PaperMC/patches/server/0715-Optimize-HashMapPalette.patch
Nassim Jahnke e035fd7034
Updated Upstream (Bukkit/CraftBukkit/Spigot)
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:
cc9aa21a SPIGOT-6399, SPIGOT-7344: Clarify collidable behavior for player entities
f23325b6 Add API for per-world simulation distances
26e1774e Add API for per-world view distances
0b541e60 Add PlayerLoginEvent#getRealAddress
5f027d2d PR-949: Add Vector#fromJOML() overloads for read-only vector types

CraftBukkit Changes:
bcf56171a PR-1321: Clean up some stuff which got missed during previous PRs
7f833a2d1 SPIGOT-7462: Players no longer drop XP after dying near a Sculk Catalyst
752aac669 Implement APIs for per world view and simulation distances
57d7ef433 Preserve empty enchantment tags for glow effect
465ec3fb4 Remove connected check on setScoreboard
f90ce621e Use one PermissibleBase for all command blocks
5876cca44 SPIGOT-7550: Fix creation of Arrow instances
f03fc3aa3 SPIGOT-7549: ServerTickManager#setTickRate incorrect Precondition
9d7f49b01 SPIGOT-7548: Fix wrong spawn location for experience orb and dropped item

Spigot Changes:
ed9ba9a4 Drop no longer required patch ignoring -o option
86b5dd6a SPIGOT-7546: Fix hardcoded check for outdated client message
aa7cde7a Remove obsolete APIs for per world view and simulation distances
6dff577e Remove obsolete patch preserving empty `ench` tags
a3bf95b8 Remove obsolete PlayerLoginEvent#getRealAddress
1b02f5d6 Remove obsolete connected check on setScoreboard patch
acf717eb Remove obsolete command block PermissibleBase patch
053fa2a9 Remove redundant patch dealing with null tile entities
2023-12-26 00:18:13 +01:00

57 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;