/// <summary>
/// This begins an async commit and starts a new transaction immediately.
/// The current transaction is considered completed in memory but not yet
/// committed to disk. This *must* be completed by calling EndAsyncCommit.
/// </summary>
public LowLevelTransaction BeginAsyncCommitAndStartNewTransaction()
{
if (Flags != TransactionFlags.ReadWrite)
{
ThrowReadTranscationCannotDoAsyncCommit();
}
if (_asyncCommitNextTransaction != null)
{
ThrowAsyncCommitAlreadyCalled();
}
// we have to check the state before we complete the transaction
// because that would change whether we need to write to the journal
var writeToJournalIsRequired = WriteToJournalIsRequired();
CommitStage1_CompleteTransaction();
var nextTx = new LowLevelTransaction(this,
writeToJournalIsRequired ? Id + 1 : Id
);
_asyncCommitNextTransaction = nextTx;
AsyncCommit = writeToJournalIsRequired
? Task.Run(() => { CommitStage2_WriteToJournal(); return(true); })
: NoWriteToJournalRequiredTask;
try
{
_env.IncrementUsageOnNewTransaction();
_env.ActiveTransactions.Add(nextTx);
_env.WriteTransactionStarted();
return(nextTx);
}
catch (Exception)
{
// failure here means that we'll try to complete the current transaction normaly
// then throw as if commit was called normally and the next transaction failed
_env.DecrementUsageOnTransactionCreationFailure();
EndAsyncCommit();
AsyncCommit = null;
_disposed |= TxState.Errored;
throw;
}
}