net.openhft.chronicle.queue

Interface AppenderListener

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface AppenderListener

A listener interface for receiving events when excerpt are durably persisted to a queue.

Implementations of this interface must be thread-safe as further discussed under onExcerpt(Wire, long).

See Also:

SingleChronicleQueueBuilder.appenderListener(AppenderListener)

Method Summary

Modifier and Type	Method and Description
void	onExcerpt(@NotNull net.openhft.chronicle.wire.Wire wire, long index) Invoked after an excerpt has been durably persisted to a queue.

Method Detail

onExcerpt

void onExcerpt(@NotNull
               @NotNull net.openhft.chronicle.wire.Wire wire,
               long index)

Invoked after an excerpt has been durably persisted to a queue.

The Thread that invokes this method is unspecified and may change, even from invocation to invocation. This means implementations must ensure thread-safety to guarantee correct behaviour. In particular, it is an error to assume the appending Thread will always be used do invoke this method.

If this method throws an Exception, it is relayed to the call site. Therefore, care should be taken to minimise the probability of throwing Exceptions.

It is imperative that actions performed by the method are as performant as possible as any delay incurred by the invocation of this method will carry over to the appender used to actually persist the message (i.e. both for synchronous and asynchronous appenders actually storing messages).

No promise is given as to when this method is invoked. However, eventually the method will be called for each excerpt persisted to the queue.

No promise is given as to the order in which invocations are made of this method.

Parameters:

wire - representing access to the excerpt that was stored (non-null).

index - in the queue where the except was placed (non-negative)