From 1a04d57dd734612577e65e09c312cc46a0e507fb Mon Sep 17 00:00:00 2001
From: Maxmani <mikael.hannukainen@gmail.com>
Date: Sat, 24 Feb 2024 03:39:58 +0200
Subject: [PATCH] Iterate entity trackers faster

---
 .../gensouhacks/core/ChunkMapMixin.java       | 24 +++++++++++++++++++
 src/main/resources/mixins.core.json           |  1 +
 2 files changed, 25 insertions(+)
 create mode 100644 src/main/java/net/gensokyoreimagined/gensouhacks/core/ChunkMapMixin.java

diff --git a/src/main/java/net/gensokyoreimagined/gensouhacks/core/ChunkMapMixin.java b/src/main/java/net/gensokyoreimagined/gensouhacks/core/ChunkMapMixin.java
new file mode 100644
index 0000000..082ec3b
--- /dev/null
+++ b/src/main/java/net/gensokyoreimagined/gensouhacks/core/ChunkMapMixin.java
@@ -0,0 +1,24 @@
+package net.gensokyoreimagined.gensouhacks.core;
+
+import it.unimi.dsi.fastutil.ints.Int2ObjectLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import net.minecraft.server.level.ChunkMap;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(ChunkMap.class)
+public class ChunkMapMixin {
+
+    @Mutable
+    @Shadow @Final public Int2ObjectMap<ChunkMap.TrackedEntity> entityMap;
+
+    @Inject(method = "<init>", at = @At("RETURN"))
+    private void reassignEntityTrackers(CallbackInfo ci) {
+        this.entityMap = new Int2ObjectLinkedOpenHashMap<>();
+    }
+}
diff --git a/src/main/resources/mixins.core.json b/src/main/resources/mixins.core.json
index 5d5c04b..35ca897 100644
--- a/src/main/resources/mixins.core.json
+++ b/src/main/resources/mixins.core.json
@@ -6,6 +6,7 @@
   "target": "@env(DEFAULT)",
   "compatibilityLevel": "JAVA_17",
   "server": [
+    "ChunkMapMixin",
     "MixinSpongeSIMD"
   ]
 }