/// <summary>
/// Implements the interface for the proxy type.
/// </summary>
/// <param name="context">The current builder context.</param>
/// <param name="interfaceType">The interface type.</param>
private void ImplementInterfaces(ProxyBuilderContext context, Type interfaceType)
{
this.ImplementInterface(context, interfaceType);
var interfaces = interfaceType.GetInterfaces();
if (interfaces != null)
{
foreach (var iface in interfaces)
{
this.ImplementInterfaces(context, iface);
}
}
}
/// <summary>
/// Emits the IL for the <see cref="IProxiedObject"/> interfaces 'ProxiedObject' property.
/// </summary>
/// <param name="context">The proxy builder context.</param>
private void EmitIProxiedObjectInterface(ProxyBuilderContext context)
{
var propertyProxiedObject = context
.TypeBuilder
.NewProperty <object>("ProxiedObject")
.Getter(m => m
.Public()
.Virtual()
.HideBySig()
.NewSlot()
.Body()
.LdArg0()
.LdFld(context.BaseObjectField)
.Ret());
}
/// <summary>
/// Adds a constructor to the proxy type.
/// </summary>
/// <param name="context">The current builder context.</param>
private void EmitConstructor(ProxyBuilderContext context)
{
// Build Constructor.
var constructorBuilder = context
.TypeBuilder
.NewConstructor()
.Public()
.HideBySig()
.SpecialName()
.RTSpecialName()
.Param(context.BaseType, "target")
.Body()
.LdArg0()
.LdArg1()
.StFld(context.BaseObjectField)
.Ret();
}
/// <summary>
/// Emits the IL to call a proxy method implementation.
/// </summary>
/// <param name="context">The proxy builder context.</param>
/// <param name="methodIL">The methods <see cref="ILGenerator"/>.</param>
/// <param name="methodInfo">The method to implement.</param>
/// <param name="methodArgTypes">The methods arguments.</param>
private void EmitCallToProxyImplementation(
ProxyBuilderContext context,
IEmitter methodIL,
MethodInfo methodInfo,
Type[] methodArgTypes)
{
MethodInfo invokeMethod = typeof(IProxy).GetMethod("Invoke", new Type[] { typeof(MethodInfo), typeof(object[]) });
MethodInfo invokeAsyncMethod = typeof(IProxy).GetMethod("InvokeAsync", new Type[] { typeof(MethodInfo), typeof(object[]) });
MethodInfo makeGenericMethod = typeof(MethodInfo).GetMethod("MakeGenericMethod", new Type[] { typeof(Type[]) });
methodIL
.DeclareLocal(typeof(Type[]), out ILocal localGenArgTypes)
.DeclareLocal(typeof(object[]), out ILocal localArguments)
.DeclareLocal(typeof(MethodInfo), out ILocal localMethodInfo);
if (methodInfo.IsGenericMethodDefinition == true)
{
Type[] genArgTypes = methodInfo.GetGenericArguments();
methodIL.Array(
typeof(Type),
localGenArgTypes,
genArgTypes.Length,
(index) =>
{
methodIL.EmitTypeOf(genArgTypes[index]);
});
}
methodIL.Nop();
// Build the arguments array.
methodIL.Array(
typeof(object),
localArguments,
methodArgTypes.Length,
(index) =>
{
methodIL
.LdArg(index + 1)
.Conv(methodArgTypes[index], typeof(object), false);
});
methodIL.Nop();
if (methodInfo.IsGenericMethodDefinition == true)
{
// Get the MethodInfo of the method being called on the proxy.
methodIL
.EmitMethod(methodInfo, methodInfo.DeclaringType)
.LdLoc(localGenArgTypes)
.CallVirt(makeGenericMethod)
.StLoc(localMethodInfo);
}
else
{
// Get the MethodInfo of the method being called on the proxy.
methodIL
.EmitMethod(methodInfo, methodInfo.DeclaringType)
.StLoc(localMethodInfo);
}
methodIL.Nop();
#if ASYNCCALL
if (methodInfo.ReturnType == typeof(Task) ||
(methodInfo.ReturnType.IsGenericType == true && methodInfo.ReturnType.GetGenericTypeDefinition() == typeof(Task <>)))
{
var actualReturnType = methodInfo.ReturnType.GetGenericArguments()[0];
var asyncTaskExecutorType = typeof(AsyncTaskExecutor <>).MakeGenericType(actualReturnType);
var asyncTaskExecutorTypeCtor = asyncTaskExecutorType.GetConstructor(new[] { typeof(IProxy), typeof(MethodInfo), typeof(object[]) });
var asyncTaskExecutorExecuteAsync = asyncTaskExecutorType.GetMethod("ExecuteAsync");
methodIL
.DeclareLocal(asyncTaskExecutorType, out ILocal localAsyncProxy)
.DeclareLocal(typeof(Task <>).MakeGenericType(actualReturnType), out ILocal localReturn)
/* class
*/
.LdArg0()
.LdFld(context.BaseObjectField)
.LdLoc(localMethodInfo)
.LdLoc(localArguments)
.Newobj(asyncTaskExecutorTypeCtor)
.StLoc(localAsyncProxy)
.LdLoc(localAsyncProxy)
.Call(asyncTaskExecutorExecuteAsync)
.StLoc(localReturn)
/* Struct
* .LdLocAS(localAsyncProxy)
* .LdArg0()
* .LdFld(context.BaseObjectField)
* .LdLoc(localMethodInfo)
* .LdLoc(localArguments)
* .Call(asyncTaskExecutorTypeCtor)
* .LdLocAS(localAsyncProxy)
* .Call(asyncTaskExecutorExecuteAsync)
* .StLoc(localReturn)
*/
.LdLoc(localReturn);
}
else
#endif
{
// Call the proxy implementations invoke method.
