source: trunk/sources/HeuristicLab.PluginInfrastructure/3.3/LightweightApplicationManager.cs @ 7492

Last change on this file since 7492 was 7492, checked in by mkommend, 8 years ago

#1774: Improved performance of type discovery for generic types.

File size: 10.4 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2012 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using System;
23using System.Collections.Generic;
24using System.Linq;
25using System.Reflection;
26
27namespace HeuristicLab.PluginInfrastructure {
28
29  /// <summary>
30  /// Lightweight application manager is set as the application manager as long as the plugin infrastructure is uninitialized.
31  /// The list of plugins and applications is empty. The default application manager is necessary to provide the type discovery
32  /// functionality in unit tests.
33  /// </summary>
34  internal sealed class LightweightApplicationManager : IApplicationManager {
35    internal LightweightApplicationManager() {
36      AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);
37    }
38
39    Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args) {
40      return null;
41    }
42
43
44    #region IApplicationManager Members
45    /// <summary>
46    /// Gets an empty list of plugins. (LightweightApplicationManager doesn't support plugin discovery)
47    /// </summary>
48    public IEnumerable<IPluginDescription> Plugins {
49      get { return new IPluginDescription[0]; }
50    }
51
52    /// <summary>
53    /// Gets an empty list of applications. (LightweightApplicationManager doesn't support application discovery)
54    /// </summary>
55    public IEnumerable<IApplicationDescription> Applications {
56      get { return new IApplicationDescription[0]; }
57    }
58
59    /// <summary>
60    /// Creates an instance of all types that are subtypes or the same type of the specified type
61    /// </summary>
62    /// <typeparam name="T">Most general type.</typeparam>
63    /// <returns>Enumerable of the created instances.</returns>
64    public IEnumerable<T> GetInstances<T>() where T : class {
65      return GetInstances(typeof(T)).Cast<T>();
66    }
67
68    /// <summary>
69    /// Creates an instance of all types that are subtypes or the same type of the specified type
70    /// </summary>
71    /// <param name="type">Most general type.</param>
72    /// <returns>Enumerable of the created instances.</returns>
73    public IEnumerable<object> GetInstances(Type type) {
74      List<object> instances = new List<object>();
75      foreach (Type t in GetTypes(type)) {
76        object instance = null;
77        try { instance = Activator.CreateInstance(t); }
78        catch { }
79        if (instance != null) instances.Add(instance);
80      }
81      return instances;
82    }
83
84    /// <summary>
85    /// Finds all instantiable types that are subtypes or equal to the specified types.
86    /// </summary>
87    /// <param name="types">Most general types for which to find matching types.</param>
88    /// <remarks>Return only types that are instantiable
89    /// (interfaces, abstract classes... are not returned)</remarks>
90    /// <param name="includeGenericTypeDefinitions">Specifies if generic type definitions shall be included</param>
91    /// <returns>Enumerable of the discovered types.</returns>
92    public IEnumerable<Type> GetTypes(IEnumerable<Type> types, bool onlyInstantiable = true, bool includeGenericTypeDefinitions = false, bool assignableToAllTypes = true) {
93      IEnumerable<Type> result = GetTypes(types.First(), onlyInstantiable, includeGenericTypeDefinitions);
94      foreach (Type type in types.Skip(1)) {
95        IEnumerable<Type> discoveredTypes = GetTypes(type, onlyInstantiable, includeGenericTypeDefinitions);
96        if (assignableToAllTypes) result = result.Intersect(discoveredTypes);
97        else result = result.Union(discoveredTypes);
98      }
99      return result;
100    }
101
102    /// <summary>
103    /// Finds all types that are subtypes or equal to the specified type.
104    /// </summary>
105    /// <param name="type">Most general type for which to find matching types.</param>
106    /// <param name="onlyInstantiable">Return only types that are instantiable
107    /// (interfaces, abstract classes... are not returned)</param>
108    /// <param name="includeGenericTypeDefinitions">Specifies if generic type definitions shall be included</param>
109    /// <returns>Enumerable of the discovered types.</returns>
110    public IEnumerable<Type> GetTypes(Type type, bool onlyInstantiable = true, bool includeGenericTypeDefinitions = false) {
111      return from asm in AppDomain.CurrentDomain.GetAssemblies()
112             from t in GetTypes(type, asm, onlyInstantiable, includeGenericTypeDefinitions)
113             select t;
114    }
115
116    /// <summary>
117    /// Gets types that are assignable (same of subtype) to the specified type only from the given assembly.
118    /// </summary>
119    /// <param name="type">Most general type we want to find.</param>
120    /// <param name="assembly">Assembly that should be searched for types.</param>
