Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/Microsoft/SqlServer/Server/sqlcontext.cs

@@ -0,0 +1,142 @@
+//------------------------------------------------------------------------------
+// <copyright file="SqlContext.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+// <owner current="true" primary="false">[....]</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;
+        }
+    }
+}