mcs/class/System.Web.Mvc2/System.Web.Mvc/TypeCacheUtil.cs

   1 /* ****************************************************************************\r
   2  *\r
   3  * Copyright (c) Microsoft Corporation. All rights reserved.\r
   4  *\r
   5  * This software is subject to the Microsoft Public License (Ms-PL). \r
   6  * A copy of the license can be found in the license.htm file included \r
   7  * in this distribution.\r
   8  *\r
   9  * You must not remove this notice, or any other, from this software.\r
  10  *\r
  11  * ***************************************************************************/\r
  12 \r
  13 namespace System.Web.Mvc {\r
  14     using System;\r
  15     using System.Collections;\r
  16     using System.Collections.Generic;\r
  17     using System.Diagnostics.CodeAnalysis;\r
  18     using System.IO;\r
  19     using System.Linq;\r
  20     using System.Reflection;\r
  21 \r
  22     internal static class TypeCacheUtil {\r
  23 \r
  24         private static IEnumerable<Type> FilterTypesInAssemblies(IBuildManager buildManager, Predicate<Type> predicate) {\r
  25             // Go through all assemblies referenced by the application and search for types matching a predicate\r
  26             IEnumerable<Type> typesSoFar = Type.EmptyTypes;\r
  27 \r
  28             ICollection assemblies = buildManager.GetReferencedAssemblies();\r
  29             foreach (Assembly assembly in assemblies) {\r
  30                 Type[] typesInAsm;\r
  31                 try {\r
  32                     typesInAsm = assembly.GetTypes();\r
  33                 }\r
  34                 catch (ReflectionTypeLoadException ex) {\r
  35                     typesInAsm = ex.Types;\r
  36                 }\r
  37                 typesSoFar = typesSoFar.Concat(typesInAsm);\r
  38             }\r
  39             return typesSoFar.Where(type => TypeIsPublicClass(type) && predicate(type));\r
  40         }\r
  41 \r
  42         public static List<Type> GetFilteredTypesFromAssemblies(string cacheName, Predicate<Type> predicate, IBuildManager buildManager) {\r
  43             TypeCacheSerializer serializer = new TypeCacheSerializer();\r
  44 \r
  45             // first, try reading from the cache on disk\r
  46             List<Type> matchingTypes = ReadTypesFromCache(cacheName, predicate, buildManager, serializer);\r
  47             if (matchingTypes != null) {\r
  48                 return matchingTypes;\r
  49             }\r
  50 \r
  51             // if reading from the cache failed, enumerate over every assembly looking for a matching type\r
  52             matchingTypes = FilterTypesInAssemblies(buildManager, predicate).ToList();\r
  53 \r
  54             // finally, save the cache back to disk\r
  55             SaveTypesToCache(cacheName, matchingTypes, buildManager, serializer);\r
  56 \r
  57             return matchingTypes;\r
  58         }\r
  59 \r
  60         [SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes",\r
  61             Justification = "Cache failures are not fatal, and the code should continue executing normally.")]\r
  62         internal static List<Type> ReadTypesFromCache(string cacheName, Predicate<Type> predicate, IBuildManager buildManager, TypeCacheSerializer serializer) {\r
  63             try {\r
  64                 using (Stream stream = buildManager.ReadCachedFile(cacheName)) {\r
  65                     if (stream != null) {\r
  66                         using (StreamReader reader = new StreamReader(stream)) {\r
  67                             List<Type> deserializedTypes = serializer.DeserializeTypes(reader);\r
  68                             if (deserializedTypes != null && deserializedTypes.All(type => TypeIsPublicClass(type) && predicate(type))) {\r
  69                                 // If all read types still match the predicate, success!\r
  70                                 return deserializedTypes;\r
  71                             }\r
  72                         }\r
  73                     }\r
  74                 }\r
  75             }\r
  76             catch {\r
  77             }\r
  78 \r
  79             return null;\r
  80         }\r
  81 \r
  82         [SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes",\r
  83             Justification = "Cache failures are not fatal, and the code should continue executing normally.")]\r
  84         internal static void SaveTypesToCache(string cacheName, IList<Type> matchingTypes, IBuildManager buildManager, TypeCacheSerializer serializer) {\r
  85             try {\r
  86                 using (Stream stream = buildManager.CreateCachedFile(cacheName)) {\r
  87                     if (stream != null) {\r
  88                         using (StreamWriter writer = new StreamWriter(stream)) {\r
  89                             serializer.SerializeTypes(matchingTypes, writer);\r
  90                         }\r
  91                     }\r
  92                 }\r
  93             }\r
  94             catch {\r
  95             }\r
  96         }\r
  97 \r
  98         private static bool TypeIsPublicClass(Type type) {\r
  99             return (type != null && type.IsPublic && type.IsClass && !type.IsAbstract);\r
 100         }\r
 101 \r
 102     }\r
 103 }\r