mcs/class/System.Web/System.Web.UI/BasePartialCachingControl.cs

   1 //
   2 // System.Web.UI.BasePartialCachingControl.cs
   3 //
   4 // Author:
   5 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   6 //   Jackson Harper (jackson@ximian.com)
   7 //
   8 // (C) 2003 Andreas Nahr
   9 // Copyright (C) 2004-2005 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.IO;
  32 using System.Text;
  33 using System.ComponentModel;
  34 using System.Security.Permissions;
  35 using System.Web.Caching;
  36
  37 namespace System.Web.UI
  38 {
  39         // CAS
  40         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  41         [AspNetHostingPermission (SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  42         // attributes
  43         [ToolboxItem (false)]
  44         public abstract class BasePartialCachingControl : Control
  45         {
  46                 CacheDependency dependency;
  47                 string ctrl_id;
  48                 string guid;
  49                 int duration;
  50                 string varyby_params;
  51                 string varyby_controls;
  52                 string varyby_custom;
  53                 DateTime expirationTime;
  54                 bool slidingExpiration;
  55
  56                 Control control;
  57                 ControlCachePolicy cachePolicy;
  58                 string cacheKey;
  59                 string cachedData;
  60
  61                 protected BasePartialCachingControl()
  62                 {
  63                 }
  64
  65                 internal string CtrlID {
  66                         get { return ctrl_id; }
  67                         set { ctrl_id = value; }
  68                 }
  69
  70                 internal string Guid {
  71                         get { return guid; }
  72                         set { guid = value; }
  73                 }
  74
  75                 internal int Duration {
  76                         get { return duration; }
  77                         set { duration = value; }
  78                 }
  79
  80                 internal string VaryByParams {
  81                         get { return varyby_params; }
  82                         set { varyby_params = value; }
  83                 }
  84
  85                 internal string VaryByControls {
  86                         get { return varyby_controls; }
  87                         set { varyby_controls = value; }
  88                 }
  89
  90                 internal string VaryByCustom {
  91                         get { return varyby_custom; }
  92                         set { varyby_custom = value; }
  93                 }
  94
  95                 internal DateTime ExpirationTime {
  96                         get { return expirationTime; }
  97                         set { expirationTime = value; }
  98                 }
  99
 100                 internal bool SlidingExpiration {
 101                         get { return slidingExpiration; }
 102                         set { slidingExpiration = value; }
 103                 }
 104                 internal string ProviderName {
 105                         get; set;
 106                 }
 107                 internal abstract Control CreateControl ();
 108
 109                 public override void Dispose ()
 110                 {
 111                         if (dependency != null) {
 112                                 dependency.Dispose ();
 113                                 dependency = null;
 114                         }
 115                 }
 116
 117                 void RetrieveCachedContents ()
 118                 {
 119                         cacheKey = CreateKey ();
 120                         OutputCacheProvider provider = GetProvider ();
 121                         cachedData = provider.Get (cacheKey) as string;
 122                 }
 123                 OutputCacheProvider GetProvider ()
 124                 {
 125                         string providerName = ProviderName;
 126                         OutputCacheProvider provider;
 127
 128                         if (String.IsNullOrEmpty (providerName))
 129                                 provider = OutputCache.DefaultProvider;
 130                         else {
 131                                 provider = OutputCache.GetProvider (providerName);
 132                                 if (provider == null)
 133                                         provider = OutputCache.DefaultProvider;
 134                         }
 135
 136                         return provider;
 137                 }
 138
 139                 void OnDependencyChanged (string key, object value, CacheItemRemovedReason reason)
 140                 {
 141                         Console.WriteLine ("{0}.OnDependencyChanged (\"{0}\", {1}, {2})", this, key, value, reason);
 142                         GetProvider ().Remove (key);
 143                 }
 144
 145                 internal override void InitRecursive (Control namingContainer)
 146                 {
 147                         RetrieveCachedContents ();
 148                         if (cachedData == null) {
 149                                 control = CreateControl ();
 150                                 Controls.Add (control);
 151                         } else
 152                                 control = null;
 153
 154                         base.InitRecursive (namingContainer);
 155                 }
 156                 protected internal override void Render (HtmlTextWriter output)
 157                 {
 158                         if (cachedData != null) {
 159                                 output.Write (cachedData);
 160                                 return;
 161                         }
 162
 163                         if (control == null) {
 164                                 base.Render (output);
 165                                 return;
 166                         }
 167
 168                         HttpContext context = HttpContext.Current;
 169                         StringWriter writer = new StringWriter ();
 170                         TextWriter prev = context.Response.SetTextWriter (writer);
 171                         HtmlTextWriter txt_writer = new HtmlTextWriter (writer);
 172                         string text;
 173                         try {
 174                                 control.RenderControl (txt_writer);
 175                         } finally {
 176                                 text = writer.ToString ();
 177                                 context.Response.SetTextWriter (prev);
 178                                 output.Write (text);
 179                         }
 180                         OutputCacheProvider provider = GetProvider ();
 181                         DateTime utcExpire = DateTime.UtcNow.AddSeconds (duration);
 182                         provider.Set (cacheKey, text, utcExpire);;
 183                         context.InternalCache.Insert (cacheKey, text, dependency, utcExpire.ToLocalTime (),
 184                                                       Cache.NoSlidingExpiration, CacheItemPriority.Normal,
 185                                                       null);
 186                 }
 187
 188                 public ControlCachePolicy CachePolicy
 189                 {
 190                         get {
 191                                 if (cachePolicy == null)
 192                                         cachePolicy = new ControlCachePolicy (this);
 193
 194                                 return cachePolicy;
 195                         }
 196                 }
 197
 198                 public CacheDependency Dependency {
 199                         get {return dependency;}
 200                         set {dependency = value;}
 201                 }
 202
 203                 string CreateKey ()
 204                 {
 205                         StringBuilder builder = new StringBuilder ();
 206                         HttpContext context = HttpContext.Current;
 207
 208                         builder.Append ("PartialCachingControl\n");
 209                         builder.Append ("GUID: " + guid + "\n");
 210
 211                         if (varyby_params != null && varyby_params.Length > 0) {
 212                                 string[] prms = varyby_params.Split (';');
 213                                 for (int i=0; i<prms.Length; i++) {
 214                                         string val = context.Request.Params [prms [i]];
 215                                         builder.Append ("VP:");
 216                                         builder.Append (prms [i]);
 217                                         builder.Append ('=');
 218                                         builder.Append (val != null ? val : "__null__");
 219                                         builder.Append ('\n');
 220                                 }
 221                         }
 222
 223                         if (varyby_controls != null && varyby_params.Length > 0) {
 224                                 string[] prms = varyby_controls.Split (';');
 225                                 for (int i=0; i<prms.Length; i++) {
 226                                         string val = context.Request.Params [prms [i]];
 227                                         builder.Append ("VCN:");
 228                                         builder.Append (prms [i]);
 229                                         builder.Append ('=');
 230                                         builder.Append (val != null ? val : "__null__");
 231                                         builder.Append ('\n');
 232                                 }
 233                         }
 234
 235                         if (varyby_custom != null) {
 236                                 string val = context.ApplicationInstance.GetVaryByCustomString (context,
 237                                                 varyby_custom);
 238                                 builder.Append ("VC:");
 239                                 builder.Append (varyby_custom);
 240                                 builder.Append ('=');
 241                                 builder.Append (val != null ? val : "__null__");
 242                                 builder.Append ('\n');
 243                         }
 244
 245                         return builder.ToString ();
 246                 }
 247         }
 248 }
 249