R3944Realms/ModernFix-fix
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Drastically simplify and document chunk system memory usage patch

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embeddedt 2026-02-28 16:42:42 -05:00
parent 49d800ff27
commit ee34dcf96e
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GPG Key ID: A69433EC199B5613
1 changed files with 19 additions and 42 deletions
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61
src/main/java/org/embeddedt/modernfix/common/mixin/bugfix/paper_chunk_patches/ChunkMapMixin.java
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@ -1,22 +1,18 @@
package org.embeddedt.modernfix.common.mixin.bugfix.paper_chunk_patches;
import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
import com.mojang.datafixers.util.Either;
import net.minecraft.server.level.*;
import net.minecraft.server.level.progress.ChunkProgressListener;
import net.minecraft.util.thread.BlockableEventLoop;
import net.minecraft.world.level.ChunkPos;
import net.minecraft.world.level.chunk.ChunkAccess;
import net.minecraft.world.level.chunk.ChunkStatus;
import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplateManager;
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.ModifyArg;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.Executor;
@ -25,18 +21,6 @@ import java.util.concurrent.Executor;
public abstract class ChunkMapMixin {
@Shadow @Final private BlockableEventLoop<Runnable> mainThreadExecutor;
@Shadow @Final private ChunkMap.DistanceManager distanceManager;
@Shadow protected abstract CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>> protoChunkToFullChunk(ChunkHolder arg);
@Shadow @Final private ServerLevel level;
@Shadow @Final private ThreadedLevelLightEngine lightEngine;
@Shadow @Final private ChunkProgressListener progressListener;
@Shadow protected abstract CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>> scheduleChunkGeneration(ChunkHolder chunkHolder, ChunkStatus chunkStatus);
@Shadow @Final private StructureTemplateManager structureTemplateManager;
/* https://github.com/PaperMC/Paper/blob/ver/1.17.1/patches/server/0752-Fix-chunks-refusing-to-unload-at-low-TPS.patch */
@ModifyArg(method = "prepareAccessibleChunk", at = @At(value = "INVOKE", target = "Ljava/util/concurrent/CompletableFuture;thenApplyAsync(Ljava/util/function/Function;Ljava/util/concurrent/Executor;)Ljava/util/concurrent/CompletableFuture;"), index = 1)
private Executor useMainThreadExecutor(Executor executor) {
@ -45,31 +29,24 @@ public abstract class ChunkMapMixin {
/**
* @author embeddedt
* @reason revert 1.17 chunk system changes, significantly reduces time and RAM needed to load chunks
* @reason 1.17+ uses getNow to check if the parent future is ready, and calls scheduleChunkGeneration as soon as
* it is found to not be ready. In the latter scenario, a massive number of extra CompletableFutures are allocated
* even if they are not actually necessary if the future is waited for. To prevent this, if the parent future
* is not done, we wait for it to complete and then retry schedule(). This will either detect an adequate
* status and return a loading future, or re-enter this injector with the parent future completed, in which case
* we proceed to schedule generation as originally requested.
*/
@Inject(method = "schedule", at = @At("HEAD"), cancellable = true)
private void useLegacySchedulingLogic(ChunkHolder holder, ChunkStatus requiredStatus, CallbackInfoReturnable<CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>>> cir) {
if(requiredStatus != ChunkStatus.EMPTY && !requiredStatus.hasLoadDependencies()) {
ChunkPos chunkpos = holder.getPos();
CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>> future = holder.getOrScheduleFuture(requiredStatus.getParent(), (ChunkMap)(Object)this);
cir.setReturnValue(future.thenComposeAsync((either) -> {
Optional<ChunkAccess> optional = either.left();
if (requiredStatus == ChunkStatus.LIGHT) {
this.distanceManager.addTicket(TicketType.LIGHT, chunkpos, 33 + ChunkStatus.getDistance(ChunkStatus.LIGHT), chunkpos);
}
// from original method
if (optional.isPresent() && optional.get().getStatus().isOrAfter(requiredStatus)) {
CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>> completablefuture = requiredStatus.load(this.level, this.structureTemplateManager, this.lightEngine, (arg2) -> {
return this.protoChunkToFullChunk(holder);
}, (ChunkAccess)optional.get());
this.progressListener.onStatusChange(chunkpos, requiredStatus);
return completablefuture;
} else {
return this.scheduleChunkGeneration(holder, requiredStatus);
}
}, this.mainThreadExecutor).thenComposeAsync(CompletableFuture::completedFuture, this.mainThreadExecutor));
@WrapOperation(method = "schedule", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/level/ChunkMap;scheduleChunkGeneration(Lnet/minecraft/server/level/ChunkHolder;Lnet/minecraft/world/level/chunk/ChunkStatus;)Ljava/util/concurrent/CompletableFuture;"))
private CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>> mfix$avoidSchedulingGenerationPrematurely(ChunkMap map, ChunkHolder holder, ChunkStatus status, Operation<CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>>> original) {
if (!status.hasLoadDependencies()) {
var parentFuture = holder.getOrScheduleFuture(status.getParent(), map);
if (!parentFuture.isDone()) {
return parentFuture.thenComposeAsync(
either -> map.schedule(holder, status),
this.mainThreadExecutor
);
}
}
return original.call(map, holder, status);
}
}