mcs/class/referencesource/System/net/System/Net/Cache/RequestCacheManager.cs

   1 /*++
   2 Copyright (c) Microsoft Corporation
   3
   4 Module Name:
   5
   6     RequestCacheManager.cs
   7
   8 Abstract:
   9     The class implements the app domain wide configuration
  10     for request cache aware clients
  11
  12 Author:
  13
  14     Alexei Vopilov    21-Dec-2002
  15
  16 Revision History:
  17
  18     Jan 25 2004 - Changed the visibility of the class from public to internal, compressed unused logic.
  19
  20 --*/
  21 namespace System.Net.Cache {
  22 using System;
  23 using System.Collections;
  24 using System.Net.Configuration;
  25 using System.Configuration;
  26
  27
  28     /// <summary>  Specifies app domain-wide default settings for request caching </summary>
  29     internal sealed class RequestCacheManager {
  30         private RequestCacheManager() {}
  31
  32         private static volatile RequestCachingSectionInternal s_CacheConfigSettings;
  33
  34         private static readonly RequestCacheBinding s_BypassCacheBinding = new RequestCacheBinding (null, null, new RequestCachePolicy(RequestCacheLevel.BypassCache));
  35
  36         private static volatile RequestCacheBinding s_DefaultGlobalBinding;
  37         private static volatile RequestCacheBinding s_DefaultHttpBinding;
  38         private static volatile RequestCacheBinding s_DefaultFtpBinding;
  39
  40         //
  41         // ATN: the caller MUST use uri.Scheme as a parameter, otheriwse cannot do schme ref comparision
  42         //
  43         internal static RequestCacheBinding GetBinding(string internedScheme)
  44         {
  45             if (internedScheme == null)
  46                 throw new ArgumentNullException("uriScheme");
  47
  48             if (s_CacheConfigSettings == null)
  49                 LoadConfigSettings();
  50
  51             if(s_CacheConfigSettings.DisableAllCaching)
  52                 return s_BypassCacheBinding;
  53
  54             if (internedScheme.Length == 0)
  55                 return s_DefaultGlobalBinding;
  56
  57             if ((object)internedScheme == (object)Uri.UriSchemeHttp || (object)internedScheme == (object)Uri.UriSchemeHttps)
  58                 return s_DefaultHttpBinding;
  59
  60             if ((object)internedScheme == (object)Uri.UriSchemeFtp)
  61                 return s_DefaultFtpBinding;
  62
  63             return s_BypassCacheBinding;
  64         }
  65
  66         internal static bool IsCachingEnabled
  67         {
  68             get
  69             {
  70                 if (s_CacheConfigSettings == null)
  71                     LoadConfigSettings();
  72
  73                 return !s_CacheConfigSettings.DisableAllCaching;
  74             }
  75         }
  76
  77         //
  78         internal static void SetBinding(string uriScheme, RequestCacheBinding binding)
  79         {
  80             if (uriScheme == null)
  81                 throw new ArgumentNullException("uriScheme");
  82
  83             if (s_CacheConfigSettings == null)
  84                 LoadConfigSettings();
  85
  86             if(s_CacheConfigSettings.DisableAllCaching)
  87                 return;
  88
  89             if (uriScheme.Length == 0)
  90                 s_DefaultGlobalBinding = binding;
  91             else if (uriScheme == Uri.UriSchemeHttp || uriScheme == Uri.UriSchemeHttps)
  92                 s_DefaultHttpBinding = binding;
  93             else if (uriScheme == Uri.UriSchemeFtp)
  94                 s_DefaultFtpBinding = binding;
  95         }
  96         //
  97         private static void LoadConfigSettings()
  98         {
  99             // Any concurent access shall go here and block until we've grabbed the config settings
 100             lock (s_BypassCacheBinding)
 101             {
 102                 if (s_CacheConfigSettings == null)
 103                 {
 104                     RequestCachingSectionInternal settings = RequestCachingSectionInternal.GetSection();
 105
 106                     s_DefaultGlobalBinding = new RequestCacheBinding (settings.DefaultCache, settings.DefaultHttpValidator, settings.DefaultCachePolicy);
 107                     s_DefaultHttpBinding = new RequestCacheBinding (settings.DefaultCache, settings.DefaultHttpValidator, settings.DefaultHttpCachePolicy);
 108                     s_DefaultFtpBinding = new RequestCacheBinding (settings.DefaultCache, settings.DefaultFtpValidator, settings.DefaultFtpCachePolicy);
 109
 110                     s_CacheConfigSettings = settings;
 111                 }
 112             }
 113         }
 114     }
 115
 116     //
 117     //
 118     internal class RequestCacheBinding  {
 119         private RequestCache          m_RequestCache;
 120         private RequestCacheValidator m_CacheValidator;
 121         private RequestCachePolicy    m_Policy;
 122
 123
 124         internal RequestCacheBinding (RequestCache requestCache, RequestCacheValidator cacheValidator, RequestCachePolicy  policy) {
 125             m_RequestCache = requestCache;
 126             m_CacheValidator = cacheValidator;
 127             m_Policy = policy;
 128         }
 129
 130         internal RequestCache Cache {
 131             get {return m_RequestCache;}
 132         }
 133
 134         internal RequestCacheValidator Validator {
 135             get {return m_CacheValidator;}
 136         }
 137
 138         internal RequestCachePolicy Policy {
 139             get {return m_Policy;}
 140         }
 141
 142     }
 143 }