mcs/class/System.Web/System.Web.UI.WebControls/DataSourceCacheManager.cs

   1 //
   2 // System.Web.UI.WebControls.DataSourceCacheManager
   3 //
   4 // Authors:
   5 //      Vladimir Krasnov (vladimirk@mainsoft.com)
   6 //
   7 // Mainsoft (www.mainsoft.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 #if NET_2_0
  30
  31 using System;
  32 using System.Web;
  33 using System.Web.UI;
  34 using System.Web.Caching;
  35 using System.Collections;
  36 using System.Collections.Specialized;
  37 using System.Text;
  38
  39 namespace System.Web.UI.WebControls
  40 {
  41         internal class DataSourceCacheManager
  42         {
  43                 readonly int cacheDuration;
  44                 readonly string cacheKeyDependency;
  45                 readonly string controlID;
  46                 readonly DataSourceCacheExpiry cacheExpirationPolicy;
  47                 readonly Control owner;
  48                 readonly HttpContext context;
  49
  50                 internal DataSourceCacheManager (int cacheDuration, string cacheKeyDependency,
  51                         DataSourceCacheExpiry cacheExpirationPolicy, Control owner, HttpContext context)
  52                 {
  53                         this.cacheDuration = cacheDuration;
  54                         this.cacheKeyDependency = cacheKeyDependency;
  55                         this.cacheExpirationPolicy = cacheExpirationPolicy;
  56                         this.controlID = owner.UniqueID;
  57                         this.owner = owner;
  58                         this.context = context;
  59
  60                         if (DataCache [controlID] == null)
  61                                 DataCache [controlID] = new object ();
  62                 }
  63
  64                 internal void Expire ()
  65                 {
  66                         DataCache [controlID] = new object ();
  67                 }
  68
  69                 internal object GetCachedObject (string methodName, ParameterCollection parameters)
  70                 {
  71                         return DataCache [GetKeyFromParameters (methodName, parameters)];
  72                 }
  73
  74                 internal void SetCachedObject (string methodName, ParameterCollection parameters, object o)
  75                 {
  76                         if (o == null)
  77                                 return;
  78
  79                         string key = GetKeyFromParameters (methodName, parameters);
  80
  81                         if (DataCache [key] != null)
  82                                 DataCache.Remove (key);
  83
  84                         DateTime absoluteExpiration = Cache.NoAbsoluteExpiration;
  85                         TimeSpan slidindExpiraion = Cache.NoSlidingExpiration;
  86
  87                         if (cacheDuration > 0) {
  88                                 if (cacheExpirationPolicy == DataSourceCacheExpiry.Absolute)
  89                                         absoluteExpiration = DateTime.Now.AddSeconds (cacheDuration);
  90                                 else
  91                                         slidindExpiraion = new TimeSpan (cacheDuration * 10000);
  92                         }
  93
  94                         string [] dependencies;
  95                         if (cacheKeyDependency.Length > 0)
  96                                 dependencies = new string [] { cacheKeyDependency, controlID };
  97                         else
  98                                 dependencies = new string [] { controlID };
  99
 100                         DataCache.Add (key, o,
 101                                 new CacheDependency (new string [] { }, dependencies),
 102                                 absoluteExpiration, slidindExpiraion, CacheItemPriority.Default, null);
 103                 }
 104
 105                 static Cache DataCache
 106                 {
 107                         get
 108                         {
 109                                 if (HttpContext.Current != null)
 110                                         return HttpContext.Current.Cache;
 111
 112                                 throw new InvalidOperationException ("HttpContext.Current is null.");
 113                         }
 114                 }
 115
 116                 string GetKeyFromParameters (string methodName, ParameterCollection parameters)
 117                 {
 118                         StringBuilder sb = new StringBuilder (methodName);
 119
 120                         for (int i = 0; i < parameters.Count; i++) {
 121                                 sb.Append (parameters [i].Name);
 122                                 sb.Append (parameters [i].GetValue (context, owner));
 123                         }
 124
 125                         return sb.ToString ();
 126                 }
 127         }
 128 }
 129
 130 #endif