sqlpipe.cs source code in C# .NET

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/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / Microsoft / SqlServer / Server / sqlpipe.cs / 1305376 / sqlpipe.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
// [....]
// daltodov 
//----------------------------------------------------------------------------- 

namespace Microsoft.SqlServer.Server { 

    using System;
    using System.Collections;
    using System.Collections.Generic; 
    using System.Data;
    using System.Data.Sql; 
    using System.Data.Common; 
    using System.Data.SqlClient;
    using System.Data.SqlTypes; 
    using System.Diagnostics;

    // SqlPipe
    //    Abstraction of TDS data/message channel exposed to user. 
    public sealed class SqlPipe {
 
        SmiContext              _smiContext; 
        SmiRecordBuffer         _recordBufferSent;          // Last recordBuffer sent to pipe (for push model SendEnd).
        SqlMetaData[]           _metaDataSent;              // Metadata of last resultset started (for push model). Overloaded to indicate if push started or not (non-null/null) 
        SmiEventSink_Default    _eventSink;                 // Eventsink to use when calling SmiContext entrypoints
        bool                    _isBusy;                    // Is this pipe currently handling an operation?
        bool                    _hadErrorInResultSet;       // true if an exception was thrown from within various bodies; used to control cleanup during SendResultsEnd
 

        internal SqlPipe( SmiContext smiContext ) { 
            _smiContext = smiContext; 
            _eventSink = new SmiEventSink_Default();
        } 


        //
        // Public methods 
        //
        public void ExecuteAndSend( SqlCommand command ) { 
            SetPipeBusy( ); 
            try {
                EnsureNormalSendValid( "ExecuteAndSend" ); 

                if ( null == command ) {
                    throw ADP.ArgumentNull( "command" );
                } 

                SqlConnection connection = command.Connection; 
 
                // if the command doesn't have a connection set up, try to set one up on it's behalf
                if ( null == connection ) { 
                    using ( SqlConnection newConnection = new SqlConnection( "Context Connection=true" ) ) {
                        newConnection.Open( );

                        // use try-finally to restore command's connection property to it's original state 
                        try {
                            command.Connection = newConnection; 
                            command.ExecuteToPipe( _smiContext ); 
                        }
                        finally { 
                            command.Connection = null;
                        }
                    }
                } 
                else {
                    // validate connection state 
                    if ( ConnectionState.Open != connection.State ) { 
                        throw ADP.ClosedConnectionError();
                    } 

                    // validate connection is current scope's connection
                    SqlInternalConnectionSmi internalConnection = connection.InnerConnection as SqlInternalConnectionSmi;
 
                    if ( null == internalConnection ) {
                        throw SQL.SqlPipeCommandHookedUpToNonContextConnection( ); 
                    } 

                    command.ExecuteToPipe( _smiContext ); 
                }
            }
            finally {
                ClearPipeBusy( ); 
            }
        } 
 
        // Equivalent to TSQL PRINT statement -- sends an info-only message.
        public void Send( string message ) { 
            ADP.CheckArgumentNull(message, "message");

            if ( SmiMetaData.MaxUnicodeCharacters < message.Length ) {
                throw SQL.SqlPipeMessageTooLong( message.Length ); 
            }
 
            SetPipeBusy( ); 
            try {
                EnsureNormalSendValid( "Send" ); 

                _smiContext.SendMessageToPipe( message, _eventSink );

                // Handle any errors that are reported. 
                _eventSink.ProcessMessagesAndThrow();
            } 
            finally { 
                ClearPipeBusy( );
            } 
        }

        // Send results from SqlDataReader
        public void Send( SqlDataReader reader ) { 
            ADP.CheckArgumentNull(reader, "reader");
 
            SetPipeBusy( ); 
            try {
                EnsureNormalSendValid( "Send" ); 
                do {
                    SmiExtendedMetaData[] columnMetaData = reader.GetInternalSmiMetaData();

                    if (null != columnMetaData && 0 != columnMetaData.Length) { // SQLBUDT #340528 -- don't send empty results. 
                        using ( SmiRecordBuffer recordBuffer = _smiContext.CreateRecordBuffer(columnMetaData, _eventSink) ) {
                            _eventSink.ProcessMessagesAndThrow(); // Handle any errors that are reported. 
 

