public static object HandleInvocation(
IProxy target, InvocationFactory invocationFactory,
Type[] genericArguments, object[] parameterValues, object returnValue)
{
var invocation = invocationFactory.CreateInvocation(target, genericArguments, parameterValues, returnValue);
var invocationInterceptor = target.InvocationInterceptor;
invocationInterceptor.OnInvocation(invocation);
return(invocation.returnValue);
}
MethodInfo[] GetBaseMethods(Type interfaceType)
{
if (interfaceType.IsDelegateType())
{
return new[] { interfaceType.GetMethod(DelegateInvokeMethodName) }
}
;
var interfaceMethods = GetInterfaceMethods(interfaceType);
var objectMethods = GetVirtualMethodsDeclaredInObject();
return(interfaceMethods.Concat(objectMethods).ToArray());
}
ConstructorInfo GetBaseConstructor(Type baseType)
{
return(baseType.GetConstructor(
BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance,
null,
new[] { typeof(object), typeof(IInvocationInterceptor) },
null));
}
MethodInfo[] GetInterfaceMethods(Type interfaceType)
{
var interfaceMethods = new List <MethodInfo>(interfaceType.GetMethods());
foreach (Type subInterfaceType in interfaceType.GetInterfaces())
{
interfaceMethods.AddRange(GetInterfaceMethods(subInterfaceType));
}
return(interfaceMethods.Distinct().ToArray());
}
MethodInfo[] GetVirtualMethodsDeclaredInObject()
{
return(typeof(object).GetMethods().Where(method => method.IsVirtual).ToArray());
}
FieldInfo[] ImplementClassConstructor(TypeBuilder typeBuilder, MethodInfo[] baseMethods)
{
var constructorBuilder = typeBuilder.DefineConstructor(MethodAttributes.Static, CallingConventions.Standard, null);
var ilGenerator = constructorBuilder.GetILGenerator();
var invocationFactoryFields = new FieldInfo[baseMethods.Length];
for (int i = 0; i < baseMethods.Length; i++)
{
var baseMethod = baseMethods[i];
var declaringType = baseMethod.DeclaringType;
var invocationFactoryField = ImplementInvocationFactoriesField(typeBuilder, i);
if (baseMethod.IsGenericMethodDefinition)
{
string methodTextRepresentation = InvocationFactory.GetTextRepresentationForMethod(baseMethod);
ilGenerator.Emit(OpCodes.Ldtoken, declaringType);
ilGenerator.Emit(OpCodes.Call, Methods.GetTypeFromHandle);
ilGenerator.Emit(OpCodes.Ldstr, methodTextRepresentation);
ilGenerator.Emit(OpCodes.Call, Methods.GetInvocationFactoryForMethodTextRepresentation);
ilGenerator.Emit(OpCodes.Stsfld, invocationFactoryField);
}
else
{
ilGenerator.Emit(OpCodes.Ldtoken, baseMethod);
ilGenerator.Emit(OpCodes.Ldtoken, declaringType);
ilGenerator.Emit(OpCodes.Call, Methods.GetMethodFromHandle);
ilGenerator.Emit(OpCodes.Call, Methods.GetInvocationFactoryForMethod);
ilGenerator.Emit(OpCodes.Stsfld, invocationFactoryField);
}
invocationFactoryFields[i] = invocationFactoryField;
}
ilGenerator.Emit(OpCodes.Ret);
return(invocationFactoryFields);
}
FieldInfo ImplementInvocationFactoriesField(TypeBuilder typeBuilder, int fieldIndex)
{
string fieldName = string.Format(InvocationFactoryFieldNameFormat, fieldIndex);
var fieldType = typeof(InvocationFactory);
var fieldAttributes = FieldAttributes.Private | FieldAttributes.Static | FieldAttributes.InitOnly;
return(typeBuilder.DefineField(fieldName, fieldType, fieldAttributes));
}
void ImplementConstructor(TypeBuilder typeBuilder, ConstructorInfo baseConstructor)
{
var methodAttributes = MethodAttributes.Public;
var callingConvention = baseConstructor.CallingConvention;
