/// <summary>
/// Rolls back the current transaction.
/// </summary>
/// <exception cref="TransactionException">Thrown if the stack is empty.</exception>
internal void Rollback()
{
Transaction transaction;
using (TimedLock.Lock(syncLock))
{
if (base.Count == 0)
{
throw new TransactionException(EmptyMsg);
}
transaction = base.Pop();
if (base.Count == 0)
{
manager.Trace(0, "Begin rollback BASE", "ID=" + id.ToString());
}
else
{
manager.Trace(0, string.Format("Begin rollback NESTED [{0}]", base.Count), "ID=" + id.ToString());
}
// Submit the operations being undone back to the
// resource in the reverse order that they were
// originally performed.
ITransactedResource resource = manager.Resource;
UpdateContext context = new UpdateContext(manager, false, false, true, ID);
List <ILogPosition> positions;
positions = operationLog.GetPositionsTo(transaction.Position);
if (resource.BeginUndo(context))
{
for (int i = 0; i < positions.Count; i++)
{
var operation = operationLog.Read(manager.Resource, positions[i]);
manager.Trace(0, "Undo: " + operation.Description, "ID=" + id.ToString());
resource.Undo(context, operation);
}
}
resource.EndUndo(context);
if (base.Count == 0)
{
manager.EndTransaction(this);
manager.Trace(0, "End rollback BASE", "ID=" + id.ToString());
}
else
{
operationLog.Truncate(transaction.Position);
manager.Trace(0, string.Format("End rollback NESTED [{0}]", base.Count), "ID=" + id.ToString());
}
}
}
