mcs/class/corlib/System.Text/ASCIIEncoding.cs

   1 /*
   2  * ASCIIEncoding.cs - Implementation of the "System.Text.ASCIIEncoding" class.
   3  *
   4  * Copyright (c) 2001  Southern Storm Software, Pty Ltd
   5  * Copyright (C) 2003 Novell, Inc.
   6  * Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining
   9  * a copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  * OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27 namespace System.Text
  28 {
  29
  30 using System;
  31
  32 [Serializable]
  33 [MonoTODO ("Fix serialization compatibility with MS.NET")]
  34 public class ASCIIEncoding : Encoding
  35 {
  36         // Magic number used by Windows for "ASCII".
  37         internal const int ASCII_CODE_PAGE = 20127;
  38
  39         // Constructor.
  40         public ASCIIEncoding () : base(ASCII_CODE_PAGE) {
  41                 body_name = header_name = web_name= "us-ascii";
  42                 encoding_name = "US-ASCII";
  43                 is_mail_news_display = true;
  44                 is_mail_news_save = true;
  45         }
  46
  47         // Get the number of bytes needed to encode a character buffer.
  48         public override int GetByteCount (char[] chars, int index, int count)
  49         {
  50                 if (chars == null) {
  51                         throw new ArgumentNullException ("chars");
  52                 }
  53                 if (index < 0 || index > chars.Length) {
  54                         throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
  55                 }
  56                 if (count < 0 || count > (chars.Length - index)) {
  57                         throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
  58                 }
  59                 return count;
  60         }
  61
  62         // Convenience wrappers for "GetByteCount".
  63         public override int GetByteCount (String s)
  64         {
  65                 if (s == null) {
  66                         throw new ArgumentNullException ("s");
  67                 }
  68                 return s.Length;
  69         }
  70
  71         // Get the bytes that result from encoding a character buffer.
  72         public override int GetBytes (char[] chars, int charIndex, int charCount,
  73                                                                  byte[] bytes, int byteIndex)
  74         {
  75                 if (chars == null) {
  76                         throw new ArgumentNullException ("chars");
  77                 }
  78                 if (bytes == null) {
  79                         throw new ArgumentNullException ("bytes");
  80                 }
  81                 if (charIndex < 0 || charIndex > chars.Length) {
  82                         throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_Array"));
  83                 }
  84                 if (charCount < 0 || charCount > (chars.Length - charIndex)) {
  85                         throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_Array"));
  86                 }
  87                 if (byteIndex < 0 || byteIndex > bytes.Length) {
  88                         throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
  89                 }
  90                 if ((bytes.Length - byteIndex) < charCount) {
  91                         throw new ArgumentException (_("Arg_InsufficientSpace"));
  92                 }
  93                 int count = charCount;
  94                 char ch;
  95                 while (count-- > 0) {
  96                         ch = chars [charIndex++];
  97                         if (ch < (char)0x80) {
  98                                 bytes [byteIndex++] = (byte)ch;
  99                         } else {
 100                                 bytes [byteIndex++] = (byte)'?';
 101                         }
 102                 }
 103                 return charCount;
 104         }
 105
 106         // Convenience wrappers for "GetBytes".
 107         public override int GetBytes (String s, int charIndex, int charCount,
 108                                                                  byte[] bytes, int byteIndex)
 109         {
 110                 if (s == null) {
 111                         throw new ArgumentNullException ("s");
 112                 }
 113                 if (bytes == null) {
 114                         throw new ArgumentNullException ("bytes");
 115                 }
 116                 if (charIndex < 0 || charIndex > s.Length) {
 117                         throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_StringIndex"));
 118                 }
 119                 if (charCount < 0 || charCount > (s.Length - charIndex)) {
 120                         throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_StringRange"));
 121                 }
 122                 if (byteIndex < 0 || byteIndex > bytes.Length) {
 123                         throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
 124                 }
 125                 if ((bytes.Length - byteIndex) < charCount) {
 126                         throw new ArgumentException (_("Arg_InsufficientSpace"));
 127                 }
 128                 int count = charCount;
 129                 char ch;
 130                 while (count-- > 0) {
 131                         ch = s [charIndex++];
 132                         if (ch < (char)0x80) {
 133                                 bytes [byteIndex++] = (byte)ch;
 134                         } else {
 135                                 bytes [byteIndex++] = (byte)'?';
 136                         }
 137                 }
 138                 return charCount;
 139         }
 140
 141         // Get the number of characters needed to decode a byte buffer.
