Adding custom latency delay

[bendgk]

I'm experimenting with latency and how it affects Minecraft clients and servers.

What would be the easiest way to introduce "fake" latency between a node-minecraft-protocol client and a java server?

Essentially I'm thinking of something like being able to delay all packet writes by a custom spoofedLatency field.

Any way to currently do this? Where should I look if I wanted to implement such a feature?

[IceTank]

You can make this by using a proxy to connect to a server. Then relay the packets after a certain delay. Or you can overwrite the write function off a client or server and replace it with a dummy function that takes the arguments and writes them after a while. Delaying packets can cause instability tho.

[bendgk]

So I forked the repo, and used setTimeout to delay the write and writeRaw functions found in client.js however that didn't seem to work, the node player never seems to be able to join the server. I then tried to do the same in
deserializer.on('data', () =>{}) however that lead to deserialization problems.

If you have time, could you care to elaborate why this is happening and what a possible remedy may be?

I may just end up writing a proxy, seems like the most hassle free solution...

you can view my changes to client.js here

[IceTank]

You can use the proxy example and change this line to use something like setTimeout to delay the write

node-minecraft-protocol/examples/proxy/proxy.js

Line 108 in 836675b

if (!endedTargetClient) { targetClient.write(meta.name, data) }

Or you can do something like this

const client = createClient(...)
const originalWrite = client.write
client.write = (...args) => {
  setTimeout(() => {
    originalWrite(...args)
  }, 500)
}