private Task <StreamEventsPage> ReadSteamBackwards(string streamId, int start, int count)
{
var connection = _getConnection();
var results = connection.Table <SqliteEvent>()
.Where(e => e.StreamId == streamId)
.OrderByDescending(e => e.SequenceNumber)
.Skip(start)
.Take(count)
// Must enumerate the results before selecting a StreamEvent else activation
// exception from Sqlite.Net trying create a StreamEvent. Comment out the
// line below if you want to see the test(s) fail.
.ToArray()
.Select(@event => @event.ToStreamEvent())
.ToArray();
var streamEventsPage = new StreamEventsPage(
streamId: streamId,
status: PageReadStatus.Success,
fromStreamVersion: start,
nextStreamVersion: results[0].StreamVersion - 1,
lastStreamVersion: results[0].StreamVersion,
direction: ReadDirection.Backward,
isEndOfStream: true,
events: results);
return(Task.FromResult(streamEventsPage));
}
public ReadStreamTheory(
string streamId,
int start,
int pageSize,
StreamEventsPage expectedStreamEventsPage)
{
StreamId = streamId;
Start = start;
PageSize = pageSize;
ExpectedStreamEventsPage = expectedStreamEventsPage;
}
protected override Task <StreamEventsPage> ReadStreamBackwardsInternal(
string streamId,
int fromVersionInclusive,
int count,
CancellationToken cancellationToken = new CancellationToken())
{
if (_isDisposed)
{
throw new ObjectDisposedException(nameof(InMemoryEventStore));
}
_lock.EnterReadLock();
try
{
InMemoryStream stream;
if (!_streams.TryGetValue(streamId, out stream))
{
var notFound = new StreamEventsPage(streamId,
PageReadStatus.StreamNotFound,
fromVersionInclusive,
-1,
-1,
ReadDirection.Backward,
true);
return(Task.FromResult(notFound));
}
if (stream.IsDeleted)
{
var deleted = new StreamEventsPage(streamId,
PageReadStatus.StreamDeleted,
fromVersionInclusive,
0,
0,
ReadDirection.Backward,
true);
return(Task.FromResult(deleted));
}
var events = new List <StreamEvent>();
var i = fromVersionInclusive == StreamVersion.End ? stream.Events.Count - 1 : fromVersionInclusive;
while (i >= 0 && count > 0)
{
var inMemoryStreamEvent = stream.Events[i];
var streamEvent = new StreamEvent(
streamId,
inMemoryStreamEvent.EventId,
inMemoryStreamEvent.StreamVersion,
inMemoryStreamEvent.Checkpoint,
inMemoryStreamEvent.Created,
inMemoryStreamEvent.Type,
inMemoryStreamEvent.JsonData,
inMemoryStreamEvent.JsonMetadata);
events.Add(streamEvent);
i--;
count--;
}
var lastStreamVersion = stream.Events.Last().StreamVersion;
var nextStreamVersion = events.Last().StreamVersion - 1;
var endOfStream = nextStreamVersion < 0;
var page = new StreamEventsPage(
streamId,
PageReadStatus.Success,
fromVersionInclusive,
nextStreamVersion,
lastStreamVersion,
ReadDirection.Backward,
endOfStream,
events.ToArray());
return(Task.FromResult(page));
}
finally
{
_lock.ExitReadLock();
}
}
