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Cleanup faster random generator #641

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Merged
Dreeam-qwq merged 2 commits into from
Feb 11, 2026
Merged

Cleanup faster random generator #641

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fda9d7d
Cleanup faster random generator
HaHaWTH Feb 11, 2026
47fa8e6
Update config
HaHaWTH Feb 11, 2026
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34 changes: 6 additions & 28 deletions leaf-server/src/main/java/org/dreeam/leaf/config/modules/opt/FastRNG.java
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Original file line number Diff line number Diff line change
Expand Up @@ -4,8 +4,6 @@
import org.dreeam.leaf.config.EnumConfigCategory;
import org.dreeam.leaf.config.LeafConfig;

import java.util.random.RandomGeneratorFactory;

public class FastRNG extends ConfigModules {

public String getBasePath() {
Expand All @@ -14,11 +12,8 @@ public String getBasePath() {

public static boolean enabled = false;
public static boolean enableForWorldgen = false;
public static String randomGenerator = "Xoroshiro128PlusPlus";
public static boolean warnForSlimeChunk = true;
public static boolean useLegacyForSlimeChunk = false;
@Deprecated
public static boolean useDirectImpl = false;

public static boolean worldgen = false;
public static boolean worldgenEnabled() {
Expand All @@ -29,22 +24,14 @@ public static boolean worldgenEnabled() {
public void onLoaded() {
config.addCommentRegionBased(getBasePath(), """
Use faster random generator?
Requires a JVM that supports RandomGenerator.
Requires a JVM that supports Xoroshiro128PlusPlus.
Some JREs don't support this.""",
"""
是否使用更快的随机生成器?
需要支持 RandomGenerator 的 JVM.
需要支持 Xoroshiro128PlusPlus 的 JVM.
一些 JRE 不支持此功能.""");

enabled = config.getBoolean(getBasePath() + ".enabled", enabled);
randomGenerator = config.getString(getBasePath() + ".random-generator", randomGenerator,
config.pickStringRegionBased(
"""
Which random generator will be used?
See https://openjdk.org/jeps/356""",
"""
使用什么种类的随机生成器.
请参阅 https://openjdk.org/jeps/356"""));
enableForWorldgen = config.getBoolean(getBasePath() + ".enable-for-worldgen", enableForWorldgen,
config.pickStringRegionBased(
"""
Expand All @@ -63,21 +50,12 @@ public void onLoaded() {
to follow vanilla behavior.""",
"""
是否使用原版随机生成器来生成史莱姆区块."""));
useDirectImpl = config.getBoolean(getBasePath() + ".use-direct-implementation", useDirectImpl,
config.pickStringRegionBased(
"""
Use direct random implementation instead of delegating to Java's RandomGenerator.
This may improve performance but potentially changes RNG behavior.""",
"""
使用直接随机实现而不是委派给 RandomGenerator.
这可能会提高性能, 但可能会改变 RNG 行为."""));

if (enabled) {
try {
RandomGeneratorFactory.of(randomGenerator);
} catch (Exception e) {
LeafConfig.LOGGER.error("Faster random generator is enabled but {} is not supported by your JVM, " +
"falling back to legacy random source.", randomGenerator);
Class.forName("org.dreeam.leaf.util.math.random.FasterRandomSource");
} catch (Throwable ignored) {
LeafConfig.LOGGER.error("Faster random generator is enabled but Xoroshiro128PlusPlus is not supported by your JVM, " +
"falling back to legacy random source.");
enabled = false;
}
}
Expand Down
61 changes: 2 additions & 59 deletions leaf-server/src/main/java/org/dreeam/leaf/util/math/random/FasterRandomSource.java
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Original file line number Diff line number Diff line change
Expand Up @@ -6,45 +6,24 @@
import net.minecraft.world.level.levelgen.BitRandomSource;
import net.minecraft.world.level.levelgen.PositionalRandomFactory;
import net.minecraft.world.level.levelgen.RandomSupport;
import org.dreeam.leaf.config.modules.opt.FastRNG;
import org.jspecify.annotations.NullMarked;

import java.util.random.RandomGenerator;
import java.util.random.RandomGeneratorFactory;

