Handling NotApplied Messages

When CME detects a message sequence number gap from the customer and sends the NotApplied message, the Handler calls the OnixS::CME::iLink3::SessionListener::onNotApplied method. If this methods returns

• OnixS::CME::iLink3::NotAppliedAction::SendGapFill, then the Handler will send the Sequence message. This message will instruct the exchange to ignore the gap and start with its NextSeqNo value as the valid sequence number.
• OnixS::CME::iLink3::NotAppliedAction::DoNothing, then no messages are sent in the reply. The exchange will not accept any subsequent message having a higher than expected sequence number until the customer replay business messages with those missing sequence numbers.

Note

If the OnixS::CME::iLink3::SessionListener::onNotApplied method is not overridden in the derived class, then it returns OnixS::CME::iLink3::NotAppliedAction::Default.

See also

The NotApplied CME article.

Code Example

using namespace OnixS::CME::iLink3;

class NotAppliedListener : public SessionListener
{
public:

    NotAppliedAction::Enum onNotApplied(const Messaging::NotApplied513& msg, Session*) override
    {
        std::cout << msg.msgCount() << " messages were lost by the exchange, started from the sequence number " << msg.fromSeqNo() << std::endl;

        const bool SendGapFill = true;

        return SendGapFill ? NotAppliedAction::SendGapFill : NotAppliedAction::DoNothing;
    }
};