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

   1 //\r
   2 // System.Data.Common.Key.cs\r
   3 //\r
   4 // Author:\r
   5 //   Boris Kirzner  <borisk@mainsoft.com>\r
   6 //   Konstantin Triger (kostat@mainsoft.com)\r
   7 //\r
   8 \r
   9 /*\r
  10   * Copyright (c) 2002-2004 Mainsoft Corporation.\r
  11   *\r
  12   * Permission is hereby granted, free of charge, to any person obtaining a\r
  13   * copy of this software and associated documentation files (the "Software"),\r
  14   * to deal in the Software without restriction, including without limitation\r
  15   * the rights to use, copy, modify, merge, publish, distribute, sublicense,\r
  16   * and/or sell copies of the Software, and to permit persons to whom the\r
  17   * Software is furnished to do so, subject to the following conditions:\r
  18   *\r
  19   * The above copyright notice and this permission notice shall be included in\r
  20   * all copies or substantial portions of the Software.\r
  21   *\r
  22   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
  23   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\r
  24   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\r
  25   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\r
  26   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING\r
  27   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER\r
  28   * DEALINGS IN THE SOFTWARE.\r
  29   */\r
  30 \r
  31 using System;\r
  32 using Mono.Data.SqlExpressions;\r
  33 using System.ComponentModel;\r
  34 \r
  35 namespace System.Data.Common\r
  36 {\r
  37         internal class Key\r
  38         {\r
  39                 #region Fields\r
  40 \r
  41                 DataTable _table;\r
  42                 DataColumn[] _columns;\r
  43                 ListSortDirection[] _sortDirection;\r
  44                 DataViewRowState _rowStateFilter;\r
  45                 IExpression _filter;\r
  46                 //Currently IExpression.Eval does not receive DataRowVersion\r
  47                 //      and always uses the _current version\r
  48                 //so need a temp row for Eval calls\r
  49                 DataRow _tmpRow;\r
  50 \r
  51                 #endregion //Fields\r
  52 \r
  53                 #region Constructors\r
  54 \r
  55                 internal Key(DataTable table,DataColumn[] columns,ListSortDirection[] sort, DataViewRowState rowState, IExpression filter)\r
  56                 {\r
  57                         _table = table;\r
  58                         _filter = filter;\r
  59                         if (_filter != null)\r
  60                                 _tmpRow = _table.NewNotInitializedRow();\r
  61                         _columns = columns;\r
  62                         if (sort != null && sort.Length == columns.Length) {\r
  63                                 _sortDirection = sort;\r
  64                         }\r
  65                         else {\r
  66                                 _sortDirection = new ListSortDirection[columns.Length];\r
  67                                 for(int i=0; i < _sortDirection.Length; i++) {\r
  68                                         _sortDirection[i] = ListSortDirection.Ascending;\r
  69                                 }\r
  70                         }\r
  71 \r
  72                         if (rowState != DataViewRowState.None)\r
  73                                 _rowStateFilter = rowState;\r
  74                         else\r
  75                                 // FIXME : what is the correct value ?\r
  76                                 _rowStateFilter = DataViewRowState.CurrentRows;\r
  77                 }\r
  78 \r
  79                 #endregion // Constructors\r
  80 \r
  81                 #region Properties\r
  82 \r
  83                 internal DataColumn[] Columns\r
  84                 {\r
  85                         get {\r
  86                                 return _columns;\r
  87                         }\r
  88                 }\r
  89 \r
  90                 internal DataTable Table\r
  91                 {\r
  92                         get {\r
  93                                 return _table;\r
  94                         }\r
  95                 }\r
  96 \r
  97                 ListSortDirection[] Sort \r
  98                 {\r
  99                         get {\r
 100                                 return _sortDirection;\r
 101                         }\r
 102                 }\r
 103 \r
 104                 internal DataViewRowState RowStateFilter\r
 105                 {\r
 106                         get {\r
 107                                 return _rowStateFilter;\r
 108                         }\r
 109 \r
 110                         set {\r
 111                                 _rowStateFilter = value;\r
 112                         }\r
 113                 }\r
 114 \r
 115                 internal bool HasFilter\r
 116                 {\r
 117                         get { return _filter != null; }\r
 118                 }\r
 119 \r
 120                 #endregion // Properties\r
 121 \r
 122                 #region Methods\r
 123 \r
 124                 internal int CompareRecords(int first, int second)\r
 125                 {\r
 126                         if (first == second) {\r
 127                                 return 0;\r
 128                         }\r
 129 \r
 130                         for(int i = 0; i < Columns.Length; i++) {\r
 131 \r
 132                                 int res = Columns[i].CompareValues(first,second);\r
 133 \r
 134                                 if (res == 0) {\r
 135                                         continue;\r
 136                                 }\r
 137 \r
 138                                 return (Sort[i] == ListSortDirection.Ascending) ? res : -res;\r
 139                         }\r
 140                         return 0;\r
 141                 }\r
 142 \r
 143                 internal int GetRecord(DataRow row)\r
 144                 {\r
 145                         int index = Key.GetRecord(row,_rowStateFilter);\r
 146                         if (_filter == null)\r
 147                                 return index;\r
 148 \r
 149                         if (index < 0)\r
 150                                 return index;\r
 151 \r
 152                         return CanContain (index) ? index : -1;\r
 153                 }\r
 154 \r
 155                 internal bool CanContain (int index)\r
 156                 {\r
 157                         if (_filter == null)\r
 158                                 return true;\r
 159 \r
 160                         _tmpRow._current = index;\r
 161                         return _filter.EvalBoolean(_tmpRow);\r
 162                 }\r
 163 \r
 164                 internal bool ContainsVersion (DataRowState state, DataRowVersion version)\r
 165                 {\r
 166                         switch (state) {\r
