again, very annoying that we have to account for this (it makes it easier for attackers to waste CPU time and memory), but we don't really have much of a choice.
some persona skins are insanely bloated and get split into hundreds of parts.
it's quite annoying that we have to accommodate this, but we can't keep allowing players to experience login timeouts without an obvious indication what's wrong.
Prior to this commit, upgrade schemas would be applied to blockstates with the same version, as there wasn't any way to know if they should be applied or not given Mojang's tendency to forget to bump the version.
However, it occurred to me that we only need to do this if there are multiple schemas present for the same version ID, which is rarely the case.
This allows skipping costly logic for blockstates on the newest version (the common case), reducing the time taken to process the blockstate for upgrading by over 30%.
Overall, this translates into less than 10% real performance improvement for chunk loading, but it's still a worthwhile improvement.
this will be useful for preventing resource pack sending from overloading the network.
it's not the best solution for that (since it means the RTT will limit the pack download speed), but it's easier than implementing congestion control and will work fine in most cases.
this is a pain :(
It appears the client always sorts the keys in alphabetical order due to use of std::map. However I'm not sure of the exact ordering behaviour, so it needs to be investigated.
closes#4912
I didn't merge the original PR because this needs to be checked for explicitly registered handlers as well as auto-detected ones from listeners.
