Leaf/patches/server/0041-Petal-reduce-work-done-by-game-event-system.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: peaches94 <peachescu94@gmail.com>
Date: Sun, 10 Jul 2022 13:29:20 -0500
Subject: [PATCH] Petal: reduce work done by game event system

Original license: GPL v3
Original project: https://github.com/Bloom-host/Petal

1. going into game event dispatching can be expensive so run the checks before dispatching

2. EuclideanGameEventListenerRegistry is not used concurrently so we ban that usage for improved performance with allays

diff --git a/src/main/java/net/minecraft/world/level/block/entity/SculkCatalystBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/SculkCatalystBlockEntity.java
index 83481539e058e5f428d9951e409fed62ef159e5c..ef2b60aa7686c92d27ce146ef320e05eea127c87 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/SculkCatalystBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/SculkCatalystBlockEntity.java
@@ -65,7 +65,7 @@ public class SculkCatalystBlockEntity extends BlockEntity implements GameEventLi
         return this.catalystListener;
     }
 
-    public static class CatalystListener implements GameEventListener {
+    public class CatalystListener implements GameEventListener { // Leaf - petal
 
         public static final int PULSE_TICKS = 8;
         final SculkSpreader sculkSpreader;
@@ -135,6 +135,13 @@ public class SculkCatalystBlockEntity extends BlockEntity implements GameEventLi
             world.playSound((Player) null, pos, SoundEvents.SCULK_CATALYST_BLOOM, SoundSource.BLOCKS, 2.0F, 0.6F + random.nextFloat() * 0.4F);
         }
 
+    // Leaf start - petal
+    @Override
+    public boolean listensToEvent(GameEvent gameEvent, GameEvent.Context context) {
+        return !SculkCatalystBlockEntity.this.isRemoved() && gameEvent == GameEvent.ENTITY_DIE && context.sourceEntity() instanceof LivingEntity;
+    }
+    // Leaf end - petal
+
         private void tryAwardItSpreadsAdvancement(Level world, LivingEntity deadEntity) {
             LivingEntity entityliving1 = deadEntity.getLastHurtByMob();
 
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 f52b314dd0ed83682b6a60c66b21eefd2cefb793..3a13de668a90d50b18214a91fd92d8b287bd76da 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
@@ -80,7 +80,18 @@ public class LevelChunk extends ChunkAccess {
     private Supplier<FullChunkStatus> fullStatus;
     @Nullable
     private LevelChunk.PostLoadProcessor postLoad;
-    private final Int2ObjectMap<GameEventListenerRegistry> gameEventListenerRegistrySections;
+    // Leaf start - petal
+    private final GameEventListenerRegistry[] gameEventListenerRegistrySections;
+    private static final int GAME_EVENT_DISPATCHER_RADIUS = 2;
+
+    private static int getGameEventSectionIndex(int sectionIndex) {
+        return sectionIndex + GAME_EVENT_DISPATCHER_RADIUS;
+    }
+
+    private static int getGameEventSectionLength(int sectionCount) {
+        return sectionCount + (GAME_EVENT_DISPATCHER_RADIUS * 2);
+    }
+    // Leaf end - petal
     private final LevelChunkTicks<Block> blockTicks;
     private final LevelChunkTicks<Fluid> fluidTicks;
     public volatile FullChunkStatus chunkStatus = FullChunkStatus.INACCESSIBLE; // Paper - rewrite chunk system
@@ -105,7 +116,7 @@ public class LevelChunk extends ChunkAccess {
         super(pos, upgradeData, world, net.minecraft.server.MinecraftServer.getServer().registryAccess().registryOrThrow(Registries.BIOME), inhabitedTime, sectionArrayInitializer, blendingData); // Paper - Anti-Xray - The world isn't ready yet, use server singleton for registry
         this.tickersInLevel = Maps.newHashMap();
         this.level = (ServerLevel) world; // CraftBukkit - type
-        this.gameEventListenerRegistrySections = new Int2ObjectOpenHashMap();
+        this.gameEventListenerRegistrySections = new GameEventListenerRegistry[getGameEventSectionLength(this.getSectionsCount())]; // Leaf - petal
         Heightmap.Types[] aheightmap_type = Heightmap.Types.values();
         int j = aheightmap_type.length;
 
@@ -303,9 +314,23 @@ public class LevelChunk extends ChunkAccess {
         if (world instanceof ServerLevel) {
             ServerLevel worldserver = (ServerLevel) world;
 
-            return (GameEventListenerRegistry) this.gameEventListenerRegistrySections.computeIfAbsent(ySectionCoord, (j) -> {
-                return new EuclideanGameEventListenerRegistry(worldserver, ySectionCoord, this::removeGameEventListenerRegistry);
-            });
+            // Leaf start - petal
+            int sectionIndex = getGameEventSectionIndex(this.getSectionIndexFromSectionY(ySectionCoord));
+
+            // drop game events that are too far away (32 blocks) from loaded sections
+            // this matches the highest radius of game events in the game
+            if (sectionIndex < 0 || sectionIndex >= this.gameEventListenerRegistrySections.length) {
+                return GameEventListenerRegistry.NOOP;
+            }
+
+            var dispatcher = this.gameEventListenerRegistrySections[sectionIndex];
+
+            if (dispatcher == null) {
+                dispatcher = this.gameEventListenerRegistrySections[sectionIndex] = new EuclideanGameEventListenerRegistry(worldserver, ySectionCoord, this::removeGameEventListenerRegistry);
+            }
+
+            return dispatcher;
+            // Leaf end - petal
         } else {
             return super.getListenerRegistry(ySectionCoord);
         }
@@ -678,7 +703,7 @@ public class LevelChunk extends ChunkAccess {
     }
 
