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

   1 // -----------------------------------------------------------------------\r
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.\r
   3 // -----------------------------------------------------------------------\r
   4 using System;\r
   5 using System.Diagnostics.CodeAnalysis;\r
   6 using System.Globalization;\r
   7 using System.Linq;\r
   8 using System.Reflection;\r
   9 using System.Threading;\r
  10 using Microsoft.Internal;\r
  11 \r
  12 namespace System.ComponentModel.Composition.ReflectionModel\r
  13 {\r
  14     public struct LazyMemberInfo\r
  15     {\r
  16         private readonly MemberTypes _memberType;\r
  17         private MemberInfo[] _accessors;\r
  18         private readonly Func<MemberInfo[]> _accessorsCreator;\r
  19 \r
  20         public LazyMemberInfo(MemberInfo member)\r
  21         {\r
  22             Requires.NotNull(member, "member");\r
  23             EnsureSupportedMemberType(member.MemberType, "member");\r
  24 \r
  25             this._accessorsCreator = null;\r
  26             this._memberType = member.MemberType;\r
  27             \r
  28             switch(this._memberType)\r
  29             {\r
  30                 case MemberTypes.Property:\r
  31                     PropertyInfo property = (PropertyInfo)member;\r
  32                     Assumes.NotNull(property);\r
  33                     this._accessors = new MemberInfo[] { property.GetGetMethod(true), property.GetSetMethod(true) };\r
  34                     break;\r
  35                 case MemberTypes.Event:\r
  36                     EventInfo event_ = (EventInfo)member;\r
  37                     this._accessors = new MemberInfo[] { event_.GetRaiseMethod(true), event_.GetAddMethod(true), event_.GetRemoveMethod(true) };\r
  38                     break;\r
  39                 default:\r
  40                     this._accessors = new MemberInfo[] { member };\r
  41                     break;\r
  42             }\r
  43         }\r
  44 \r
  45         public LazyMemberInfo(MemberTypes memberType, params MemberInfo[] accessors)\r
  46         {\r
  47             EnsureSupportedMemberType(memberType, "memberType");\r
  48             Requires.NotNull(accessors, "accessors");\r
  49             \r
  50             string errorMessage;\r
  51             if (!LazyMemberInfo.AreAccessorsValid(memberType, accessors, out errorMessage))\r
  52             {\r
  53                 throw new ArgumentException(errorMessage, "accessors");\r
  54             }\r
  55 \r
  56             this._memberType = memberType;\r
  57             this._accessors = accessors;\r
  58             this._accessorsCreator = null;\r
  59         }\r
  60 \r
  61         public LazyMemberInfo(MemberTypes memberType, Func<MemberInfo[]> accessorsCreator)\r
  62         {\r
  63             EnsureSupportedMemberType(memberType, "memberType");\r
  64             Requires.NotNull(accessorsCreator, "accessorsCreator");\r
  65 \r
  66             this._memberType = memberType;\r
  67             this._accessors = null;\r
  68             this._accessorsCreator = accessorsCreator;\r
  69         }\r
  70 \r
  71         public MemberTypes MemberType\r
  72         {\r
  73             get { return this._memberType; }\r
  74         }\r
  75 \r
  76         public MemberInfo[] GetAccessors()\r
  77         {\r
  78             if ((this._accessors == null) && (this._accessorsCreator != null))\r
  79             {\r
  80                 MemberInfo[] accessors = this._accessorsCreator.Invoke();\r
  81 \r
  82                 string errorMessage;\r
  83                 if (!LazyMemberInfo.AreAccessorsValid(this.MemberType, accessors, out errorMessage))\r
  84                 {\r
  85                     throw new InvalidOperationException(errorMessage);\r
  86                 }\r
  87 \r
  88                 this._accessors = accessors;\r
  89             }\r
  90 \r
  91             return this._accessors;\r
  92         }\r
  93 \r
  94         public override int GetHashCode()\r
  95         {\r
  96             if (this._accessorsCreator != null)\r
  97             {\r
  98                 return this.MemberType.GetHashCode() ^ this._accessorsCreator.GetHashCode();\r
  99             }\r
 100             else\r
 101             {\r
 102                 Assumes.NotNull(this._accessors);\r
 103                 Assumes.NotNull(this._accessors[0]);\r
 104                 return this.MemberType.GetHashCode() ^ this._accessors[0].GetHashCode();\r
 105             }\r