@NullMarked
public final class FasterRandomSource 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> RANDOM_GENERATOR_FACTORY = RandomGeneratorFactory.of(FastRNG.randomGenerator);
private static final RandomGeneratorFactory<RandomGenerator> RANDOM_GENERATOR_FACTORY = RandomGeneratorFactory.of("Xoroshiro128PlusPlus");
private RandomGenerator delegate;
@Deprecated
private long seed;
public static final FasterRandomSource SHARED_INSTANCE = new FasterRandomSource(RandomSupport.generateUniqueSeed());
@Deprecated
private static final boolean useDirectImpl = FastRNG.useDirectImpl;

public FasterRandomSource(long seed) {
this.seed = seed;
this.delegate = RANDOM_GENERATOR_FACTORY.create(seed);
}

private FasterRandomSource(RandomGenerator.SplittableGenerator randomGenerator) {
this.seed = randomGenerator.nextLong();
this.delegate = randomGenerator;
}

@Override
public RandomSource fork() {
if (useDirectImpl) {
return new FasterRandomSource(this.nextLong());
}
return RANDOM_GENERATOR_FACTORY.isSplittable()
? new FasterRandomSource(((RandomGenerator.SplittableGenerator) this.delegate).split())
: new FasterRandomSource(this.nextLong());
return new FasterRandomSource(this.nextLong());
}

@Override
Expand All @@ -54,15 +33,11 @@ public PositionalRandomFactory forkPositional() {

@Override
public void setSeed(long seed) {
this.seed = seed;
this.delegate = RANDOM_GENERATOR_FACTORY.create(seed);
}

@Override
public int next(int bits) {
if (useDirectImpl) {
return (int) ((seed = seed * MULTIPLIER + INCREMENT & SEED_MASK) >>> (INT_BITS - bits));
}
return (int) (nextLong() >>> (64 - bits));
}

Expand Down Expand Up @@ -98,73 +73,41 @@ public void parityConfigString(StringBuilder info) {

@Override
public int nextInt() {
if (useDirectImpl) {
return (int) (((seed = seed * MULTIPLIER + INCREMENT & SEED_MASK) >>> 16) ^
((seed = seed * MULTIPLIER + INCREMENT & SEED_MASK) >>> 32));
}
return delegate.nextInt();
}

@Override
public int nextInt(int bound) {
if (useDirectImpl && bound > 0) {
if ((bound & -bound) == bound) {
return (int) ((bound * (long) next(31)) >> 31);
}
int bits, val;
do {
bits = next(31);
val = bits % bound;
} while (bits - val + (bound - 1) < 0);
return val;
}
return delegate.nextInt(bound);
}

@Override
public int nextInt(int origin, int bound) {
if (useDirectImpl && bound > 0) {
return origin + this.nextInt(bound - origin);
}
return delegate.nextInt(origin, bound);
}

@Override
public long nextLong() {
if (useDirectImpl) {
return ((long) next(32) << 32) + next(32);
}
return delegate.nextLong();
}

@Override
public boolean nextBoolean() {
if (useDirectImpl) {
return next(1) != 0;
}
return delegate.nextBoolean();
}

@Override
public float nextFloat() {
if (useDirectImpl) {
return next(24) / ((float) (1 << 24));
}
return delegate.nextFloat();
}

@Override
public double nextDouble() {
if (useDirectImpl) {
return (((long) next(26) << 27) + next(27)) / (double) (1L << 53);
}
return delegate.nextDouble();
}

@Override
public double nextGaussian() {
// delegate Gaussian distribution to RandomGenerator
// as direct implementation would be complex (i aint doin allat)
return delegate.nextGaussian();
}
}