mcs/class/System.Data/System.Data.Common/DbProviderFactories.cs

   1 //
   2 // System.Data.Common.DbProviderFactories.cs
   3 //
   4 // Author:
   5 //   Sureshkumar T (tsureshkumar@novell.com)
   6 //   Tim Coleman (tim@timcoleman.com)
   7 //
   8 // Copyright (C) Tim Coleman, 2003
   9 //
  10
  11 //
  12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 #if NET_2_0
  35
  36 using System.Threading;
  37 using System.Reflection;
  38 using System.Collections;
  39 using System.Configuration;
  40
  41 namespace System.Data.Common {
  42         public sealed class DbProviderFactories
  43         {
  44                 private static object configEntries = null; // DataSet
  45
  46                 private const string CONFIG_SECTION_NAME        = "system.data";
  47                 private const string CONFIG_SEC_TABLE_NAME      = "DbProviderFactories";
  48
  49                 #region Constructors
  50                 private DbProviderFactories ()
  51                 {
  52                 }
  53                 #endregion Constructors
  54
  55                 #region Methods
  56
  57                 public static DbProviderFactory GetFactory (DataRow providerRow)
  58                 {
  59                         string assemblyType = (string) providerRow ["AssemblyQualifiedName"];
  60                         Type type = Type.GetType (assemblyType, false, true);
  61                         if (type != null && type.IsSubclassOf (typeof (DbProviderFactory))) {
  62                                 // Provider factories are singletons with Instance field having
  63                                 // the sole instance
  64                                 FieldInfo field = type.GetField ("Instance", BindingFlags.Public |
  65                                                                  BindingFlags.Static);
  66                                 if (field != null) {
  67                                         return field.GetValue (null) as DbProviderFactory;
  68                                 }
  69
  70                         }
  71
  72                         throw new ConfigurationException("DataProvider is missing!");
  73                 }
  74
  75                 public static DbProviderFactory GetFactory (string providerInvariantName)
  76                 {
  77                         DataTable table = GetFactoryClasses ();
  78                         if (table != null) {
  79                                 DataRow row = table.Rows.Find (providerInvariantName);
  80                                 if (row != null)
  81                                         return GetFactory (row);
  82                         }
  83                         throw new ConfigurationException ("DataProvider is not found!");
  84                 }
  85
  86                 public static DataTable GetFactoryClasses ()
  87                 {
  88                         DataSet ds = GetConfigEntries ();
  89                         DataTable table = ds != null ? ds.Tables [CONFIG_SEC_TABLE_NAME] : null;
  90                         if (table != null)
  91                                 table = table.Copy (); // avoid modifications by user
  92                         return table;
  93                 }
  94
  95                 #endregion // Methods
  96
  97                 #region Internal Methods
  98                 internal static DataSet GetConfigEntries ()
  99                 {
 100
 101                         if (configEntries != null)
 102                                 return configEntries as DataSet;
 103
 104                         DataSet ds = (DataSet) ConfigurationSettings.GetConfig (CONFIG_SECTION_NAME);
 105                         Interlocked.CompareExchange (ref configEntries, ds, null);
 106                         return configEntries as DataSet;
 107                 }
 108                 #endregion Internal Methods
 109         }
 110 }
 111
 112 #endif // NET_2_0