Interface ServerLoginNetworking.LoginSynchronizer

Enclosing class:

ServerLoginNetworking

Functional Interface:

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

@FunctionalInterface
@NonExtendable
public static interface ServerLoginNetworking.LoginSynchronizer

Allows blocking client log-in until all futures passed into waitFor(Future) are completed.

Method Summary

Modifier and Type	Method	Description
void	waitFor(Future<?> future)	Allows blocking client log-in until the future is done.

Method Details

waitFor

void waitFor(Future<?> future)

Allows blocking client log-in until the future is done.

Since packet reception happens on netty's event loops, this allows handlers to perform logic on the Server Thread, etc. For instance, a handler can prepare an upcoming query request or check necessary login data on the server thread.

Here is an example where the player log-in is blocked so that a credential check and building of a followup query request can be performed properly on the logical server thread before the player successfully logs in:

ServerLoginNetworking.registerGlobalReceiver(CHECK_CHANNEL, (server, listener, understood, buf, synchronizer, responseSender) -> {
	if (!understood) {
		listener.disconnect(Component.literal("Only accept clients that can check!"));
		return;
	}

	String checkMessage = buf.readString(32767);

	// Just send the CompletableFuture returned by the server's submit method
	synchronizer.waitFor(server.submit(() -> {
		LoginInfoChecker checker = LoginInfoChecker.get(server);

		if (!checker.check(listener.getUserName(), checkMessage)) {
			listener.disconnect(Component.literal("Invalid credentials!"));
			return;
		}

		responseSender.send(UPCOMING_CHECK, checker.buildSecondQueryPacket(listener, checkMessage));
	}));
});

Usually it is enough to pass the return value for BlockableEventLoop.submit(Runnable) for future.

Parameters:

future - the future that must be done before the player can log in