From bd9ace578b65e71b4f72a2cb9f7fb0dcebf4682f Mon Sep 17 00:00:00 2001
From: Jason <jasonpenilla2@me.com>
Date: Wed, 13 Jan 2021 16:04:51 -0800
Subject: [PATCH] Add a config option to limit the number of entities of each
 type to load/save in a chunk (#4792)

---
 ...649-Entity-load-save-limit-per-chunk.patch | 90 +++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 Spigot-Server-Patches/0649-Entity-load-save-limit-per-chunk.patch

diff --git a/Spigot-Server-Patches/0649-Entity-load-save-limit-per-chunk.patch b/Spigot-Server-Patches/0649-Entity-load-save-limit-per-chunk.patch
new file mode 100644
index 000000000..63edb0445
--- /dev/null
+++ b/Spigot-Server-Patches/0649-Entity-load-save-limit-per-chunk.patch
@@ -0,0 +1,90 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: jmp <jasonpenilla2@me.com>
+Date: Wed, 18 Nov 2020 20:52:25 -0800
+Subject: [PATCH] Entity load/save limit per chunk
+
+Adds a config option to limit the number of entities saved and loaded
+to a chunk. The default values of -1 disable the limit. Although
+defaults are only included for certain entites, this allows setting
+limits for any entity type.
+
+diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+index c5495e02c3fe271b26f62ea2ec64e07957edf37e..234d2daecc5d0bf6a99c0a5f4a87f947a15029d9 100644
+--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
++++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+@@ -11,6 +11,7 @@ import com.destroystokyo.paper.antixray.ChunkPacketBlockControllerAntiXray.Engin
+ import net.minecraft.server.EntityVindicator;
+ import net.minecraft.server.EntityZombie;
+ import net.minecraft.server.EnumDifficulty;
++import net.minecraft.server.EntityTypes;
+ import org.bukkit.Bukkit;
+ import org.bukkit.Material;
+ import org.bukkit.configuration.ConfigurationSection;
+@@ -761,4 +762,18 @@ public class PaperWorldConfig {
+             EnumDifficulty.class
+         );
+     }
++
++    public Map<EntityTypes<?>, Integer> entityPerChunkSaveLimits = new HashMap<>();
++    private void entityPerChunkSaveLimits() {
++        getInt("entity-per-chunk-save-limit.experience_orb", -1);
++        getInt("entity-per-chunk-save-limit.snowball", -1);
++        getInt("entity-per-chunk-save-limit.ender_pearl", -1);
++        getInt("entity-per-chunk-save-limit.arrow", -1);
++        EntityTypes.getEntityNameList().forEach(name -> {
++            final EntityTypes<?> type = EntityTypes.getByName(name.getKey()).orElseThrow(() -> new IllegalStateException("Unknown Entity Type: " + name.toString()));
++            final String path = ".entity-per-chunk-save-limit." + name.getKey();
++            final int value = config.getInt("world-settings." + worldName + path, config.getInt("world-settings.default" + path, -1)); // get without setting defaults
++            if (value != -1) entityPerChunkSaveLimits.put(type, value);
++        });
++    }
+ }
+diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+index 8e7da2c5f3852920ec5fbcdd2bff4d299e6aa499..060ef42bc8f22688071fa375bd4dbab8dd2c1e9e 100644
+--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
++++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+@@ -495,11 +495,22 @@ public class ChunkRegionLoader {
+ 
+             chunk.d(false);
+ 
++            // Paper start
++            final Map<EntityTypes<?>, Integer> savedEntityCounts = Maps.newHashMap();
+             for (int j = 0; j < chunk.getEntitySlices().length; ++j) {
+                 Iterator iterator1 = chunk.getEntitySlices()[j].iterator();
+ 
+                 while (iterator1.hasNext()) {
+                     Entity entity = (Entity) iterator1.next();
++                    final EntityTypes<?> entityType = entity.getEntityType();
++                    final int saveLimit = worldserver.paperConfig.entityPerChunkSaveLimits.getOrDefault(entityType, -1);
++                    if (saveLimit > -1) {
++                        if (savedEntityCounts.getOrDefault(entityType, 0) >= saveLimit) {
++                            continue;
++                        }
++                        savedEntityCounts.merge(entityType, 1, Integer::sum);
++                    }
++                    // Paper end
+                     NBTTagCompound nbttagcompound4 = new NBTTagCompound();
+                     // Paper start
+                     if (asyncsavedata == null && !entity.dead && (int) Math.floor(entity.locX()) >> 4 != chunk.getPos().x || (int) Math.floor(entity.locZ()) >> 4 != chunk.getPos().z) {
+@@ -630,10 +641,21 @@ public class ChunkRegionLoader {
+         NBTTagList nbttaglist = nbttagcompound.getList("Entities", 10);
+         World world = chunk.getWorld();
+ 
++        // Paper start
++        final Map<EntityTypes<?>, Integer> loadedEntityCounts = Maps.newHashMap();
+         for (int i = 0; i < nbttaglist.size(); ++i) {
+             NBTTagCompound nbttagcompound1 = nbttaglist.getCompound(i);
+ 
+             EntityTypes.a(nbttagcompound1, world, (entity) -> {
++                final EntityTypes<?> entityType = entity.getEntityType();
++                final int saveLimit = world.paperConfig.entityPerChunkSaveLimits.getOrDefault(entityType, -1);
++                if (saveLimit > -1) {
++                    if (loadedEntityCounts.getOrDefault(entityType, 0) >= saveLimit) {
++                        return entity;
++                    }
++                    loadedEntityCounts.merge(entityType, 1, Integer::sum);
++                }
++                // Paper end
+                 chunk.a(entity);
+                 return entity;
+             });