public bool CanCreateInvocationDelegateFor(MethodInfo serviceMethod)
{
return
serviceMethod.ReturnType == typeof(Task) && serviceMethod.IsAsyncCallable() && !serviceMethod.IsStatic &&
(serviceMethod.NumberOfParameters() == 1 ||
(serviceMethod.NumberOfParameters() == 2 && serviceMethod.TypeOfSecondParameter() == typeof(CancellationToken)));
}
public Delegate CreateInvocationDelegate(MethodInfo serviceMethod, ServiceMethodInvocationContext context)
{
if (!this.CanCreateInvocationDelegateFor(serviceMethod))
{
throw new ArgumentException(
"Method " + serviceMethod + " should have a single parameter, be marked as async or return a Task, and should not be static",
"serviceMethod");
}
ParameterExpression request = Expression.Parameter(typeof(object), "request");
ParameterExpression cancel = Expression.Parameter(typeof(CancellationToken), "cancel");
Action<object, CancellationToken> lambda = Expression.Lambda<Action<object, CancellationToken>>(
serviceMethod.NumberOfParameters() == 1?
AsyncServiceMethodCall.CreateCallExpression(serviceMethod, context, request):
AsyncServiceMethodCall.CreateCallExpression(serviceMethod, context, request, cancel),
request,
cancel).Compile();
return new Func<object, CancellationToken, Task<object>>((r, c) =>
{
lambda(r, c);
return TaskEx.FromResult(context.DefaultResponse);
});
}
private static bool IsSingleParameterWithOptionalCancellationToken(MethodInfo method)
{
return
method.NumberOfParameters() == 1 ||
(method.NumberOfParameters() == 2 && method.TypeOfSecondParameter() == typeof(CancellationToken));
}
public bool CanCreateInvocationDelegateFor(MethodInfo serviceMethod)
{
return !serviceMethod.IsAsyncCallable() && !serviceMethod.IsStatic && serviceMethod.NumberOfParameters() == 1;
}
