Leaf/patches/server/0076-Faster-Random-Generator.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: HaHaWTH <fsjk947@gmail.com>
Date: Fri, 3 May 2024 01:12:58 +0800
Subject: [PATCH] Faster Random Generator


diff --git a/src/main/java/net/minecraft/util/RandomSource.java b/src/main/java/net/minecraft/util/RandomSource.java
index 7762c8186035fdf60e11d9f1844516b61f442206..c2f0b5933c61168cbde507f04674e95b78e2d7f3 100644
--- a/src/main/java/net/minecraft/util/RandomSource.java
+++ b/src/main/java/net/minecraft/util/RandomSource.java
@@ -6,6 +6,7 @@ import net.minecraft.world.level.levelgen.PositionalRandomFactory;
 import net.minecraft.world.level.levelgen.RandomSupport;
 import net.minecraft.world.level.levelgen.SingleThreadedRandomSource;
 import net.minecraft.world.level.levelgen.ThreadSafeLegacyRandomSource;
+import org.dreeam.leaf.util.math.random.TheFasterRandom;
 
 public interface RandomSource {
     @Deprecated
@@ -23,16 +24,16 @@ public interface RandomSource {
 
     @Deprecated
     static RandomSource createThreadSafe() {
-        return new ThreadSafeLegacyRandomSource(RandomSupport.generateUniqueSeed());
-    }
+        return org.dreeam.leaf.config.modules.opt.FastRNG.enabled ? new TheFasterRandom(RandomSupport.generateFasterSeed()) : new ThreadSafeLegacyRandomSource(RandomSupport.generateUniqueSeed());
+    } // Leaf - Faster RNG
 
     static RandomSource create(long seed) {
-        return new LegacyRandomSource(seed);
-    }
+        return org.dreeam.leaf.config.modules.opt.FastRNG.enabled ? new TheFasterRandom(seed) : new LegacyRandomSource(seed);
+    } // Leaf - Faster RNG
 
     static RandomSource createNewThreadLocalInstance() {
-        return new SingleThreadedRandomSource(ThreadLocalRandom.current().nextLong());
-    }
+        return org.dreeam.leaf.config.modules.opt.FastRNG.enabled ? new TheFasterRandom(RandomSupport.generateFasterSeed()) : new SingleThreadedRandomSource(ThreadLocalRandom.current().nextLong());
+    } // Leaf - Faster RNG
 
     RandomSource fork();
 
diff --git a/src/main/java/org/dreeam/leaf/config/modules/opt/FastRNG.java b/src/main/java/org/dreeam/leaf/config/modules/opt/FastRNG.java
new file mode 100644
index 0000000000000000000000000000000000000000..13b3adcf44f1c41ffda8ee5ceee085be01991324
--- /dev/null
+++ b/src/main/java/org/dreeam/leaf/config/modules/opt/FastRNG.java
@@ -0,0 +1,31 @@
+package org.dreeam.leaf.config.modules.opt;
+
+import com.electronwill.nightconfig.core.file.CommentedFileConfig;
+import org.dreeam.leaf.config.ConfigInfo;
+import org.dreeam.leaf.config.EnumConfigCategory;
+import org.dreeam.leaf.config.IConfigModule;
+
+public class FastRNG implements IConfigModule {
+
+    @Override
+    public EnumConfigCategory getCategory() {
+        return EnumConfigCategory.PERFORMANCE;
+    }
+
+    @Override
+    public String getBaseName() {
+        return "use_faster_random_generator";
+    }
+
+    @ConfigInfo(baseName = "enabled")
+    public static boolean enabled = false;
+
+    @Override
+    public void onLoaded(CommentedFileConfig config) {
+        config.setComment("performance.use_faster_random_generator", """
+                Use faster random generator? (Up to 100X faster)
+                Requires a JVM that supports RandomGenerator and the LXM generators.
+                Some JREs don't support this and will cause a crash.
+                """);
+    }
+}
diff --git a/src/main/java/org/dreeam/leaf/util/math/random/TheFasterRandom.java b/src/main/java/org/dreeam/leaf/util/math/random/TheFasterRandom.java
new file mode 100644
index 0000000000000000000000000000000000000000..c13c8e5a2fba4267eb254e75f993bc6a9b861f6e
--- /dev/null
+++ b/src/main/java/org/dreeam/leaf/util/math/random/TheFasterRandom.java
@@ -0,0 +1,89 @@
+package org.dreeam.leaf.util.math.random;
+
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.levelgen.BitRandomSource;
+import net.minecraft.world.level.levelgen.LegacyRandomSource;
+import net.minecraft.world.level.levelgen.PositionalRandomFactory;
+
+import java.util.random.RandomGenerator;
+import java.util.random.RandomGeneratorFactory;
+
+
+public class TheFasterRandom implements BitRandomSource {
+    private static final int INT_BITS = 48;
+    private static final long SEED_MASK = 0xFFFFFFFFFFFFL;
+    private static final long MULTIPLIER = 25214903917L;
+    private static final long INCREMENT = 11L;
+    private static final RandomGeneratorFactory<RandomGenerator.SplittableGenerator> RANDOM_GENERATOR_FACTORY = RandomGeneratorFactory.of(
+            "L64X128MixRandom");
+
+    private long seed;
+    private RandomGenerator.SplittableGenerator randomGenerator;
+
+    public TheFasterRandom(long seed) {
+        this.seed = seed;
+        this.randomGenerator = RANDOM_GENERATOR_FACTORY.create(seed);
+    }
+
+    public TheFasterRandom(long seed, RandomGenerator.SplittableGenerator randomGenerator) {
+        this.seed = seed;
+        this.randomGenerator = randomGenerator;
+    }
+
+    @Override
+    public RandomSource fork() {
+        return new TheFasterRandom(seed, randomGenerator.split());
+    }
+
+    @Override
+    public PositionalRandomFactory forkPositional() {
+        return new LegacyRandomSource.LegacyPositionalRandomFactory(this.seed);
+    }
+
+    @Override
+    public void setSeed(long seed) {
+        this.seed = seed;
+        this.randomGenerator = RANDOM_GENERATOR_FACTORY.create(seed);
+    }
+
+    @Override
+    public int next(int bits) {
+        // >>> instead of Mojang's >> fixes MC-239059
+        return (int) ((seed * MULTIPLIER + INCREMENT & SEED_MASK) >>> INT_BITS - bits);
+    }
+
+    @Override
+    public int nextInt() {
+        return randomGenerator.nextInt();
+    }
+
+    @Override
+    public int nextInt(int bound) {
+        return randomGenerator.nextInt(bound);
+    }
+
+    @Override
+    public long nextLong() {
+        return randomGenerator.nextLong();
+    }
+
+    @Override
+    public boolean nextBoolean() {
+        return randomGenerator.nextBoolean();
+    }
+
+    @Override
+    public float nextFloat() {
+        return randomGenerator.nextFloat();
+    }
+
+    @Override
+    public double nextDouble() {
+        return randomGenerator.nextDouble();
+    }
+
+    @Override
+    public double nextGaussian() {
+        return randomGenerator.nextGaussian();
+    }
+}