From 8314c4b05f828a38ac63ec22faf148a4c98029f5 Mon Sep 17 00:00:00 2001
From: Taiyou06 <kaandindar21@gmail.com>
Date: Sat, 6 Jul 2024 07:54:01 +0300
Subject: [PATCH] ServerChunkManager - Alloc reduction

---
 .../nitori/core/ServerChunkManagerMixin.java  | 39 +++++++++++++++++++
 src/main/resources/mixins.core.json           |  3 +-
 2 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/net/gensokyoreimagined/nitori/core/ServerChunkManagerMixin.java

diff --git a/src/main/java/net/gensokyoreimagined/nitori/core/ServerChunkManagerMixin.java b/src/main/java/net/gensokyoreimagined/nitori/core/ServerChunkManagerMixin.java
new file mode 100644
index 0000000..7ea8508
--- /dev/null
+++ b/src/main/java/net/gensokyoreimagined/nitori/core/ServerChunkManagerMixin.java
@@ -0,0 +1,39 @@
+package net.gensokyoreimagined.nitori.core;
+
+import net.minecraft.server.level.ChunkHolder;
+import net.minecraft.server.level.ServerChunkCache;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.ArrayList;
+import java.util.function.BooleanSupplier;
+
+@Mixin(ServerChunkCache.class)
+public class ServerChunkManagerMixin {
+    private final ArrayList<ChunkHolder> cachedChunkList = new ArrayList<>();
+
+    @Redirect(
+            method = "tickChunks()V",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lcom/google/common/collect/Lists;newArrayListWithCapacity(I)Ljava/util/ArrayList;",
+                    remap = false
+            )
+    )
+    private ArrayList<ChunkHolder> redirectChunksListClone(int initialArraySize) {
+        ArrayList<ChunkHolder> list = this.cachedChunkList;
+        list.clear(); // Ensure the list is empty before re-using it
+        list.ensureCapacity(initialArraySize);
+
+        return list;
+    }
+
+    @Inject(method = "tick(Ljava/util/function/BooleanSupplier;Z)V", at = @At("HEAD"))
+    private void preTick(BooleanSupplier shouldKeepTicking, boolean tickChunks, CallbackInfo ci) {
+        // Ensure references aren't leaked through this list
+        this.cachedChunkList.clear();
+    }
+}
\ No newline at end of file
diff --git a/src/main/resources/mixins.core.json b/src/main/resources/mixins.core.json
index b6a7922..2a452da 100755
--- a/src/main/resources/mixins.core.json
+++ b/src/main/resources/mixins.core.json
@@ -31,6 +31,7 @@
     "MixinPlayerList",
     "MixinCraftPlayer",
     "StateMixin",
-    "WorldMixin"
+    "WorldMixin",
+    "ServerChunkManagerMixin"
   ]
 }