internal async Task <object> CallMethodAsync(RpcCall call)
{
var response = await _connection.SendMessageAsync(call);
if (response.Status != RequestStatus.Success)
{
throw new InvalidOperationException(
$"The remote procedure call to '{call.MethodName}' failed ({response.Status})");
}
if (response.Response is RpcReturn returnMessage)
{
if (!returnMessage.IsSuccessful)
{
throw new InvalidOperationException($"The remote procedure call to '{call.MethodName}' failed " +
$"({returnMessage.Error ?? "no details"})");
}
return(returnMessage.Value);
}
throw new InvalidOperationException(
$"The remote procedure call to '{call.MethodName}' failed (invalid response message)");
}
public static async Task <RpcReturn> InvokeMethodAsync(object rpcTarget, RpcConnection connection, RpcCall call)
{
// Current limitations
// - no support for overloaded methods
if (string.IsNullOrEmpty(call.MethodName))
{
return(RpcReturn.Faulted("No method name specified"));
}
var method = rpcTarget.GetType().GetMethod(call.MethodName);
if (method == null)
{
return(RpcReturn.Faulted(
$"No method with name '{call.MethodName}' could be found (attempted call: {call.ToString()})"));
}
// Parameter check
var formalParams = method.GetParameters();
var actualParams = call.Parameters.ToList();
if (call.Parameters.Length > formalParams.Length)
{
return(RpcReturn.Faulted("Parameter mismatch: Too many arguments specified " +
$"(attempted call: {call.ToString()}, local method: {method.ToDescriptionString()})"));
}
for (var i = 0; i < formalParams.Length; i++)
{
var formalParam = formalParams[i];
var actualParam = (actualParams.Count <= i) ? null : actualParams[i];
if (actualParam == null)
{
actualParams.Add(actualParam = Type.Missing);
}
else if (!formalParam.ParameterType.IsAssignableFrom(actualParam.GetType()))
{
return(RpcReturn.Faulted("Parameter mismatch: Got value of type " +
$"'{actualParam.GetType().FullName}' for parameter " +
$"'{formalParam.ParameterType.FullName} {formalParam.Name}' " +
$"(attempted call: {call.ToString()}, local method: {method.ToDescriptionString()})"));
}
if (formalParam.CustomAttributes.Any(a => a.AttributeType == typeof(RpcCallerAttribute)) &&
formalParam.ParameterType.IsAssignableFrom(typeof(RpcConnection)))
{
// Insert RpcProxy into [RpcCaller]-annotated parameter
actualParams[i] = connection;
}
else if (actualParam == Type.Missing && !formalParam.IsOptional)
{
return(RpcReturn.Faulted("Parameter mismatch: Not enough parameters specified " +
$"(attempted call: {call.ToString()}, local method: {method.ToDescriptionString()})"));
}
}
// Invoke method
try
{
var returnValue = method.Invoke(rpcTarget, actualParams.ToArray());
if (returnValue is Task)
{
await(Task) returnValue;
if (returnValue.GetType().GetGenericTypeDefinition() == typeof(Task <>) &&
returnValue.GetType().GetGenericArguments()[0].Name != "VoidTaskResult")
{
returnValue = ((dynamic)returnValue).Result;
}
else
{
returnValue = null;
}
}
return(RpcReturn.Success(returnValue));
}
catch (Exception e)
{
return(RpcReturn.Faulted($"Local execution failed (exception: {e.ToString()})"));
}
}
internal async Task <object[]> CallMethodAsync(RpcCall call)
{
var results = await Task.WhenAll(_proxies.Select(proxy => proxy.CallMethodAsync(call)));
return(results);
}
