public override void CommitAndRestartTx()
{
/*
* This method is use by the Cypher runtime to cater for PERIODIC COMMIT, which allows a single query to
* periodically, after x number of rows, to commit a transaction and spawn a new one.
*
* To still keep track of the running stream after switching transactions, we need to open the new transaction
* before closing the old one. This way, a query will not disappear and appear when switching transactions.
*
* Since our transactions are thread bound, we must first unbind the old transaction from the thread before
* creating a new one. And then we need to do that thread switching again to close the old transaction.
*/
CheckNotTerminated();
CollectTransactionExecutionStatistic();
// (1) Unbind current transaction
QueryRegistryOperations oldQueryRegistryOperations = _statement.queryRegistration();
Statement oldStatement = _statement;
InternalTransaction oldTransaction = _transaction;
KernelTransaction oldKernelTx = _txBridge.getKernelTransactionBoundToThisThread(true);
_txBridge.unbindTransactionFromCurrentThread();
// (2) Create, bind, register, and unbind new transaction
_transaction = _graph.beginTransaction(TransactionType, SecurityContextConflict);
_kernelTransaction = _txBridge.getKernelTransactionBoundToThisThread(true);
_statement = _kernelTransaction.acquireStatement();
_statement.queryRegistration().registerExecutingQuery(_executingQuery);
_txBridge.unbindTransactionFromCurrentThread();
// (3) Rebind old transaction just to commit and close it (and unregister as a side effect of that)
_txBridge.bindTransactionToCurrentThread(oldKernelTx);
oldQueryRegistryOperations.UnregisterExecutingQuery(_executingQuery);
try
{
oldStatement.Close();
oldTransaction.Success();
oldTransaction.Close();
}
catch (Exception t)
{
// Corner case: The old transaction might have been terminated by the user. Now we also need to
// terminate the new transaction.
_txBridge.bindTransactionToCurrentThread(_kernelTransaction);
_transaction.failure();
_transaction.close();
_txBridge.unbindTransactionFromCurrentThread();
throw t;
}
// (4) Unbind the now closed old transaction and rebind the new transaction for continued execution
_txBridge.unbindTransactionFromCurrentThread();
_txBridge.bindTransactionToCurrentThread(_kernelTransaction);
}
internal virtual void CloseTransactionForPeriodicCommit()
{
_tx.close();
}
