Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/OleDb/OleDbEnumerator.cs

@@ -0,0 +1,96 @@
+//------------------------------------------------------------------------------
+// <copyright file="OleDbEnumerator.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.OleDb {
+
+    using System;
+    using System.ComponentModel;
+    using System.Data.Common;
+    using System.Globalization;
+    using System.Security;
+    using System.Security.Permissions;
+
+    public sealed class OleDbEnumerator  {
+
+        public OleDbEnumerator() {
+        }
+
+        public DataTable GetElements() {
+            OleDbConnection.ExecutePermission.Demand();
+             
+            DataTable dataTable = new DataTable("MSDAENUM"); // WebData 112482
+            dataTable.Locale = CultureInfo.InvariantCulture;
+            OleDbDataReader dataReader = GetRootEnumerator();
+            OleDbDataAdapter.FillDataTable(dataReader, dataTable);
+            return dataTable;
+        }
+
+        static public OleDbDataReader GetEnumerator(Type type) {
+            OleDbConnection.ExecutePermission.Demand();
+
+            return GetEnumeratorFromType(type);
+        }
+        
+        static internal OleDbDataReader GetEnumeratorFromType(Type type) { // WebData 99005
+            // will demand security appropriately
+            object value = Activator.CreateInstance(type, System.Reflection.BindingFlags.Public|System.Reflection.BindingFlags.Instance, null, null, CultureInfo.InvariantCulture, null);
+            return GetEnumeratorReader(value);
+        }
+        
+        static private OleDbDataReader GetEnumeratorReader(object value) {
+            NativeMethods.ISourcesRowset srcrowset = null;
+
+            try {
+                srcrowset = (NativeMethods.ISourcesRowset) value;
+            }
+            catch(InvalidCastException) {
+                throw ODB.ISourcesRowsetNotSupported();
+            }
+            if (null == srcrowset) {
+                throw ODB.ISourcesRowsetNotSupported();
+            }
+            value = null; // still held by ISourcesRowset, reused for IRowset
+
+            int propCount = 0;
+            IntPtr propSets = ADP.PtrZero;
+
+            Bid.Trace("<oledb.ISourcesRowset.GetSourcesRowset|API|OLEDB> IID_IRowset\n");
+            OleDbHResult hr = srcrowset.GetSourcesRowset(ADP.PtrZero, ODB.IID_IRowset, propCount, propSets, out value);
+            Bid.Trace("<oledb.ISourcesRowset.GetSourcesRowset|API|OLEDB|RET> %08X{HRESULT}\n", hr);
+
+            Exception f = OleDbConnection.ProcessResults(hr, null, null);
+            if (null != f) {
+                throw f;
+            }
+
+            OleDbDataReader dataReader = new OleDbDataReader(null, null, 0, CommandBehavior.Default);
+            dataReader.InitializeIRowset(value, ChapterHandle.DB_NULL_HCHAPTER, ADP.RecordsUnaffected);
+            dataReader.BuildMetaInfo();
+            dataReader.HasRowsRead();
+            return dataReader;
+        }
+        
+        static public OleDbDataReader GetRootEnumerator() {
+            OleDbConnection.ExecutePermission.Demand();
+
+            IntPtr hscp;
+            Bid.ScopeEnter(out hscp, "<oledb.OleDbEnumerator.GetRootEnumerator|API>\n");
+            try {
+                //readonly Guid CLSID_MSDAENUM = new Guid(0xc8b522d0,0x5cf3,0x11ce,0xad,0xe5,0x00,0xaa,0x00,0x44,0x77,0x3d);
+                //Type msdaenum = Type.GetTypeFromCLSID(CLSID_MSDAENUM, true);
+                const string PROGID_MSDAENUM = "MSDAENUM";
+                Type msdaenum = Type.GetTypeFromProgID(PROGID_MSDAENUM, true);
+                return GetEnumeratorFromType(msdaenum);
+            }
+            finally {
+                Bid.ScopeLeave(ref hscp);
+            }
+        }
+    }
+}
+