Package net.fabricmc.fabric.api.networking.v1

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 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, handler, understood, buf, synchronizer, responseSender) -&gt; {
 	if (!understood) {
 		handler.disconnect(Text.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(() -&gt; {
 		LoginInfoChecker checker = LoginInfoChecker.get(server);

 		if (!checker.check(handler.getConnectionInfo(), checkMessage)) {
 			handler.disconnect(Text.literal("Invalid credentials!"));
 			return;
 		}

 		responseSender.send(UPCOMING_CHECK, checker.buildSecondQueryPacket(handler, checkMessage));
 	}));
 });
      Usually it is enough to pass the return value for ThreadExecutor.submit(Runnable) for future.

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