mcs/class/System.ComponentModel.Composition/src/ComponentModel/System/ComponentModel/Composition/ReflectionModel/ReflectionComposablePartDefinition.cs

   1 // -----------------------------------------------------------------------\r
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.\r
   3 // -----------------------------------------------------------------------\r
   4 using System;\r
   5 using System.Collections.Generic;\r
   6 using System.ComponentModel.Composition.Primitives;\r
   7 using System.Diagnostics.CodeAnalysis;\r
   8 using System.Linq;\r
   9 using System.Reflection;\r
  10 using System.Threading;\r
  11 using Microsoft.Internal;\r
  12 \r
  13 namespace System.ComponentModel.Composition.ReflectionModel\r
  14 {\r
  15     internal class ReflectionComposablePartDefinition : ComposablePartDefinition, ICompositionElement\r
  16     {\r
  17         private readonly IReflectionPartCreationInfo _creationInfo;\r
  18 \r
  19         private volatile IEnumerable<ImportDefinition> _imports;\r
  20         private volatile IEnumerable<ExportDefinition> _exports;\r
  21         private volatile IDictionary<string, object> _metadata;\r
  22         private volatile ConstructorInfo _constructor;\r
  23         private object _lock = new object();\r
  24 \r
  25         public ReflectionComposablePartDefinition(IReflectionPartCreationInfo creationInfo)\r
  26         {\r
  27             Assumes.NotNull(creationInfo);\r
  28             this._creationInfo = creationInfo;\r
  29         }\r
  30 \r
  31         public Type GetPartType()\r
  32         {\r
  33             return this._creationInfo.GetPartType();\r
  34         }\r
  35 \r
  36         public Lazy<Type> GetLazyPartType()\r
  37         {\r
  38             return this._creationInfo.GetLazyPartType();\r
  39         }\r
  40 \r
  41         public ConstructorInfo GetConstructor()\r
  42         {\r
  43             if (this._constructor == null)\r
  44             {\r
  45                 ConstructorInfo constructor = this._creationInfo.GetConstructor();\r
  46                 lock (this._lock)\r
  47                 {\r
  48                     if (this._constructor == null)\r
  49                     {\r
  50                         this._constructor = constructor;\r
  51                     }\r
  52                 }\r
  53             }\r
  54 \r
  55             return this._constructor;\r
  56         }\r
  57 \r
  58         public override IEnumerable<ExportDefinition> ExportDefinitions\r
  59         {\r
  60             get\r
  61             {\r
  62                 if (this._exports == null)\r
  63                 {\r
  64                     ExportDefinition[] exports = this._creationInfo.GetExports().ToArray();\r
  65                     lock (this._lock)\r
  66                     {\r
  67                         if (this._exports == null)\r
  68                         {\r
  69                             this._exports = exports;\r
  70                         }\r
  71                     }\r
  72                 }\r
  73                 return this._exports;\r
  74             }\r
  75         }\r
  76 \r
  77         public override IEnumerable<ImportDefinition> ImportDefinitions\r
  78         {\r
  79             get\r
  80             {\r
  81                 if (this._imports == null)\r
  82                 {\r
  83                     ImportDefinition[] imports = this._creationInfo.GetImports().ToArray();\r
  84                     lock (this._lock)\r
  85                     {\r
  86                         if (this._imports == null)\r
  87                         {\r
  88                             this._imports = imports;\r
  89                         }\r
  90                     }\r
  91                 }\r
  92                 return this._imports;\r
  93             }\r
  94         }\r
  95 \r
  96         public override IDictionary<string, object> Metadata\r
  97         {\r
  98             get\r
  99             {\r
 100                 if (this._metadata == null)\r
 101                 {\r
 102                     IDictionary<string, object> metadata = this._creationInfo.GetMetadata().AsReadOnly();\r
 103                     lock (this._lock)\r
 104                     {\r
 105                         if (this._metadata == null)\r
 106                         {\r
 107                             this._metadata = metadata;\r
 108                         }\r
 109                     }\r
 110                 }\r
 111                 return this._metadata;\r
 112             }\r
 113         }\r
 114 \r
 115         internal bool IsDisposalRequired\r
 116         {\r
 117             get\r
 118             {\r
 119                 return this._creationInfo.IsDisposalRequired;\r
 120             }\r
 121         }\r
 122 \r
 123         [SuppressMessage("Microsoft.Reliability", "CA2000:Dispose objects before losing scope")]\r
 124         public override ComposablePart CreatePart()\r
 125         {\r
 126             if (this.IsDisposalRequired)\r
 127             {\r
 128                 return new DisposableReflectionComposablePart(this);\r
 129             }\r
 130             else\r
 131             {\r
 132                 return new ReflectionComposablePart(this);\r
 133             }\r
 134         }\r
 135 \r
 136         string ICompositionElement.DisplayName\r
 137         {\r
 138             get { return this._creationInfo.DisplayName; }\r
 139         }\r
 140 \r
 141         ICompositionElement ICompositionElement.Origin\r
 142         {\r
 143             get { return this._creationInfo.Origin; }\r
 144         }\r
 145 \r
 146         public override string ToString()\r
 147         {\r
 148             return this._creationInfo.DisplayName;\r
 149         }\r
 150     }\r
 151 }\r