                            _smiContext.SendResultsStartToPipe( recordBuffer, _eventSink ); 
                            _eventSink.ProcessMessagesAndThrow(); // Handle any errors that are reported.

                            try {
                                while( reader.Read( ) ) { 
                                    if (SmiContextFactory.Instance.NegotiatedSmiVersion >= SmiContextFactory.KatmaiVersion) {
                                        ValueUtilsSmi.FillCompatibleSettersFromReader(_eventSink, recordBuffer, new List(columnMetaData), reader); 
                                    } 
                                    else {
                                        ValueUtilsSmi.FillCompatibleITypedSettersFromReader(_eventSink, recordBuffer, columnMetaData, reader); 
                                    }

                                    _smiContext.SendResultsRowToPipe( recordBuffer, _eventSink );
                                    _eventSink.ProcessMessagesAndThrow(); // Handle any errors that are reported. 
                                }
                            } 
                            finally { 
                                _smiContext.SendResultsEndToPipe( recordBuffer, _eventSink );
                                _eventSink.ProcessMessagesAndThrow(); // Handle any errors that are reported. 
                            }
                        }
                    }
                } 
                while ( reader.NextResult( ) );
            } 
            finally { 
                ClearPipeBusy( );
            } 
        }

        public void Send( SqlDataRecord record ) {
            ADP.CheckArgumentNull(record, "record"); 

            SetPipeBusy( ); 
            try { 
                EnsureNormalSendValid( "Send" );
 
                if (0 != record.FieldCount) { // SQLBUDT #340564 -- don't send empty records.

                    SmiRecordBuffer recordBuffer;
                    if (record.RecordContext == _smiContext) { 
                        recordBuffer = record.RecordBuffer;
                    } else {    // SendResultsRowToPipe() only takes a RecordBuffer created by an SmiContext 
                        SmiExtendedMetaData[] columnMetaData = record.InternalGetSmiMetaData(); 
                        recordBuffer = _smiContext.CreateRecordBuffer(columnMetaData, _eventSink);
                        if (SmiContextFactory.Instance.NegotiatedSmiVersion >= SmiContextFactory.KatmaiVersion) { 
                            ValueUtilsSmi.FillCompatibleSettersFromRecord(_eventSink, recordBuffer, columnMetaData, record, null /* no default values */);
                        }
                        else {
                            ValueUtilsSmi.FillCompatibleITypedSettersFromRecord(_eventSink, recordBuffer, columnMetaData, record); 
                        }
                    } 
 
                    _smiContext.SendResultsStartToPipe( recordBuffer, _eventSink );
                    _eventSink.ProcessMessagesAndThrow(); // Handle any errors that are reported. 

                    //  If SendResultsStartToPipe succeeded, then SendResultsEndToPipe must be called.
                    try {
                        _smiContext.SendResultsRowToPipe( recordBuffer, _eventSink ); 
                        _eventSink.ProcessMessagesAndThrow(); // Handle any errors that are reported.
                    } 
                    finally { 
                        _smiContext.SendResultsEndToPipe( recordBuffer, _eventSink );
                        _eventSink.ProcessMessagesAndThrow(); // Handle any errors that are reported. 
                    }
                }
            }
            finally { 
                ClearPipeBusy( );
            } 
        } 

        public void SendResultsStart( SqlDataRecord record ) { 
            ADP.CheckArgumentNull(record, "record");

            SetPipeBusy( );
            try { 
                EnsureNormalSendValid( "SendResultsStart" );
 
                SmiRecordBuffer recordBuffer = record.RecordBuffer; 
                if (record.RecordContext == _smiContext) {
                    recordBuffer = record.RecordBuffer; 
                } else {
                    recordBuffer = _smiContext.CreateRecordBuffer(record.InternalGetSmiMetaData(), _eventSink);    // Only MetaData needed for sending start
                }
                _smiContext.SendResultsStartToPipe( recordBuffer, _eventSink ); 

