0086-c2me-reduce_allocs.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: ishland <ishlandmc@yeah.net>
Date: Mon, 24 Jan 2022 10:56:10 -0500
Subject: [PATCH] c2me: reduce_allocs

Copyright (c) 2021-2022 ishland

Original code by RelativityMC, licensed under MIT
You can find the original code on https://github.com/RelativityMC/C2ME-fabric (Yarn mappings)

diff --git a/src/main/java/com/ishland/c2me/opts/allocs/common/ObjectCachingUtils.java b/src/main/java/com/ishland/c2me/opts/allocs/common/ObjectCachingUtils.java
new file mode 100644
index 0000000000000000000000000000000000000000..b1229bae2e74d22065c723c6d3eaf9a97d572b04
--- /dev/null
+++ b/src/main/java/com/ishland/c2me/opts/allocs/common/ObjectCachingUtils.java
@@ -0,0 +1,23 @@
+package com.ishland.c2me.opts.allocs.common;
+
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+
+import java.util.BitSet;
+import java.util.function.IntFunction;
+
+public class ObjectCachingUtils {
+
+    private static final IntFunction<BitSet> bitSetConstructor = BitSet::new;
+
+    public static ThreadLocal<Int2ObjectOpenHashMap<BitSet>> BITSETS = ThreadLocal.withInitial(Int2ObjectOpenHashMap::new);
+
+    private ObjectCachingUtils() {
+    }
+
+    public static BitSet getCachedOrNewBitSet(int bits) {
+        final BitSet bitSet = BITSETS.get().computeIfAbsent(bits, bitSetConstructor);
+        bitSet.clear();
+        return bitSet;
+    }
+
+}
diff --git a/src/main/java/com/ishland/c2me/opts/allocs/common/PooledFeatureContext.java b/src/main/java/com/ishland/c2me/opts/allocs/common/PooledFeatureContext.java
new file mode 100644
index 0000000000000000000000000000000000000000..4c84006c90bda4849b27879d5218f98e6d98f1dc
--- /dev/null
+++ b/src/main/java/com/ishland/c2me/opts/allocs/common/PooledFeatureContext.java
@@ -0,0 +1,68 @@
+package com.ishland.c2me.opts.allocs.common;
+
+import java.util.Optional;
+import net.minecraft.core.BlockPos;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.WorldGenLevel;
+import net.minecraft.world.level.chunk.ChunkGenerator;
+import net.minecraft.world.level.levelgen.feature.ConfiguredFeature;
+import net.minecraft.world.level.levelgen.feature.FeaturePlaceContext;
+import net.minecraft.world.level.levelgen.feature.configurations.FeatureConfiguration;
+
+public class PooledFeatureContext<FC extends FeatureConfiguration> extends FeaturePlaceContext<FC> {
+
+    public static final ThreadLocal<SimpleObjectPool<PooledFeatureContext<?>>> POOL = ThreadLocal.withInitial(() -> new SimpleObjectPool<>(unused -> new PooledFeatureContext<>(), unused -> {}, 2048));
+
+    private Optional<ConfiguredFeature<?, ?>> feature;
+    private WorldGenLevel world;
+    private ChunkGenerator generator;
+    private RandomSource random;
+    private BlockPos origin;
+    private FC config;
+
+    public PooledFeatureContext() {
+        super(null, null, null, null, null, null);
+    }
+
+    public void reInit(Optional<ConfiguredFeature<?, ?>> feature, WorldGenLevel world, ChunkGenerator generator, RandomSource random, BlockPos origin, FC config) {
+        this.feature = feature;
+        this.world = world;
+        this.generator = generator;
+        this.random = random;
+        this.origin = origin;
+        this.config = config;
+    }
+
+    public void reInit() {
+        this.feature = null;
+        this.world = null;
+        this.generator = null;
+        this.random = null;
