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 using System.Threading;
  35 using System.Reflection;
  36 using System.Collections;
  37 using System.Configuration;
  38
  39 namespace System.Data.Common {
  40         public static class DbProviderFactories
  41         {
  42                 private static object configEntries; // DataSet
  43
  44                 internal const string CONFIG_SECTION_NAME        = "system.data";
  45                 internal const string CONFIG_SEC_TABLE_NAME      = "DbProviderFactories";
  46
  47                 #region Methods
  48
  49                 public static DbProviderFactory GetFactory (DataRow providerRow)
  50                 {
  51                         string assemblyType = (string) providerRow ["AssemblyQualifiedName"];
  52                         Type type = Type.GetType (assemblyType, false, true);
  53                         if (type != null && type.IsSubclassOf (typeof (DbProviderFactory))) {
  54                                 // Provider factories are singletons with Instance field having
  55                                 // the sole instance
  56                                 FieldInfo field = type.GetField ("Instance", BindingFlags.Public |
  57                                         BindingFlags.Static);
  58                                 if (field != null) {
  59                                         return field.GetValue (null) as DbProviderFactory;
  60                                 }
  61                         }
  62
  63                         throw new ConfigurationErrorsException("Failed to find or load the registered .Net Framework Data Provider.");
  64                 }
  65
  66                 public static DbProviderFactory GetFactory (string providerInvariantName)
  67                 {
  68                         if (providerInvariantName == null)
  69                                 throw new ArgumentNullException ("providerInvariantName");
  70
  71                         DataTable table = GetFactoryClasses ();
  72                         if (table != null) {
  73                                 DataRow row = table.Rows.Find (providerInvariantName);
  74                                 if (row != null)
  75                                         return GetFactory (row);
  76                         }
  77
  78                         throw new ConfigurationErrorsException (String.Format("Failed to find or load the registered .Net Framework Data Provider '{0}'.", providerInvariantName));
  79                 }
  80
  81 #if NET_4_5
  82                 public static DbProviderFactory GetFactory (DbConnection connection)
  83                 {
  84                         if (connection == null)
  85                                 throw new ArgumentNullException ("connection");
  86
  87                         return connection.DbProviderFactory;
  88                 }
  89 #endif
  90
  91                 public static DataTable GetFactoryClasses ()
  92                 {
  93                                 DataSet ds = GetConfigEntries ();
  94                                 DataTable table = ds != null ? ds.Tables [CONFIG_SEC_TABLE_NAME] : null;
  95                                 if (table != null)
  96                                         table = table.Copy (); // avoid modifications by user
  97                                 return table;
  98                 }
  99
 100                 #endregion // Methods
 101
 102                 #region Internal Methods
 103
 104                 internal static DataSet GetConfigEntries ()
 105                 {
 106                         if (configEntries != null)
 107                                 return configEntries as DataSet;
 108
 109                         DataSet ds = (DataSet) ConfigurationManager.GetSection (CONFIG_SECTION_NAME);
 110                         Interlocked.CompareExchange (ref configEntries, ds, null);
 111                         return configEntries as DataSet;
 112                 }
 113
 114                 #endregion Internal Methods
 115         }
 116 }