Paper/patches/server/0354-Optimise-getChunkAt-calls-for-loaded-chunks.patch
Spottedleaf 01a13871de
Rewrite chunk system (#8177)
Patch documentation to come

Issues with the old system that are fixed now:
- World generation does not scale with cpu cores effectively.
- Relies on the main thread for scheduling and maintaining chunk state, dropping chunk load/generate rates at lower tps.
- Unreliable prioritisation of chunk gen/load calls that block the main thread.
- Shutdown logic is utterly unreliable, as it has to wait for all chunks to unload - is it guaranteed that the chunk system is in a state on shutdown that it can reliably do this? Watchdog shutdown also typically failed due to thread checks, which is now resolved.
- Saving of data is not unified (i.e can save chunk data without saving entity data, poses problems for desync if shutdown is really abnormal.
- Entities are not loaded with chunks. This caused quite a bit of headache for Chunk#getEntities API, but now the new chunk system loads entities with chunks so that they are ready whenever the chunk loads in. Effectively brings the behavior back to 1.16 era, but still storing entities in their own separate regionfiles.

The above list is not complete. The patch documentation will complete it.

New chunk system hard relies on starlight and dataconverter, and most importantly the new concurrent utilities in ConcurrentUtil.

Some of the old async chunk i/o interface (i.e the old file io thread reroutes _some_ calls to the new file io thread) is kept for plugin compat reasons. It will be removed in the next major version of minecraft.

The old legacy chunk system patches have been moved to the removed folder in case we need them again.
2022-09-26 01:02:51 -07:00

67 Zeilen
3.0 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Sat, 25 Jan 2020 17:04:35 -0800
Subject: [PATCH] Optimise getChunkAt calls for loaded chunks
bypass the need to get a player chunk, then get the either,
then unwrap it...
diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
index 2d0a8668d1828fe085631079798a36374a0d4844..f3375712ae25ef1503a030b3059477f350d922da 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -420,6 +420,12 @@ public class ServerChunkCache extends ChunkSource {
return this.getChunk(x, z, leastStatus, create);
}, this.mainThreadProcessor).join();
} else {
+ // Paper start - optimise for loaded chunks
+ LevelChunk ifLoaded = this.getChunkAtIfLoadedMainThread(x, z);
+ if (ifLoaded != null) {
+ return ifLoaded;
+ }
+ // Paper end
ProfilerFiller gameprofilerfiller = this.level.getProfiler();
gameprofilerfiller.incrementCounter("getChunk");
@@ -463,39 +469,7 @@ public class ServerChunkCache extends ChunkSource {
if (!io.papermc.paper.util.TickThread.isTickThread()) { // Paper - rewrite chunk system
return null;
} else {
- this.level.getProfiler().incrementCounter("getChunkNow");
- long k = ChunkPos.asLong(chunkX, chunkZ);
-
- for (int l = 0; l < 4; ++l) {
- if (k == this.lastChunkPos[l] && this.lastChunkStatus[l] == ChunkStatus.FULL) {
- ChunkAccess ichunkaccess = this.lastChunk[l];
-
- return ichunkaccess instanceof LevelChunk ? (LevelChunk) ichunkaccess : null;
- }
- }
-
- ChunkHolder playerchunk = this.getVisibleChunkIfPresent(k);
-
- if (playerchunk == null) {
- return null;
- } else {
- Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure> either = (Either) playerchunk.getFutureIfPresent(ChunkStatus.FULL).getNow(null); // CraftBukkit - decompile error
-
- if (either == null) {
- return null;
- } else {
- ChunkAccess ichunkaccess1 = (ChunkAccess) either.left().orElse(null); // CraftBukkit - decompile error
-
- if (ichunkaccess1 != null) {
- this.storeInCache(k, ichunkaccess1, ChunkStatus.FULL);
- if (ichunkaccess1 instanceof LevelChunk) {
- return (LevelChunk) ichunkaccess1;
- }
- }
-
- return null;
- }
- }
+ return this.getChunkAtIfLoadedMainThread(chunkX, chunkZ); // Paper - optimise for loaded chunks
}
}