public virtual IEnumerable <StreamHead> GetStreamsToSnapshot(int maxThreshold)
{
Logger.Debug(Messages.GettingStreamsToSnapshot);
return(TryMongo(() =>
{
IMongoQuery query = Query.GTE("Unsnapshotted", maxThreshold);
return PersistedStreamHeads.Find(query).SetSortOrder(SortBy.Descending("Unsnapshotted")).Select(x => x.ToStreamHead());
}));
}
public virtual bool AddSnapshot(ISnapshot snapshot)
{
CheckIfSnapshotEnabled();
if (snapshot == null)
{
return(false);
}
if (Logger.IsDebugEnabled)
{
Logger.Debug(Messages.AddingSnapshot, snapshot.StreamId, snapshot.BucketId, snapshot.StreamRevision);
}
try
{
BsonDocument mongoSnapshot = snapshot.ToMongoSnapshot(_serializer);
var query = Builders <BsonDocument> .Filter.Eq(MongoShapshotFields.Id, mongoSnapshot[MongoShapshotFields.Id]);
var update = Builders <BsonDocument> .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.UpdateOne(query, update, new UpdateOptions()
{
IsUpsert = true
});
// 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.Find(Builders <BsonDocument> .Filter.Eq(MongoStreamHeadFields.Id, streamHeadId))
.First()
.ToStreamHead();
int unsnapshotted = streamHead.HeadRevision - snapshot.StreamRevision;
PersistedStreamHeads.UpdateOne(
Builders <BsonDocument> .Filter
.Eq(MongoStreamHeadFields.Id, streamHeadId),
Builders <BsonDocument> .Update
.Set(MongoStreamHeadFields.SnapshotRevision, snapshot.StreamRevision)
.Set(MongoStreamHeadFields.Unsnapshotted, unsnapshotted)
);
return(true);
}
catch (Exception)
{
return(false);
}
}
/// <inheritdoc/>
public virtual IEnumerable <IStreamHead> GetStreamsToSnapshot(string bucketId, int maxThreshold)
{
CheckIfSnapshotEnabled();
Logger.LogDebug(Messages.GettingStreamsToSnapshot);
return(TryMongo(() =>
{
var query = Builders <BsonDocument> .Filter.Gte(MongoStreamHeadFields.Unsnapshotted, maxThreshold);
return PersistedStreamHeads
.Find(query)
.Sort(Builders <BsonDocument> .Sort.Descending(MongoStreamHeadFields.Unsnapshotted))
.ToEnumerable()
.Select(x => x.ToStreamHead());
}));
}