private bool CheckAndRemoveIfExpired(KvKey key, VectorClock currentClock, KvMetadata metadataToCheck, WriteTransaction txn = null)
{
if (metadataToCheck == null || metadataToCheck.Status == Active && currentClock.TicksOffsetUtc < metadataToCheck.Expiry.TicksOffsetUtc)
{
return(true);
}
if (metadataToCheck.Status == Active && currentClock.TicksOffsetUtc < metadataToCheck.Expiry.TicksOffsetUtc)
{
if (txn != null)
{
RemoveExpired(txn, ToTableKey(key), metadataToCheck.Expiry);
}
else
{
_lmdb.WriteAsync(tx => RemoveExpired(tx, ToTableKey(key), metadataToCheck.Expiry), false);
}
}
return(false);
}
public TableKey ToTableKey(KvKey key) => new TableKey(key.Key);
public KvMetadata TryGetMetadata(AbstractTransaction txn, KvKey key) => _metadataTable.TryGet(txn, key);
public KvKey[] KeysByPrefix(AbstractTransaction txn, KvKey startFrom, uint page, uint pageSize) => txn.KeysByPrefix(_table, ToTableKey(startFrom), page, pageSize).Select(FromTableKey).ToArray();
public void Erase(WriteTransaction txn, KvKey key) => txn.Delete(_table, ToTableKey(key));
public bool AddOrUpdate(WriteTransaction txn, KvKey key, KvMetadata metadata) => txn.AddOrUpdate(_table, ToTableKey(key), ToTableValue(metadata));
public KvMetadata TryGet(AbstractTransaction txn, KvKey key) => TryGet(txn, ToTableKey(key));
public async Task <ulong> SyncHandler(WriteLogEvent syncEvent)
{
var posn = syncEvent.LocallySaved.GetReplicaValue(_targetReplicaId);
if (!posn.HasValue)
{
throw new EventLogException($"Broken syncEvent.LocallySaved during replication '{syncEvent.LocallySaved}'. For replica '{_targetReplicaId}'");
}
var pos = posn.Value;
if (_cancellationToken.IsCancellationRequested)
{
return(pos);
}
switch (syncEvent.LoggedEventCase)
{
case WriteLogEvent.LoggedEventOneofCase.Updated:
var addedOrUpdated = syncEvent.Updated;
await _lmdb.WriteAsync(txn =>
{
var addMetadata = new KvMetadata
{
Status = Active,
Expiry = addedOrUpdated.Expiry,
Action = Replicated,
Originated = syncEvent.Originated,
ValueMetadata = syncEvent.ValueMetadata,
CorrelationId = syncEvent.CorrelationId
};
var wasUpdated = _kvTable.Add(
txn,
new KvKey(addedOrUpdated.Key),
addMetadata,
new KvValue(addedOrUpdated.Value),
(key, vcOld, vcNew) => vcOld.Earlier(vcNew));
_replicationTable.SetLastPos(txn, _targetReplicaId, pos);
_kvTable.StatusTable.IncrementCounters(txn, replicatedAdds: 1);
// TODO: Should we do anything if the value wasn't updated? Maybe logging?
}, false, true);
break;
case WriteLogEvent.LoggedEventOneofCase.Deleted:
var deleted = syncEvent.Deleted;
await _lmdb.WriteAsync(txn =>
{
_updateClock(txn, _targetReplicaId, syncEvent.LocallySaved.GetReplicaValue(_targetReplicaId));
var delMetadata = new KvMetadata
{
Status = KvMetadata.Types.Status.Deleted,
Expiry = syncEvent.LocallySaved.TicksOffsetUtc.ToTimestamp(),
Action = Replicated,
Originated = syncEvent.Originated,
OriginatorReplicaId = syncEvent.OriginatorReplicaId,
CorrelationId = syncEvent.CorrelationId,
ValueMetadata = syncEvent.ValueMetadata,
};
var kvKey = new KvKey(deleted.Key);
_kvTable.Delete(txn, kvKey, delMetadata);
_replicationTable.SetLastPos(txn, _targetReplicaId, pos);
_kvTable.StatusTable.IncrementCounters(txn, replicatedDeletes: 1);
// TODO: Should we do anything if the value wasn't updated? Maybe logging?
}, false, true);
break;
case WriteLogEvent.LoggedEventOneofCase.None:
throw new ArgumentException("syncEvent", $"Unexpected LogEvent case: {syncEvent.LoggedEventCase}");
default:
throw new ArgumentOutOfRangeException();
}
return(pos);
}