var parameterTypes = (from parameter in baseConstructor.GetParameters() select parameter.ParameterType).ToList();
var constructorBuilder = typeBuilder.DefineConstructor(methodAttributes, callingConvention, parameterTypes.ToArray());
var ilGenerator = constructorBuilder.GetILGenerator();
ilGenerator.Emit(OpCodes.Ldarg_0);
for (int i = 0; i < parameterTypes.Count; i++)
{
ilGenerator.Emit(OpCodes.Ldarg, i + 1);
}
ilGenerator.Emit(OpCodes.Call, baseConstructor);
ilGenerator.Emit(OpCodes.Ret);
}
void ImplementMethods(TypeBuilder typeBuilder, MethodInfo[] baseMethods, FieldInfo[] invocationFactoryFields)
{
for (int i = 0; i < baseMethods.Length; i++)
{
var baseMethod = baseMethods[i];
var invocationFactoryField = invocationFactoryFields[i];
ImplementMethod(typeBuilder, baseMethod, invocationFactoryField);
}
}
void ImplementMethod(TypeBuilder typeBuilder, MethodInfo baseMethod, FieldInfo invocationFactoryField)
{
string methodName;
var methodAttributes = MethodAttributes.HideBySig | MethodAttributes.Virtual | MethodAttributes.Final | MethodAttributes.NewSlot;
bool isMethodOverride;
if (baseMethod.DeclaringType.IsDelegateType())
{
methodName = DelegateInvokeMethodName;
methodAttributes |= MethodAttributes.Public;
isMethodOverride = false;
}
else
{
methodName = GetProxyMethodName(baseMethod);
methodAttributes |= MethodAttributes.Private;
isMethodOverride = true;
}
var methodBuilder = typeBuilder.DefineMethod(methodName, methodAttributes);
DefineMethodSignature(methodBuilder, baseMethod);
EmitMethodBody(methodBuilder, baseMethod, invocationFactoryField);
if (isMethodOverride)
{
typeBuilder.DefineMethodOverride(methodBuilder, baseMethod);
}
}
void DefineMethodSignature(MethodBuilder methodBuilder, MethodInfo baseMethod)
{
if (baseMethod.IsGenericMethodDefinition)
{
var baseGenericArguments = baseMethod.GetGenericArguments();
var genericParameterBuilders = methodBuilder.DefineGenericParameters(baseGenericArguments.Select(type => type.Name).ToArray());
for (int i = 0; i < genericParameterBuilders.Length; i++)
{
var baseGenericArgument = baseGenericArguments[i];
var genericParameterBuilder = genericParameterBuilders[i];
foreach (var baseTypeConstraint in baseGenericArgument.GetGenericParameterConstraints())
{
if (baseTypeConstraint.IsInterface)
{
genericParameterBuilder.SetInterfaceConstraints(baseTypeConstraint);
}
else
{
genericParameterBuilder.SetBaseTypeConstraint(baseTypeConstraint);
}
}
}
}
var baseMethodParameters = baseMethod.GetParameters();
methodBuilder.SetParameters(baseMethodParameters.Select(parameter => parameter.ParameterType).ToArray());
methodBuilder.SetReturnType(baseMethod.ReturnType);
for (int i = 0; i < baseMethodParameters.Length; i++)
{
var parameter = baseMethodParameters[i];
methodBuilder.DefineParameter(i, parameter.Attributes, parameter.Name);
}
}
void EmitMethodBody(MethodBuilder methodBuilder, MethodInfo baseMethod, FieldInfo invocationFactoryField)
{
var ilGenerator = methodBuilder.GetILGenerator();
ilGenerator.DeclareLocal(typeof(InvocationFactory));
ilGenerator.DeclareLocal(typeof(Type[]));
ilGenerator.DeclareLocal(typeof(object[]));
if (baseMethod.ReturnType != typeof(void))
{
ilGenerator.DeclareLocal(baseMethod.ReturnType);
}
EmitLoadInvocationFactoriesField(ilGenerator, invocationFactoryField);
EmitBuildGenericArgumentsArray(ilGenerator, baseMethod);
EmitBuildParameterValuesArray(ilGenerator, baseMethod);
EmitCallHandleInvocation(ilGenerator, baseMethod);
