public virtual bool AddSnapshot(ISnapshot snapshot)
{
if (snapshot == null)
{
return(false);
}
Logger.Debug(Messages.AddingSnapshot, snapshot.StreamId, snapshot.BucketId, snapshot.StreamRevision);
try
{
BsonDocument mongoSnapshot = snapshot.ToMongoSnapshot(_serializer);
IMongoQuery query = Query.EQ(MongoShapshotFields.Id, mongoSnapshot[MongoShapshotFields.Id]);
UpdateBuilder update = Update.Set(MongoShapshotFields.Payload, mongoSnapshot[MongoShapshotFields.Payload]);
// Doing an upsert instead of an insert allows us to overwrite an existing snapshot and not get stuck with a
// stream that needs to be snapshotted because the insert fails and the SnapshotRevision isn't being updated.
PersistedSnapshots.Update(query, update, UpdateFlags.Upsert);
// More commits could have been made between us deciding that a snapshot is required and writing it so just
// resetting the Unsnapshotted count may be a little off. Adding snapshots should be a separate process so
// this is a good chance to make sure the numbers are still in-sync - it only adds a 'read' after all ...
BsonDocument streamHeadId = GetStreamHeadId(snapshot.BucketId, snapshot.StreamId);
StreamHead streamHead = PersistedStreamHeads.FindOneById(streamHeadId).ToStreamHead();
int unsnapshotted = streamHead.HeadRevision - snapshot.StreamRevision;
PersistedStreamHeads.Update(
Query.EQ(MongoStreamHeadFields.Id, streamHeadId),
Update.Set(MongoStreamHeadFields.SnapshotRevision, snapshot.StreamRevision).Set(MongoStreamHeadFields.Unsnapshotted, unsnapshotted));
return(true);
}
catch (Exception)
{
return(false);
}
}