PaperMC/patches/server/0323-Optimise-Chunk-getFluid.patch
Bjarne Koll c5a10665b8
Remove wall-time / unused skip tick protection (#11412)
Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
2024-09-19 16:36:07 +02:00

61 lines
3.1 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Tue, 14 Jan 2020 14:59:08 -0800
Subject: [PATCH] Optimise Chunk#getFluid
Removing the try catch and generally reducing ops should make it
faster on its own, however removing the try catch makes it
easier to inline due to code size
diff --git a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
index 6775217c065026aa61fce56a17c93010209b6941..59f9ff720e92c69e11afe7f6ccecd81b0e54a74d 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
@@ -270,18 +270,20 @@ public class LevelChunk extends ChunkAccess {
}
public FluidState getFluidState(int x, int y, int z) {
- try {
- int l = this.getSectionIndex(y);
-
- if (l >= 0 && l < this.sections.length) {
- LevelChunkSection chunksection = this.sections[l];
+ // Paper start - Perf: Optimise Chunk#getFluid
+ // try { // Remove try catch
+ int index = this.getSectionIndex(y);
+ if (index >= 0 && index < this.sections.length) {
+ LevelChunkSection chunksection = this.sections[index];
if (!chunksection.hasOnlyAir()) {
- return chunksection.getFluidState(x & 15, y & 15, z & 15);
+ return chunksection.states.get((y & 15) << 8 | (z & 15) << 4 | x & 15).getFluidState();
+ // Paper end - Perf: Optimise Chunk#getFluid
}
}
return Fluids.EMPTY.defaultFluidState();
+ /* // Paper - Perf: Optimise Chunk#getFluid
} catch (Throwable throwable) {
CrashReport crashreport = CrashReport.forThrowable(throwable, "Getting fluid state");
CrashReportCategory crashreportsystemdetails = crashreport.addCategory("Block being got");
@@ -291,6 +293,7 @@ public class LevelChunk extends ChunkAccess {
});
throw new ReportedException(crashreport);
}
+ */ // Paper - Perf: Optimise Chunk#getFluid
}
// CraftBukkit start
diff --git a/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java b/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
index 2c153af611399e884752f8256bee4fe32de5c572..90d1c3e23e753c29660f7d993b3c90ac022941c3 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
@@ -43,7 +43,7 @@ public class LevelChunkSection {
}
public FluidState getFluidState(int x, int y, int z) {
- return ((BlockState) this.states.get(x, y, z)).getFluidState();
+ return this.states.get(x, y, z).getFluidState(); // Paper - Perf: Optimise Chunk#getFluid; diff on change - we expect this to be effectively just getType(x, y, z).getFluid(). If this changes we need to check other patches that use IBlockData#getFluid.
}
public void acquire() {