protected override async Task <ReadModelUpdateResult <TReadModel> > UpdateAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
var readModel = readModelEnvelope.ReadModel;
if (readModel == null)
{
readModel = await ReadModelFactory.CreateAsync(
readModelEnvelope.ReadModelId,
cancellationToken)
.ConfigureAwait(false);
}
await ReadModelDomainEventApplier.UpdateReadModelAsync(
readModel,
domainEvents,
readModelContext,
cancellationToken)
.ConfigureAwait(false);
return(readModelEnvelope.AsModifedResult(
readModel,
readModelEnvelope.Version.GetValueOrDefault() + 1 // the best we can do
));
}
private async Task <TReadModel> GetOrCreateReadModel(ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
return(readModelEnvelope.ReadModel
?? await ReadModelFactory
.CreateAsync(readModelEnvelope.ReadModelId, cancellationToken)
.ConfigureAwait(false));
}
protected override async Task <ReadModelEnvelope <TReadModel> > UpdateAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
var readModel = readModelEnvelope.ReadModel ?? new TReadModel();
await ReadModelDomainEventApplier.UpdateReadModelAsync(readModel, domainEvents, readModelContext, cancellationToken).ConfigureAwait(false);
return(ReadModelEnvelope <TReadModel> .With(readModel));
}
protected override async Task <ReadModelUpdateResult <TReadModel> > UpdateAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
if (!domainEvents.Any())
{
throw new ArgumentException("No domain events");
}
var expectedVersion = domainEvents.Min(d => d.AggregateSequenceNumber) - 1;
var envelopeVersion = readModelEnvelope.Version;
IReadOnlyCollection <IDomainEvent> eventsToApply;
if (envelopeVersion.HasValue && expectedVersion != envelopeVersion)
{
var version = envelopeVersion.Value;
if (expectedVersion < version)
{
Log.Verbose(() =>
$"Read model '{typeof(TReadModel)}' with ID '{readModelEnvelope.ReadModelId}' already has version {version} compared to {expectedVersion}, skipping");
return(readModelEnvelope.AsUnmodifedResult());
}
// Apply missing events
TIdentity identity = domainEvents.Cast <IDomainEvent <TAggregate, TIdentity> >().First().AggregateIdentity;
eventsToApply = await _eventStore.LoadEventsAsync <TAggregate, TIdentity>(
identity,
(int)version + 1,
cancellationToken)
.ConfigureAwait(false);
Log.Verbose(() =>
$"Read model '{typeof(TReadModel)}' with ID '{readModelEnvelope.ReadModelId}' is missing some events {version} < {expectedVersion}, adding them (got {eventsToApply.Count} events)");
}
else
{
eventsToApply = domainEvents;
Log.Verbose(() =>
$"Read model '{typeof(TReadModel)}' with ID '{readModelEnvelope.ReadModelId}' has version {expectedVersion} (or none), applying events");
}
return(await ApplyUpdatesAsync(
readModelContext,
eventsToApply,
readModelEnvelope,
cancellationToken)
.ConfigureAwait(false));
}
protected override async Task <ReadModelEnvelope <TReadModel> > UpdateAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
var readModel = readModelEnvelope.ReadModel ?? await ReadModelFactory.CreateAsync(readModelEnvelope.ReadModelId, cancellationToken).ConfigureAwait(false);
await ReadModelDomainEventApplier.UpdateReadModelAsync(readModel, domainEvents, readModelContext, cancellationToken).ConfigureAwait(false);
var readModelVersion = domainEvents.Max(e => e.AggregateSequenceNumber);
return(ReadModelEnvelope <TReadModel> .With(readModelEnvelope.ReadModelId, readModel, readModelVersion));
}
private async Task <ReadModelUpdateResult <TReadModel> > ApplyUpdatesAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
TReadModel readModel = await GetOrCreateReadModel(readModelEnvelope, cancellationToken);
await ReadModelDomainEventApplier
.UpdateReadModelAsync(readModel, domainEvents, readModelContext, cancellationToken)
.ConfigureAwait(false);
var readModelVersion = Math.Max(
domainEvents.Max(e => e.AggregateSequenceNumber),
readModelEnvelope.Version.GetValueOrDefault());
return(readModelEnvelope.AsModifedResult(readModel, readModelVersion));
}
