public override async Task QueryStreamAsync(
QueryEnvelope queryEnvelope,
IServerStreamWriter <ResponseEnvelope> responseStream,
ServerCallContext callContext
)
{
var streamPatterns = JsonConvert.DeserializeObject <string[]>(queryEnvelope.StreamPattern);
try {
var broker = new GrpcBroker(queryEnvelope);
await Run(broker, responseStream, streamPatterns);
} catch (Exception ex) {
Log.ErrorException(ex, "Error running Rx query");
await ClientOnError(responseStream, ex);
}
}
public override async Task QueryStreamAsync(
QueryEnvelope queryEnvelope,
IServerStreamWriter <ResponseEnvelope> responseStream,
ServerCallContext callContext)
{
try
{
var broker = new GrpcBroker(queryEnvelope);
await Run(broker, responseStream);
}
catch (Exception ex)
{
await ClientOnError(responseStream, ex);
throw;
}
}
private async Task Run(GrpcBroker broker, IServerStreamWriter <ResponseEnvelope> responseStream)
{
var isComplete = false;
var isError = false;
var eventCount = 0;
using (var sub = broker.Observable.Subscribe(
async e => await ClientOnNext(responseStream, e),
async ex => await ClientOnError(responseStream, ex),
async() => await ClientOnCompleted(responseStream)))
{
do
{
var @event = Activator.CreateInstance(broker.SourceType);
broker.SourceType.GetProperty("CustomerId").SetValue(@event, Guid.NewGuid());
broker.SourceType.GetProperty("Email").SetValue(@event, "*****@*****.**");
broker.SourceType.GetProperty("PhoneNumber").SetValue(@event, "09-" + random.Next(0, 6));
broker.Observer.OnNext(@event);
await Task.Delay(random.Next(0, 500));
if (eventCount++ > 5)
{
isComplete = random.Next(0, 20) == 0;
isError = !isComplete && random.Next(0, 20) == 0;
}
} while (!isComplete && !isError);
if (isComplete)
{
broker.Observer.OnCompleted();
}
else if (isError)
{
broker.Observer.OnError(new Exception("Example error"));
}
}
}
private async Task Run(GrpcBroker broker, IServerStreamWriter <ResponseEnvelope> responseStream, string[] streamPatterns)
{
var done = false;
var position = new TFPos();
var operationId = Guid.NewGuid();
RxSubjectEnvelope envelope = null;
void GetNextBatch(TFPos pos)
{
envelope = envelope ?? new RxSubjectEnvelope(
broker.SourceType,
broker.RegisteredTypes,
broker.Observer,
streamPatterns,
GetNextBatch);
var message = BuildMessage(operationId, envelope, pos);
_publisher.Publish(message);
}
using (var sub = broker.Observable.Subscribe(
async e => { try { await ClientOnNext(responseStream, e); } catch { done = true; } },
async ex => { await ClientOnError(responseStream, ex); done = true; },
async() => { await ClientOnCompleted(responseStream); done = true; })
) {
GetNextBatch(position);
// TODO: Investiate the following
// Waiting for completion this way isn't good but gRpc has an issue running inside
// another thread via Task.Run or qbservable.RunAsync(): 'Response stream is already completed'
while (!done)
{
await Task.Delay(25);
}
}
}
