public void Handle(ClientMessage.ReadEventsBackwards message)
{
_externalRequestQueue.Publish(
new ClientMessage.ReadEventsBackwards(
message.CorrelationId, new PublishToWrapEnvelop(_inputQueue, message.Envelope),
message.EventStreamId, message.FromEventNumber, message.MaxCount, message.ResolveLinks));
}
void IHandle <ClientMessage.ReadEventsBackwards> .Handle(ClientMessage.ReadEventsBackwards message)
{
EventRecord[] records;
EventRecord[] links = null;
var lastCommitPosition = _readIndex.LastCommitPosition;
var result = _readIndex.TryReadRecordsBackwards(message.EventStreamId, message.FromEventNumber, message.MaxCount, out records);
var nextEventNumber = result == RangeReadResult.Success & records.Length > 0
? records[records.Length - 1].EventNumber - 1
: -1;
if (result == RangeReadResult.Success && records.Length > 1)
{
for (var index = 1; index < records.Length; index++)
{
if (records[index].EventNumber != records[index - 1].EventNumber - 1)
{
throw new Exception(string.Format(
"Invalid order of events has been detected in read index for the event stream '{0}'. "
+ "The event {1} at position {2} goes after the event {3} at position {4}",
message.EventStreamId,
records[index].EventNumber,
records[index].LogPosition,
records[index - 1].EventNumber,
records[index - 1].LogPosition));
}
}
}
if (result == RangeReadResult.Success && message.ResolveLinks)
{
links = ResolveLinkToEvents(records);
}
message.Envelope.ReplyWith(
new ClientMessage.ReadEventsBackwardsCompleted(message.CorrelationId,
message.EventStreamId,
records,
links,
result,
nextEventNumber,
records.Length == 0 ? lastCommitPosition : (long?)null));
}