private async Task <string> HandleRequestAsync(JsonRpcRequest jsonRpcRequest, CancellationToken cancellationToken)
{
var methodName = jsonRpcRequest.Method;
if (!MetadataProvider.TryGetMetadata(methodName, out var prodecureMetadata))
{
return(Error(JsonRpcErrorCodes.MethodNotFound, $"'{methodName}' method not found.", jsonRpcRequest.Id));
}
try
{
var methodParameters = prodecureMetadata.Parameters;
var parameters = new List <object>();
if (jsonRpcRequest.Parameters is JArray jarr)
{
var count = methodParameters.Count < jarr.Count ? methodParameters.Count : jarr.Count;
for (int i = 0; i < count; i++)
{
parameters.Add(jarr[i].ToObject(methodParameters[i].type, DefaultSerializer));
}
}
else if (jsonRpcRequest.Parameters is JObject jobj)
{
for (int i = 0; i < methodParameters.Count; i++)
{
var param = methodParameters[i];
if (!jobj.ContainsKey(param.name))
{
return(Error(JsonRpcErrorCodes.InvalidParams,
$"A value for the '{param.name}' is missing.", jsonRpcRequest.Id));
}
parameters.Add(jobj[param.name].ToObject(param.type, DefaultSerializer));
}
}
// Special case: if there is a missing parameter and the procedure is expecting a CancellationTokenSource
// then pass the cancellationToken we have. This will allow us to cancel async requests when the server is stopped.
if (parameters.Count == methodParameters.Count - 1)
{
var position = methodParameters.FindIndex(x => x.type == typeof(CancellationToken));
if (position > -1)
{
parameters.Insert(position, cancellationToken);
}
}
if (parameters.Count < methodParameters.Count(x => !x.isOptional))
{
return(Error(JsonRpcErrorCodes.InvalidParams,
$"{methodParameters.Count} parameters were expected but {parameters.Count} were received.", jsonRpcRequest.Id));
}
var missingParameters = methodParameters.Count() - parameters.Count();
parameters.AddRange(methodParameters.TakeLast(missingParameters).Select(x => x.defaultValue));
var result = prodecureMetadata.MethodInfo.Invoke(Service, parameters.ToArray());
if (jsonRpcRequest.IsNotification) // the client is not interested in getting a response
{
return(string.Empty);
}
JsonRpcResponse response = null;
if (prodecureMetadata.MethodInfo.IsAsync())
{
if (!prodecureMetadata.MethodInfo.ReturnType.IsGenericType)
{
await((Task)result).ConfigureAwait(false);
response = JsonRpcResponse.CreateResultResponse(jsonRpcRequest.Id, null);
}
else
{
var ret = await((dynamic)result).ConfigureAwait(false);
response = JsonRpcResponse.CreateResultResponse(jsonRpcRequest.Id, ret);
}
}
else
{
response = JsonRpcResponse.CreateResultResponse(jsonRpcRequest.Id, result);
}
return(response.ToJson(DefaultSettings));
}
catch (TargetInvocationException e)
{
var code = e.InnerException switch
{
ArgumentException _ => JsonRpcErrorCodes.InvalidParameter,
RpcException rpcExc => rpcExc.Code,
_ => JsonRpcErrorCodes.InternalError
};
return(Error(code, e.InnerException.Message, jsonRpcRequest.Id));
}
catch (Exception e)
{
return(Error(JsonRpcErrorCodes.InternalError, e.Message, jsonRpcRequest.Id));
}
}
private string Error(JsonRpcErrorCodes code, string reason, string id)
{
var response = JsonRpcResponse.CreateErrorResponse(id, code, reason);
return(id is { }