                // Handle any errors that are reported. 
                _eventSink.ProcessMessagesAndThrow(); 

                // remember sent buffer info so it can be used in send row/end. 
                _recordBufferSent = recordBuffer;
                _metaDataSent = record.InternalGetMetaData();
            }
            finally { 
                ClearPipeBusy( );
            } 
        } 

        public void SendResultsRow( SqlDataRecord record ) { 
            ADP.CheckArgumentNull(record, "record");

            SetPipeBusy( );
            try { 
                EnsureResultStarted( "SendResultsRow" );
 
                if ( _hadErrorInResultSet ) { 
                    throw SQL.SqlPipeErrorRequiresSendEnd();
                } 

                // Assume error state unless cleared below
                _hadErrorInResultSet = true;
 
                SmiRecordBuffer recordBuffer;
                if (record.RecordContext == _smiContext) { 
                    recordBuffer = record.RecordBuffer; 
                } else {
                    SmiExtendedMetaData[] columnMetaData = record.InternalGetSmiMetaData(); 
                    recordBuffer = _smiContext.CreateRecordBuffer(columnMetaData, _eventSink);
                    if (SmiContextFactory.Instance.NegotiatedSmiVersion >= SmiContextFactory.KatmaiVersion) {
                        ValueUtilsSmi.FillCompatibleSettersFromRecord(_eventSink, recordBuffer, columnMetaData, record, null /* no default values */);
                    } 
                    else {
                        ValueUtilsSmi.FillCompatibleITypedSettersFromRecord(_eventSink, recordBuffer, columnMetaData, record); 
                    } 
                }
                _smiContext.SendResultsRowToPipe( recordBuffer, _eventSink ); 

                // Handle any errors that are reported.
                _eventSink.ProcessMessagesAndThrow();
 
                // We successfully traversed the send, clear error state
                _hadErrorInResultSet = false; 
            } 
            finally {
                ClearPipeBusy( ); 
            }
        }

        public void SendResultsEnd( ) { 
            SetPipeBusy( );
            try { 
                EnsureResultStarted( "SendResultsEnd" ); 

                _smiContext.SendResultsEndToPipe( _recordBufferSent, _eventSink ); 

                // Once end called down to native code, assume end of resultset
                _metaDataSent = null;
                _recordBufferSent = null; 
                _hadErrorInResultSet = false;
 
                // Handle any errors that are reported. 
                _eventSink.ProcessMessagesAndThrow();
            } 
            finally {
                ClearPipeBusy( );
            }
        } 

        // This isn't speced, but it may not be a bad idea to implement... 
        public bool IsSendingResults { 
            get {
                return null != _metaDataSent; 
            }
        }

        internal void OnOutOfScope( ) { 
            _metaDataSent = null;
            _recordBufferSent = null; 
            _hadErrorInResultSet = false; 
            _isBusy = false;
        } 

        // Pipe busy status.
        //    Ensures user code cannot call any APIs while a send is in progress.
        // 
        //    Public methods must call this method before sending anything to the unmanaged pipe.
        //    Once busy status is set, it must clear before returning from the calling method 
        //        ( i.e. clear should be in a finally block). 
        private void SetPipeBusy( ) {
            if ( _isBusy ) { 
                throw SQL.SqlPipeIsBusy( );
            }
            _isBusy = true;
        } 

        // Clear the pipe's busy status. 
        private void ClearPipeBusy( ) { 
            _isBusy = false;
        } 

        //
        // State validation
        //    One of the Ensure* validation methods should appear at the top of every public method 
        //
 
        // Default validation method 
        //    Ensures Pipe is not currently transmitting a push-model resultset
        private void EnsureNormalSendValid( string methodName ) { 
            if ( IsSendingResults ) {
                throw SQL.SqlPipeAlreadyHasAnOpenResultSet( methodName );
            }
        } 

        private void EnsureResultStarted( string methodName ) { 
            if ( !IsSendingResults ) { 
                throw SQL.SqlPipeDoesNotHaveAnOpenResultSet( methodName );
            } 
        }
    }
}
 


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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