sqlcontext.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / Microsoft / SqlServer / Server / sqlcontext.cs / 1305376 / sqlcontext.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
// [....]
// daltodov 
//----------------------------------------------------------------------------- 

namespace Microsoft.SqlServer.Server { 

    using System;
    using System.Data.Common;
    using System.Data.SqlClient; 
    using System.Data.SqlTypes;
    using System.Diagnostics; 
    using System.Security.Principal; 

    public sealed class SqlContext { 

        // There are no publicly visible instance methods/properties on SqlContext.
        //  With the current design, the user should never get an actual instance of
        //  this class.  Instances are only used internally to hold owned objects 
        //  such as SqlPipe and SqlTriggerContext.
 
        private SmiContext        _smiContext; 
        private SqlPipe           _pipe;
        private SqlTriggerContext _triggerContext; 

        private SqlContext( SmiContext smiContext ) {
            _smiContext = smiContext;
            _smiContext.OutOfScope += new EventHandler(OnOutOfScope); 
        }
 
        // 
        //  Public API
        // 

        public static bool IsAvailable {
            get {
                bool result = InOutOfProcHelper.InProc; 
                return result;
            } 
        } 

        // Get the SqlPipe (if any) for the current scope. 
        public static SqlPipe Pipe {
            get {
                return CurrentContext.InstancePipe;
            } 
        }
 
        // Get the SqlTriggerContext (if any) for the current scope. 
        public static SqlTriggerContext TriggerContext {
            get { 
                return CurrentContext.InstanceTriggerContext;
            }
        }
 
        public static WindowsIdentity WindowsIdentity{
            get { 
                return CurrentContext.InstanceWindowsIdentity; 
            }
        } 

        //
        // Internal class methods
        // 

        // CurrentContext should be the *only* way to get to an instance of SqlContext. 
        private static SqlContext CurrentContext { 
            get {
                SmiContext smiContext = SmiContextFactory.Instance.GetCurrentContext(); 

                SqlContext result = (SqlContext)smiContext.GetContextValue( (int)SmiContextFactory.ContextKey.SqlContext );

                if ( null == result ) { 
                    result = new SqlContext( smiContext );
                    smiContext.SetContextValue( (int)SmiContextFactory.ContextKey.SqlContext, result ); 
                } 

                return result; 
            }
        }

        // 
        //  Internal instance methods
        // 
        private SqlPipe InstancePipe { 
            get {
                if ( null == _pipe && _smiContext.HasContextPipe ) { 
                    _pipe = new SqlPipe( _smiContext );
                }

                Debug.Assert( null == _pipe || _smiContext.HasContextPipe, "Caching logic error for contained pipe!" ); 

                return _pipe; 
            } 
        }
 
        private SqlTriggerContext InstanceTriggerContext {
            get {
                if ( null == _triggerContext ) {
                    bool[]               columnsUpdated; 
                    TriggerAction        triggerAction;
                    SqlXml               eventInstanceData; 
                    SmiEventSink_Default eventSink = new SmiEventSink_Default(); 

                    _smiContext.GetTriggerInfo(eventSink, out columnsUpdated, out triggerAction, out eventInstanceData); 

                    eventSink.ProcessMessagesAndThrow();

                    if (TriggerAction.Invalid != triggerAction) { 
                        _triggerContext = new SqlTriggerContext( triggerAction, columnsUpdated, eventInstanceData );
                    } 
                } 

                return _triggerContext; 
            }
        }

        private WindowsIdentity InstanceWindowsIdentity { 
            get {
                return _smiContext.WindowsIdentity; 
            } 
        }
 
        // Called whenever the context goes out of scope, we need to make
        // sure that we release internal state, such as the pipe's record buffer
        private void OnOutOfScope( object s, EventArgs e ) {
            if (Bid.AdvancedOn) { 
                Bid.Trace( " SqlContext is out of scope\n" );
            } 
 
            if ( null != _pipe ) {
                _pipe.OnOutOfScope(); 
            }

            _triggerContext = null;
        } 
    }
} 

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

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
sqlcontext.cs source code in C# .NET

Source code for the .NET framework in C#

Code:

Link Menu
