mcs/class/referencesource/System.Data/System/Data/Odbc/OdbcConnectionString.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="OdbcConnectionString.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.Odbc {
  10
  11     using System;
  12     using System.Collections;
  13     using System.Data;
  14     using System.Data.Common;
  15     using System.Security;
  16     using System.Security.Permissions;
  17     using System.Text;
  18
  19     internal sealed class OdbcConnectionString : DbConnectionOptions {
  20         // instances of this class are intended to be immutable, i.e readonly
  21         // used by pooling classes so it is much easier to verify correctness
  22         // when not worried about the class being modified during execution
  23
  24         private static class KEY {
  25             internal const string SaveFile                  = "savefile";
  26         }
  27
  28         private readonly string _expandedConnectionString;
  29
  30         internal OdbcConnectionString(string connectionString, bool validate) : base(connectionString, null, true) {
  31             if (!validate) {
  32                 string filename = null;
  33                 int position = 0;
  34                 _expandedConnectionString = ExpandDataDirectories(ref filename, ref position);
  35             }
  36             if (validate || (null == _expandedConnectionString)) {
  37                 // do not check string length if it was expanded because the final result may be shorter than the original
  38                 if ((null != connectionString) && (ODBC32.MAX_CONNECTION_STRING_LENGTH < connectionString.Length)) { // MDAC 83536
  39                     throw ODBC.ConnectionStringTooLong();
  40                 }
  41             }
  42         }
  43
  44         protected internal override System.Security.PermissionSet CreatePermissionSet() {
  45             System.Security.PermissionSet permissionSet;
  46             if (ContainsKey(KEY.SaveFile)) {
  47                 permissionSet = new NamedPermissionSet("FullTrust");
  48             }
  49             else {
  50                 permissionSet = new System.Security.PermissionSet(System.Security.Permissions.PermissionState.None);
  51                 permissionSet.AddPermission(new OdbcPermission(this));
  52             }
  53             return permissionSet;
  54         }
  55
  56         protected internal override string Expand() {
  57             if (null != _expandedConnectionString) {
  58                 return _expandedConnectionString;
  59             }
  60             else {
  61                 return base.Expand();
  62             }
  63         }
  64     }
  65 }