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