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                         }\r
  75                         else {\r
  76                                 // FIXME : what is the correct value ?\r
  77                                 _rowStateFilter = DataViewRowState.CurrentRows;\r
  78                         }\r
  79                 }\r
  80 \r
  81                 #endregion // Constructors\r
  82 \r
  83                 #region Properties\r
  84 \r
  85                 internal DataColumn[] Columns\r
  86                 {\r
  87                         get {\r
  88                                 return _columns;\r
  89                         }\r
  90                 }\r
  91 \r
  92                 internal DataTable Table\r
  93                 {\r
  94                         get {\r
  95                                 return _table;\r
  96                         }\r
  97                 }\r
  98 \r
  99                 ListSortDirection[] Sort \r
 100                 {\r
 101                         get {\r
 102                                 return _sortDirection;\r
 103                         }\r
 104                 }\r
 105 \r
 106                 internal DataViewRowState RowStateFilter\r
 107                 {\r
 108                         get {\r
 109                                 return _rowStateFilter;\r
 110                         }\r
 111 \r
 112                         set {\r
 113                                 _rowStateFilter = value;\r
 114                         }\r
 115                 }\r
 116 \r
 117                 #endregion // Properties\r
 118 \r
 119                 #region Methods\r
 120 \r
 121                 internal int CompareRecords(int first, int second)\r
 122                 {\r
 123                         if (first == second) {\r
 124                                 return 0;\r
 125                         }\r
 126 \r
 127                         for(int i = 0; i < Columns.Length; i++) {\r
 128 \r
 129                                 int res = Columns[i].CompareValues(first,second);\r
 130 \r
 131                                 if (res == 0) {\r
 132                                         continue;\r
 133                                 }\r
 134 \r
 135                                 return (Sort[i] == ListSortDirection.Ascending) ? res : -res;\r
 136                         }\r
 137                         return 0;\r
 138                 }\r
 139 \r
 140                 internal int GetRecord(DataRow row)\r
 141                 {\r
 142                         int index = Key.GetRecord(row,_rowStateFilter);\r
 143                         if (_filter == null)\r
 144                                 return index;\r
 145 \r
 146                         if (index < 0)\r
 147                                 return index;\r
 148 \r
 149                         _tmpRow._current = index;\r
 150                         return _filter.EvalBoolean(_tmpRow) ? index : -1;\r
 151                 }\r
 152 \r
 153                 internal static int GetRecord(DataRow row, DataViewRowState rowStateFilter)\r
 154                 {\r
 155 \r
 156                         if (row.Original == row.Current) {\r
 157                                  if ((rowStateFilter & DataViewRowState.Unchanged) != DataViewRowState.None) {\r
 158                                          return row.Current;\r
 159                                  }\r
 160                         }\r
 161                         else if (row.Original == -1) {\r
 162                                   if ((rowStateFilter & DataViewRowState.Added) != DataViewRowState.None) {\r
 163                                         return row.Current;\r
 164                                   }\r
 165                         }\r
 166                         else if (row.Current == -1) {\r
 167                                      if ((rowStateFilter & DataViewRowState.Deleted) != DataViewRowState.None) {\r
 168                                                 return row.Original;\r
 169                                          }\r
 170                         }\r
 171                         else if ((rowStateFilter & DataViewRowState.ModifiedCurrent) != DataViewRowState.None) {\r
 172                                 return row.Current;\r
 173                         }\r
 174                         else if ((rowStateFilter & DataViewRowState.ModifiedOriginal) != DataViewRowState.None) {\r
 175                                 return row.Original;\r
 176                         }\r
 177 \r
 178             return -1;\r
 179                 }\r
 180 \r
 181                 /// <summary>\r
 182                 /// Checks for key equality to parameters set given\r
 183                 /// </summary>\r
 184                 /// <param name="columns">Columns the key consits of. If this parameter is null, it does not affects equality check</param>\r
 185                 /// <param name="sort">Sort order of columns. If this parameter is null, it does not affects equality check</param>\r
 186                 /// <param name="rowState">DataViewRowState to check for.If this parameter is null, it does not affects equality check</param>\r
 187                 /// <param name="unique">Indicates whenever the index managed by this key allows non-uniqie keys to appear.</param>\r
 188                 /// <param name="strict">Indicates whenever unique parameter should affect the equality check.</param>\r
 189                 /// <returns></returns>\r
 190                 internal bool Equals(DataColumn[] columns, ListSortDirection[] sort, DataViewRowState rowState, IExpression filter) \r
 191                 {\r
 192                         if (rowState != DataViewRowState.None && RowStateFilter != rowState) {\r
 193                                 return false;\r
 194                         }\r
 195 \r
 196                         if (_filter != filter)\r
 197                                 return false;\r
 198 \r
 199                         if (Columns.Length != columns.Length) {\r
 200                                 return false;\r
 201                         }\r
 202 \r
 203                         if (sort != null && Sort.Length != sort.Length) {\r
 204                                 return false;\r
 205                         }\r
 206 \r
 207                         if (sort != null) {\r
 208                                 for(int i=0; i < columns.Length; i++) {\r
 209                                         if (Sort[i] != sort[i] || Columns[i] != columns[i]) {\r
 210                                                 return false;\r
 211                                         }\r
 212                                 }\r
 213                         }\r
 214                         else {\r
 215                                 for(int i=0; i < columns.Length; i++) {\r
 216                                         if (Columns[i] != columns[i]) {\r
 217                                                 return false;\r
 218                                         }\r
 219                                 }\r
 220                         }\r
 221                         return true;\r
 222                 }\r
 223 \r
 224                 #endregion // Methods\r
 225         }\r
 226 }\r