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

   1 //------------------------------------------------------------------------------
   2 // <copyright file="SqlConnectionPoolGroupProviderInfo.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 // <owner current="true" primary="false">Microsoft</owner>
   7 //------------------------------------------------------------------------------
   8
   9 namespace System.Data.SqlClient
  10 {
  11     using System;
  12     using System.Data;
  13     using System.Data.Common;
  14     using System.Data.ProviderBase;
  15
  16     sealed internal class SqlConnectionPoolGroupProviderInfo : DbConnectionPoolGroupProviderInfo {
  17         private string _alias;
  18         private System.Security.PermissionSet _failoverPermissionSet;
  19         private string _failoverPartner;
  20         private bool _useFailoverPartner;
  21
  22         internal SqlConnectionPoolGroupProviderInfo(SqlConnectionString connectionOptions) {
  23             // This is for the case where the user specified the failover partner
  24             // in the connection string and we have not yet connected to get the
  25             // env change.
  26             _failoverPartner = connectionOptions.FailoverPartner;
  27
  28             if (ADP.IsEmpty(_failoverPartner)) {
  29                 _failoverPartner = null;
  30             }
  31         }
  32
  33         internal string FailoverPartner {
  34             get {
  35                 return _failoverPartner;
  36             }
  37         }
  38
  39         internal bool UseFailoverPartner {
  40             get {
  41                 return _useFailoverPartner;
  42             }
  43         }
  44
  45         internal void AliasCheck(string server) {
  46             if (_alias != server) {
  47                 lock(this) {
  48                     if (null == _alias) {
  49                         _alias = server;
  50                     }
  51                     else if (_alias != server) {
  52                         Bid.Trace("<sc.SqlConnectionPoolGroupProviderInfo|INFO> alias change detected. Clearing PoolGroup\n");
  53                         base.PoolGroup.Clear();
  54                         _alias = server;
  55                     }
  56                 }
  57             }
  58         }
  59
  60         private System.Security.PermissionSet CreateFailoverPermission(SqlConnectionString userConnectionOptions, string actualFailoverPartner) {
  61             string keywordToReplace;
  62
  63             // RULES FOR CONSTRUCTING THE CONNECTION STRING TO DEMAND ON:
  64             //
  65             // 1) If no Failover Partner was specified in the original string:
  66             //
  67             //          Server=actualFailoverPartner
  68             //
  69             // 2) If Failover Partner was specified in the original string:
  70             //
  71             //          Server=originalValue; Failover Partner=actualFailoverPartner
  72             //
  73             // NOTE: in all cases, when we get a failover partner name from
  74             //       the server, we will use that name over what was specified
  75             //       in the original connection string.
  76
  77             if (null == userConnectionOptions[SqlConnectionString.KEY.FailoverPartner]) {
  78                 keywordToReplace = SqlConnectionString.KEY.Data_Source;
  79             }
  80             else {
  81                 keywordToReplace = SqlConnectionString.KEY.FailoverPartner;
  82             }
  83
  84             string failoverConnectionString = userConnectionOptions.ExpandKeyword(keywordToReplace, actualFailoverPartner);
  85             return (new SqlConnectionString(failoverConnectionString)).CreatePermissionSet();
  86         }
  87
  88         internal void FailoverCheck(SqlInternalConnection connection, bool actualUseFailoverPartner, SqlConnectionString userConnectionOptions, string actualFailoverPartner) {
  89             if (UseFailoverPartner != actualUseFailoverPartner) {
  90                 //
  91                 Bid.Trace("<sc.SqlConnectionPoolGroupProviderInfo|INFO> Failover detected. failover partner='%ls'. Clearing PoolGroup\n", actualFailoverPartner);
  92                 base.PoolGroup.Clear();
  93                 _useFailoverPartner = actualUseFailoverPartner;
  94             }
  95             // Only construct a new permission set when we're connecting to the
  96             // primary data source, not the failover partner.
  97             if (!_useFailoverPartner && _failoverPartner != actualFailoverPartner) {
  98                 // NOTE: we optimisitically generate the permission set to keep
  99                 //       lock short, but we only do this when we get a new
 100                 //       failover partner.
 101                 //
 102
 103                 System.Security.PermissionSet failoverPermissionSet = CreateFailoverPermission(userConnectionOptions, actualFailoverPartner);
 104
 105                 lock (this) {
 106                     if (_failoverPartner != actualFailoverPartner) {
 107                         _failoverPartner = actualFailoverPartner;
 108                         _failoverPermissionSet = failoverPermissionSet;
 109                     }
 110                 }
 111             }
 112         }
 113
 114         internal void FailoverPermissionDemand() {
 115             if (_useFailoverPartner) {
 116                 // Note that we only demand when there is a permission set, which only
 117                 // happens once we've identified a failover situation in FailoverCheck
 118                 System.Security.PermissionSet failoverPermissionSet = _failoverPermissionSet;
 119                 if (null != failoverPermissionSet) {
 120                     // demand on pooled failover connections
 121                     failoverPermissionSet.Demand();
 122                 }
 123             }
 124         }
 125     }
 126 }