private async Task <FastForwardResult> FastForward(IStreamStore from, IStreamStore to, string branchId)
{
var fastForwardResult = new FastForwardResult();
var page = await from.ListStreams();
while (page.StreamIds.Length > 0)
{
foreach (var s in page.StreamIds.Where(x => x.StartsWith(branchId)))
{
var localPosition = await from.LastPosition(s);
var remotePosition = await to.LastPosition(s);
if (localPosition == remotePosition)
{
continue;
}
var eventPage = await from.ReadStreamForwards(s, Math.Max(remotePosition + 1, 0), Configuration.BatchSize);
var appendMessages = new List <NewStreamMessage>();
if (eventPage.Messages.Length == 0 && localPosition >= ExpectedVersion.EmptyStream)
{
await to.AppendToStream(s, remotePosition, appendMessages.ToArray());
}
var metadata = await from.GetStreamMetadata(s);
await to.SetStreamMetadata(s, ExpectedVersion.Any, metadata.MaxAge, metadata.MaxCount, metadata.MetadataJson);
while (eventPage.Messages.Length > 0)
{
appendMessages.Clear();
foreach (var m in eventPage.Messages)
{
var payload = await m.GetJsonData();
var message = new NewStreamMessage(m.MessageId, m.Type, payload, m.JsonMetadata);
appendMessages.Add(message);
}
var result = await to.AppendToStream(s, remotePosition, appendMessages.ToArray());
fastForwardResult.NumberOfMessages += result.CurrentVersion - Math.Max(remotePosition, ExpectedVersion.EmptyStream);
eventPage = await eventPage.ReadNext();
}
fastForwardResult.NumberOfStreams++;
}
page = await page.Next();
}
fastForwardResult.ResultStatus = Status.Success;
return(fastForwardResult);
}