PaperFixes

A collection of bug and performance fixes from CraftBukkit, Spigot, and Paper in a Forge mod.\ This is a performance mod and bugs and incompatibilities could occur, please open an issue if you find any.\

Current Fixes

Common (Integrated & Dedicated Server)

• Chest open and close sounds are no longer processed in the tile entity tick loop
• Invalid mob spawners are removed when detected
• MC-54738
• Explosions no longer process dead entities
• Block density is cached so that expensive lookup operations aren't done every time there's an explosion
• MC-80966
• The outbound packet queue for a player is cleared on disconnect
• MC-133373
• MC-98153
• The game tick look has been significantly improved and catches up on missed ticks instead of skipping them. There are two options, always try to keep the TPS at 19 or higher (default) and no sleep on lag.
• The improved tick loop comes with a new command for viewing TPS, /tps. The command provides a quick overview of average TPS from the last five seconds, one minute, five minutes, and fifteen minutes. This command appears to be inaccurate for some unknown reason, and I would generally recommend Spark for accurate TPS, tick usage, and system information.
• (Disabled by default) Null (invalid or broken) tile entities that could exist when a world is having its entities updated are removed when detected.
• The ability to toggle spawn chunks if they're not being used. See below to find out why you might not want them enabled.
  • Spawn chunks are a 25x25 area of chunks around spawn that is always loaded by the game.
  • A smaller 19x19 chunk area is constantly fully ticked, except random ticks, as if a player were in it.
  • This is the equivalent of three and a half players' worth of ticked chunks if you use the default ten-chunk (10x10 area) view distance.
• Entities now use a shared Random instance. Before, the game created a new Random instance for each entity, which is just unnecessary memory usage. This also removes the rand.setSeed call from EntitySquid since it's pointless and would also just cause an error to be printed every time a squid spawns.
• The entity data manager now uses an Int2ObjectOpenHashMap for entries which has a smaller memory footprint and is significantly faster.
• The game will no longer attempt to add null block info to a crash report.
• Region files now have their headers loaded entirely instead of the previous method of loading them in chunks which hurt performance instead of helping it.
• Instead of closing every region in the region file cache when it reaches 256 regions, the game will close the region that is accessed the least.
• The chunk provider caches the last accessed chunk. This can make a big difference in chunk loading and world generation as the game commonly accesses the same chunks multiple times in a row.
• getCanSpawnHere in EntityWaterMob has been corrected and checks if the entity can spawn in the given area instead of immediately returning true.
• Enchantments on items are sorted by their IDs to fix issues with the game thinking items that are the same are different.
• The chunk loader's saving has been greatly improved, removing a random 10ms sleep call and using a queue instead of a hash map for proper queueing and popping instead of throwing iterators everywhere. This fixes slowdowns when many chunks are queued to be saved and fixes race conditions that could cause chunks to fail to save. If you toggle enableIoThreadSleep on, the thread will only sleep for 2ms instead of the 10ms from before but will use more memory again.

Client

• The client chunk provider caches the last accessed chunk the same way the server provider does.

Known Incompatibilities

• The improved tick loop is not compatible with the mixin.bugfix.slow_tps_catchup option from VintageFix (removed as of commit ecbc3e1) and the tick loop changes from Forged Carpet and likely from any other mod.
• removeNullTileEntities breaks Botania's flowers because of some odd way that Botania was written.
• Bad core mods can cause re-entry errors and crash the game as soon as it starts. This is not PaperFixes' fault and is unavoidable because these mods are loading game classes too early. The only solution is to replace them with a fork that fixes the problems.\ An incomplete list of problematic core mods and solutions:
  • Quark: Replace with Quark: RoTN Edition (Thanks to sahih_international for finding this)