public async Task Start()
{
var position = await _checkpointStore.GetCheckpoint();
_subscription = _isAllStream
? await _client.SubscribeToAllAsync(
GetAllStreamPosition(),
EventAppeared,
subscriptionDropped : SubscriptionDropped)
: await _client.SubscribeToStreamAsync(
_streamName,
GetStreamPosition(),
EventAppeared
);
FromAll GetAllStreamPosition()
=> position.HasValue
? FromAll.After(new Position(position.Value, position.Value))
: FromAll.Start;
FromStream GetStreamPosition()
=> position.HasValue
? FromStream.After(position.Value)
: FromStream.Start;
}
protected override async ValueTask Subscribe(CancellationToken cancellationToken)
{
var filterOptions = new SubscriptionFilterOptions(
Options.EventFilter ?? EventTypeFilter.ExcludeSystemEvents(),
Options.CheckpointInterval,
async(_, p, ct) => {
// This doesn't allow to report tie time gap
LastProcessed = new EventPosition(p.CommitPosition, DateTime.Now);
await StoreCheckpoint(LastProcessed, ct).NoContext();
}
);
var(_, position) = await GetCheckpoint(cancellationToken).NoContext();
var fromAll = position == null ? FromAll.Start : FromAll.After(new Position(position.Value, position.Value));
Subscription = await EventStoreClient.SubscribeToAllAsync(
fromAll,
HandleEvent,
Options.ResolveLinkTos,
HandleDrop,
filterOptions,
Options.Credentials,
cancellationToken
).NoContext();
async Task HandleEvent(
global::EventStore.Client.StreamSubscription _,
ResolvedEvent re,
CancellationToken ct
)
=> await HandleInternal(CreateContext(re, ct)).NoContext();
void HandleDrop(
global::EventStore.Client.StreamSubscription _,
SubscriptionDroppedReason reason,
Exception?ex
)
=> Dropped(EsdbMappings.AsDropReason(reason), ex);
}