From ee7fcdafc090b838ab215bd53a6b93d868157b79 Mon Sep 17 00:00:00 2001
From: IzzelAliz <csh2001331@126.com>
Date: Tue, 3 May 2022 10:53:23 +0800
Subject: [PATCH] Optimize entity tracker effective range compute

Per TeaCon profiling results, getIndirectPassengers can take up to 50% tick time and most of it is stream.
---
 .../general/EntityMixin_Optimize.java         | 46 +++++++++++++++++++
 ...xins.arclight.impl.forge.optimization.json |  1 +
 2 files changed, 47 insertions(+)
 create mode 100644 arclight-common/src/main/java/io/izzel/arclight/common/mixin/optimization/general/EntityMixin_Optimize.java

diff --git a/arclight-common/src/main/java/io/izzel/arclight/common/mixin/optimization/general/EntityMixin_Optimize.java b/arclight-common/src/main/java/io/izzel/arclight/common/mixin/optimization/general/EntityMixin_Optimize.java
new file mode 100644
index 00000000..285e45b0
--- /dev/null
+++ b/arclight-common/src/main/java/io/izzel/arclight/common/mixin/optimization/general/EntityMixin_Optimize.java
@@ -0,0 +1,46 @@
+package io.izzel.arclight.common.mixin.optimization.general;
+
+import com.google.common.collect.ImmutableList;
+import net.minecraft.world.entity.Entity;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+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.CallbackInfoReturnable;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.stream.Stream;
+
+@Mixin(Entity.class)
+public abstract class EntityMixin_Optimize {
+
+    @Shadow public ImmutableList<Entity> passengers;
+
+    @Inject(method = "getIndirectPassengersStream", cancellable = true, at = @At("HEAD"))
+    private void arclight$emptyPassenger(CallbackInfoReturnable<Stream<Entity>> cir) {
+        if (this.passengers.isEmpty()) {
+            cir.setReturnValue(Stream.empty());
+        }
+    }
+
+    /**
+     * @author IzzelAliz
+     * @reason
+     */
+    @Overwrite
+    public Iterable<Entity> getIndirectPassengers() {
+        if (this.passengers.isEmpty()) {
+            return Collections.emptyList();
+        } else {
+            var list = new ArrayList<Entity>();
+            for (var entity : this.passengers) {
+                list.add(entity);
+                list.addAll((Collection<? extends Entity>) entity.getIndirectPassengers());
+            }
+            return list;
+        }
+    }
+}
diff --git a/arclight-common/src/main/resources/mixins.arclight.impl.forge.optimization.json b/arclight-common/src/main/resources/mixins.arclight.impl.forge.optimization.json
index 36560763..db2b0c83 100644
--- a/arclight-common/src/main/resources/mixins.arclight.impl.forge.optimization.json
+++ b/arclight-common/src/main/resources/mixins.arclight.impl.forge.optimization.json
@@ -8,6 +8,7 @@
     "ClassInheritanceMultiMapMixin",
     "ConnectionMixin_Optimize",
     "EntityDataManagerMixin_Optimize",
+    "EntityMixin_Optimize",
     "GoalMixin",
     "MobMixin_Optimization",
     "ResourceKeyMixin_Optimize",