 142         public override int GetCharCount (byte[] bytes, int index, int count)
 143         {
 144                 if (bytes == null) {
 145                         throw new ArgumentNullException ("bytes");
 146                 }
 147                 if (index < 0 || index > bytes.Length) {
 148                         throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
 149                 }
 150                 if (count < 0 || count > (bytes.Length - index)) {
 151                         throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
 152                 }
 153                 return count;
 154         }
 155
 156         // Get the characters that result from decoding a byte buffer.
 157         public override int GetChars (byte[] bytes, int byteIndex, int byteCount,
 158                                                                  char[] chars, int charIndex)
 159         {
 160                 if (bytes == null) {
 161                         throw new ArgumentNullException ("bytes");
 162                 }
 163                 if (chars == null) {
 164                         throw new ArgumentNullException ("chars");
 165                 }
 166                 if (byteIndex < 0 || byteIndex > bytes.Length) {
 167                         throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
 168                 }
 169                 if (byteCount < 0 || byteCount > (bytes.Length - byteIndex)) {
 170                         throw new ArgumentOutOfRangeException ("byteCount", _("ArgRange_Array"));
 171                 }
 172                 if (charIndex < 0 || charIndex > chars.Length) {
 173                         throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_Array"));
 174                 }
 175                 if ((chars.Length - charIndex) < byteCount) {
 176                         throw new ArgumentException (_("Arg_InsufficientSpace"));
 177                 }
 178                 int count = byteCount;
 179                 while (count-- > 0) {
 180                         char c = (char)(bytes [byteIndex++]);
 181                         if (c > 127)
 182                                 c = '?';
 183                         chars [charIndex++] = c;
 184                 }
 185                 return byteCount;
 186         }
 187
 188         // Get the maximum number of bytes needed to encode a
 189         // specified number of characters.
 190         public override int GetMaxByteCount (int charCount)
 191         {
 192                 if (charCount < 0) {
 193                         throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_NonNegative"));
 194                 }
 195                 return charCount;
 196         }
 197
 198         // Get the maximum number of characters needed to decode a
 199         // specified number of bytes.
 200         public override int GetMaxCharCount (int byteCount)
 201         {
 202                 if (byteCount < 0) {
 203                         throw new ArgumentOutOfRangeException ("byteCount", _("ArgRange_NonNegative"));
 204                 }
 205                 return byteCount;
 206         }
 207
 208         // Decode a buffer of bytes into a string.
 209         public override String GetString (byte[] bytes, int index, int count)
 210         {
 211                 if (bytes == null) {
 212                         throw new ArgumentNullException ("bytes");
 213                 }
 214                 if (index < 0 || index > bytes.Length) {
 215                         throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
 216                 }
 217                 if (count < 0 || count > (bytes.Length - index)) {
 218                         throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
 219                 }
 220                 if (count == 0)
 221                     return String.Empty;
 222                 unsafe {
 223                         fixed (byte *ss = &bytes [0]) {
 224                                 return new String ((sbyte*)ss, index, count);
 225                         }
 226                 }
 227         }
 228         public override String GetString (byte[] bytes)
 229         {
 230                 if (bytes == null) {
 231                         throw new ArgumentNullException ("bytes");
 232                 }
 233                 int count = bytes.Length;
 234                 if (count == 0)
 235                     return String.Empty;
 236                 unsafe {
 237                         fixed (byte *ss = &bytes [0]) {
 238                                 return new String ((sbyte*)ss, 0, count);
 239                         }
 240                 }
 241         }
 242
 243 }; // class ASCIIEncoding
 244
 245 }; // namespace System.Text