mcs/class/corlib/System.IO/TextReader.cs

   1 //\r
   2 // System.IO.TextReader\r
   3 //\r
   4 // Authors:\r
   5 //   Marcin Szczepanski (marcins@zipworld.com.au)\r
   6 //   Miguel de Icaza (miguel@gnome.org)\r
   7 //\r
   8 \r
   9 //\r
  10 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)\r
  11 //\r
  12 // Permission is hereby granted, free of charge, to any person obtaining\r
  13 // a copy of this software and associated documentation files (the\r
  14 // "Software"), to deal in the Software without restriction, including\r
  15 // without limitation the rights to use, copy, modify, merge, publish,\r
  16 // distribute, sublicense, and/or sell copies of the Software, and to\r
  17 // permit persons to whom the Software is furnished to do so, subject to\r
  18 // the following conditions:\r
  19 // \r
  20 // The above copyright notice and this permission notice shall be\r
  21 // included in all copies or substantial portions of the Software.\r
  22 // \r
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,\r
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\r
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE\r
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION\r
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION\r
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  30 //\r
  31 \r
  32 using System;\r
  33 using System.Runtime.InteropServices;\r
  34 \r
  35 namespace System.IO {\r
  36 \r
  37         [Serializable]\r
  38 #if NET_2_0\r
  39         [ComVisible (true)]\r
  40 #endif\r
  41         public abstract class TextReader : MarshalByRefObject, IDisposable {\r
  42                 \r
  43                 protected TextReader() { }\r
  44                 \r
  45                 public static readonly TextReader Null;\r
  46                 \r
  47                 public virtual void Close()\r
  48                 { \r
  49                         Dispose(true);\r
  50                 }\r
  51 \r
  52 #if NET_2_0\r
  53                 public void Dispose ()\r
  54 #else\r
  55                 void System.IDisposable.Dispose()\r
  56 #endif                  \r
  57                 {\r
  58                         Dispose(true);\r
  59                 }\r
  60 \r
  61                 protected virtual void Dispose (bool disposing)\r
  62                 {\r
  63                         if (disposing){\r
  64                                 // If we are explicitly disposed, we can avoid finalization.\r
  65                                 GC.SuppressFinalize (this);\r
  66                         }\r
  67                         return;\r
  68                 }\r
  69                 \r
  70                 public virtual int Peek()\r
  71                 {\r
  72                         return -1;\r
  73                 }\r
  74                 \r
  75                 public virtual int Read()\r
  76                 {\r
  77                         return -1;\r
  78                 }\r
  79                 \r
  80 \r
  81                 public virtual int Read ([In, Out] char[] buffer, int index, int count)\r
  82                 {\r
  83                         int c, i;\r
  84                         \r
  85                         for (i = 0; i < count; i++) {\r
  86                                 if ((c = Read ()) == -1)\r
  87                                         return i;\r
  88                                 buffer [index + i] = (char)c;\r
  89                         }\r
  90                         \r
  91                         return i;\r
  92                 }\r
  93                 \r
  94                 public virtual int ReadBlock ([In, Out] char [] buffer, int index, int count)\r
  95                 {\r
  96                         int total_read_count = 0;\r
  97                         int current_read_count = 0;\r
  98 \r
  99                         do {\r
 100                                 current_read_count = Read (buffer, index, count);\r
 101                                 index += current_read_count;\r
 102                                 total_read_count += current_read_count;\r
 103                                 count -= current_read_count;\r
 104                         } while (current_read_count != 0 && count > 0);\r
 105 \r
 106                         return total_read_count;\r
 107                 }\r
 108 \r
 109                 public virtual string ReadLine()\r
 110                 { \r
 111                         return String.Empty;\r
 112                 }\r
 113 \r
 114                 public virtual string ReadToEnd()\r
 115                 { \r
 116                         return String.Empty;\r
 117                 }\r
 118 \r
 119                 public static TextReader Synchronized (TextReader reader)\r
 120                 {\r
 121                         if (reader == null)\r
 122                                 throw new ArgumentNullException ("reader is null");\r
 123                         if (reader is SynchronizedReader)\r
 124                                 return reader;\r
 125 \r
 126                         return new SynchronizedReader (reader);\r
 127                 }       \r
 128         }\r
 129 \r
 130         //\r
 131         // Synchronized Reader implementation, used internally.\r
 132         //\r
 133         [Serializable]\r
 134         internal class SynchronizedReader : TextReader {\r
 135                 TextReader reader;\r
 136                 \r
 137                 public SynchronizedReader (TextReader reader)\r
 138                 {\r
 139                         this.reader = reader;\r
 140                 }\r
 141 \r
 142                 public override void Close ()\r
 143                 {\r
 144                         lock (this){\r
 145                                 reader.Close ();\r
 146                         }\r
 147                 }\r
 148 \r
 149                 public override int Peek ()\r
 150                 {\r
 151                         lock (this){\r
 152                                 return reader.Peek ();\r
 153                         }\r
 154                 }\r
 155 \r
 156                 public override int ReadBlock (char [] buffer, int index, int count)\r
 157                 {\r
 158                         lock (this){\r
 159                                 return reader.ReadBlock (buffer, index, count);\r
 160                         }\r
 161                 }\r
 162 \r
 163                 public override string ReadLine ()\r
 164                 {\r
 165                         lock (this){\r
 166                                 return reader.ReadLine ();\r
 167                         }\r
 168                 }\r
 169 \r
 170                 public override string ReadToEnd ()\r
 171                 {\r
 172                         lock (this){\r
 173                                 return reader.ReadToEnd ();\r
 174                         }\r
 175                 }\r
 176 #region Read Methods\r
 177                 public override int Read ()\r
 178                 {\r
 179                         lock (this){\r
 180                                 return reader.Read ();\r
 181                         }\r
 182                 }\r
 183 \r
 184                 public override int Read (char [] buffer, int index, int count)\r
 185                 {\r
 186                         lock (this){\r
 187                                 return reader.Read (buffer, index, count);\r
 188                         }\r
 189                 }\r
 190 #endregion\r
 191                 \r
 192         }\r
 193 }\r