
            if (!stateObj.TryReadInt32(out keyVersion)) {
                return false;
            }

            // Read the key MD Version
            byte[] keyMDVersion = new byte[8];
            if (!stateObj.TryReadByteArray(keyMDVersion, 0, 8)) {
                return false;
            }

            // Read the value count
            if (!stateObj.TryReadByte (out cekValueCount)) {
                return false;
            }

            for (int i = 0; i < cekValueCount; i++) {
                // Read individual CEK values
                byte[] encryptedCek;
                string keyPath;
                string keyStoreName;
                byte algorithmLength;
                string algorithmName;
                ushort shortValue;
                byte byteValue;
                int length;

                // Read the length of encrypted CEK 
                if (!stateObj.TryReadUInt16 (out shortValue)) {
                    return false; 
                }

                length = shortValue;
                encryptedCek = new byte[length];

                // Read the actual encrypted CEK
                if (!stateObj.TryReadByteArray (encryptedCek, 0, length)) {
                    return false;
                }

                // Read the length of key store name
                if (!stateObj.TryReadByte (out byteValue)) {
                    return false;
                }

                length = byteValue;

                // And read the key store name now
                if (!stateObj.TryReadString(length, out keyStoreName)) {
                    return false;
                }

                // Read the length of key Path
                if (!stateObj.TryReadUInt16 (out shortValue)) {
                    return false;
                }

                length = shortValue;

                // Read the key path string
                if (!stateObj.TryReadString(length, out keyPath)) {
                    return false;
                }

                // Read the length of the string carrying the encryption algo
                if (!stateObj.TryReadByte(out algorithmLength)) {
                    return false;
                }

                length = (int)algorithmLength;

                // Read the string carrying the encryption algo  (eg. RSA_PKCS_OAEP)
                if (!stateObj.TryReadString(length, out algorithmName)) {
                    return false;
                }

                // Add this encrypted CEK blob to our list of encrypted values for the CEK
                entry.Add(encryptedCek, 
                    databaseId: dbId, 
                    cekId: keyId, 
//.........这里部分代码省略.........

        internal bool TryProcessAltMetaData(int cColumns, TdsParserStateObject stateObj, out _SqlMetaDataSet metaData) {
            Debug.Assert(cColumns > 0, "should have at least 1 column in altMetaData!");

            metaData = null;
            _SqlMetaDataSet altMetaDataSet = new _SqlMetaDataSet(cColumns, null);
            int[] indexMap = new int[cColumns];

            if (!stateObj.TryReadUInt16(out altMetaDataSet.id)) {
                return false;
            }

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

            while (byCols > 0) {
                if (!stateObj.TrySkipBytes(2)) { // ignore ColNum ...
                    return false;
                }
                byCols--;
            }

            // pass 1, read the meta data off the wire
            for (int i = 0; i < cColumns; i++) {
                // internal meta data class
                _SqlMetaData col = altMetaDataSet[i];

                if (!stateObj.TryReadByte(out col.op)) {
                    return false;
                }
                if (!stateObj.TryReadUInt16(out col.operand)) {
                    return false;
                }

                // TCE is not applicable to AltMetadata.
                if (!TryCommonProcessMetaData(stateObj, col, null, fColMD: false, columnEncryptionSetting: SqlCommandColumnEncryptionSetting.Disabled)) {
                    return false;
                }

                if (ADP.IsEmpty(col.column)) {
                    // create column name from op
                    switch (col.op) {
                        case TdsEnums.AOPAVG:
                            col.column = "avg";
                            break;

                        case TdsEnums.AOPCNT:
                            col.column = "cnt";
                            break;

                        case TdsEnums.AOPCNTB:
                            col.column = "cntb";
                            break;

                        case TdsEnums.AOPMAX:
                            col.column = "max";
                            break;

                        case TdsEnums.AOPMIN:
                            col.column = "min";
                            break;

                        case TdsEnums.AOPSUM:
                            col.column = "sum";
                            break;

                        case TdsEnums.AOPANY:
                            col.column = "any";
                            break;

                        case TdsEnums.AOPNOOP:
                            col.column = "noop";
                            break;

                        case TdsEnums.AOPSTDEV:
                            col.column = "stdev";
                            break;

                        case TdsEnums.AOPSTDEVP:
                            col.column = "stdevp";
                            break;

                        case TdsEnums.AOPVAR:
                            col.column = "var";
                            break;

                        case TdsEnums.AOPVARP:
                            col.column = "varp";
                            break;
                    }
                }
                indexMap[i] = i;
            }

            altMetaDataSet.indexMap = indexMap;
            altMetaDataSet.visibleColumns = cColumns;

            metaData = altMetaDataSet;
            return true;
//.........这里部分代码省略.........

        internal bool TryProcessTceCryptoMetadata (TdsParserStateObject stateObj, 
            SqlMetaDataPriv col, 
            SqlTceCipherInfoTable? cipherTable, 
            SqlCommandColumnEncryptionSetting columnEncryptionSetting,
            bool isReturnValue) {
            Debug.Assert(isReturnValue == (cipherTable == null), "Ciphertable is not set iff this is a return value");

            // Read the ordinal into cipher table
            ushort index = 0;
            UInt32 userType;

            // For return values there is not cipher table and no ordinal.
            if (cipherTable.HasValue) {
                if (!stateObj.TryReadUInt16(out index)) {
                    return false;
                }

