class/System.Data.DataSetExtensions/System.Data/RowEnumerableDataReader.cs

   1 //
   2 // RowEnumerableDataReader.cs
   3 //
   4 // Author:
   5 //   Atsushi Enomoto  <atsushi@ximian.com>
   6 //
   7 // Copyright (C) 2008 Novell, Inc. http://www.novell.com
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System;
  32 using System.Collections;
  33 using System.Collections.Generic;
  34 using System.Linq;
  35
  36 namespace System.Data
  37 {
  38         internal class RowEnumerableDataReader : IDataReader
  39         {
  40                 EnumerableRowCollection source;
  41                 IEnumerator e;
  42                 int depth;
  43
  44                 public RowEnumerableDataReader (IEnumerable source, int depth)
  45                 {
  46                         this.source = source as EnumerableRowCollection;
  47                         if (this.source == null)
  48                                 this.source = new EnumerableRowCollection<DataRow> ((IEnumerable<DataRow>) source);
  49                         this.depth = depth;
  50                 }
  51
  52                 public DataRow Current {
  53                         get { return e != null ? (DataRow) e.Current : null; }
  54                 }
  55
  56                 public int Depth {
  57                         get { return depth; }
  58                 }
  59
  60                 public bool IsClosed {
  61                         get { return e == null; }
  62                 }
  63
  64                 public int RecordsAffected {
  65                         get { return -1; }
  66                 }
  67
  68                 public void Close ()
  69                 {
  70                         e = null;
  71                 }
  72
  73                 public DataTable GetSchemaTable ()
  74                 {
  75                         return new DataTableReader (source.Table).GetSchemaTable ();
  76                 }
  77
  78                 public bool NextResult ()
  79                 {
  80                         return e.MoveNext ();
  81                 }
  82
  83                 public bool Read ()
  84                 {
  85                         if (e == null)
  86                                 e = ((IEnumerable) source).GetEnumerator ();
  87                         return NextResult ();
  88                 }
  89
  90                 // IDisposable
  91                 public void Dispose ()
  92                 {
  93                         Close ();
  94                 }
  95
  96                 // IDataRecord
  97
  98                 DataTable GetTable ()
  99                 {
 100                         DataRow r = Current;
 101                         if (r == null)
 102                                 foreach (DataRow rr in source) {
 103                                         r = rr;
 104                                         break;
 105                                 }
 106                         return r.Table;
 107                 }
 108
 109                 public int FieldCount {
 110                         get { return GetTable ().Columns.Count; }
 111                 }
 112
 113                 public object this [int i] {
 114                         get { return Current [i]; }
 115                 }
 116
 117                 public object this [string name] {
 118                         get { return Current [name]; }
 119                 }
 120
 121                 public string GetDataTypeName (int i)
 122                 {
 123                         return GetFieldType (i).Name;
 124                 }
 125
 126                 public Type GetFieldType (int i)
 127                 {
 128                         return GetTable ().Columns [i].DataType;
 129                 }
 130
 131                 public string GetName (int i)
 132                 {
 133                         return GetTable ().Columns [i].ColumnName;
 134                 }
 135
 136                 public int GetOrdinal (string name)
 137                 {
 138                         return GetTable ().Columns [name].Ordinal;
 139                 }
 140
 141                 public long GetBytes (int i, long fieldOffset, byte [] buffer, int bufferoffset, int length)
 142                 {
 143                         // FIXME: do we need it?
 144                         throw new NotSupportedException ();
 145                 }
 146
 147                 public long GetChars (int i, long fieldOffset, char [] buffer, int bufferoffset, int length)
 148                 {
 149                         // FIXME: do we need it?
 150                         throw new NotSupportedException ();
 151                 }
 152
 153                 public IDataReader GetData (int i)
 154                 {
 155                         // FIXME: do we need it?
 156                         throw new NotSupportedException ();
 157                 }
 158
 159                 public int GetValues (object [] values)
 160                 {
 161                         int fieldCount = FieldCount;
 162                         int i;
 163
 164                         //target object is byval so we can not just assign new object[] to values , calling side will not change
 165                         //hence copy each item into values
 166                         for (i = 0; i < values.Length && i < fieldCount; ++i)
 167                                 values[i] = Current[i];
 168                         return i - 1;
 169                 }
 170
 171                 public bool IsDBNull (int i)
 172                 {
 173                         return Current.IsNull (i);
 174                 }
 175
 176                 public bool GetBoolean (int i)
 177                 {
 178                         return (bool) Current [i];
 179                 }
 180
 181                 public byte GetByte (int i)
 182                 {
 183                         return (byte) Current [i];
 184                 }
 185
 186                 public char GetChar (int i)
 187                 {
 188                         return (char) Current [i];
 189                 }
 190
 191                 public DateTime GetDateTime (int i)
 192                 {
 193                         return (DateTime) Current [i];
 194                 }
 195
 196                 public decimal GetDecimal (int i)
 197                 {
 198                         return (decimal) Current [i];
 199                 }
 200
 201                 public double GetDouble (int i)
 202                 {
 203                         return (double) Current [i];
 204                 }
 205
 206                 public float GetFloat (int i)
 207                 {
 208                         return (float) Current [i];
 209                 }
 210
 211                 public Guid GetGuid (int i)
 212                 {
 213                         return (Guid) Current [i];
 214                 }
 215
 216                 public short GetInt16 (int i)
 217                 {
 218                         return (short) Current [i];
 219                 }
 220
 221                 public int GetInt32 (int i)
 222                 {
 223                         return (int) Current [i];
 224                 }
 225
 226                 public long GetInt64 (int i)
 227                 {
 228                         return (long) Current [i];
 229                 }
 230
 231                 public string GetString (int i)
 232                 {
 233                         return (string) Current [i];
 234                 }
 235
 236                 public object GetValue (int i)
 237                 {
 238                         return Current [i];
 239                 }
 240         }
 241 }