From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 28 Mar 2016 19:55:45 -0400
Subject: [PATCH] Only process BlockPhysicsEvent if a plugin has a listener

Saves on some object allocation and processing when no plugin listens to this

diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 0d58b58537de49ddb7c8c841e9077af4e727ba82..46eaa77f33a375da80f8290883f6ed1f321be87e 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -1383,6 +1383,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
 
         while (iterator.hasNext()) {
             ServerLevel worldserver = (ServerLevel) iterator.next();
+            worldserver.hasPhysicsEvent =  org.bukkit.event.block.BlockPhysicsEvent.getHandlerList().getRegisteredListeners().length > 0; // Paper
 
             this.profiler.push(() -> {
                 return worldserver + " " + worldserver.dimension().location();
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index 5df7fe061fdfd7f1455cf283973be471d878ffb2..c2dc2ec29949074e71d0b4e5244ec71587f01178 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -198,6 +198,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
     private int tickPosition;
     public final LevelStorageSource.LevelStorageAccess convertable;
     public final UUID uuid;
+    public boolean hasPhysicsEvent = true; // Paper
 
     @Override public LevelChunk getChunkIfLoaded(int x, int z) { // Paper - this was added in world too but keeping here for NMS ABI
         return this.chunkSource.getChunk(x, z, false);
diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 1f1601f0e7f30bb44c57c771b93e7aa8be3e9725..322edb169e9b482aac71292b992d4a3c2622b2d8 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -473,7 +473,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
                 // CraftBukkit start
                 iblockdata1.updateIndirectNeighbourShapes(this, blockposition, k, j - 1); // Don't call an event for the old block to limit event spam
                 CraftWorld world = ((ServerLevel) this).getWorld();
-                if (world != null) {
+                if (world != null && ((ServerLevel)this).hasPhysicsEvent) { // Paper
                     BlockPhysicsEvent event = new BlockPhysicsEvent(world.getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ()), CraftBlockData.fromData(iblockdata));
                     this.getCraftServer().getPluginManager().callEvent(event);
 
@@ -586,7 +586,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
             try {
                 // CraftBukkit start
                 CraftWorld world = ((ServerLevel) this).getWorld();
-                if (world != null) {
+                if (world != null && ((ServerLevel)this).hasPhysicsEvent) { // Paper
                     BlockPhysicsEvent event = new BlockPhysicsEvent(world.getBlockAt(pos.getX(), pos.getY(), pos.getZ()), CraftBlockData.fromData(iblockdata), world.getBlockAt(neighborPos.getX(), neighborPos.getY(), neighborPos.getZ()));
                     this.getCraftServer().getPluginManager().callEvent(event);
 
diff --git a/src/main/java/net/minecraft/world/level/block/BushBlock.java b/src/main/java/net/minecraft/world/level/block/BushBlock.java
index 24227939493f852a88477c84160bda1605291eb0..1f8cf302d2309aec2955832ffafd87f14934e141 100644
--- a/src/main/java/net/minecraft/world/level/block/BushBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/BushBlock.java
@@ -4,6 +4,7 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.tags.BlockTags;
 import net.minecraft.tags.Tag;
+import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.BlockGetter;
 import net.minecraft.world.level.LevelAccessor;
 import net.minecraft.world.level.LevelReader;
@@ -25,7 +26,7 @@ public class BushBlock extends Block {
     public BlockState updateShape(BlockState state, Direction direction, BlockState neighborState, LevelAccessor world, BlockPos pos, BlockPos neighborPos) {
         // CraftBukkit start
         if (!state.canSurvive(world, pos)) {
-            if (!org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) {
+            if (!(world instanceof ServerLevel && ((ServerLevel) world).hasPhysicsEvent) || !org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) { // Paper
                 return Blocks.AIR.defaultBlockState();
             }
         }
diff --git a/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java b/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java
index 9edf1b87e59d589b053e5b4fee15faa221718c2f..65a163d93a293e1e0a12a300d6335a700099cac2 100644
--- a/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java
@@ -4,6 +4,7 @@ import javax.annotation.Nullable;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.util.Mth;
+import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
@@ -93,7 +94,7 @@ public class DoublePlantBlock extends BushBlock {
 
     protected static void preventCreativeDropFromBottomPart(Level world, BlockPos pos, BlockState state, Player player) {
         // CraftBukkit start
-        if (org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) {
+        if (((ServerLevel)world).hasPhysicsEvent && org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) { // Paper
             return;
         }
         // CraftBukkit end