methodIL
.LdArg0()
.LdFld(context.BaseObjectField)
.LdLoc(localMethodInfo)
.LdLoc(localArguments)
.CallVirt(invokeMethod);
// Does the method have a return type?
if (methodInfo.ReturnType != typeof(void))
{
methodIL.Conv(typeof(object), methodInfo.ReturnType, false);
}
else
{
// Remove the returned value
methodIL.Pop();
}
var parms = methodInfo.GetParameters();
if (parms.Any() == true)
{
int index = 0;
foreach (var parm in parms)
{
if (parm.IsOut == true)
{
methodIL
.LdArg(parm.Position + 1)
.LdLoc(localArguments)
.LdcI4(index)
.LdElemRef()
.StIndRef()
.Nop();
}
index++;
}
}
}
methodIL.Ret();
}
/// <summary>
/// Implements the interface for the proxy type.
/// </summary>
/// <param name="context">The current builder context.</param>
/// <param name="interfaceType">The interface type.</param>
private void ImplementInterface(ProxyBuilderContext context, Type interfaceType)
{
var propertyMethods = new Dictionary <string, IMethodBuilder>();
foreach (var memberInfo in interfaceType.GetMembers())
{
if (memberInfo.MemberType == MemberTypes.Method)
{
MethodInfo methodInfo = (MethodInfo)memberInfo;
Type[] methodArgs = methodInfo
.GetParameters()
.Select(p => p.ParameterType)
.ToArray();
Type[] genericArguments = null;
var methodBuilder = context
.TypeBuilder
.NewMethod(methodInfo.Name)
.MethodAttributes(MethodAttributes.Public | MethodAttributes.Virtual)
.Params(methodArgs)
.Returns(methodInfo.ReturnType);
if (methodInfo.ContainsGenericParameters == true)
{
genericArguments = methodInfo.GetGenericArguments();
foreach (var arg in genericArguments)
{
methodBuilder.NewGenericParameter(arg.Name)
.Attributes = arg.GenericParameterAttributes;
}
}
var methodIL = methodBuilder.Body();
this.EmitCallToProxyImplementation(context, methodIL, methodInfo, methodArgs);
if (methodInfo.IsProperty() == true)
{
propertyMethods.Add(methodInfo.Name, methodBuilder);
}
}
else if (memberInfo.MemberType == MemberTypes.Property)
{
var propertyBuilder = context
.TypeBuilder
.NewProperty(memberInfo.Name, ((PropertyInfo)memberInfo).PropertyType)
.Attributes(PropertyAttributes.SpecialName);
if (propertyMethods.TryGetValue(
memberInfo.PropertyGetName(),
out IMethodBuilder getMethod) == true)
{
propertyBuilder.GetMethod = getMethod;
}
if (propertyMethods.TryGetValue(
memberInfo.PropertySetName(),
out IMethodBuilder setMethod) == true)
{
propertyBuilder.SetMethod = setMethod;
}
}
}
}
/// <summary>
/// Generate the proxy type.
/// </summary>
/// <param name="proxyType">The interface the proxy type must implement.</param>
/// <param name="proxyTargetType">The target type to receive the proxied calls.</param>
/// <param name="proxyBaseType">The base type.</param>
/// <param name="action">An action to allow build type injection.</param>
/// <param name="proxyOptions">The proxy generation options.</param>
/// <returns>A <see cref="Type"/> representing the proxy type.</returns>
private Type GenerateProxyType(
Type proxyType,
Type proxyTargetType,
Type proxyBaseType,
Action <IProxyBuilderContext> action,
ProxyOptions proxyOptions = null)
{
if (proxyBaseType?.IsInterface == true)
{
throw new ArgumentException("Argument cannot be an interface", "proxyBaseType");
}
if (proxyType.IsInterface == false &&
proxyType != proxyBaseType)
{
throw new ArgumentException("Argument is not an interface", "proxyType");
}
if (typeof(IProxy).IsAssignableFrom(proxyTargetType) == false)
{
throw new ArgumentException("Argument does not implement <IProxy>", "proxiedType");
}
var typeName = proxyOptions?.TypeName ?? TypeName(proxyType, proxyTargetType);
var typeBuilder = TypeFactory
.Default
.NewType(typeName)
.Public()
.Implements(typeof(IProxiedObject));
if (proxyType.IsInterface == true)
{
typeBuilder.Implements(proxyType);
}
if (proxyBaseType != null)
{
typeBuilder.InheritsFrom(proxyBaseType);
}
var targetField = typeBuilder
.NewField <IProxy>("target")
.Private();
var context = new ProxyBuilderContext(
typeBuilder,
proxyType,
proxyTargetType,
targetField,
null);
action?.Invoke(context);
if (proxyType.IsInterface == true)
{
this.ImplementInterfaces(context, context.NewType);
}
this.EmitConstructor(context);
this.EmitIProxiedObjectInterface(context);
return(context
.TypeBuilder
.CreateType());
}
