PaperMC/patches/server/0671-Optimize-HashMapPalette.patch
Nassim Jahnke 31699ae9a8
Updated Upstream (Bukkit/CraftBukkit) (#10242)
* Updated Upstream (Bukkit/CraftBukkit)

Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
a6a9d2a4 Remove some old ApiStatus.Experimental annotations
be72314c SPIGOT-7300, PR-829: Add new DamageSource API providing enhanced information about entity damage
b252cf05 SPIGOT-7576, PR-970: Add methods in MushroomCow to change stew effects
b1c689bd PR-902: Add Server#isLoggingIPs to get log-ips configuration
08f86d1c PR-971: Add Player methods for client-side potion effects
2e3024a9 PR-963: Add API for in-world structures
a23292a7 SPIGOT-7530, PR-948: Improve Resource Pack API with new 1.20.3 functionality
1851857b SPIGOT-3071, PR-969: Add entity spawn method with spawn reason
cde4c52a SPIGOT-5553, PR-964: Add EntityKnockbackEvent

CraftBukkit Changes:
38fd4bd50 Fix accidentally renamed internal damage method
80f0ce4be SPIGOT-7300, PR-1180: Add new DamageSource API providing enhanced information about entity damage
7e43f3b16 SPIGOT-7581: Fix typo in BlockMushroom
ea14b7d90 SPIGOT-7576, PR-1347: Add methods in MushroomCow to change stew effects
4c687f243 PR-1259: Add Server#isLoggingIPs to get log-ips configuration
22a541a29 Improve support for per-world game rules
cb7dccce2 PR-1348: Add Player methods for client-side potion effects
b8d6109f0 PR-1335: Add API for in-world structures
4398a1b5b SPIGOT-7577: Make CraftWindCharge#explode discard the entity
e74107678 Fix Crafter maximum stack size
0bb0f4f6a SPIGOT-7530, PR-1314: Improve Resource Pack API with new 1.20.3 functionality
4949f556d SPIGOT-3071, PR-1345: Add entity spawn method with spawn reason
20ac73ca2 PR-1353: Fix Structure#place not working as documented with 0 palette
3c1b77871 SPIGOT-6911, PR-1349: Change max book length in CraftMetaBook
333701839 SPIGOT-7572: Bee nests generated without bees
f48f4174c SPIGOT-5553, PR-1336: Add EntityKnockbackEvent
2024-02-11 22:28:00 +01:00

57 lines
3.3 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: stonar96 <minecraft.stonar96@gmail.com>
Date: Sun, 17 Jan 2021 01:11:36 +0100
Subject: [PATCH] Optimize HashMapPalette
HashMapPalette uses an instance of CrudeIncrementalIntIdentityHashBiMap
internally. A Palette has a preset maximum size = 1 << bits.
CrudeIncrementalIntIdentityHashBiMap has an initial size but is
automatically resized. The CrudeIncrementalIntIdentityHashBiMap is created
with the maximum size in the constructor of HashMapPalette, with the aim
that it doesn't need to be resized anymore. However, there are two things
that I think Mojang hasn't considered here:
1) The CrudeIncrementalIntIdentityHashBiMap is resized, when its initial
size is reached and not the next time, when a further object is added.
2) HashMapPalette adds objects (unnecessarily) before checking if the
initial size of CrudeIncrementalIntIdentityHashBiMap is reached.
This means to actually avoid resize operations in
CrudeIncrementalIntIdentityHashBiMap, one has to add 2 to the initial size
or add 1 and check the size before adding objects. This commit implements
the second approach. Note that this isn't only an optimization but also
makes async reads of Palettes fail-safe. An async read while the
CrudeIncrementalIntIdentityHashBiMap is resized is fatal and can even lead
to corrupted data. This is also something that Anti-Xray is currently
relying on.
diff --git a/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java b/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java
index 26e093243c70313b777483d9555fb1557443c9b8..92c360f02ef6be77c6c8eee3226947468194ec23 100644
--- a/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java
+++ b/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java
@@ -20,7 +20,7 @@ public class HashMapPalette<T> implements Palette<T> {
}
public HashMapPalette(IdMap<T> idList, int indexBits, PaletteResize<T> listener) {
- this(idList, indexBits, listener, CrudeIncrementalIntIdentityHashBiMap.create(1 << indexBits));
+ this(idList, indexBits, listener, CrudeIncrementalIntIdentityHashBiMap.create((1 << indexBits) + 1)); // Paper - Perf: Avoid unnecessary resize operation in CrudeIncrementalIntIdentityHashBiMap
}
private HashMapPalette(IdMap<T> idList, int indexBits, PaletteResize<T> listener, CrudeIncrementalIntIdentityHashBiMap<T> map) {
@@ -38,10 +38,16 @@ public class HashMapPalette<T> implements Palette<T> {
public int idFor(T object) {
int i = this.values.getId(object);
if (i == -1) {
- i = this.values.add(object);
- if (i >= 1 << this.bits) {
+ // Paper start - Perf: Avoid unnecessary resize operation in CrudeIncrementalIntIdentityHashBiMap and optimize
+ // We use size() instead of the result from add(K)
+ // This avoids adding another object unnecessarily
+ // Without this change, + 2 would be required in the constructor
+ if (this.values.size() >= 1 << this.bits) {
i = this.resizeHandler.onResize(this.bits + 1, object);
+ } else {
+ i = this.values.add(object);
}
+ // Paper end - Perf: Avoid unnecessary resize operation in CrudeIncrementalIntIdentityHashBiMap and optimize
}
return i;