EmitReflectOutgoingParameterValues(ilGenerator, baseMethod);
ilGenerator.Emit(OpCodes.Ret);
}
void EmitLoadInvocationFactoriesField(ILGenerator ilGenerator, FieldInfo invocationFactoriesField)
{
ilGenerator.Emit(OpCodes.Ldsfld, invocationFactoriesField);
ilGenerator.Emit(OpCodes.Stloc_0);
}
void EmitBuildGenericArgumentsArray(ILGenerator ilGenerator, MethodInfo baseMethod)
{
if (!baseMethod.IsGenericMethodDefinition)
{
ilGenerator.Emit(OpCodes.Ldnull);
ilGenerator.Emit(OpCodes.Stloc_1);
return;
}
var genericMethodArguments = baseMethod.GetGenericArguments();
ilGenerator.Emit(OpCodes.Ldc_I4, genericMethodArguments.Length);
ilGenerator.Emit(OpCodes.Newarr, typeof(Type));
ilGenerator.Emit(OpCodes.Stloc_1);
for (int i = 0; i < genericMethodArguments.Length; i++)
{
ilGenerator.Emit(OpCodes.Ldloc_1);
ilGenerator.Emit(OpCodes.Ldc_I4, i);
ilGenerator.Emit(OpCodes.Ldtoken, genericMethodArguments[i]);
ilGenerator.Emit(OpCodes.Call, Methods.GetTypeFromHandle);
ilGenerator.Emit(OpCodes.Stelem_Ref);
}
}
void EmitBuildParameterValuesArray(ILGenerator ilGenerator, MethodInfo baseMethod)
{
var baseMethodParameters = baseMethod.GetParameters();
ilGenerator.Emit(OpCodes.Ldc_I4, baseMethodParameters.Length);
ilGenerator.Emit(OpCodes.Newarr, typeof(object));
ilGenerator.Emit(OpCodes.Stloc_2);
for (int i = 0; i < baseMethodParameters.Length; i++)
{
var parameter = baseMethodParameters[i];
var parameterType = parameter.ParameterType;
ilGenerator.Emit(OpCodes.Ldloc_2);
ilGenerator.Emit(OpCodes.Ldc_I4, i);
ilGenerator.Emit(OpCodes.Ldarg, i + 1);
if (parameterType.IsByRef)
{
parameterType = parameterType.GetElementType();
ilGenerator.EmitLoadIndirect(parameterType);
}
EmitBoxValue(ilGenerator, parameterType);
ilGenerator.Emit(OpCodes.Stelem_Ref);
}
}
void EmitLoadDefaultReturnValue(ILGenerator ilGenerator, Type returnType)
{
ilGenerator.Emit(OpCodes.Ldloca_S, 3);
ilGenerator.Emit(OpCodes.Initobj, returnType);
ilGenerator.Emit(OpCodes.Ldloc_3);
EmitBoxValue(ilGenerator, returnType);
}
void EmitBoxValue(ILGenerator ilGenerator, Type parameterType)
{
if (parameterType.IsValueType || parameterType.IsGenericParameter)
{
ilGenerator.Emit(OpCodes.Box, parameterType);
}
}
void EmitCallHandleInvocation(ILGenerator ilGenerator, MethodInfo baseMethod)
{
ilGenerator.Emit(OpCodes.Ldarg_0);
ilGenerator.Emit(OpCodes.Ldloc_0);
ilGenerator.Emit(OpCodes.Ldloc_1);
ilGenerator.Emit(OpCodes.Ldloc_2);
if (baseMethod.ReturnType == typeof(void))
{
ilGenerator.Emit(OpCodes.Ldnull);
ilGenerator.Emit(OpCodes.Call, Methods.HandleInvocation);
ilGenerator.Emit(OpCodes.Pop);
}
else
{
EmitLoadDefaultReturnValue(ilGenerator, baseMethod.ReturnType);
ilGenerator.Emit(OpCodes.Call, Methods.HandleInvocation);
ilGenerator.Emit(OpCodes.Unbox_Any, baseMethod.ReturnType);
}
}
void EmitReflectOutgoingParameterValues(ILGenerator ilGenerator, MethodInfo baseMethod)
{
var baseMethodParameters = baseMethod.GetParameters();
for (int i = 0; i < baseMethodParameters.Length; i++)
{
var parameter = baseMethodParameters[i];
var parameterType = parameter.ParameterType;
if (!parameterType.IsByRef)
{
continue;
}
parameterType = parameterType.GetElementType();
ilGenerator.Emit(OpCodes.Ldarg, i + 1);
ilGenerator.Emit(OpCodes.Ldloc_2);
ilGenerator.Emit(OpCodes.Ldc_I4, i);
ilGenerator.Emit(OpCodes.Ldelem_Ref);
ilGenerator.Emit(OpCodes.Unbox_Any, parameterType);
ilGenerator.EmitStoreIndirect(parameterType);
}
}