 106         }\r
 107 \r
 108         public override bool Equals(object obj)\r
 109         {\r
 110             LazyMemberInfo that = (LazyMemberInfo)obj;\r
 111 \r
 112             // Difefrent member types mean different members\r
 113             if (this._memberType != that._memberType)\r
 114             {\r
 115                 return false;\r
 116             }\r
 117 \r
 118             // if any of the lazy memebers create accessors in a delay-loaded fashion, we simply compare the creators\r
 119             if ((this._accessorsCreator != null) || (that._accessorsCreator != null))\r
 120             {\r
 121                 return object.Equals(this._accessorsCreator, that._accessorsCreator);\r
 122             }\r
 123 \r
 124             // we are dealing with explicitly passed accessors in both cases\r
 125             Assumes.NotNull(this._accessors);\r
 126             Assumes.NotNull(that._accessors);\r
 127             return this._accessors.SequenceEqual(that._accessors);\r
 128         }\r
 129 \r
 130         public static bool operator ==(LazyMemberInfo left, LazyMemberInfo right)\r
 131         {\r
 132             return left.Equals(right);\r
 133         }\r
 134 \r
 135         public static bool operator !=(LazyMemberInfo left, LazyMemberInfo right)\r
 136         {\r
 137             return !left.Equals(right);\r
 138         }\r
 139 \r
 140         private static void EnsureSupportedMemberType(MemberTypes memberType, string argument)\r
 141         {\r
 142             MemberTypes supportedTypes = MemberTypes.TypeInfo | MemberTypes.NestedType | MemberTypes.Constructor | MemberTypes.Field | MemberTypes.Method | MemberTypes.Property | MemberTypes.Event;\r
 143             Requires.IsInMembertypeSet(memberType, argument, supportedTypes);\r
 144         }\r
 145 \r
 146         private static bool AreAccessorsValid(MemberTypes memberType, MemberInfo[] accessors, out string errorMessage)\r
 147         {\r
 148             errorMessage = string.Empty;\r
 149             if (accessors == null)\r
 150             {\r
 151                 errorMessage = Strings.LazyMemberInfo_AccessorsNull;\r
 152                 return false;\r
 153             }\r
 154 \r
 155             if (accessors.All(accessor => accessor == null))\r
 156             {\r
 157                 errorMessage = Strings.LazyMemberInfo_NoAccessors;\r
 158                 return false;\r
 159             }\r
 160 \r
 161             switch (memberType)\r
 162             {\r
 163                 case MemberTypes.Property:\r
 164                     if (accessors.Length != 2)\r
 165                     {\r
 166                         errorMessage = Strings.LazyMemberInfo_InvalidPropertyAccessors_Cardinality;\r
 167                         return false;\r
 168                     }\r
 169 \r
 170                     if (accessors.Where(accessor => (accessor != null) && (accessor.MemberType != MemberTypes.Method)).Any())\r
 171                     {\r
 172                         errorMessage = Strings.LazyMemberinfo_InvalidPropertyAccessors_AccessorType;\r
 173                         return false;\r
 174                     }\r
 175 \r
 176                     break;\r
 177 \r
 178                 case MemberTypes.Event:\r
 179                     if (accessors.Length != 3)\r
 180                     {\r
 181                         errorMessage = Strings.LazyMemberInfo_InvalidEventAccessors_Cardinality;\r
 182                         return false;\r
 183                     }\r
 184 \r
 185                     if (accessors.Where(accessor => (accessor != null) && (accessor.MemberType != MemberTypes.Method)).Any())\r
 186                     {\r
 187                         errorMessage = Strings.LazyMemberinfo_InvalidPropertyAccessors_AccessorType;\r
 188                         return false;\r
 189                     }\r
 190 \r
 191                     break;\r
 192 \r
 193                 default:\r
 194                     if (\r
 195                         (accessors.Length != 1) ||\r
 196                         ((accessors.Length == 1) && (accessors[0].MemberType != memberType)))\r
 197                     {\r
 198                         errorMessage = string.Format(CultureInfo.CurrentCulture, Strings.LazyMemberInfo_InvalidAccessorOnSimpleMember, memberType);\r
 199                         return false;\r
 200                     }\r
 201                    \r
 202                     break;\r
 203             }\r
 204             return true;\r
 205         }\r
 206     }\r
 207 }\r