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 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(CaseInsensitiveHashCodeProvider.Default,
  73                                                CaseInsensitiveComparer.Default);
  74                 }
  75
  76                 internal string[] GetHeaderNames ()
  77                 {
  78                         string[] names;
  79
  80                         if (vary_by_unspecified) {
  81                                 names = new string[1];
  82                                 names[0] = "*";
  83                         }
  84                         else {
  85                                 int builtin_count = ((vary_by_accept ? 1 : 0)
  86                                                      + (vary_by_user_agent ? 1 : 0)
  87                                                      + (vary_by_user_charset ? 1 : 0)
  88                                                      + (vary_by_user_language ? 1 : 0));
  89
  90                                 names = new string [fields.Count + builtin_count];
  91
  92                                 int i = 0;
  93                                 if (vary_by_accept) names[i++] = "Accept";
  94                                 if (vary_by_user_agent) names[i++] = "User-Agent";
  95                                 if (vary_by_user_charset) names[i++] = "Accept-Charset";
  96                                 if (vary_by_user_language) names[i++] = "Accept-Language";
  97
  98                                 fields.Keys.CopyTo (names, builtin_count);
  99                         }
 100
 101                         return names;
 102                 }
 103
 104                 public bool AcceptTypes {
 105                         get {
 106                                 return vary_by_accept;
 107                         }
 108                         set {
 109                                 vary_by_unspecified = false;
 110                                 vary_by_accept = value;
 111                         }
 112                 }
 113
 114                 public bool UserAgent {
 115                         get {
 116                                 return vary_by_user_agent;
 117                         }
 118                         set {
 119                                 vary_by_unspecified = false;
 120                                 vary_by_user_agent = value;
 121                         }
 122                 }
 123
 124                 public bool UserCharSet {
 125                         get {
 126                                 return vary_by_user_charset;
 127                         }
 128                         set {
 129                                 vary_by_unspecified = false;
 130                                 vary_by_user_charset = value;
 131                         }
 132                 }
 133
 134                 public bool UserLanguage {
 135                         get {
 136                                 return vary_by_user_language;
 137                         }
 138                         set {
 139                                 vary_by_unspecified = false;
 140                                 vary_by_user_language = value;
 141                         }
 142                 }
 143
 144                 public bool this [ string header ] {
 145                         get {
 146                                 if (header == null)
 147                                         throw new ArgumentNullException ();
 148
 149                                 return fields.Contains (header);
 150                         }
 151                         set {
 152                                 if (header == null)
 153                                         throw new ArgumentNullException ();
 154
 155                                 vary_by_unspecified = false;
 156                                 if (value)
 157                                         if (!fields.Contains (header))
 158                                                 fields.Add (header, true);
 159                                 else
 160                                         fields.Remove (header);
 161                         }
 162                 }
 163
 164                 public void VaryByUnspecifiedParameters ()
 165                 {
 166                         fields.Clear();
 167
 168                         vary_by_unspecified =
 169                           vary_by_accept =
 170                           vary_by_user_agent =
 171                           vary_by_user_charset =
 172                           vary_by_user_language = false;
 173
 174                         vary_by_unspecified = true;
 175                 }
 176         }
 177
 178 }