mcs/class/System.Data/System.Data/Node.cs

   1
   2 //
   3 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   4 //
   5 // Permission is hereby granted, free of charge, to any person obtaining
   6 // a copy of this software and associated documentation files (the
   7 // "Software"), to deal in the Software without restriction, including
   8 // without limitation the rights to use, copy, modify, merge, publish,
   9 // distribute, sublicense, and/or sell copies of the Software, and to
  10 // permit persons to whom the Software is furnished to do so, subject to
  11 // the following conditions:
  12 //
  13 // The above copyright notice and this permission notice shall be
  14 // included in all copies or substantial portions of the Software.
  15 //
  16 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  20 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  21 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23 //
  24 using System;
  25
  26 namespace System.Data
  27 {
  28         /// <summary>
  29         /// Summary description for Node.
  30         /// </summary>
  31         internal class Node
  32         {
  33                 protected int _iBalance;    // currently, -2 means 'deleted'
  34                 internal Node _nNext;       // node of next index (nNext==null || nNext.iId=iId+1)
  35                 protected Node _nLeft;
  36                 protected Node _nRight;
  37                 protected Node _nParent;
  38
  39                 protected DataRow _row;
  40
  41                 public Node(DataRow row)
  42                 {
  43                         _row = row;
  44                 }
  45
  46                 internal int GetBalance()
  47                 {
  48                         if (_iBalance == -2)
  49                                 throw new SystemException ("Node is deleted.");
  50
  51                         return _iBalance;
  52                 }
  53
  54                 internal void Delete()
  55                 {
  56                         _iBalance = -2;
  57                         _nLeft = null;
  58                         _nRight = null;
  59                         _nParent = null;
  60                 }
  61
  62
  63                 internal DataRow Row
  64                 {
  65                         get {
  66                                 return _row;
  67                         }
  68                 }
  69
  70                 internal Node Left
  71                 {
  72                         get {
  73                                 if (_iBalance == -2)
  74                                         throw new SystemException ("Node is deleted.");
  75
  76                                 return _nLeft;
  77                         }
  78
  79                         set {
  80                                 if (_iBalance == -2)
  81                                         throw new SystemException ("Node is deleted.");
  82
  83                                 _nLeft = value;
  84                         }
  85                 }
  86
  87                 internal Node Right
  88                 {
  89                         get {
  90                                 if (_iBalance == -2)
  91                                         throw new SystemException ("Node is deleted.");
  92                                 return _nRight;
  93                         }
  94
  95                         set {
  96                                 if (_iBalance == -2)
  97                                         throw new SystemException ("Node is deleted.");
  98
  99                                 _nRight = value;
 100                         }
 101                 }
 102
 103
 104                 internal Node Parent
 105                 {
 106                         get {
 107                                 if (_iBalance == -2)
 108                                         throw new SystemException ("Node is deleted.");
 109
 110                                 return _nParent;
 111                         }
 112
 113                         set {
 114                                 if (_iBalance == -2)
 115                                         throw new SystemException ("Node is deleted.");
 116                                 _nParent = value;
 117                         }
 118                 }
 119
 120                 internal bool IsRoot()
 121                 {
 122                         return _nParent == null;
 123                 }
 124
 125
 126                 internal void SetBalance(int b)
 127                 {
 128
 129                         if (_iBalance == -2)
 130                                 throw new SystemException ("Node is deleted.");
 131
 132                         _iBalance = b;
 133                 }
 134
 135                 internal bool From()
 136                 {
 137
 138                         if (this.IsRoot()){
 139                                 return true;
 140                         }
 141
 142                         if (_iBalance == -2)
 143                                 throw new SystemException ("Node is deleted.");
 144                         Node parent = Parent;
 145
 146                         return Equals(parent.Left);
 147                 }
 148
 149                 internal Object[] GetData()
 150                 {
 151
 152                         if (_iBalance == -2)
 153                                 throw new SystemException ("Node is deleted.");
 154                         return _row.ItemArray;
 155                 }
 156
 157                 internal bool Equals(Node n)
 158                 {
 159
 160                         if (_iBalance == -2)
 161                                 throw new SystemException ("Node is deleted.");
 162
 163                         return n == this;
 164                 }
 165         }
 166 }