PaperMC/Spigot-Server-Patches/0324-Use-ConcurrentHashMap-in-JsonList.patch
Shane Freeder ea855e2b46 Updated Upstream (Bukkit/CraftBukkit/Spigot)
Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Developers!: You will need to clean up your work/Minecraft/1.13.2 folder
for this

Also, restore a patch that was dropped in the last upstream

Bukkit Changes:
279eeab3 Fix command description not being set
96e2bb18 Remove debug print from SyntheticEventTest

CraftBukkit Changes:
d3ed1516 Fix dangerously threaded beacons
217a293d Don't relocate joptsimple to allow --help to work.
1be05a21 Prepare for imminent Java 12 release
a49270b2 Mappings Update
5259d80c SPIGOT-4669: Fix PlayerTeleportEvent coordinates for relative teleports

Spigot Changes:
e6eb36f2 Rebuild patches
2019-03-20 01:55:16 +00:00

103 lines
4.5 KiB
Diff

From b52072b894657cdc5b9820705e7ecddb1c335316 Mon Sep 17 00:00:00 2001
From: egg82 <phantom_zero@ymail.com>
Date: Tue, 7 Aug 2018 01:24:23 -0600
Subject: [PATCH] Use ConcurrentHashMap in JsonList
This is specifically aimed at fixing #471
Using a ConcurrentHashMap because thread safety
The performance benefit of Map over ConcurrentMap is negligabe at best in this scenaio, as most operations will be get and not add or remove
Even without considering the use-case the benefits are still negligable
Original ideas for the system included an expiration policy and/or handler
The simpler solution was to use a computeIfPresent in the get method
This will simultaneously have an O(1) lookup time and automatically expire any values
Since the get method (nor other similar methods) don't seem to have a critical need to flush the map to disk at any of these points further processing is simply wasteful
Meaning the original function expired values unrelated to the current value without actually having any explicit need to
The h method was heavily modified to be much more efficient in its processing
Also instead of being called on every get, it's now called just before a save
This will eliminate stale values being flushed to disk
Modified isEmpty to use the isEmpty() method instead of the slightly confusing size() < 1
The point of this is readability, but does have a side-benefit of a small microptimization
Finally, added a couple obfhelpers for the modified code
diff --git a/src/main/java/net/minecraft/server/JsonList.java b/src/main/java/net/minecraft/server/JsonList.java
index 026ef7939..b7cde4d41 100644
--- a/src/main/java/net/minecraft/server/JsonList.java
+++ b/src/main/java/net/minecraft/server/JsonList.java
@@ -35,7 +35,8 @@ public class JsonList<K, V extends JsonListEntry<K>> {
protected static final Logger a = LogManager.getLogger();
protected final Gson b;
private final File c;
- private final Map<String, V> d = Maps.newHashMap();
+ // Paper - replace HashMap is ConcurrentHashMap
+ private final Map<String, V> d = Maps.newConcurrentMap(); private final Map<String, V> getBackingMap() { return this.d; } // Paper - OBFHELPER
private boolean e = true;
private static final ParameterizedType f = new ParameterizedType() {
public Type[] getActualTypeArguments() {
@@ -84,8 +85,13 @@ public class JsonList<K, V extends JsonListEntry<K>> {
@Nullable
public V get(K k0) {
- this.h();
- return (V) this.d.get(this.a(k0)); // CraftBukkit - fix decompile error
+ // Paper start
+ // this.h();
+ // return (V) this.d.get(this.a(k0)); // CraftBukkit - fix decompile error
+ return (V) this.getBackingMap().computeIfPresent(this.getMappingKey(k0), (k, v) -> {
+ return v.hasExpired() ? null : v;
+ });
+ // Paper end
}
public void remove(K k0) {
@@ -114,9 +120,11 @@ public class JsonList<K, V extends JsonListEntry<K>> {
// CraftBukkit end
public boolean isEmpty() {
- return this.d.size() < 1;
+ // return this.d.size() < 1; // Paper
+ return this.getBackingMap().isEmpty(); // Paper - readability is the goal. As an aside, isEmpty() uses only sumCount() and a comparison. size() uses sumCount(), casts, and boolean logic
}
+ protected final String getMappingKey(K k0) { return a(k0); } // Paper - OBFHELPER
protected String a(K k0) {
return k0.toString();
}
@@ -125,8 +133,9 @@ public class JsonList<K, V extends JsonListEntry<K>> {
return this.d.containsKey(this.a(k0));
}
+ private void removeStaleEntries() { h(); } // Paper - OBFHELPER
private void h() {
- List<K> list = Lists.newArrayList();
+ /*List<K> list = Lists.newArrayList();
Iterator iterator = this.d.values().iterator();
while (iterator.hasNext()) {
@@ -143,8 +152,10 @@ public class JsonList<K, V extends JsonListEntry<K>> {
K k0 = (K) iterator.next(); // CraftBukkit - decompile error
this.d.remove(this.a(k0));
- }
+ }*/
+ this.getBackingMap().values().removeIf(JsonListEntry::hasExpired);
+ // Paper end
}
protected JsonListEntry<K> a(JsonObject jsonobject) {
@@ -156,6 +167,7 @@ public class JsonList<K, V extends JsonListEntry<K>> {
}
public void save() throws IOException {
+ this.removeStaleEntries(); // Paper - remove expired values before saving
Collection<V> collection = this.d.values();
String s = this.b.toJson(collection);
BufferedWriter bufferedwriter = null;
--
2.21.0