public override async Task Start(CancellationToken cancellationToken)
{
if (_nextVersion == StreamVersion.End)
{
// Get the last stream version and subscribe from there.
var eventsPage = await ReadonlyStreamStore.ReadStreamBackwards(
_streamId,
StreamVersion.End,
1,
cancellationToken).NotOnCapturedContext();
//Only new Messages, i.e. the one after the current last one
_nextVersion = eventsPage.LastStreamVersion + 1;
}
await base.Start(cancellationToken);
}
public override async Task Start(CancellationToken cancellationToken)
{
if (FromPosition == Position.End)
{
// Get the last stream version and subscribe from there.
var eventsPage = await ReadonlyStreamStore.ReadAllBackwards(
Position.End,
1,
cancellationToken).NotOnCapturedContext();
// If fromPosition = 0, we have empty store, so start from zero, otherwise, the next position is
// one after the FromPosition.
_nextPosition = eventsPage.FromPosition == 0 ? 0 : eventsPage.FromPosition + 1;
}
await base.Start(cancellationToken).NotOnCapturedContext();
}
protected override async Task <bool> DoFetch()
{
var allMessagesPage = await ReadonlyStreamStore
.ReadAllForwards(
_nextPosition,
PageSize,
IsDisposed)
.NotOnCapturedContext();
bool isEnd = allMessagesPage.IsEnd;
foreach (var streamMessage in allMessagesPage.Messages)
{
if (IsDisposed.IsCancellationRequested)
{
return(true);
}
try
{
await StreamMessageReceived(streamMessage).NotOnCapturedContext();
LastPosition = streamMessage.Position;
_nextPosition = streamMessage.Position + 1;
}
catch (Exception ex)
{
try
{
SubscriptionDropped.Invoke(ex.Message, ex);
}
catch
{
//TODO logging
}
finally
{
Dispose();
}
}
}
return(isEnd);
}
protected override async Task <bool> DoFetch()
{
var streamMessagesPage = await ReadonlyStreamStore
.ReadStreamForwards(
_streamId,
_nextVersion,
PageSize,
IsDisposed)
.NotOnCapturedContext();
bool isEnd = streamMessagesPage.IsEndOfStream;
foreach (var message in streamMessagesPage.Messages)
{
if (IsDisposed.IsCancellationRequested)
{
return(true);
}
_nextVersion = message.StreamVersion + 1;
_lastVersion = message.StreamVersion;
try
{
await StreamMessageReceived(message).NotOnCapturedContext();
}
catch (Exception ex)
{
try
{
SubscriptionDropped.Invoke(ex.Message, ex);
}
catch (Exception ex2)
{
// Need to log this
}
finally
{
Dispose();
}
}
}
return(isEnd);
}