+        this.origin = null;
+        this.config = null;
+    }
+
+    public WorldGenLevel level() {
+        return this.world;
+    }
+
+    public ChunkGenerator chunkGenerator() {
+        return this.generator;
+    }
+
+    public RandomSource random() {
+        return this.random;
+    }
+
+    public BlockPos origin() {
+        return this.origin;
+    }
+
+    public FC config() {
+        return this.config;
+    }
+
+    public Optional<ConfiguredFeature<?, ?>> topFeature() {
+        return this.feature;
+    }
+}
diff --git a/src/main/java/com/ishland/c2me/opts/allocs/common/SimpleObjectPool.java b/src/main/java/com/ishland/c2me/opts/allocs/common/SimpleObjectPool.java
new file mode 100644
index 0000000000000000000000000000000000000000..b989019847f73ba3af57f7428699c9c869d6332f
--- /dev/null
+++ b/src/main/java/com/ishland/c2me/opts/allocs/common/SimpleObjectPool.java
@@ -0,0 +1,57 @@
+package com.ishland.c2me.opts.allocs.common;
+
+import com.google.common.base.Preconditions;
+
+import java.util.Objects;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+public class SimpleObjectPool<T> {
+
+    private final Function<SimpleObjectPool<T>, T> constructor;
+    private final Consumer<T> initializer;
+    private final int size;
+
+    private final Object[] cachedObjects;
+    private int allocatedCount = 0;
+
+    public SimpleObjectPool(Function<SimpleObjectPool<T>, T> constructor, Consumer<T> initializer, int size) {
+        this.constructor = Objects.requireNonNull(constructor);
+        this.initializer = Objects.requireNonNull(initializer);
+        Preconditions.checkArgument(size > 0);
+        this.cachedObjects = new Object[size];
+        this.size = size;
+
+        for (int i = 0; i < size; i++) {
+            final T object = constructor.apply(this);
+            this.cachedObjects[i] = object;
+        }
+    }
+
+    public T alloc() {
+        final T object;
+        synchronized (this) {
+            if (this.allocatedCount >= this.size) { // oversized, falling back to normal alloc
+                object = this.constructor.apply(this);
+                return object;
+            }
+
+            // get an object from the array
+            final int ordinal = this.allocatedCount++;
+            object = (T) this.cachedObjects[ordinal];
+            this.cachedObjects[ordinal] = null;
+        }
+
+        this.initializer.accept(object); // initialize the object
+
+        return object;
+    }
+
+    public void release(T object) {
+        synchronized (this) {
+            if (this.allocatedCount == 0) return; // pool is full
+            this.cachedObjects[--this.allocatedCount] = object; // store the object into the pool
+        }
+    }
+
+}
diff --git a/src/main/java/net/minecraft/resources/ResourceLocation.java b/src/main/java/net/minecraft/resources/ResourceLocation.java
index 7017dd42f832d928f1008a05f01701667d951644..4e767dd8f9594e8a8f5d71e2bfd8c976c0032f98 100644
--- a/src/main/java/net/minecraft/resources/ResourceLocation.java
+++ b/src/main/java/net/minecraft/resources/ResourceLocation.java
@@ -27,6 +27,7 @@ public class ResourceLocation implements Comparable<ResourceLocation> {
     public static final String REALMS_NAMESPACE = "realms";
     protected final String namespace;
     protected final String path;
+    private String cachedString = null; // Mirai - c2me: opts allocs
 
