private void InitMethodsFromType(Type type, bool isAttributedMethodsOnly)
{
foreach (var methodInfo in type.GetMethods())
{
RpcMethodAttribute methodAttr = GetMethodAttribute(methodInfo);
if (methodAttr != null || !isAttributedMethodsOnly)
{
RpcMethodDescriptor method = new RpcMethodDescriptor(methodInfo, methodAttr, mName);
if (mMethods.ContainsKey(method.Name))
{
mMethods[method.Name].Merge(method);
}
else
{
mMethods.Add(method.Name, method);
}
}
}
//for classes checking the public methods is enough, but for an interface we must check the other
//interfaces implemented too
if (type.IsInterface)
{
foreach (var interfaceType in type.GetInterfaces())
{
InitMethodsFromType(interfaceType, isAttributedMethodsOnly);
}
}
}
public void InvokeMethod(object service, string methodName, List <RpcMessage.Parameter> parameters, RpcMessage resultMessage)
{
RpcMethodDescriptor method = GetMethod(methodName);
if (method != null)
{
method.Invoke(service, parameters, resultMessage);
}
else
{
//return an error message to the client if it is expecting a result, otherwise we fail silently
if (resultMessage != null)
{
resultMessage.ResultMessage.IsFailed = true;
resultMessage.ResultMessage.ErrorMessage = String.Format("Unknown method '{1}' in service '{0}'",
Name, methodName);
}
}
}
public void Merge(RpcMethodDescriptor method)
{
Debug.Assert(method.mName == mName && method.mServiceName == mServiceName);
if (mReturnType != null && method.mReturnType != null && mReturnType != method.mReturnType)
{
throw new ArgumentException(
String.Format("Invalid declarations for method '{0}', the return types are not consistent.", mName));
}
if (mParameterTypes != null && method.mParameterTypes != null &&
!mParameterTypes.SequenceEqual(method.mParameterTypes))
{
throw new ArgumentException(
String.Format("Invalid declarations for method '{0}', the parameter types are not consistent.", mName));
}
if (mSyncMethodInfo != null && method.mSyncMethodInfo != null)
{
throw new ArgumentException(
String.Format("Invalid declarations for method '{0}', more than one synchronous call found.", mName));
}
if (mAsyncBeginMethodInfo != null && method.mAsyncBeginMethodInfo != null)
{
throw new ArgumentException(
String.Format("Invalid declarations for method '{0}', more than one begin async call found.", mName));
}
if (mAsyncEndMethodInfo != null && method.mAsyncEndMethodInfo != null)
{
throw new ArgumentException(
String.Format("Invalid declarations for method '{0}', more than one end async call found.", mName));
}
mReturnType = mReturnType ?? method.mReturnType;
mParameterTypes = mParameterTypes ?? method.mParameterTypes;
mSyncMethodInfo = mSyncMethodInfo ?? method.mSyncMethodInfo;
mAsyncBeginMethodInfo = mAsyncBeginMethodInfo ?? method.mAsyncBeginMethodInfo;
mAsyncEndMethodInfo = mAsyncEndMethodInfo ?? method.mAsyncEndMethodInfo;
}
public static Delegate BuildThunk(RpcMethodDescriptor method)
{
var dynMethod = new DynamicMethod("ServiceThunk", typeof(void),
new[] { typeof(object), typeof(IList <RpcMessage.Parameter>), typeof(RpcMessage.Result) },
typeof(ServiceThunkBuilder).Module);
ILGenerator ilGen = dynMethod.GetILGenerator();
//verify number of parameters
ilGen.Emit(OpCodes.Ldarg_1); //push IList<RpcMessage.Parameter>
ilGen.Emit(OpCodes.Ldc_I4, method.ParameterTypes.Length); //push number of expected parameters
ilGen.Emit(OpCodes.Ldarg_2); //push RpcMessage.Result
ilGen.Emit(OpCodes.Call, typeof(ServiceThunkHelpers).GetMethod("VerifyParameterCount"));
Label paramVerifyLabel = ilGen.DefineLabel();
ilGen.Emit(OpCodes.Brtrue, paramVerifyLabel);
ilGen.Emit(OpCodes.Ret);
ilGen.MarkLabel(paramVerifyLabel);
//load the RpcMessage.Result to the stack, for the call to set the result
if (method.ReturnType != typeof(void))
{
ilGen.Emit(OpCodes.Ldarg_2);
}
//load the service instance to the stack, for the call to the service instance
ilGen.Emit(OpCodes.Ldarg_0);
//load the service call parameters to the stack, if they are the wrong type then an error is stored
//in the result message and we return early
MethodInfo paramIndexer = typeof(IList <RpcMessage.Parameter>).GetProperty("Item").GetGetMethod();
for (int i = 0; i < method.ParameterTypes.Length; ++i)
{
Type paramType = method.ParameterTypes[i];
//get RpcMessage.Parameter by calling IList indexer
ilGen.Emit(OpCodes.Ldarg_1);
ilGen.Emit(OpCodes.Ldc_I4, i);
ilGen.Emit(OpCodes.Callvirt, paramIndexer);
ilGen.Emit(OpCodes.Ldarg_2); //push RpcMessage.Result
LocalBuilder paramLocal = ilGen.DeclareLocal(paramType);
ilGen.Emit(OpCodes.Ldloca, (short)paramLocal.LocalIndex); //push ref to result local
EmitParameter(ilGen, paramType);
Label continueLabel = ilGen.DefineLabel();
ilGen.Emit(OpCodes.Brtrue, continueLabel); //success, continue with next parameter
//failed, stack cleanup
for (int j = 0; j < i; ++j)
{
ilGen.Emit(OpCodes.Pop); //pop previous parameters
}
ilGen.Emit(OpCodes.Pop); //pop service instance
if (method.ReturnType != typeof(void))
{
ilGen.Emit(OpCodes.Pop); //pop RpcMessage.Result
}
ilGen.Emit(OpCodes.Ret);
ilGen.MarkLabel(continueLabel);
//now push the actual parameter ready for the actual call
ilGen.Emit(OpCodes.Ldloc, paramLocal.LocalIndex);
}
//now call the actual service instance method
ilGen.Emit(OpCodes.Callvirt, method.SyncCallMethod);
//get the return value, storing it in the result message. We know the type, no need for any error
//checking
if (method.ReturnType != typeof(void))
{
//check if result is null
ilGen.Emit(OpCodes.Ldarg_2);
ilGen.Emit(OpCodes.Ldnull);
Label nullReturnLabel = ilGen.DefineLabel();
ilGen.Emit(OpCodes.Beq, nullReturnLabel);
//convert return value to a message and store it in the result message
ThunkHelpers.EmitParameterToMessage(ilGen, method.ReturnType);
ilGen.Emit(OpCodes.Call, typeof(RpcMessage.Result).GetProperty("CallResult").GetSetMethod());
ilGen.Emit(OpCodes.Ret);
ilGen.MarkLabel(nullReturnLabel);
ilGen.Emit(OpCodes.Pop); //pop return value
ilGen.Emit(OpCodes.Pop); //pop result message
}
ilGen.Emit(OpCodes.Ret);
return(dynMethod.CreateDelegate(typeof(RpcServer.MethodDelegate)));
}
