private async Task <long> StreamEventsToProjections(ExclusiveEventStoreCatchupQuery query)
{
long eventsProcessedOutOfBatch = 0;
foreach (var storedEvent in query.Events)
{
eventsProcessedOutOfBatch++;
IncludeReadModelsNeeding(storedEvent);
if (cancellationDisposable.IsDisposed)
{
break;
}
IEvent @event = null;
var now = Clock.Now();
try
{
@event = await UpdateProjectorsAndCursors(
query,
storedEvent,
eventsProcessedOutOfBatch,
now);
}
catch (Exception ex)
{
var error = @event == null
? SerializationError(ex, storedEvent)
: new Domain.EventHandlingError(ex, @event: @event);
ReadModelUpdate.ReportFailure(
error,
createReadModelDbContext);
}
var status = new ReadModelCatchupStatus
{
BatchCount = query.BatchMatchedEventCount,
NumberOfEventsProcessed = eventsProcessedOutOfBatch,
CurrentEventId = storedEvent.Id,
EventTimestamp = storedEvent.Timestamp,
StatusTimeStamp = now,
CatchupName = Name
};
if (status.IsEndOfBatch)
{
// reset the re-entrancy flag
running = 0;
query.Dispose();
}
ReportStatus(status);
}
return(eventsProcessedOutOfBatch);
}
private static void CreateUnitOfWork(
UnitOfWork <ReadModelUpdate> unitOfWork,
Action <ReadModelUpdate> setSubject)
{
var update = new ReadModelUpdate
{
Transaction = new TransactionScope(TransactionScopeOption.RequiresNew, new TransactionOptions
{
IsolationLevel = IsolationLevel.ReadCommitted
})
};
setSubject(update);
}
private static void CreateUnitOfWork(
UnitOfWork<ReadModelUpdate> unitOfWork,
Action<ReadModelUpdate> setSubject)
{
var update = new ReadModelUpdate
{
Transaction = new TransactionScope(TransactionScopeOption.RequiresNew,
new TransactionOptions
{
IsolationLevel = IsolationLevel.ReadCommitted
}, TransactionScopeAsyncFlowOption.Enabled)
};
setSubject(update);
}
/// <summary> /// Reports event handling errors via the specified database. /// </summary> /// <param name="bus">The bus.</param> /// <param name="createDbContext">The database.</param> /// <returns></returns> public static IDisposable ReportErrorsToDatabase(this IEventBus bus, Func <DbContext> createDbContext) => bus.Errors.Subscribe(e => ReadModelUpdate.ReportFailure(e, createDbContext));
/// <summary>
/// Initializes the <see cref="ReadModelCatchup{TDbContext}"/> class.
/// </summary>
static ReadModelCatchup()
{
ReadModelUpdate.ConfigureUnitOfWork();
}
private async Task <long> StreamEventsToProjections(ExclusiveEventStoreCatchupQuery query)
{
long eventsProcessed = 0;
foreach (var storedEvent in query.Events)
{
eventsProcessed++;
IncludeReadModelsNeeding(storedEvent);
if (cancellationDisposable.IsDisposed)
{
break;
}
IEvent @event = null;
var now = Clock.Now();
try
{
// update projectors
@event = storedEvent.ToDomainEvent();
if (@event != null)
{
using (var work = CreateUnitOfWork(@event))
{
await bus.PublishAsync(@event);
var infos = work.Resource <DbContext>().Set <ReadModelInfo>();
subscribedReadModelInfos.ForEach(i =>
{
var eventsRemaining = query.ExpectedNumberOfEvents - eventsProcessed;
infos.Attach(i);
i.LastUpdated = now;
i.CurrentAsOfEventId = storedEvent.Id;
i.LatencyInMilliseconds = (now - @event.Timestamp).TotalMilliseconds;
i.BatchRemainingEvents = eventsRemaining;
if (eventsProcessed == 1)
{
i.BatchStartTime = now;
i.BatchTotalEvents = query.ExpectedNumberOfEvents;
}
if (i.InitialCatchupStartTime == null)
{
i.InitialCatchupStartTime = now;
i.InitialCatchupEvents = query.ExpectedNumberOfEvents;
}
if (eventsRemaining == 0 && i.InitialCatchupEndTime == null)
{
i.InitialCatchupEndTime = now;
}
});
work.VoteCommit();
}
}
else
{
throw new SerializationException(string.Format(
"Deserialization: Event type '{0}.{1}' not found",
storedEvent.StreamName,
storedEvent.Type));
}
}
catch (Exception ex)
{
var error = @event == null
? SerializationError(ex, storedEvent)
: new Domain.EventHandlingError(ex, @event: @event);
ReadModelUpdate.ReportFailure(
error,
() => CreateReadModelDbContext());
}
var status = new ReadModelCatchupStatus
{
BatchCount = query.ExpectedNumberOfEvents,
NumberOfEventsProcessed = eventsProcessed,
CurrentEventId = storedEvent.Id,
EventTimestamp = storedEvent.Timestamp,
StatusTimeStamp = now,
CatchupName = Name
};
if (status.IsEndOfBatch)
{
// reset the re-entrancy flag
running = 0;
query.Dispose();
}
ReportStatus(status);
}
return(eventsProcessed);
}
static ProjectorExtensions()
{
ReadModelUpdate.ConfigureUnitOfWork();
}
/// <summary>
/// Reports event handling errors via the specified database.
/// </summary>
/// <param name="bus">The bus.</param>
/// <param name="db">The database.</param>
/// <returns></returns>
public static IDisposable ReportErrorsToDatabase(this IEventBus bus, Func <DbContext> db)
{
return(bus.Errors.Subscribe(e => ReadModelUpdate.ReportFailure(e, db)));
}