     protected ResourceLocation(String[] id) {
         this.namespace = StringUtils.isEmpty(id[0]) ? "minecraft" : id[0];
@@ -99,7 +100,16 @@ public class ResourceLocation implements Comparable<ResourceLocation> {
 
     @Override
     public String toString() {
-        return this.namespace + ":" + this.path;
+        // Mirai start - c2me: opts allocs
+        /**
+         * @author ishland
+         * @reason cache toString
+         */
+        if (this.cachedString != null) return this.cachedString;
+        final String s = this.namespace + ":" + this.path;
+        this.cachedString = s;
+        return s;
+        // Mirai end
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/level/levelgen/feature/ConfiguredFeature.java b/src/main/java/net/minecraft/world/level/levelgen/feature/ConfiguredFeature.java
index 2f67705132df06ae6231dd1b89a4f61a90616ef5..1013df19df55316200169f6c3deec8876ea4686a 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/feature/ConfiguredFeature.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/feature/ConfiguredFeature.java
@@ -12,6 +12,10 @@ import net.minecraft.util.RandomSource;
 import net.minecraft.world.level.WorldGenLevel;
 import net.minecraft.world.level.chunk.ChunkGenerator;
 import net.minecraft.world.level.levelgen.feature.configurations.FeatureConfiguration;
+// Mirai start - c2me: opts allocs
+import com.ishland.c2me.opts.allocs.common.PooledFeatureContext;
+import com.ishland.c2me.opts.allocs.common.SimpleObjectPool;
+// Mirai end
 
 public record ConfiguredFeature<FC extends FeatureConfiguration, F extends Feature<FC>>(F feature, FC config) {
     public static final Codec<ConfiguredFeature<?, ?>> DIRECT_CODEC = Registry.FEATURE.byNameCodec().dispatch((configuredFeature) -> {
@@ -21,7 +25,22 @@ public record ConfiguredFeature<FC extends FeatureConfiguration, F extends Featu
     public static final Codec<HolderSet<ConfiguredFeature<?, ?>>> LIST_CODEC = RegistryCodecs.homogeneousList(Registry.CONFIGURED_FEATURE_REGISTRY, DIRECT_CODEC);
 
     public boolean place(WorldGenLevel world, ChunkGenerator chunkGenerator, RandomSource random, BlockPos origin) {
-        return this.feature.place(this.config, world, chunkGenerator, random, origin);
+        // Mirai start - c2me: opts allocs
+        /**
+         * @author ishland
+         * @reason pool FeatureContext
+         */
+        if (!world.ensureCanWrite(origin)) return false;
+        final SimpleObjectPool<PooledFeatureContext<?>> pool = PooledFeatureContext.POOL.get();
+        final PooledFeatureContext<FC> context = (PooledFeatureContext<FC>) pool.alloc();
+        try {
+            context.reInit(java.util.Optional.empty(), world, chunkGenerator, random, origin, this.config);
+            return this.feature.place(context);
+        } finally {
+            context.reInit();
+            pool.release(context);
+        }
+        // Mirai end
     }
 
     public Stream<ConfiguredFeature<?, ?>> getFeatures() {
diff --git a/src/main/java/net/minecraft/world/level/levelgen/feature/OreFeature.java b/src/main/java/net/minecraft/world/level/levelgen/feature/OreFeature.java
index b2f36a998437e2a63a3cbc6c3aa95b1402bff2f1..d69a57f67eeb99f3db4f80d13b9f0276ce4603af 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/feature/OreFeature.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/feature/OreFeature.java
@@ -54,7 +54,7 @@ public class OreFeature extends Feature<OreConfiguration> {
 
     protected boolean doPlace(WorldGenLevel world, RandomSource randomSource, OreConfiguration config, double startX, double endX, double startZ, double endZ, double startY, double endY, int x, int y, int z, int horizontalSize, int verticalSize) {
         int i = 0;
-        BitSet bitSet = new BitSet(horizontalSize * verticalSize * horizontalSize);
+        BitSet bitSet = com.ishland.c2me.opts.allocs.common.ObjectCachingUtils.getCachedOrNewBitSet(horizontalSize * verticalSize * horizontalSize); // Mirai - c2me: opts allocs
         BlockPos.MutableBlockPos mutableBlockPos = new BlockPos.MutableBlockPos();
         int j = config.size;
         double[] ds = new double[j * 4];