     private void removeGameEventListenerRegistry(int ySectionCoord) {
-        this.gameEventListenerRegistrySections.remove(ySectionCoord);
+        this.gameEventListenerRegistrySections[getGameEventSectionIndex(this.getSectionIndexFromSectionY(ySectionCoord))] = null; // Leaf - petal
     }
 
     private void removeBlockEntityTicker(BlockPos pos) {
diff --git a/src/main/java/net/minecraft/world/level/gameevent/EuclideanGameEventListenerRegistry.java b/src/main/java/net/minecraft/world/level/gameevent/EuclideanGameEventListenerRegistry.java
index 95c840f9bee51adef9bb00da5f53a5b011c0575e..1259d5d2ce58dd24b77a01d175a2037c17ed7791 100644
--- a/src/main/java/net/minecraft/world/level/gameevent/EuclideanGameEventListenerRegistry.java
+++ b/src/main/java/net/minecraft/world/level/gameevent/EuclideanGameEventListenerRegistry.java
@@ -13,8 +13,8 @@ import net.minecraft.world.phys.Vec3;
 
 public class EuclideanGameEventListenerRegistry implements GameEventListenerRegistry {
     private final List<GameEventListener> listeners = Lists.newArrayList();
-    private final Set<GameEventListener> listenersToRemove = Sets.newHashSet();
-    private final List<GameEventListener> listenersToAdd = Lists.newArrayList();
+    //private final Set<GameEventListener> listenersToRemove = Sets.newHashSet(); // Leaf - petal - Not necessary
+    //private final List<GameEventListener> listenersToAdd = Lists.newArrayList(); // Leaf - petal
     private boolean processing;
     private final ServerLevel level;
     private final int sectionY;
@@ -34,7 +34,7 @@ public class EuclideanGameEventListenerRegistry implements GameEventListenerRegi
     @Override
     public void register(GameEventListener listener) {
         if (this.processing) {
-            this.listenersToAdd.add(listener);
+            throw new java.util.ConcurrentModificationException(); // Leaf - petal - Disallow concurrent modification
         } else {
             this.listeners.add(listener);
         }
@@ -45,7 +45,7 @@ public class EuclideanGameEventListenerRegistry implements GameEventListenerRegi
     @Override
     public void unregister(GameEventListener listener) {
         if (this.processing) {
-            this.listenersToRemove.add(listener);
+            throw new java.util.ConcurrentModificationException(); // Leaf - petal - Disallow concurrent modification
         } else {
             this.listeners.remove(listener);
         }
@@ -65,7 +65,7 @@ public class EuclideanGameEventListenerRegistry implements GameEventListenerRegi
 
             while (iterator.hasNext()) {
                 GameEventListener gameEventListener = iterator.next();
-                if (this.listenersToRemove.remove(gameEventListener)) {
+                if (false) { // Leaf - petal - Disallow concurrent modification
                     iterator.remove();
                 } else {
                     Optional<Vec3> optional = getPostableListenerPosition(this.level, pos, gameEventListener);
@@ -79,6 +79,8 @@ public class EuclideanGameEventListenerRegistry implements GameEventListenerRegi
             this.processing = false;
         }
 
+        // Leaf start - petal
+        /*
         if (!this.listenersToAdd.isEmpty()) {
             this.listeners.addAll(this.listenersToAdd);
             this.listenersToAdd.clear();
@@ -88,6 +90,8 @@ public class EuclideanGameEventListenerRegistry implements GameEventListenerRegi
             this.listeners.removeAll(this.listenersToRemove);
             this.listenersToRemove.clear();
         }
+         */
+        // Leaf end - petal
 
         return bl;
     }
diff --git a/src/main/java/net/minecraft/world/level/gameevent/GameEventDispatcher.java b/src/main/java/net/minecraft/world/level/gameevent/GameEventDispatcher.java
index 37ae0f928440af5b2fdfe68ad6c9c54e8c95c82c..039e31df469742eff5b176b9f269b88025f45721 100644
--- a/src/main/java/net/minecraft/world/level/gameevent/GameEventDispatcher.java
+++ b/src/main/java/net/minecraft/world/level/gameevent/GameEventDispatcher.java
@@ -44,6 +44,7 @@ public class GameEventDispatcher {
         int k1 = SectionPos.blockToSectionCoord(blockposition.getZ() + i);
         List<GameEvent.ListenerInfo> list = new ArrayList();
         GameEventListenerRegistry.ListenerVisitor gameeventlistenerregistry_a = (gameeventlistener, vec3d1) -> {
+            if (!gameeventlistener.listensToEvent(event, emitter)) return; // Leaf - petal - If they don't listen, ignore
             if (gameeventlistener.getDeliveryMode() == GameEventListener.DeliveryMode.BY_DISTANCE) {
                 list.add(new GameEvent.ListenerInfo(event, emitterPos, emitter, gameeventlistener, vec3d1));
             } else {
diff --git a/src/main/java/net/minecraft/world/level/gameevent/GameEventListener.java b/src/main/java/net/minecraft/world/level/gameevent/GameEventListener.java
index a4148dd326b10b0eb2bc7884691d79dcda60e010..ead325a818dca2e204ec79a06161adbaf439c9c3 100644
--- a/src/main/java/net/minecraft/world/level/gameevent/GameEventListener.java
+++ b/src/main/java/net/minecraft/world/level/gameevent/GameEventListener.java
@@ -22,4 +22,10 @@ public interface GameEventListener {
     public interface Holder<T extends GameEventListener> {
         T getListener();
     }
+
+    // Leaf start - petal - Add check for seeing if this listener cares about an event
+    default boolean listensToEvent(GameEvent gameEvent, GameEvent.Context context) {
+        return true;
+    }
+    // Leaf end - petal
 }