Max collisions optimization (#1038)

* Lift entity limit up to the `getOtherEntities` method so it bails early

This has the potential to prevent a lot of bounding box computation

* Clean up decompiled code

* Fix raw generic types

This doesn't alter the signature, but it helps the compiler warn about misuse of the type later on

* Actually abort forEach when `limit` entities have been checked

`throw`ing a known exception is the easiest way to `break` out of a forEach call

src/main/java/carpet/fakes/WorldInterface.java

@@ -5,12 +5,18 @@ import net.minecraft.block.entity.BlockEntity;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
 import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Box;
+import org.jetbrains.annotations.Nullable;
 
+import java.util.List;
 import java.util.Map;
+import java.util.function.Predicate;
 
 public interface WorldInterface
 {
-    Map<EntityType, Entity> getPrecookedMobs();
+    Map<EntityType<?>, Entity> getPrecookedMobs();
     
     boolean setBlockStateWithBlockEntity(BlockPos blockPos, BlockState blockState, BlockEntity newBlockEntity, int int1);
+
+    List<Entity> getOtherEntitiesLimited(@Nullable Entity except, Box box, Predicate<? super Entity> predicate, int limit);
 }

src/main/java/carpet/mixins/LivingEntity_maxCollisionsMixin.java

@@ -1,6 +1,7 @@
 package carpet.mixins;
 
 import carpet.CarpetSettings;
+import carpet.fakes.WorldInterface;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.LivingEntity;
@@ -28,33 +29,35 @@ public abstract class LivingEntity_maxCollisionsMixin extends Entity
     @Shadow protected abstract void pushAway(Entity entity_1);
 
     @Inject(method = "tickCramming", cancellable = true, at = @At("HEAD"))
-    private void tickPushingReplacement(CallbackInfo ci)
-    {
-        List<Entity> list_1 = this.world.getOtherEntities(this, this.getBoundingBox(), EntityPredicates.canBePushedBy(this));
-        if (!list_1.isEmpty()) {
-            int int_1 = this.world.getGameRules().getInt(GameRules.MAX_ENTITY_CRAMMING);
-            int int_2;
-            if (int_1 > 0 && list_1.size() > int_1 - 1 && this.random.nextInt(4) == 0) {
-                int_2 = 0;
+    private void tickPushingReplacement(CallbackInfo ci) {
+        List<Entity> entities;
+        if (CarpetSettings.maxEntityCollisions > 0)
+            entities = ((WorldInterface) this.world).getOtherEntitiesLimited(
+                    this,
+                    this.getBoundingBox(),
+                    EntityPredicates.canBePushedBy(this),
+                    CarpetSettings.maxEntityCollisions);
+        else
+            entities = this.world.getOtherEntities(this, this.getBoundingBox(), EntityPredicates.canBePushedBy(this));
 
-                for(int int_3 = 0; int_3 < list_1.size(); ++int_3) {
-                    if (!((Entity)list_1.get(int_3)).hasVehicle()) {
-                        ++int_2;
+        if (!entities.isEmpty()) {
+            int maxEntityCramming = this.world.getGameRules().getInt(GameRules.MAX_ENTITY_CRAMMING);
+            if (maxEntityCramming > 0 && entities.size() > maxEntityCramming - 1 && this.random.nextInt(4) == 0) {
+                int candidates = 0;
+
+                for (Entity entity : entities) {
+                    if (!entity.hasVehicle()) {
+                        ++candidates;
                     }
                 }
 
-                if (int_2 > int_1 - 1) {
+                if (candidates > maxEntityCramming - 1) {
                     this.damage(DamageSource.CRAMMING, 6.0F);
                 }
             }
 