 167                                 case DataRowState.Unchanged:\r
 168                                         if ((_rowStateFilter & DataViewRowState.Unchanged) != DataViewRowState.None)\r
 169                                                 return ((version & DataRowVersion.Default) != 0);\r
 170                                         break;\r
 171                                 case DataRowState.Added:\r
 172                                         if ((_rowStateFilter & DataViewRowState.Added) != DataViewRowState.None)\r
 173                                                 return ((version & DataRowVersion.Default) != 0);\r
 174                                         break;\r
 175                                 case DataRowState.Deleted:\r
 176                                         if ((_rowStateFilter & DataViewRowState.Deleted) != DataViewRowState.None)\r
 177                                                 return (version == DataRowVersion.Original);\r
 178                                         break;\r
 179                                 default:\r
 180                                         if ((_rowStateFilter & DataViewRowState.ModifiedCurrent) != DataViewRowState.None)\r
 181                                                 return ((version & DataRowVersion.Default) != 0);\r
 182                                         if ((_rowStateFilter & DataViewRowState.ModifiedOriginal) != DataViewRowState.None)\r
 183                                                 return (version == DataRowVersion.Original);\r
 184                                         break;\r
 185                         }\r
 186 \r
 187                         return false;\r
 188                 }\r
 189 \r
 190                 internal static int GetRecord(DataRow row, DataViewRowState rowStateFilter)\r
 191                 {\r
 192                         switch (row.RowState) {\r
 193                                 case DataRowState.Unchanged: {\r
 194                                         if ((rowStateFilter & DataViewRowState.Unchanged) != DataViewRowState.None)\r
 195                                                 return row.Proposed >= 0 ? row.Proposed : row.Current;\r
 196                                         break;\r
 197                                 }\r
 198                                 case DataRowState.Added: {\r
 199                                         if ((rowStateFilter & DataViewRowState.Added) != DataViewRowState.None)\r
 200                                                 return row.Proposed >= 0 ? row.Proposed : row.Current;\r
 201                                         break;\r
 202                                 }\r
 203                                 case DataRowState.Deleted: {\r
 204                                         if ((rowStateFilter & DataViewRowState.Deleted) != DataViewRowState.None)\r
 205                                                 return row.Original;\r
 206                                         break;\r
 207                                 }\r
 208                                 default:\r
 209                                         if ((rowStateFilter & DataViewRowState.ModifiedCurrent) != DataViewRowState.None)\r
 210                                                 return row.Proposed >= 0 ? row.Proposed : row.Current;\r
 211                                         if ((rowStateFilter & DataViewRowState.ModifiedOriginal) != DataViewRowState.None)\r
 212                                                 return row.Original;\r
 213                                         break;\r
 214                         }\r
 215 \r
 216                         return -1;\r
 217                 }\r
 218 \r
 219                 /// <summary>\r
 220                 /// Checks for key equality to parameters set given\r
 221                 /// </summary>\r
 222                 /// <param name="columns">Columns the key consits of. If this parameter is null, it does not affects equality check</param>\r
 223                 /// <param name="sort">Sort order of columns. If this parameter is null, it does not affects equality check</param>\r
 224                 /// <param name="rowState">DataViewRowState to check for.If this parameter is null, it does not affects equality check</param>\r
 225                 /// <param name="unique">Indicates whenever the index managed by this key allows non-uniqie keys to appear.</param>\r
 226                 /// <param name="strict">Indicates whenever unique parameter should affect the equality check.</param>\r
 227                 /// <returns></returns>\r
 228                 internal bool Equals(DataColumn[] columns, ListSortDirection[] sort, DataViewRowState rowState, IExpression filter) \r
 229                 {\r
 230                         if (rowState != DataViewRowState.None && RowStateFilter != rowState) {\r
 231                                 return false;\r
 232                         }\r
 233 \r
 234                         if (_filter != null) {\r
 235                                 if (!_filter.Equals (filter))\r
 236                                         return false;\r
 237                         }\r
 238                         else if (filter != null)\r
 239                                         return false;\r
 240 \r
 241                         if (Columns.Length != columns.Length) {\r
 242                                 return false;\r
 243                         }\r
 244 \r
 245                         if (sort != null && Sort.Length != sort.Length) {\r
 246                                 return false;\r
 247                         }\r
 248 \r
 249                         if (sort != null) {\r
 250                                 for(int i=0; i < columns.Length; i++) {\r
 251                                         if (Sort[i] != sort[i] || Columns[i] != columns[i]) {\r
 252                                                 return false;\r
 253                                         }\r
 254                                 }\r
 255                         }\r
 256                         else {\r
 257                                 for(int i=0; i < columns.Length; i++) {\r
 258                                         if (Sort [i] != ListSortDirection.Ascending || Columns[i] != columns[i]) {\r
 259                                                 return false;\r
 260                                         }\r
 261                                 }\r
 262                         }\r
 263                         return true;\r
 264                 }\r
 265 \r
 266                 internal bool DependsOn (DataColumn column)\r
 267                 {\r
 268                         if (_filter == null)\r
 269                                 return false;\r
 270 \r
 271                         return _filter.DependsOn (column);\r
 272                 }\r
 273 \r
 274                 #endregion // Methods\r
 275         }\r
 276 }\r