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

   1 //
   2 // System.Web.Compilation.AggregateCacheDependency
   3 //
   4 // Authors:
   5 //   Marek Habersack (grendello@gmail.com)
   6 //
   7 // (C) 2006 Marek Habersack
   8 //
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29 #if NET_2_0
  30 using System;
  31 using System.Collections.Generic;
  32 using System.Text;
  33 using System.Web;
  34
  35 namespace System.Web.Caching
  36 {
  37         public sealed class AggregateCacheDependency : CacheDependency
  38         {
  39                 private object dependenciesLock = new object();
  40                 private List <CacheDependency> dependencies;
  41
  42                 public AggregateCacheDependency ()
  43                 {}
  44
  45                 public void Add (params CacheDependency [] dependencies)
  46                 {
  47                         if (dependencies == null)
  48                                 throw new ArgumentNullException ("dependencies");
  49                         if (dependencies.Length == 0)
  50                                 return;
  51
  52                         bool somethingChanged = false;
  53                         foreach (CacheDependency dep in dependencies)
  54                                 if (dep == null || dep.IsUsed)
  55                                         throw new InvalidOperationException ("Cache dependency already in use");
  56                                 else if (!somethingChanged && dep != null && dep.HasChanged)
  57                                         somethingChanged = true;
  58
  59                         lock (dependenciesLock) {
  60                                 if (this.dependencies == null)
  61                                         this.dependencies = new List <CacheDependency> (dependencies.Length);
  62                                 this.dependencies.AddRange (dependencies);
  63                                 base.Start = DateTime.UtcNow;
  64                         }
  65                         if (somethingChanged)
  66                                 base.SignalDependencyChanged ();
  67                 }
  68
  69                 public override string GetUniqueID ()
  70                 {
  71                         if (dependencies == null || dependencies.Count == 0)
  72                                 return null;
  73
  74                         StringBuilder sb = new StringBuilder ();
  75                         lock (dependenciesLock) {
  76                                 string depid = null;
  77                                 foreach (CacheDependency dep in dependencies) {
  78                                         depid = dep.GetUniqueID ();
  79                                         if (String.IsNullOrEmpty (depid))
  80                                                 return null;
  81                                         sb.Append (depid);
  82                                         sb.Append (';');
  83                                 }
  84                         }
  85                         return sb.ToString ();
  86                 }
  87         }
  88 }
  89 #endif
  90