Paper/patches/server/0717-Optimize-HashMapPalette.patch
Jake Potrebic de04cbced5
Updated Upstream (Bukkit/CraftBukkit) (#10034)
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:
f29cb801 Separate checkstyle-suppressions file is not required
86f99bbe SPIGOT-7540, PR-946: Add ServerTickManager API
d4119585 SPIGOT-6903, PR-945: Add BlockData#getMapColor
b7a2ed41 SPIGOT-7530, PR-947: Add Player#removeResourcePack
9dd56255 SPIGOT-7527, PR-944: Add WindCharge#explode()
994a6163 Attempt upgrade of resolver libraries

CraftBukkit Changes:
b3b43a6ad Add Checkstyle check for unused imports
13fb3358e SPIGOT-7544: Scoreboard#getEntries() doesn't get entries but class names
3dda99c06 SPIGOT-7540, PR-1312: Add ServerTickManager API
2ab4508c0 SPIGOT-6903, PR-1311: Add BlockData#getMapColor
1dbdbbed4 PR-1238: Remove unnecessary sign ticking
659728d2a MC-264285, SPIGOT-7439, PR-1237: Fix unbreakable flint and steel is completely consumed while igniting creeper
e37e29ce0 Increase outdated build delay
c00438b39 SPIGOT-7530, PR-1313: Add Player#removeResourcePack
492dd80ce SPIGOT-7527, PR-1310: Add WindCharge#explode()
e11fbb9d7 Upgrade MySQL driver
9f3a0bd2a Attempt upgrade of resolver libraries
60d16d7ca PR-1306: Centralize Bukkit and Minecraft entity conversion

Spigot Changes:
06d602e7 Rebuild patches
2023-12-16 18:09:28 -08:00

58 lines
3.2 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..7b7b614e5c3a30be89eeea2d25112fc9bcb3052c 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 - 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 - 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
}
return i;