/// <summary>
/// Deletes the snapshot identified by <paramref name="metadata" />.
/// This call is protected with a circuit-breaker
/// </summary>
protected override Task DeleteAsync(SnapshotMetadata metadata)
{
var table = _client.Value.GetTableReference(_settings.TableName);
TableOperation getOperation = TableOperation.Retrieve <SnapshotEntry>(metadata.PersistenceId, SnapshotEntry.ToRowKey(metadata.SequenceNr));
TableResult result = table.Execute(getOperation);
TableOperation deleteOperation = TableOperation.Delete((SnapshotEntry)result.Result);
return(table.ExecuteAsync(deleteOperation));
}
private static SelectedSnapshot ToSelectedSnapshot(SnapshotEntry entry)
{
var payload = JsonConvert.DeserializeObject(entry.Payload, Type.GetType(entry.Manifest));
return(new SelectedSnapshot(new SnapshotMetadata(entry.PartitionKey, long.Parse(entry.RowKey), new DateTime(entry.SnapshotTimestamp)), payload));
}
/// <summary>
/// Asynchronously saves a snapshot.
/// This call is protected with a circuit-breaker
/// </summary>
protected override Task SaveAsync(SnapshotMetadata metadata, object snapshot)
{
var table = _client.Value.GetTableReference(_settings.TableName);
TableOperation upsertOperation = TableOperation.Insert(ToSnapshotEntry(metadata, snapshot));
var entity = (SnapshotEntry)table.Execute(TableOperation.Retrieve <SnapshotEntry>(metadata.PersistenceId, SnapshotEntry.ToRowKey(metadata.SequenceNr))).Result;
if (entity != null)
{
entity.Payload = JsonConvert.SerializeObject(snapshot);
upsertOperation = TableOperation.Replace(entity);
}
return(table.ExecuteAsync(upsertOperation));
}
private static TableQuery <SnapshotEntry> BuildSnapshotTableQuery(string persistenceId, SnapshotSelectionCriteria criteria)
{
string comparsion = TableQuery.CombineFilters(
TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, persistenceId),
TableOperators.And,
TableQuery.GenerateFilterCondition("RowKey", QueryComparisons.LessThanOrEqual, SnapshotEntry.ToRowKey(criteria.MaxSequenceNr)));
if (criteria.MaxTimeStamp != DateTime.MinValue && criteria.MaxTimeStamp != DateTime.MaxValue)
{
comparsion = TableQuery.CombineFilters(
comparsion,
TableOperators.And,
TableQuery.GenerateFilterConditionForLong("SnapshotTimestamp", QueryComparisons.LessThanOrEqual, criteria.MaxTimeStamp.Ticks));
}
return(new TableQuery <SnapshotEntry>().Where(comparsion));
}