private ProcessSchedulerDelegate BuildRequestDelegate(IRequestDescriptor <IHandlerDescriptor?> descriptors, Request request, RequestInvocationHandle handle)
{
return(async(cancellationToken) =>
{
try
{
var result = await InvokeRequestAsync(cancellationToken).ConfigureAwait(false);
_outputHandler.Send(result.Value);
}
finally
{
handle.Dispose();
}
});
async Task <ErrorResponse> InvokeRequestAsync(CancellationToken cancellationToken)
{
using var timeoutCts = new CancellationTokenSource(_requestTimeout);
using var combinedCts = CancellationTokenSource.CreateLinkedTokenSource(handle.CancellationTokenSource.Token, timeoutCts.Token, cancellationToken);
using var timer = _logger.TimeDebug("Processing request {Method}:{Id}", request.Method, request.Id);
try
{
var result = await _requestRouter.RouteRequest(descriptors, request, combinedCts.Token).ConfigureAwait(false);
return(result);
}
catch (OperationCanceledException)
{
if (timeoutCts.IsCancellationRequested)
{
_logger.LogTrace("Request {Method}:{Id} was cancelled, due to timeout", request.Method, request.Id);
return(new RequestCancelled(request.Id, request.Method));
}
_logger.LogTrace("Request {Method}:{Id} was cancelled", request.Method, request.Id);
return(new RequestCancelled(request.Id, request.Method));
}
catch (RpcErrorException e)
{
_logger.LogCritical(Events.UnhandledRequest, e, "Failed to handle request {Method}:{Id}", request.Method, request.Id);
return(new RpcError(
request.Id,
request.Method,
new ErrorMessage(e.Code, e.Message, e.Error)));
}
catch (Exception e)
{
_logger.LogCritical(Events.UnhandledRequest, e, "Failed to handle request {Method}:{Id}. Unhandled exception", request.Method, request.Id);
return(new InternalError(request.Id, request.Method, e.ToString()));
}
}
}
private void HandleRequest(string request)
{
JToken payload;
try
{
payload = JToken.Parse(request);
}
catch
{
_outputHandler.Send(new ParseError());
return;
}
if (!_receiver.IsValid(payload))
{
_outputHandler.Send(new InvalidRequest());
return;
}
var(requests, hasResponse) = _receiver.GetRequests(payload);
if (hasResponse)
{
foreach (var response in requests.Where(x => x.IsResponse).Select(x => x.Response))
{
var id = response.Id is string s?long.Parse(s) : response.Id is long l ? l : -1;
if (id < 0)
{
continue;
}
var tcs = _responseRouter.GetRequest(id);
if (tcs is null)
{
continue;
}
if (response is ServerResponse serverResponse)
{
tcs.SetResult(serverResponse.Result);
}
else if (response is ServerError serverError)
{
tcs.SetException(new JsonRpcException(serverError));
}
}
return;
}
foreach (var item in requests)
{
if (item.IsRequest)
{
var descriptor = _requestRouter.GetDescriptor(item.Request);
if (descriptor is null)
{
continue;
}
var type = _requestProcessIdentifier.Identify(descriptor);
_requestRouter.StartRequest(item.Request.Id);
_scheduler.Add(
type,
item.Request.Method,
async() => {
try
{
var result = await _requestRouter.RouteRequest(descriptor, item.Request, CancellationToken.None);
if (result.IsError && result.Error is RequestCancelled)
{
return;
}
_outputHandler.Send(result.Value);
}
catch (Exception e)
{
_logger.LogCritical(Events.UnhandledRequest, e, "Unhandled exception executing request {Method}@{Id}", item.Request.Method, item.Request.Id);
// TODO: Should we rethrow or swallow?
// If an exception happens... the whole system could be in a bad state, hence this throwing currently.
throw;
}
}
);
}
if (item.IsNotification)
{
var descriptor = _requestRouter.GetDescriptor(item.Notification);
if (descriptor is null)
{
continue;
}
// We need to special case cancellation so that we can cancel any request that is currently in flight.
if (descriptor.Method == JsonRpcNames.CancelRequest)
{
var cancelParams = item.Notification.Params?.ToObject <CancelParams>();
if (cancelParams == null)
{
continue;
}
_requestRouter.CancelRequest(cancelParams.Id);
continue;
}
var type = _requestProcessIdentifier.Identify(descriptor);
_scheduler.Add(
type,
item.Notification.Method,
DoNotification(descriptor, item.Notification)
);
}
if (item.IsError)
{
// TODO:
_outputHandler.Send(item.Error);
}
}
Func <Task> DoNotification(IHandlerDescriptor descriptor, Notification notification)
{
return(async() => {
try
{
await _requestRouter.RouteNotification(descriptor, notification, CancellationToken.None);
}
catch (Exception e)
{
_logger.LogCritical(Events.UnhandledNotification, e, "Unhandled exception executing notification {Method}", notification.Method);
// TODO: Should we rethrow or swallow?