-            int limit = list_1.size();
-            if (CarpetSettings.maxEntityCollisions > 0)
-                limit = Math.min(limit, CarpetSettings.maxEntityCollisions);
-
-            for(int_2 = 0; int_2 < limit; ++int_2) {
-                Entity entity_1 = (Entity)list_1.get(int_2);
-                this.pushAway(entity_1);
+            for (Entity entity : entities) {
+                this.pushAway(entity);
             }
         }
         ci.cancel();

src/main/java/carpet/mixins/SpawnHelperMixin.java

@@ -138,7 +138,7 @@ public class SpawnHelperMixin
     {
         if (CarpetSettings.lagFreeSpawning)
         {
-            Map<EntityType, Entity> precookedMobs = ((WorldInterface)world_1).getPrecookedMobs();
+            Map<EntityType<?>, Entity> precookedMobs = ((WorldInterface)world_1).getPrecookedMobs();
             if (precookedMobs.containsKey(entityType))
                 //this mob has been <init>'s but not used yet
                 return precookedMobs.get(entityType);

src/main/java/carpet/mixins/World_getOtherEntitiesLimited.java

@@ -0,0 +1,63 @@
+package carpet.mixins;
+
+import carpet.fakes.WorldInterface;
+import com.google.common.collect.Lists;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.boss.dragon.EnderDragonEntity;
+import net.minecraft.entity.boss.dragon.EnderDragonPart;
+import net.minecraft.util.math.Box;
+import net.minecraft.util.profiler.Profiler;
+import net.minecraft.world.World;
+import net.minecraft.world.entity.EntityLookup;
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Predicate;
+
+@Mixin(World.class)
+public abstract class World_getOtherEntitiesLimited implements WorldInterface {
+
+    private static final RuntimeException CONTROL_FLOW_EXCEPTION = new RuntimeException("Should be caught for control flow in World_getOtherEntitiesLimited!");
+
+    @Override
+    public List<Entity> getOtherEntitiesLimited(@Nullable Entity except, Box box, Predicate<? super Entity> predicate, int limit) {
+        this.getProfiler().visit("getEntities");
+        AtomicInteger checkedEntities = new AtomicInteger();
+        List<Entity> list = Lists.newArrayList();
+        try {
+            this.getEntityLookup().forEachIntersects(box, (entity) -> {
+                if (checkedEntities.getAndIncrement() > limit) {
+                    throw CONTROL_FLOW_EXCEPTION;
+                }
+
+                if (entity != except && predicate.test(entity)) {
+                    list.add(entity);
+                }
+
+                if (entity instanceof EnderDragonEntity) {
+                    EnderDragonPart[] var4 = ((EnderDragonEntity) entity).getBodyParts();
+
+                    for (EnderDragonPart enderDragonPart : var4) {
+                        if (entity != except && predicate.test(enderDragonPart)) {
+                            list.add(enderDragonPart);
+                        }
+                    }
+                }
+            });
+        } catch (RuntimeException e) {
+            if (e != CONTROL_FLOW_EXCEPTION)
+                // If it wasn't the exception we were watching, rethrow it
+                throw e;
+        }
+        return list;
+    }
+
+    @Shadow
+    public abstract Profiler getProfiler();
+
+    @Shadow
+    protected abstract EntityLookup<Entity> getEntityLookup();
+}

src/main/java/carpet/mixins/World_tickMixin.java

@@ -3,23 +3,18 @@ package carpet.mixins;
 import carpet.fakes.WorldInterface;
 import carpet.helpers.TickSpeed;
 import carpet.utils.CarpetProfiler;
-import net.minecraft.block.entity.BlockEntity;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.player.PlayerEntity;
-import net.minecraft.util.profiler.Profiler;
 import net.minecraft.world.World;
 import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
 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.Redirect;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
 
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.Map;
 import java.util.function.Consumer;
 
@@ -30,9 +25,9 @@ public abstract class World_tickMixin implements WorldInterface
     CarpetProfiler.ProfilerToken currentSection;
     CarpetProfiler.ProfilerToken entitySection;
 
-    Map<EntityType, Entity> precookedMobs = new HashMap<>();
+    Map<EntityType<?>, Entity> precookedMobs = new HashMap<>();
 
-    public Map<EntityType, Entity> getPrecookedMobs()
+    public Map<EntityType<?>, Entity> getPrecookedMobs()
     {
         return precookedMobs;
     }

src/main/resources/carpet.mixins.json

@@ -86,6 +86,7 @@
     "PistonHandler_pushLimitMixin",
     "PoweredRailBlock_powerLimitMixin",
     "LivingEntity_maxCollisionsMixin",
+    "World_getOtherEntitiesLimited",
     "CoralBlockMixin",
     "CoralFanBlockMixin",
     "CoralFeatureMixin",