public async Task Store(CapturedTransportOperation operation, Action triggerAdvance, SqlConnection conn, SqlTransaction trans)
{
var localState = linkState;
var seq = await sequence.GetNextValue(conn, trans).ConfigureAwait(false);
InterlocedEx.ExchangeIfGreaterThan(ref highestSeq, seq);
if (localState.IsStale(seq))
{
var freshLinkState = await linkStateTable.Get(operation.Destination, conn, trans).ConfigureAwait(false);
UpdateCachedLinkState(freshLinkState);
localState = linkState;
}
if (localState.ShouldAdvance(seq))
{
triggerAdvance();
}
if (localState.IsStale(seq))
{
throw new ProcessCurrentMessageLaterException("Link state is stale. Processing current message later.");
}
var tableName = localState.GetTableName(seq);
var table = new OutboxTable(tableName);
try
{
operation.OutgoingMessage.Headers[RouterDeduplicationHeaders.SequenceNumber] = seq.ToString();
operation.OutgoingMessage.Headers[RouterDeduplicationHeaders.SequenceKey] = sourceKey;
operation.AssignTable(tableName);
operation.AssignSequence(seq);
var persistentOperation = Convert(operation);
await table.Insert(persistentOperation, seq, conn, trans).ConfigureAwait(false);
}
catch (SqlException e)
{
if (e.Number == 547) //Constraint violation. We used very old seq and that value cannot be used any more because the epoch has advanced.
{
var freshLinkState = await linkStateTable.Get(operation.Destination, conn, trans).ConfigureAwait(false);
UpdateCachedLinkState(freshLinkState);
throw new ProcessCurrentMessageLaterException("Link state is stale. Processing current message later.");
}
throw;
}
catch (Exception ex)
{
log.Debug($"Unhandled exception while storing outbox operation with sequence {seq}", ex);
throw;
}
}
public async Task Uninstall(string destinationKey, SqlConnection conn, SqlTransaction trans)
{
var leftTable = new OutboxTable(OutboxTable.Left(sourceKey, destinationKey));
var rightTable = new OutboxTable(OutboxTable.Right(sourceKey, destinationKey));
var sequence = new OutboxSequence(sourceKey, destinationKey);
var linkStateTable = new LinkStateTable(sourceKey);
await linkStateTable.Drop(conn, trans).ConfigureAwait(false);
await leftTable.Drop(conn, trans).ConfigureAwait(false);
await rightTable.Drop(conn, trans).ConfigureAwait(false);
await sequence.Drop(conn, trans).ConfigureAwait(false);
}
async Task <LinkState> InitializeLinkState(LinkState lockedLinkState, SqlConnection conn, SqlTransaction initTransaction)
{
if (!lockedLinkState.Initialized)
{
var initializedState = lockedLinkState.Initialize(
OutboxTable.Left(sourceKey, destinationKey),
OutboxTable.Right(sourceKey, destinationKey), epochSize);
await initializedState.HeadSession.CreateConstraint(conn, initTransaction);
await initializedState.TailSession.CreateConstraint(conn, initTransaction);
await linkStateTable.Update(destinationKey, initializedState, conn, initTransaction).ConfigureAwait(false);
return(initializedState);
}
return(lockedLinkState);
}
async Task <LinkState> Advance(Func <OutgoingMessage, Task> dispatch, SqlConnection conn)
{
//Let's actually check if our values are correct.
var queriedLinkState = await linkStateTable.Get(destinationKey, conn);
if (!queriedLinkState.ShouldAdvance(highestSeq))
{
return(queriedLinkState);
}
log.Debug($"Attempting advance epoch for destination {destinationKey} based on link state {linkState}.");
if (!queriedLinkState.IsEpochAnnounced)
{
return(await AnnounceAdvance(queriedLinkState, dispatch, conn).ConfigureAwait(false));
}
var tableName = queriedLinkState.TailSession.Table;
var table = new OutboxTable(tableName);
if (await table.HasHoles(queriedLinkState.TailSession, conn).ConfigureAwait(false))
{
var holes = await table.FindHoles(queriedLinkState.TailSession, conn).ConfigureAwait(false);
if (holes.Any())
{
await PlugHoles(table, holes, dispatch, conn).ConfigureAwait(false);
}
}
var(advanced, newState) = await TryAdvanceEpochInDatabase(conn, tableName, queriedLinkState);
if (advanced)
{
return(await AnnounceAdvance(newState, dispatch, conn).ConfigureAwait(false));
}
return(newState);
}
public Task DropConstraint(SqlConnection conn, SqlTransaction trans)
{
var table = new OutboxTable(Table);
return(table.DropConstraint(Lo, Hi, conn, trans));
}
async Task PlugHoles(OutboxTable table, List <(long Id, HoleType Type)> holes, Func <OutgoingMessage, Task> dispatch, SqlConnection conn)