// If an exception happens... the whole system could be in a bad state, hence this throwing currently.
throw;
}
});
}
}
private SchedulerDelegate RouteRequest(
IRequestDescriptor <IHandlerDescriptor?> descriptor,
Request request,
RequestInvocationHandle handle)
{
var cts = handle.CancellationTokenSource;
return((contentModifiedToken, scheduler) =>
Observable.Create <ErrorResponse>(
observer => {
// ITS A RACE!
var sub = Observable.Amb(
contentModifiedToken.Select(
_ => {
_logger.LogTrace(
"Request {Id} was abandoned due to content be modified", request.Id
);
return new ErrorResponse(
new ContentModified(request.Id, request.Method)
);
}
),
Observable.Timer(_options.RequestTimeout, scheduler).Select(
_ => new ErrorResponse(new RequestCancelled(request.Id, request.Method))
),
Observable.FromAsync(
async ct => {
using var timer = _logger.TimeDebug(
"Processing request {Method} {ResponseId}", request.Method,
request.Id
);
ct.Register(cts.Cancel);
// ObservableToToken(contentModifiedToken).Register(cts.Cancel);
try
{
var result = await _requestRouter.RouteRequest(
descriptor, request, cts.Token
).ConfigureAwait(false);
return result;
}
catch (OperationCanceledException)
{
_logger.LogTrace("Request {Id} was cancelled", request.Id);
return new RequestCancelled(request.Id, request.Method);
}
catch (RpcErrorException e)
{
_logger.LogCritical(
Events.UnhandledRequest, e,
"Failed to handle request {Method} {RequestId}", request.Method,
request.Id
);
return new RpcError(
request.Id, request.Method,
new ErrorMessage(e.Code, e.Message, e.Error)
);
}
catch (Exception e)
{
_logger.LogCritical(
Events.UnhandledRequest, e,
"Failed to handle request {Method} {RequestId}", request.Method,
request.Id
);
return new InternalError(request.Id, request.Method, e.ToString());
}
}
)
)
.Subscribe(observer);
return new CompositeDisposable(sub, handle);
}
)
.Select(
response => {
_outputHandler.Send(response.Value);
return Unit.Default;
}
));
}
private void HandleRequest(string request)
{
JToken payload;
try
{
payload = JToken.Parse(request);
}
catch
{
_outputHandler.Send(new ParseError());
return;
}
if (!_reciever.IsValid(payload))
{
_outputHandler.Send(new InvalidRequest());
return;
}
var(requests, hasResponse) = _reciever.GetRequests(payload);
if (hasResponse)
{
foreach (var response in requests.Where(x => x.IsResponse).Select(x => x.Response))
{
var id = response.Id is string s?long.Parse(s) : response.Id is long l ? l : -1;
if (id < 0)
{
continue;
}
var tcs = _responseRouter.GetRequest(id);
if (tcs is null)
{
continue;
}
if (response is ServerResponse serverResponse)
{
tcs.SetResult(serverResponse.Result);
}
else if (response is ServerError serverError)
{
tcs.SetException(new Exception(JsonConvert.SerializeObject(serverError.Error)));
}
}
return;
}
foreach (var item in requests)
{
if (item.IsRequest)
{
var descriptor = _requestRouter.GetDescriptor(item.Request);
if (descriptor is null)
{
continue;
}
var type = _requestProcessIdentifier.Identify(descriptor);
_scheduler.Add(
type,
item.Request.Method,
async() => {
try
{
var result = await _requestRouter.RouteRequest(descriptor, item.Request);
_outputHandler.Send(result.Value);
}
catch (Exception e)
{
_logger.LogCritical(Events.UnhandledRequest, e, "Unhandled exception executing request {Method}@{Id}", item.Request.Method, item.Request.Id);
// TODO: Should we rethrow or swallow?
// If an exception happens... the whole system could be in a bad state, hence this throwing currently.
throw;
}
}
);
}
else if (item.IsNotification)
{
var descriptor = _requestRouter.GetDescriptor(item.Notification);
if (descriptor is null)
{
continue;
}
var type = _requestProcessIdentifier.Identify(descriptor);
_scheduler.Add(
type,
item.Notification.Method,
async() => {
try
{
await _requestRouter.RouteNotification(descriptor, item.Notification);
}
catch (Exception e)
{
_logger.LogCritical(Events.UnhandledNotification, e, "Unhandled exception executing notification {Method}", item.Notification.Method);
// TODO: Should we rethrow or swallow?
// If an exception happens... the whole system could be in a bad state, hence this throwing currently.
throw;
}
}
);
}
else if (item.IsError)
{
// TODO:
_outputHandler.Send(item.Error);
}
}
}