/// <summary>
/// Adds a default constructor to the singleton type.
/// </summary>
/// <param name="module">The module that will host the singleton type.</param>
/// <param name="singletonName">The name of the singleton.</param>
/// <param name="typeAttributes">The type attributes that describes the singleton type.</param>
/// <param name="objectType">The object ty pe.</param>
/// <returns>A <see cref="TypeDefinition"/> that represents the singleton type.</returns>
private static TypeDefinition AddDefaultSingletonConstructor(ModuleDefinition module, string singletonName, TypeAttributes typeAttributes, TypeReference objectType)
{
// Add a default constructor and make it private
var singletonType = module.DefineClass(singletonName, "Hiro.Containers.Internal", typeAttributes, objectType);
singletonType.AddDefaultConstructor();
var constructor = singletonType.GetDefaultConstructor();
constructor.IsFamilyOrAssembly = true;
return(singletonType);
}
/// <summary>
/// Defines the nested type that will instantiate the actual singleton service instance.
/// </summary>
/// <param name="module">The module that will host the singleton type.</param>
/// <param name="singletonType">The singleton type.</param>
/// <param name="instanceField">The field that will hold the singleton instance.</param>
/// <param name="serviceMap">The service map that contains the list of dependencies in the application.</param>
/// <param name="implementation">The implementation that will instantiate the dependency.</param>
/// <param name="dependency">The dependency that will be instantiated by the singleton.</param>
/// <param name="targetMethod">The method that will be used to instantiate the actual service instance.</param>
private void DefineNestedType(ModuleDefinition module, TypeDefinition singletonType, FieldDefinition instanceField, IDictionary <IDependency, IImplementation> serviceMap, IImplementation implementation, IDependency dependency, MethodDefinition targetMethod)
{
var objectType = module.ImportType(typeof(object));
var nestedName = string.Format("Nested-{0}", dependency.GetHashCode());
const TypeAttributes nestedAttributes = TypeAttributes.NestedFamORAssem | TypeAttributes.Sealed | TypeAttributes.AutoClass | TypeAttributes.Class | TypeAttributes.AnsiClass;
var nestedType = module.DefineClass(nestedName, "Hiro.Containers.Internal", nestedAttributes, objectType);
singletonType.NestedTypes.Add(nestedType);
nestedType.Fields.Add(instanceField);
// Emit the static constructor body
var cctor = DefineNestedConstructors(module, nestedType);
EmitSingletonInstantiation(dependency, implementation, serviceMap, instanceField, cctor, module, targetMethod);
}
public TypeDefinition CreateType(string adapterName, string namespaceName, Dictionary <MethodReference, MethodReference> methodMap)
{
const TypeAttributes adapterAttributes = TypeAttributes.Public | TypeAttributes.AutoClass | TypeAttributes.AnsiClass | TypeAttributes.Class |
TypeAttributes.BeforeFieldInit;
var adapterType = _targetModule.DefineClass(adapterName, namespaceName, adapterAttributes,
_targetModule.ImportType <object>());
var fieldName = string.Format("___<>{0}__BackingField", _targetDependency.Name);
var targetField = new FieldDefinition(fieldName, _targetDependency, FieldAttributes.Private);
adapterType.Fields.Add(targetField);
adapterType.Interfaces.Add(_interfaceType);
_addAdapterConstructor.AddConstructor(adapterType, targetField);
foreach (var method in _interfaceType.Methods.Cast <MethodDefinition>())
{
_addAdapterMethod.AddMethod(adapterType, targetField, method, methodMap);
}
return(adapterType);
}
/// <summary>
/// Creates a proxy type using the given
/// <paramref name="baseType"/> as the base class
/// and ensures that the proxy type implements the given
/// interface types.
/// </summary>
/// <param name="baseType">The base class from which the proxy type will be derived.</param>
/// <param name="baseInterfaces">The list of interfaces that the proxy will implement.</param>
/// <returns>A forwarding proxy.</returns>
public Type CreateProxyType(Type baseType, IEnumerable <Type> baseInterfaces)
{
// Reuse the cached results, if possible
Type[] originalInterfaces = baseInterfaces.ToArray();
if (Cache != null && Cache.Contains(baseType, originalInterfaces))
{
return(Cache.Get(baseType, originalInterfaces));
}
if (!baseType.IsPublic)
{
throw new ArgumentException("The proxy factory can only generate proxies from public base classes.",
"baseType");
}
bool hasNonPublicInterfaces = (from t in baseInterfaces
where t.IsNotPublic
select t).Count() > 0;
if (hasNonPublicInterfaces)
{
throw new ArgumentException("The proxy factory cannot generate proxies from non-public interfaces.",
"baseInterfaces");
}
#region Determine which interfaces need to be implemented
Type actualBaseType = baseType.IsInterface ? typeof(object) : baseType;
var interfaces = new HashSet <Type>(baseInterfaces);
// Move the base type into the list of interfaces
// if the user mistakenly entered
// an interface type as the base type
if (baseType.IsInterface)
{
interfaces.Add(baseType);
}
if (InterfaceExtractor != null)
{
// Get the interfaces for the base type
InterfaceExtractor.GetInterfaces(actualBaseType, interfaces);
Type[] targetList = interfaces.ToArray();
// Extract the inherited interfaces
foreach (Type type in targetList)
{
InterfaceExtractor.GetInterfaces(type, interfaces);
}
}
#endregion
#region Generate the assembly
string assemblyName = "LinFu.Proxy";
AssemblyDefinition assembly = AssemblyFactory.DefineAssembly(assemblyName, AssemblyKind.Dll);
ModuleDefinition mainModule = assembly.MainModule;
TypeReference importedBaseType = mainModule.Import(actualBaseType);
TypeAttributes attributes = TypeAttributes.AutoClass | TypeAttributes.Class |
TypeAttributes.Public | TypeAttributes.BeforeFieldInit;
#endregion
#region Initialize the proxy type
string guid = Guid.NewGuid().ToString().Replace("-", "");
string typeName = string.Format("{0}Proxy-{1}", baseType.Name, guid);
string namespaceName = "LinFu.Proxy";
TypeDefinition proxyType = mainModule.DefineClass(typeName, namespaceName,
attributes, importedBaseType);
proxyType.AddDefaultConstructor();
#endregion
if (ProxyBuilder == null)
{
throw new NullReferenceException("The 'ProxyBuilder' property cannot be null");
}
// Add the list of interfaces to the target type
foreach (Type interfaceType in interfaces)
{
if (!interfaceType.IsInterface)
{
continue;
}
TypeReference currentType = mainModule.Import(interfaceType);
proxyType.Interfaces.Add(currentType);
}
// Hand it off to the builder for construction
ProxyBuilder.Construct(actualBaseType, interfaces, mainModule, proxyType);
// Verify the assembly, if possible
if (Verifier != null)
{
Verifier.Verify(assembly);
}
#region Compile the results
Assembly compiledAssembly = assembly.ToAssembly();
IEnumerable <Type> types = null;
try
{
types = compiledAssembly.GetTypes();
}
catch (ReflectionTypeLoadException ex)
{
types = ex.Types;
}
Type result = (from t in types
where t != null && t.IsClass
select t).FirstOrDefault();
#endregion
// Cache the result
if (Cache != null)
{
Cache.Store(result, baseType, originalInterfaces);
}
return(result);
}
