Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/SqlClient/SqlConnectionPoolGroupProviderInfo.cs

@@ -0,0 +1,126 @@
+//------------------------------------------------------------------------------
+// <copyright file="SqlConnectionPoolGroupProviderInfo.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+// <owner current="true" primary="false">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Data.SqlClient
+{
+    using System;
+    using System.Data;
+    using System.Data.Common;
+    using System.Data.ProviderBase;
+
+    sealed internal class SqlConnectionPoolGroupProviderInfo : DbConnectionPoolGroupProviderInfo {
+        private string _alias;
+        private System.Security.PermissionSet _failoverPermissionSet;
+        private string _failoverPartner;        
+        private bool _useFailoverPartner;
+        
+        internal SqlConnectionPoolGroupProviderInfo(SqlConnectionString connectionOptions) {
+            // This is for the case where the user specified the failover partner
+            // in the connection string and we have not yet connected to get the 
+            // env change.
+            _failoverPartner = connectionOptions.FailoverPartner;
+
+            if (ADP.IsEmpty(_failoverPartner)) {
+                _failoverPartner = null;
+            }
+        }
+
+        internal string FailoverPartner {
+            get {
+                return _failoverPartner;
+            }
+        }
+
+        internal bool UseFailoverPartner {
+            get {
+                return _useFailoverPartner;
+            }
+        }
+
+        internal void AliasCheck(string server) {
+            if (_alias != server) {
+                lock(this) {
+                    if (null == _alias) {
+                        _alias = server;
+                    }
+                    else if (_alias != server) {
+                        Bid.Trace("<sc.SqlConnectionPoolGroupProviderInfo|INFO> alias change detected. Clearing PoolGroup\n");
+                        base.PoolGroup.Clear();
+                        _alias = server;
+                    }
+                }
+            }
+        }
+
+        private System.Security.PermissionSet CreateFailoverPermission(SqlConnectionString userConnectionOptions, string actualFailoverPartner) {
+            string keywordToReplace;
+
+            // RULES FOR CONSTRUCTING THE CONNECTION STRING TO DEMAND ON:
+            //
+            // 1) If no Failover Partner was specified in the original string:
+            //
+            //          Server=actualFailoverPartner
+            //
+            // 2) If Failover Partner was specified in the original string:
+            //
+            //          Server=originalValue; Failover Partner=actualFailoverPartner
+            //
+            // NOTE: in all cases, when we get a failover partner name from 
+            //       the server, we will use that name over what was specified  
+            //       in the original connection string.
+            
+            if (null == userConnectionOptions[SqlConnectionString.KEY.FailoverPartner]) {
+                keywordToReplace = SqlConnectionString.KEY.Data_Source;
+            }
+            else {
+                keywordToReplace = SqlConnectionString.KEY.FailoverPartner;
+            }
+            
+            string failoverConnectionString = userConnectionOptions.ExpandKeyword(keywordToReplace, actualFailoverPartner);
+            return (new SqlConnectionString(failoverConnectionString)).CreatePermissionSet();
+        }
+
+        internal void FailoverCheck(SqlInternalConnection connection, bool actualUseFailoverPartner, SqlConnectionString userConnectionOptions, string actualFailoverPartner) {
+            if (UseFailoverPartner != actualUseFailoverPartner) {
+                // 
+                Bid.Trace("<sc.SqlConnectionPoolGroupProviderInfo|INFO> Failover detected. failover partner='%ls'. Clearing PoolGroup\n", actualFailoverPartner);
+                base.PoolGroup.Clear();
+                _useFailoverPartner = actualUseFailoverPartner;
+            }
+            // Only construct a new permission set when we're connecting to the
+            // primary data source, not the failover partner.
+            if (!_useFailoverPartner && _failoverPartner != actualFailoverPartner) {
+                // NOTE: we optimisitically generate the permission set to keep 
+                //       lock short, but we only do this when we get a new
+                //       failover partner.
+                // 
+
+                System.Security.PermissionSet failoverPermissionSet = CreateFailoverPermission(userConnectionOptions, actualFailoverPartner);
+
+                lock (this) {
+                    if (_failoverPartner != actualFailoverPartner) {
+                        _failoverPartner = actualFailoverPartner;
+                        _failoverPermissionSet = failoverPermissionSet;
+                    }
+                }
+            }
+        }
+
+        internal void FailoverPermissionDemand() {
+            if (_useFailoverPartner) {
+                // Note that we only demand when there is a permission set, which only
+                // happens once we've identified a failover situation in FailoverCheck
+                System.Security.PermissionSet failoverPermissionSet = _failoverPermissionSet;
+                if (null != failoverPermissionSet) {
+                    // demand on pooled failover connections
+                    failoverPermissionSet.Demand();
+                }
+            }        
+        }
+    }
+}