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//------------------------------------------------------------------------------
// <copyright file="SqlContext.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
// <owner current="true" primary="false">daltodov</owner>
//------------------------------------------------------------------------------
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( "<sc.SqlContext.OutOfScope|ADV> SqlContext is out of scope\n" );
}
if ( null != _pipe ) {
_pipe.OnOutOfScope();
}
_triggerContext = null;
}
}
}
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