mcs/class/System.Web/System.Web/HttpCacheVaryByHeaders.cs

   1 //
   2 // System.Web.HttpVaryByHeaders.cs
   3 //
   4 // Author:
   5 //      Chris Toshok (toshok@novell.com)
   6 //
   7
   8 //
   9 // Copyright (C) 2005-2009 Novell, Inc (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Collections;
  32 using System.Security.Permissions;
  33
  34 namespace System.Web
  35 {
  36         // CAS - no InheritanceDemand here as the class is sealed
  37         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  38         public sealed class HttpCacheVaryByHeaders
  39         {
  40                 /* I would have much rather seen this class just use the
  41                  * Hashtable, and have the getter/setters for the builtin
  42                  * fields just manipulate that Hashtable, but that doesn't
  43                  * appear to work in MS's implementation.  If you do:
  44                  *
  45                  *         vary_by_hdrs["User-Agent"] = true;
  46                  *
  47                  * then
  48                  *
  49                  *         (vary_by_hdrs.UserAgent == true)
  50                  *
  51                  * will be false, which is completely counterintuitive
  52                  * and broken. The same holds true in reverse:
  53                  *
  54                  *         vary_by_hdrs.UserAgent = true;
  55                  *
  56                  * does not mean
  57                  *
  58                  *         vary_by_hdrs["User-Agent"] == true.
  59                  */
  60                 bool vary_by_unspecified;
  61
  62                 bool vary_by_accept;
  63                 bool vary_by_user_agent;
  64                 bool vary_by_user_charset;
  65                 bool vary_by_user_language;
  66
  67                 Hashtable fields;
  68
  69                 internal HttpCacheVaryByHeaders ()
  70                 {
  71                         /* the field names are meant to be case insensitive */
  72                         fields = new Hashtable (StringComparer.InvariantCultureIgnoreCase);
  73                 }
  74
  75                 internal string[] GetHeaderNames (bool omitVaryStar)
  76                 {
  77                         string[] names;
  78
  79                         if (vary_by_unspecified && !omitVaryStar) {
  80                                 names = new string[1];
  81                                 names[0] = "*";
  82                         }
  83                         else {
  84                                 int builtin_count = ((vary_by_accept ? 1 : 0)
  85                                                      + (vary_by_user_agent ? 1 : 0)
  86                                                      + (vary_by_user_charset ? 1 : 0)
  87                                                      + (vary_by_user_language ? 1 : 0));
  88
  89                                 names = new string [fields.Count + builtin_count];
  90
  91                                 int i = 0;
  92                                 if (vary_by_accept) names[i++] = "Accept";
  93                                 if (vary_by_user_agent) names[i++] = "User-Agent";
  94                                 if (vary_by_user_charset) names[i++] = "Accept-Charset";
  95                                 if (vary_by_user_language) names[i++] = "Accept-Language";
  96
  97                                 fields.Keys.CopyTo (names, builtin_count);
  98                         }
  99
 100                         return names;
 101                 }
 102
 103                 public bool AcceptTypes {
 104                         get {
 105                                 return vary_by_accept;
 106                         }
 107                         set {
 108                                 vary_by_unspecified = false;
 109                                 vary_by_accept = value;
 110                         }
 111                 }
 112
 113                 public bool UserAgent {
 114                         get {
 115                                 return vary_by_user_agent;
 116                         }
 117                         set {
 118                                 vary_by_unspecified = false;
 119                                 vary_by_user_agent = value;
 120                         }
 121                 }
 122
 123                 public bool UserCharSet {
 124                         get {
 125                                 return vary_by_user_charset;
 126                         }
 127                         set {
 128                                 vary_by_unspecified = false;
 129                                 vary_by_user_charset = value;
 130                         }
 131                 }
 132
 133                 public bool UserLanguage {
 134                         get {
 135                                 return vary_by_user_language;
 136                         }
 137                         set {
 138                                 vary_by_unspecified = false;
 139                                 vary_by_user_language = value;
 140                         }
 141                 }
 142
 143                 public bool this [ string header ] {
 144                         get {
 145                                 if (header == null)
 146                                         throw new ArgumentNullException ();
 147
 148                                 return fields.Contains (header);
 149                         }
 150                         set {
 151                                 if (header == null)
 152                                         throw new ArgumentNullException ();
 153
 154                                 vary_by_unspecified = false;
 155                                 if (value)
 156                                         if (!fields.Contains (header))
 157                                                 fields.Add (header, true);
 158                                 else
 159                                         fields.Remove (header);
 160                         }
 161                 }
 162
 163                 public void VaryByUnspecifiedParameters ()
 164                 {
 165                         fields.Clear();
 166
 167                         vary_by_unspecified =
 168                           vary_by_accept =
 169                           vary_by_user_agent =
 170                           vary_by_user_charset =
 171                           vary_by_user_language = false;
 172
 173                         vary_by_unspecified = true;
 174                 }
 175         }
 176
 177 }