/// <summary>
/// Creates a new transaction log manager.
/// </summary>
/// <param name="engineId">The engine this transaction log manager is used for. Only used for logging purposes.</param>
/// <param name="keyValueStore">The key/value store to write transaction logs to.</param>
/// <param name="policy">The serialization policy to use when serializing objects.</param>
public TransactionLogManager(Uri engineId, IKeyValueStore keyValueStore, ISerializationPolicy policy)
{
_engineId = engineId;
_keyValueStore = keyValueStore;
_policy = policy;
_lock = new AsyncLock();
_versionedLogs = new Queue <ITransactionLog>();
_metadataTable = new SerializingKeyValueTable <string>(
_keyValueStore.GetTable(MetadataTableName),
(str, s) =>
{
using var writer = new BinaryWriter(s);
writer.Write(str);
},
s =>
{
using var reader = new BinaryReader(s);
return(reader.ReadString());
}
);
using (var t = _keyValueStore.CreateTransaction())
{
var tx = _metadataTable.Enter(t);
if (!tx.Contains(ActiveCountKey))
{
Invariant.Assert(!tx.Contains(LatestKey) && !tx.Contains(HeldCountKey), "Transaction log versioning keys are only partially populated.");
_activeCount = _heldCount = _latest = 0;
}
else
{
Invariant.Assert(tx.Contains(LatestKey) && tx.Contains(HeldCountKey), "Transaction log versioning keys are only partially populated.");
_activeCount = long.Parse(tx[ActiveCountKey], CultureInfo.InvariantCulture);
_heldCount = long.Parse(tx[HeldCountKey], CultureInfo.InvariantCulture);
_latest = long.Parse(tx[LatestKey], CultureInfo.InvariantCulture);
}
}
Tracing.Transaction_Log_Initialization(null, _engineId, _latest, _activeCount, _heldCount);
for (var i = _latest - _heldCount + 1; i <= _latest; i++)
{
_versionedLogs.Enqueue(new TransactionLog(_keyValueStore, _policy, i));
}
}
private Dictionary <string, ArtifactOperation> Coalesce(
IKeyValueStore keyValueStore,
IList <ITransactionLog> logs,
Func <ITransactionLog, IKeyValueTable <string, ArtifactOperation> > tableSelector)
{
var result = new Dictionary <string, ArtifactOperation>();
foreach (var log in logs)
{
var table = tableSelector(log);
using var tx = keyValueStore.CreateTransaction();
var txTable = table.Enter(tx);
foreach (var item in txTable)
{
if (result.TryGetValue(item.Key, out ArtifactOperation op))
{
Tracing.Transaction_Log_Coalesce(null, _parent._engineId, item.Key, op.OperationKind.ToString(), item.Value.OperationKind.ToString());
//
// SECOND
//
// Create Delete DeleteCreate
// +--------------+--------------+--------------+
// F Create | Invalid | No-op | Create |
// I +--------------+--------------+--------------+
// R Delete | DeleteCreate | Invalid | Invalid |
// S +--------------+--------------+--------------+
// T DeleteCreate | Invalid | Delete | DeleteCreate |
// +--------------+--------------+--------------+
//
switch (op.OperationKind)
{
case ArtifactOperationKind.Create:
switch (item.Value.OperationKind)
{
case ArtifactOperationKind.Create:
UpdateInvalidReplays(item.Key, item.Value, result, _invalidReplaySequence);
break;
case ArtifactOperationKind.Delete:
result.Remove(item.Key);
break;
case ArtifactOperationKind.DeleteCreate:
result[item.Key] = ArtifactOperation.Create(item.Value.Expression, item.Value.State);
break;
}
break;
case ArtifactOperationKind.Delete:
switch (item.Value.OperationKind)
{
case ArtifactOperationKind.Create:
result[item.Key] = ArtifactOperation.DeleteCreate(item.Value.Expression, item.Value.State);
break;
case ArtifactOperationKind.Delete:
UpdateInvalidReplays(item.Key, item.Value, result, _invalidReplaySequence);
break;
case ArtifactOperationKind.DeleteCreate:
UpdateInvalidReplays(item.Key, item.Value, result, _invalidReplaySequence);
break;
}
break;
case ArtifactOperationKind.DeleteCreate:
switch (item.Value.OperationKind)
{
case ArtifactOperationKind.Create:
UpdateInvalidReplays(item.Key, item.Value, result, _invalidReplaySequence);
break;
case ArtifactOperationKind.Delete:
result[item.Key] = item.Value;
break;
case ArtifactOperationKind.DeleteCreate:
result[item.Key] = item.Value;
break;
}
break;
}
}
else
{
result.Add(item.Key, item.Value);
}
}
}
return(result);
}
