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
  48                 internal DataSourceCacheManager (int cacheDuration, string cacheKeyDependency,
  49                         DataSourceCacheExpiry cacheExpirationPolicy, string controlID)
  50                 {
  51                         this.cacheDuration = cacheDuration;
  52                         this.cacheKeyDependency = cacheKeyDependency;
  53                         this.cacheExpirationPolicy = cacheExpirationPolicy;
  54                         this.controlID = controlID;
  55
  56                         if (DataCache [controlID] == null)
  57                                 DataCache [controlID] = new object ();
  58                 }
  59
  60                 internal void Expire ()
  61                 {
  62                         DataCache [controlID] = new object ();
  63                 }
  64
  65                 internal object GetCachedObject (string methodName, ParameterCollection parameters)
  66                 {
  67                         return DataCache [GetKeyFromParameters (methodName, parameters)];
  68                 }
  69
  70                 internal void SetCachedObject (string methodName, ParameterCollection parameters, object o)
  71                 {
  72                         if (o == null)
  73                                 return;
  74
  75                         string key = GetKeyFromParameters (methodName, parameters);
  76
  77                         if (DataCache [key] != null)
  78                                 DataCache.Remove (key);
  79
  80                         DateTime absoluteExpiration = Cache.NoAbsoluteExpiration;
  81                         TimeSpan slidindExpiraion = Cache.NoSlidingExpiration;
  82
  83                         if (cacheDuration > 0) {
  84                                 if (cacheExpirationPolicy == DataSourceCacheExpiry.Absolute)
  85                                         absoluteExpiration = DateTime.Now.AddSeconds (cacheDuration);
  86                                 else
  87                                         slidindExpiraion = new TimeSpan (cacheDuration * 10000);
  88                         }
  89
  90                         string [] dependencies;
  91                         if (cacheKeyDependency.Length > 0)
  92                                 dependencies = new string [] { cacheKeyDependency, controlID };
  93                         else
  94                                 dependencies = new string [] { controlID };
  95
  96                         DataCache.Add (key, o,
  97                                 new CacheDependency (new string [] { }, dependencies),
  98                                 absoluteExpiration, slidindExpiraion, CacheItemPriority.Default, null);
  99                 }
 100
 101                 static Cache DataCache
 102                 {
 103                         get
 104                         {
 105                                 if (HttpContext.Current != null)
 106                                         return HttpContext.Current.Cache;
 107
 108                                 throw new InvalidOperationException ("HttpContext.Current is null.");
 109                         }
 110                 }
 111
 112                 static string GetKeyFromParameters (string methodName, ParameterCollection parameters)
 113                 {
 114                         StringBuilder sb = new StringBuilder (methodName);
 115
 116                         for (int i = 0; i < parameters.Count; i++) {
 117                                 sb.Append (parameters [i].Name);
 118                                 sb.Append (parameters [i].DefaultValue);
 119                         }
 120
 121                         return sb.ToString ();
 122                 }
 123         }
 124 }
 125
 126 #endif