protected abstract Task <ReadModelEnvelope <TReadModel> > UpdateAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken);
protected override async Task <ReadModelUpdateResult <TReadModel> > UpdateAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
if (!domainEvents.Any())
{
throw new ArgumentException("No domain events");
}
var expectedVersion = domainEvents.Min(d => d.AggregateSequenceNumber) - 1;
var envelopeVersion = readModelEnvelope.Version;
IReadOnlyCollection <IDomainEvent> eventsToApply;
if (envelopeVersion.HasValue && expectedVersion != envelopeVersion)
{
var version = envelopeVersion.Value;
if (expectedVersion < version)
{
if (Logger.IsEnabled(LogLevel.Trace))
{
Logger.LogTrace(
"Read model {ReadModelType} with ID {Id} already has version {Version} compared to {ExpectedVersion}, skipping",
typeof(TReadModel),
readModelEnvelope.ReadModelId,
version,
expectedVersion);
}
return(readModelEnvelope.AsUnmodifedResult());
}
// Apply missing events
var identity = domainEvents.Cast <IDomainEvent <TAggregate, TIdentity> >().First().AggregateIdentity;
eventsToApply = await _eventStore.LoadEventsAsync <TAggregate, TIdentity>(
identity,
(int)version + 1,
cancellationToken)
.ConfigureAwait(false);
if (Logger.IsEnabled(LogLevel.Trace))
{
Logger.LogTrace(
"Read model {ReadModelType} with ID {Id} is missing some events {Version} < {ExpectedVersion}, adding them (got {MissingEventCount} events)",
typeof(TReadModel).PrettyPrint(),
readModelEnvelope.ReadModelId,
version,
expectedVersion,
eventsToApply.Count);
}
}
else
{
eventsToApply = domainEvents;
if (Logger.IsEnabled(LogLevel.Trace))
{
Logger.LogTrace(
"Read model {ReadModelType} with ID {Id} has version {ExpectedVersion} (or none), applying events",
typeof(TReadModel).PrettyPrint(),
readModelEnvelope.ReadModelId,
expectedVersion);
}
}
return(await ApplyUpdatesAsync(
readModelContext,
eventsToApply,
readModelEnvelope,
cancellationToken)
.ConfigureAwait(false));
}
protected override async Task <ReadModelUpdateResult <TReadModel> > UpdateAsync(
IReadModelContext readModelContext,
IReadOnlyCollection <IDomainEvent> domainEvents,
ReadModelEnvelope <TReadModel> readModelEnvelope,
CancellationToken cancellationToken)
{
if (!domainEvents.Any())
{
throw new ArgumentException("No domain events");
}
var expectedVersion = domainEvents.Min(d => d.AggregateSequenceNumber) - 1;
var version = readModelEnvelope.Version;
if (!version.HasValue || expectedVersion == version)
{
Log.Verbose(() => $"Read model '{typeof(TReadModel)}' with ID '{readModelEnvelope.ReadModelId}' has version {expectedVersion} (or none), applying events");
return(await base.UpdateAsync(
readModelContext,
domainEvents,
readModelEnvelope,
cancellationToken)
.ConfigureAwait(false));
}
if (expectedVersion < version.Value)
{
Log.Verbose(() => $"Read model '{typeof(TReadModel)}' with ID '{readModelEnvelope.ReadModelId}' already has version {version.Value} compared to {expectedVersion}, skipping");
return(readModelEnvelope.AsUnmodifedResult());
}
TReadModel readModel;
if (readModelEnvelope.ReadModel == null)
{
readModel = await ReadModelFactory.CreateAsync(
readModelEnvelope.ReadModelId,
cancellationToken)
.ConfigureAwait(false);
}
else
{
readModel = readModelEnvelope.ReadModel;
}
// Apply missing events
var identity = domainEvents.Cast <IDomainEvent <TAggregate, TIdentity> >().First().AggregateIdentity;
var missingEvents = await _eventStore.LoadEventsAsync <TAggregate, TIdentity>(
identity,
(int)version.Value + 1,
cancellationToken)
.ConfigureAwait(false);
Log.Verbose(() => $"Read model '{typeof(TReadModel)}' with ID '{readModelEnvelope.ReadModelId}' is missing some events {version.Value} < {expectedVersion}, adding them (got {missingEvents.Count} events)");
await ReadModelDomainEventApplier.UpdateReadModelAsync(
readModel,
missingEvents,
readModelContext,
cancellationToken)
.ConfigureAwait(false);
version = domainEvents.Max(e => e.AggregateSequenceNumber);
return(readModelEnvelope.AsModifedResult(
readModel,
version));
}
