mcs/class/System.Web/System.Web.Caching/OutputCacheModule.cs

   1 //
   2 // System.Web.Caching.OutputCacheModule
   3 //
   4 // Authors:
   5 //  Jackson Harper (jackson@ximian.com)
   6 //
   7 // (C) 2003 Novell, Inc (http://www.novell.com)
   8 //
   9
  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.IO;
  32 using System.Web;
  33 using System.Web.Util;
  34 using System.Collections;
  35
  36 namespace System.Web.Caching {
  37
  38         internal sealed class OutputCacheModule : IHttpModule {
  39
  40                 private CacheItemRemovedCallback response_removed;
  41
  42                 public OutputCacheModule ()
  43                 {
  44                 }
  45
  46                 public void Dispose ()
  47                 {
  48                 }
  49
  50                 public void Init (HttpApplication app)
  51                 {
  52                         app.AddOnResolveRequestCacheAsync (
  53                                 new BeginEventHandler (OnBeginRequestCache),
  54                                 new EndEventHandler (OnEndRequestCache));
  55
  56                         app.AddOnUpdateRequestCacheAsync (
  57                                 new BeginEventHandler (OnBeginUpdateCache),
  58                                 new EndEventHandler (OnEndUpdateCache));
  59
  60                         response_removed = new CacheItemRemovedCallback (OnRawResponseRemoved);
  61                 }
  62
  63                 IAsyncResult OnBeginRequestCache (object o, EventArgs args, AsyncCallback cb, object data)
  64                 {
  65                         HttpApplication app = (HttpApplication) o;
  66                         HttpContext context = app.Context;
  67
  68                         string vary_key = context.Request.FilePath;
  69                         CachedVaryBy varyby = context.Cache [vary_key] as CachedVaryBy;
  70                         string key;
  71                         CachedRawResponse c;
  72
  73                         if (varyby == null)
  74                                 goto leave;
  75
  76                         key = varyby.CreateKey (vary_key, context);
  77                         c = context.Cache [key] as CachedRawResponse;
  78
  79                         if (c != null) {
  80
  81                                 context.Response.ClearContent ();
  82                                 context.Response.BinaryWrite (c.GetData (), 0, c.ContentLength);
  83
  84                                 context.Response.ClearHeaders ();
  85                                 c.DateHeader.Value = TimeUtil.ToUtcTimeString (DateTime.Now);
  86                                 context.Response.SetCachedHeaders (c.Headers);
  87
  88                                 context.Response.StatusCode = c.StatusCode;
  89                                 context.Response.StatusDescription = c.StatusDescription;
  90
  91                                 app.CompleteRequest ();
  92                         }
  93
  94                 leave:
  95                         HttpAsyncResult result = new HttpAsyncResult (cb,this);
  96                         result.Complete (true, o, null);
  97
  98                         return result;
  99                 }
 100
 101                 void OnEndRequestCache (IAsyncResult result)
 102                 {
 103                 }
 104
 105                 IAsyncResult OnBeginUpdateCache (object o, EventArgs args, AsyncCallback cb, object data)
 106                 {
 107                         HttpApplication app = (HttpApplication) o;
 108                         HttpContext context = app.Context;
 109                         HttpAsyncResult result;
 110
 111                         if (context.Response.IsCached && context.Response.StatusCode == 200 &&
 112                             !context.Trace.IsEnabled)
 113                                 DoCacheInsert (context);
 114
 115                         result = new HttpAsyncResult (cb, this);
 116                         result.Complete (true, o, null);
 117                         return result;
 118                 }
 119
 120                 void OnEndUpdateCache (IAsyncResult result)
 121                 {
 122                 }
 123
 124                 private void DoCacheInsert (HttpContext context)
 125                 {
 126                         string vary_key = context.Request.FilePath;
 127                         string key;
 128                         CachedVaryBy varyby = context.Cache [vary_key] as CachedVaryBy;
 129                         CachedRawResponse prev = null;
 130                         bool lookup = true;
 131
 132                         if (varyby == null) {
 133                                 string path = context.Request.MapPath (vary_key);
 134                                 string [] files = new string [] { path };
 135                                 string [] keys = new string [0];
 136                                 varyby = new CachedVaryBy (context.Response.Cache, vary_key);
 137                                 context.Cache.InsertPrivate (vary_key, varyby,
 138                                                 new CacheDependency (files, keys),
 139                                                 Cache.NoAbsoluteExpiration,
 140                                                 Cache.NoSlidingExpiration,
 141                                                 CacheItemPriority.Normal, null);
 142                                 lookup = false;
 143                         }
 144
 145                         key = varyby.CreateKey (vary_key, context);
 146
 147                         if (lookup)
 148                                 prev = context.Cache [key] as CachedRawResponse;
 149
 150                         if (prev == null) {
 151                                 CachedRawResponse c = context.Response.GetCachedResponse ();
 152                                 string [] files = new string [] { };
 153                                 string [] keys = new string [] { vary_key };
 154                                 bool sliding = context.Response.Cache.Sliding;
 155
 156                                 context.Cache.InsertPrivate (key, c, new CacheDependency (files, keys),
 157                                                 (sliding ? Cache.NoAbsoluteExpiration :
 158                                                                 context.Response.Cache.Expires),
 159                                                 (sliding ? TimeSpan.FromSeconds (
 160                                                         context.Response.Cache.Duration) :
 161                                                                 Cache.NoSlidingExpiration),
 162                                                 CacheItemPriority.Normal, response_removed);
 163                                 c.VaryBy = varyby;
 164                                 varyby.ItemList.Add (key);
 165                         }
 166                 }
 167
 168                 private void OnRawResponseRemoved (string key, object value, CacheItemRemovedReason reason)
 169                 {
 170                         CachedRawResponse c = (CachedRawResponse) value;
 171
 172                         c.VaryBy.ItemList.Remove (key);
 173                         if (c.VaryBy.ItemList.Count != 0)
 174                                 return;
 175
 176                         Cache cache = HttpRuntime.Cache;
 177                         cache.Remove (c.VaryBy.Key);
 178                 }
 179         }
 180 }
 181