Hello guys.
Quick question: is there any recommended strategy for creating IEventStoreConnection objects in a web app? I’ve configured it as a singleton (using autofac), but I’ve noticed that my code will always throw a Event store connection xyz is not active error when I try to save or load events. Not sure if it helps, but here’s the code I’m using:
public class DepositoEventos : IDepositoEventos {
private const int _numeroEventosPorPagina = 200;
private readonly IEventStoreConnection _ligacaoDeposito;
private readonly ISeriadorEventos _seriadorEventos;
public DepositoEventos(IEventStoreConnection ligacaoDeposito, ISeriadorEventos seriadorEventos) {
Contract.Requires(ligacaoDeposito != null);
Contract.Requires(seriadorEventos != null);
Contract.Ensures(_ligacaoDeposito != null);
_ligacaoDeposito = ligacaoDeposito;
_seriadorEventos = seriadorEventos;
}
public async Task GravaEventos(string idStream, string tipo, IEnumerable eventosGravar, int versaoEsperada) {
var eventosPreviamenteGravadosEmConflitoEventual = await ObtemEventosParaAgregado(idStream, versaoEsperada + 1);
if (eventosGravar.Any(eventoGravar => eventosPreviamenteGravadosEmConflitoEventual.Any(eventoGravado => ExisteConflitoEventos(eventoGravar, eventoGravado)))) {
throw new ConcurrencyException();
}
//update event number
var evtVersionNumber = eventosPreviamenteGravadosEmConflitoEventual.Any() ? eventosPreviamenteGravadosEmConflitoEventual.Max(evt => evt.Versao) : versaoEsperada;
/*foreach (var evento in eventosGravar) {
evento.Versao = ++evtVersionNumber;
}*/
try {
using (var tran = await _ligacaoDeposito.StartTransactionAsync(idStream, evtVersionNumber)) {
await tran.WriteAsync(
eventosGravar.Select(eventoGravar => new EventData(Guid.NewGuid(),
eventoGravar.GetType().Name.ToLower(),
true,
_seriadorEventos.SeriaEvento(eventoGravar),
null)));
await tran.CommitAsync();
}
}
catch (WrongExpectedVersionException ex) {
throw new ConcurrencyException("", ex);
}
}
public async Task<IEnumerable> ObtemEventosParaAgregado(string idStream, int versaoEsperada = StreamPosition.Start) {
var eventos = new List();
if (versaoEsperada < 0) {
return eventos;
}
try {
var indiceProxPaginaElementos = versaoEsperada;
StreamEventsSlice paginaElementos = null;
do {
paginaElementos = await _ligacaoDeposito.ReadStreamEventsForwardAsync(idStream, indiceProxPaginaElementos, _numeroEventosPorPagina, false);
eventos.AddRange(paginaElementos.Events.Select(_seriadorEventos.DeseriaEvento));
indiceProxPaginaElementos = paginaElementos.NextEventNumber;
} while (!paginaElementos.IsEndOfStream);
}
catch (Exception ex) {
var t = “”;
}
return eventos;
}
protected virtual bool ExisteConflitoEventos(IEvento eventoGravar, IEvento eventoGravado) {
return eventoGravado.GetType() == eventoGravar.GetType();
}
}
Here’s how it’s getting instantiated:
builder.Register(c => EventStoreConnection.Create(new IPEndPoint(IPAddress.Loopback, ObtemPortaTcp())))
.As()
.SingleInstance();
This is a simple mvc app which also has another singleton component which is responsible for subscribing to the store (by using a projectionsmanager). I’ve written similar code to this in the past and it used to work well (though at the time, I did use version 2,.0).
Any clues on why I’m always getting this error? has anything changed regarding the way we use the .NET API to write/read events from the event store?
thanks.
Regards,
Luis