                // validate the index (ordinal passed)
                if (index >= cipherTable.Value.Size) {
                    Bid.Trace("<sc.TdsParser.TryProcessTceCryptoMetadata|TCE> Incorrect ordinal received %d, max tab size: %d\n", index, cipherTable.Value.Size);
                    throw SQL.ParsingErrorValue(ParsingErrorState.TceInvalidOrdinalIntoCipherInfoTable, index);
                }
            }

            // Read the user type
            if (!stateObj.TryReadUInt32(out userType)) {
                return false;
            }

            // Read the base TypeInfo
            col.baseTI = new SqlMetaDataPriv();
            if (!TryProcessTypeInfo(stateObj, col.baseTI, userType)) {
                return false;
            }

            // Read the cipher algorithm Id
            byte cipherAlgorithmId;
            if (!stateObj.TryReadByte(out cipherAlgorithmId)) {
                return false;
            }

            string cipherAlgorithmName = null;
            if (TdsEnums.CustomCipherAlgorithmId == cipherAlgorithmId) {
                // Custom encryption algorithm, read the name
                byte nameSize;
                if (!stateObj.TryReadByte(out nameSize)) {
                    return false;
                }

                if (!stateObj.TryReadString(nameSize, out cipherAlgorithmName)) {
                    return false;
                }
            }

            // Read Encryption Type. 
            byte encryptionType;
            if (!stateObj.TryReadByte(out encryptionType)) {
                return false;
            }

            // Read Normalization Rule Version.
            byte normalizationRuleVersion;
            if (!stateObj.TryReadByte(out normalizationRuleVersion)) {
                return false;
            }

            Debug.Assert(col.cipherMD == null, "col.cipherMD should be null in TryProcessTceCryptoMetadata.");

            // Check if TCE is enable and if it is set the crypto MD for the column.
            // TCE is enabled if the command is set to enabled or to resultset only and this is not a return value
            // or if it is set to use connection setting and the connection has TCE enabled.
            if ((columnEncryptionSetting == SqlCommandColumnEncryptionSetting.Enabled ||
                (columnEncryptionSetting == SqlCommandColumnEncryptionSetting.ResultSetOnly && !isReturnValue)) ||
                (columnEncryptionSetting == SqlCommandColumnEncryptionSetting.UseConnectionSetting &&
                _connHandler != null && _connHandler.ConnectionOptions != null &&
                _connHandler.ConnectionOptions.ColumnEncryptionSetting == SqlConnectionColumnEncryptionSetting.Enabled)) {
                col.cipherMD = new SqlCipherMetadata(cipherTable.HasValue ? (SqlTceCipherInfoEntry?)cipherTable.Value[index] : null,
                                                        index,
                                                        cipherAlgorithmId: cipherAlgorithmId,
                                                        cipherAlgorithmName: cipherAlgorithmName,
                                                        encryptionType: encryptionType,
                                                        normalizationRuleVersion: normalizationRuleVersion);
            }
            else {
                // If TCE is disabled mark the MD as not encrypted.
                col.isEncrypted = false;
            }

            return true;
        }

        // assumes that the current position is at the start of an altrow!
        internal bool TryGetAltRowId(TdsParserStateObject stateObj, out int id)
        {
            byte token;
            if (!stateObj.TryReadByte(out token))
            { // skip over ALTROW token
                id = 0;
                return false;
            }
            Debug.Assert((token == TdsEnums.SQLALTROW), "");

            // Start a fresh row - disable NBC since Alt Rows are never compressed
            if (!stateObj.TryStartNewRow(isNullCompressed: false))
            {
                id = 0;
                return false;
            }

            ushort shortId;
            if (!stateObj.TryReadUInt16(out shortId))
            {
                id = 0;
                return false;
            }

            id = shortId;
            return true;
        }

//.........这里部分代码省略.........
                            if (!TryProcessAltMetaData(tokenLength, stateObj, out cleanupAltMetaDataSet))
                            {
                                return false;
                            }

                            stateObj._cleanupAltMetaDataSetArray.SetAltMetaData(cleanupAltMetaDataSet);
                            if (null != dataStream)
                            {
                                byte metadataConsumedByte;
                                if (!stateObj.TryPeekByte(out metadataConsumedByte))
                                {
                                    return false;
                                }
                                if (!dataStream.TrySetAltMetaDataSet(cleanupAltMetaDataSet, (TdsEnums.SQLALTMETADATA != metadataConsumedByte)))
                                {
                                    return false;
                                }
                            }

                            break;
                        }

                    case TdsEnums.SQLALTROW:
                        {
                            if (!stateObj.TryStartNewRow(isNullCompressed: false))
                            { // altrows are not currently null compressed
                                return false;
                            }

                            // read will call run until dataReady. Must not read any data if returnimmetiately set
                            if (RunBehavior.ReturnImmediately != (RunBehavior.ReturnImmediately & runBehavior))
                            {
                                ushort altRowId;
                                if (!stateObj.TryReadUInt16(out altRowId))
                                { // get altRowId
                                    return false;
                                }

                                if (!TrySkipRow(stateObj._cleanupAltMetaDataSetArray.GetAltMetaData(altRowId), stateObj))
                                { // skip altRow
                                    return false;
                                }
                            }
                            else
                            {
                                dataReady = true;
                            }

                            break;
                        }

                    case TdsEnums.SQLENVCHANGE:
                        {
                            // ENVCHANGE must be processed synchronously (since it can modify the state of many objects)
                            stateObj._syncOverAsync = true;

                            SqlEnvChange[] env;
                            if (!TryProcessEnvChange(tokenLength, stateObj, out env))
                            {
                                return false;
                            }

                            for (int ii = 0; ii < env.Length; ii++)
                            {
                                if (env[ii] != null && !this.Connection.IgnoreEnvChange)
                                {