public async Task <IExecutionResult> TakeSnapshotAsync(string stream)
{
Optional <TAggregateRoot> root = await _rootRepository.GetAsync(stream);
root.ThrowsIf(r => !r.HasValue, new AggregateNotFoundException(stream));
Aggregate aggregate;
this._changeTracker.TryGet(stream, out aggregate);
var changes = new EventData(
Guid.NewGuid(),
typeof(TSnapshot).TypeQualifiedName(),
true,
Encoding.UTF8.GetBytes(this._eventSerializer.Serialize(((ISnapshotable)root.Value).TakeSnapshot())),
Encoding.UTF8.GetBytes(this._eventSerializer.Serialize(new EventMetadata
{
AggregateAssemblyQualifiedName = typeof(TAggregateRoot).AssemblyQualifiedName,
AggregateType = typeof(TAggregateRoot).Name,
TimeStamp = DateTime.Now,
IsSnapshot = true,
Version = Convert.ToInt32(aggregate.ExpectedVersion)
})
));
var snapShotStreamName = _streamNameProvider.GetSnapshotStreamName(root, stream);
await _connection.AppendToStreamAsync(snapShotStreamName, ExpectedVersion.Any, changes);
return(ExecutionResult.Success);
}
public async Task <Optional <TAggregateRoot> > GetAsync(string identifier)
{
Optional <Aggregate> existingAggregate = GetAggregateFromChangeTrackerIfExits(identifier);
if (existingAggregate.HasValue)
{
return(new Optional <TAggregateRoot>((TAggregateRoot)existingAggregate.Value.Root));
}
var snapshotStreamName = _streamNameProvider.GetSnapshotStreamName(typeof(TAggregateRoot), identifier);
Optional <Snapshot> snapshot = await _snapshotStore.GetLastSnapshot(snapshotStreamName);
var version = StreamPosition.Start;
if (snapshot.HasValue)
{
version = snapshot.Value.Version + 1;
}
var aggregate = await _aggregateStore.Load <TAggregateRoot>(identifier, version);
AttachAggregateToChangeTracker(aggregate);
return(new Optional <TAggregateRoot>((TAggregateRoot)aggregate.Root));
}