class/System.Data/System.Data.SqlClient.jvm/SqlXmlTextReader.cs

   1 //
   2 // System.Data.SqlClient.SqlXmlTextReader.cs
   3 //
   4 // Author:
   5 //   Konstantin Triger (kostat@mainsoft.com)
   6 //
   7 // Copyright (C) 2006 Mainsoft, corp. (http://www.mainsoft.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.IO;
  31 using System.Text;
  32 using System.Xml;
  33
  34 namespace System.Data.SqlClient {
  35         internal sealed class SqlXmlTextReader : TextReader {
  36
  37                 #region FragmentXmlTextReader
  38
  39                 sealed class FragmentXmlTextReader : XmlTextReader {
  40                         public FragmentXmlTextReader(System.IO.TextReader reader) : base(reader) {}
  41
  42                         public override bool Read() {
  43                                 do {
  44                                         if (!base.Read())
  45                                                 return false;
  46                                 }while(base.Depth == 0);
  47
  48                                 return true;
  49                         }
  50
  51                         public override int Depth {
  52                                 get {
  53                                         int depth = base.Depth;
  54                                         if (depth >= 1)
  55                                                 depth --;
  56
  57                                         return depth;
  58                                 }
  59                         }
  60                 }
  61
  62                 #endregion
  63
  64                 #region Fields
  65
  66                 bool _hasPeekedChar;
  67                 readonly char[] _peekedChar = new char[1];
  68                 readonly SqlDataReader _reader;
  69
  70                 string _data;
  71                 int _rootPosition;
  72                 int _position = -1;
  73                 bool _eof;
  74
  75                 static readonly char[] OpenRoot = new char[] {'<', 'X', '>'};
  76                 const int OpenRootLength = 3;
  77                 static readonly char[] CloseRoot = new char[] {'<', '/', 'X', '>'};
  78                 const int CloseRootLength = 4;
  79
  80                 #endregion // Fields
  81
  82                 #region Constructors
  83
  84                 private SqlXmlTextReader (SqlDataReader reader) {
  85                         _reader = reader;
  86                 }
  87
  88                 #endregion
  89
  90                 #region Methods
  91
  92                 public static XmlReader Create(SqlDataReader dataReader) {
  93                         return new FragmentXmlTextReader(new SqlXmlTextReader(dataReader));
  94                 }
  95
  96                 public override void Close() {
  97                         _reader.Close ();
  98                 }
  99
 100                 public override int Peek () {
 101                         if (!_hasPeekedChar) {
 102
 103                                 int consumed = Read(_peekedChar, 0, 1);
 104                                 if (consumed < 0)
 105                                         return -1;
 106
 107                                 _hasPeekedChar = true;
 108                         }
 109
 110                         return _peekedChar[0];
 111                 }
 112
 113                 public override int Read () {
 114                         int c = Peek();
 115                         _hasPeekedChar = false;
 116                         return c;
 117                 }
 118
 119                 public override int Read (char[] buffer, int index, int count) {
 120                         if (buffer == null)
 121                                 throw new ArgumentNullException("buffer");
 122
 123                         if (index < 0)
 124                                 throw new ArgumentOutOfRangeException("index");
 125
 126                         if (count < 0)
 127                                 throw new ArgumentOutOfRangeException("count");
 128
 129                         if (count == 0)
 130                                 return 0;
 131
 132                         int got = 0;
 133
 134                         if (_hasPeekedChar) {
 135                                 buffer[index++] = _peekedChar[0];
 136                                 count--;
 137                                 _hasPeekedChar = false;
 138                                 got ++;
 139                         }
 140
 141                         if (!_eof) {
 142                                 while (count > 0) {
 143
 144                                         if (_rootPosition < OpenRootLength) {
 145                                                 buffer[index++] = OpenRoot[_rootPosition++];
 146                                                 count --;
 147                                                 got ++;
 148                                                 continue;
 149                                         }
 150
 151                                         if (_position < 0) {
 152                                                 if (_reader.Read()) {
 153                                                         _position = 0;
 154                                                         _data = _reader.GetString(0);
 155                                                 }
 156                                                 else {
 157                                                         if(_reader.NextResult())
 158                                                                 continue;
 159                                                         else {
 160                                                                 _rootPosition = 0;
 161                                                                 _eof = true;
 162                                                                 break;
 163                                                         }
 164                                                 }
 165                                         }
 166
 167                                         int consumed = ((_position + count) > _data.Length) ? (_data.Length - (int)_position) : count;
 168                                         _data.CopyTo(_position, buffer, index, consumed);
 169
 170                                         if (consumed > 0) {
 171                                                 _position += consumed;
 172                                                 got += consumed;
 173                                                 index += consumed;
 174                                                 count -= consumed;
 175                                         }
 176                                         else
 177                                                 _position = -1;
 178                                 }
 179                         }
 180
 181                         while (count > 0 && _rootPosition < CloseRootLength) {
 182                                 buffer[index++] = CloseRoot[_rootPosition++];
 183                                 count --;
 184                                 got ++;
 185                         }
 186
 187
 188                         return got;
 189                 }
 190
 191                 #endregion // Methods
 192         }
 193 }