public async Task <IEventStream> GetStream <T>(string bucket, Id streamId, IEnumerable <Id> parents = null) where T : class, IEventSource
{
parents = parents ?? new Id[] { };
var streamName = _streamGen(typeof(T), StreamTypes.Domain, bucket, streamId, parents);
Logger.Write(LogLevel.Debug, () => $"Retreiving stream [{streamId}] in bucket [{bucket}] for type {typeof(T).FullName}");
var cached = _cache.Retreive(streamName) as IImmutableEventStream;
if (cached != null)
{
HitMeter.Mark();
Logger.Write(LogLevel.Debug, () => $"Found stream [{streamName}] in cache");
return(new EventStream <T>(cached));
}
MissMeter.Mark();
while (await CheckFrozen <T>(bucket, streamId, parents).ConfigureAwait(false))
{
Logger.Write(LogLevel.Info, () => $"Stream [{streamId}] in bucket [{bucket}] is frozen - waiting");
await Task.Delay(100).ConfigureAwait(false);
}
Logger.Write(LogLevel.Debug, () => $"Stream [{streamId}] in bucket [{bucket}] not in cache - reading from store");
ISnapshot snapshot = null;
if (typeof(ISnapshotting).IsAssignableFrom(typeof(T)))
{
snapshot = await _snapstore.GetSnapshot <T>(bucket, streamId, parents).ConfigureAwait(false);
Logger.Write(LogLevel.Debug, () =>
{
if (snapshot != null)
{
return($"Retreived snapshot for entity id [{streamId}] bucket [{bucket}] version {snapshot.Version}");
}
return($"No snapshot found for entity id [{streamId}] bucket [{bucket}]");
});
}
var events = await _store.GetEvents(streamName, start : snapshot?.Version + 1).ConfigureAwait(false);
var oobMetadata = await _store.GetMetadata(streamName, OobMetadataKey).ConfigureAwait(false);
IEnumerable <OobDefinition> oobs = null;
if (!string.IsNullOrEmpty(oobMetadata))
{
oobs = JsonConvert.DeserializeObject <IEnumerable <OobDefinition> >(oobMetadata);
}
var eventstream = new EventStream <T>(bucket, streamId, parents, oobs, events, snapshot);
_cache.Cache(streamName, eventstream.Clone());
Logger.Write(LogLevel.Debug, () => $"Stream [{streamId}] in bucket [{bucket}] read - version is {eventstream.CommitVersion}");
return(eventstream);
}