121    /// <param name="onlyInstantiable">Return only types that are instantiable
122    /// (interfaces, abstract classes...  are not returned)</param>
123    /// <returns>Enumerable of the discovered types.</returns>
124    private static IEnumerable<Type> GetTypes(Type type, Assembly assembly, bool onlyInstantiable = true, bool includeGenericTypeDefinitions = false) {
125      try {
126        var assemblyTypes = assembly.GetTypes();
127
128        var buildTypes = from t in assembly.GetTypes()
129                         where !IsNonDiscoverableType(t)
130                         where onlyInstantiable == false ||
131                               (!t.IsAbstract && !t.IsInterface && !t.HasElementType)
132                         where CheckTypeCompatibility(type, t)
133                         select BuildType(t, type);
134
135        return from t in buildTypes
136               where includeGenericTypeDefinitions || !t.IsGenericTypeDefinition
137               select t;
138      }
139      catch (TypeLoadException) {
140        return Enumerable.Empty<Type>();
141      }
142      catch (ReflectionTypeLoadException) {
143        return Enumerable.Empty<Type>();
144      }
145    }
146
147    private static bool IsNonDiscoverableType(Type t) {
148      return t.GetCustomAttributes(typeof(NonDiscoverableTypeAttribute), false).Any();
149    }
150
151    private static bool CheckTypeCompatibility(Type type, Type other) {
152      if (type.IsAssignableFrom(other))
153        return true;
154      if (type.IsGenericType && other.IsGenericType) {
155        var otherGenericArguments = other.GetGenericArguments();
156        var typeGenericArguments = type.GetGenericArguments();
157
158        //check type arguments count
159        if (otherGenericArguments.Length != typeGenericArguments.Length)
160          return false;
161
162        //check type arguments & constraints
163        int i = 0;
164        foreach (var genericArgument in typeGenericArguments) {
165          if (otherGenericArguments[i].IsGenericParameter) {
166            foreach (var constraint in otherGenericArguments[i].GetGenericParameterConstraints())
167              if (!constraint.IsAssignableFrom(genericArgument)) return false;
168          } else if (genericArgument != otherGenericArguments[i]) return false;
169          i++;
170        }
171        //check types
172        try {
173          var otherGenericTypeDefinition = other.GetGenericTypeDefinition();
174          if (type.IsAssignableFrom(otherGenericTypeDefinition.MakeGenericType(typeGenericArguments)))
175            return true;
176        }
177        catch (Exception) { }
178      }
179      return false;
180    }
181    private static Type BuildType(Type type, Type protoType) {
182      if (type.IsGenericType && protoType.IsGenericType)
183        return type.GetGenericTypeDefinition().MakeGenericType(protoType.GetGenericArguments());
184      else
185        return type;
186    }
187
188    /// <summary>
189    /// Not supported by the LightweightApplicationManager
190    /// </summary>
191    /// <param name="type"></param>
192    /// <param name="plugin"></param>
193    /// <returns></returns>
194    /// <throws>NotSupportedException</throws>
195    public IEnumerable<Type> GetTypes(Type type, IPluginDescription plugin) {
196      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
197    }
198
199    /// <summary>
200    /// Not supported by the LightweightApplicationManager
201    /// </summary>
202    /// <param name="type"></param>
203    /// <param name="plugin"></param>
204    /// <param name="onlyInstantiable"></param>
205    /// <param name="includeGenericTypeDefinitions"></param>
206    /// <returns></returns>
207    /// <throws>NotSupportedException</throws>
208    public IEnumerable<Type> GetTypes(Type type, IPluginDescription plugin, bool onlyInstantiable = true, bool includeGenericTypeDefinitions = false) {
209      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
210    }
211
212    /// <summary>
213    /// Not supported by the LightweightApplicationManager
214    /// </summary>
215    /// <param name="type"></param>
216    /// <param name="plugin"></param>
217    /// <param name="onlyInstantiable"></param>
218    /// <param name="includeGenericTypeDefinitions"></param>
219    /// <returns></returns>
220    /// <throws>NotSupportedException</throws>
221    public IEnumerable<Type> GetTypes(IEnumerable<Type> types, IPluginDescription plugin, bool onlyInstantiable = true, bool includeGenericTypeDefinitions = false, bool assignableToAllTypes = true) {
222      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
223    }
224
225    /// <summary>
226    /// Not supported by the LightweightApplicationManager
227    /// </summary>
228    /// <param name="type"></param>
229    /// <returns></returns>
230    /// <throws>NotSupportedException</throws>
231    public IPluginDescription GetDeclaringPlugin(Type type) {
232      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
233    }
234
235    #endregion
236  }
237}
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