Add feature patch hook for overrides

paper-server/src/main/java/io/papermc/paper/FeatureHooks.java

@@ -0,0 +1,72 @@
+package io.papermc.paper;
+
+import io.papermc.paper.command.PaperSubcommand;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import it.unimi.dsi.fastutil.longs.LongSet;
+import it.unimi.dsi.fastutil.longs.LongSets;
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
+import it.unimi.dsi.fastutil.objects.ObjectSet;
+import it.unimi.dsi.fastutil.objects.ObjectSets;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import net.minecraft.core.Registry;
+import net.minecraft.network.protocol.game.ClientboundLevelChunkWithLightPacket;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.biome.Biome;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.chunk.PalettedContainer;
+import org.bukkit.Chunk;
+import org.bukkit.World;
+
+public final class FeatureHooks {
+
+    public static void initChunkTaskScheduler(final boolean useParallelGen) {
+    }
+
+    public static void registerPaperCommands(final Map<Set<String>, PaperSubcommand> commands) {
+    }
+
+    public static LevelChunkSection createSection(final Registry<Biome> biomeRegistry, final Level level, final ChunkPos chunkPos, final int chunkSection) {
+        return new LevelChunkSection(biomeRegistry);
+    }
+
+    public static void sendChunkRefreshPackets(final List<ServerPlayer> playersInRange, final LevelChunk chunk) {
+        final ClientboundLevelChunkWithLightPacket refreshPacket = new ClientboundLevelChunkWithLightPacket(chunk, chunk.level.getLightEngine(), null, null);
+        for (final ServerPlayer player : playersInRange) {
+            if (player.connection == null) continue;
+
+            player.connection.send(refreshPacket);
+        }
+    }
+
+    public static PalettedContainer<BlockState> emptyPalettedBlockContainer() {
+        return new PalettedContainer<>(Block.BLOCK_STATE_REGISTRY, Blocks.AIR.defaultBlockState(), PalettedContainer.Strategy.SECTION_STATES);
+    }
+
+    public static Set<Long> getSentChunkKeys(final ServerPlayer player) {
+        final LongSet keys = new LongOpenHashSet();
+        player.getChunkTrackingView().forEach(pos -> keys.add(pos.longKey));
+        return LongSets.unmodifiable(keys);
+    }
+
+    public static Set<Chunk> getSentChunks(final ServerPlayer player) {
+        final ObjectSet<Chunk> chunks = new ObjectOpenHashSet<>();
+        final World world = player.serverLevel().getWorld();
+        player.getChunkTrackingView().forEach(pos -> {
+            final org.bukkit.Chunk chunk = world.getChunkAt(pos.longKey);
+            chunks.add(chunk);
+        });
+        return ObjectSets.unmodifiable(chunks);
+    }
+
+    public static boolean isChunkSent(final ServerPlayer player, final long chunkKey) {
+        return player.getChunkTrackingView().contains(new ChunkPos(chunkKey));
+    }
+}

paper-server/src/main/java/io/papermc/paper/command/PaperCommand.java

@@ -1,5 +1,6 @@
 package io.papermc.paper.command;
 
+import io.papermc.paper.FeatureHooks;
 import io.papermc.paper.command.subcommands.*;
 import it.unimi.dsi.fastutil.Pair;
 import java.util.ArrayList;
@@ -42,6 +43,7 @@ public final class PaperCommand extends Command {
         commands.put(Set.of("dumpitem"), new DumpItemCommand());
         commands.put(Set.of("mobcaps", "playermobcaps"), new MobcapsCommand());
         commands.put(Set.of("dumplisteners"), new DumpListenersCommand());
+        FeatureHooks.registerPaperCommands(commands);
 
         return commands.entrySet().stream()
             .flatMap(entry -> entry.getKey().stream().map(s -> Map.entry(s, entry.getValue())))

paper-server/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java

@@ -1,6 +1,7 @@
 package io.papermc.paper.configuration;
 
 import com.mojang.logging.LogUtils;
+import io.papermc.paper.FeatureHooks;
 import io.papermc.paper.configuration.constraint.Constraints;
 import io.papermc.paper.configuration.type.number.DoubleOr;
 import io.papermc.paper.configuration.type.number.IntOr;
@@ -217,6 +218,22 @@ public class GlobalConfiguration extends ConfigurationPart {
         @PostProcess
         private void postProcess() {
             ca.spottedleaf.moonrise.common.util.MoonriseCommon.adjustWorkerThreads(this.workerThreads, this.ioThreads);
+            String newChunkSystemGenParallelism = this.genParallelism;
+            if (newChunkSystemGenParallelism.equalsIgnoreCase("default")) {
+                newChunkSystemGenParallelism = "true";
+            }
+
+            final boolean useParallelGen;
+            if (newChunkSystemGenParallelism.equalsIgnoreCase("on") || newChunkSystemGenParallelism.equalsIgnoreCase("enabled")
+                || newChunkSystemGenParallelism.equalsIgnoreCase("true")) {
+                useParallelGen = true;
+            } else if (newChunkSystemGenParallelism.equalsIgnoreCase("off") || newChunkSystemGenParallelism.equalsIgnoreCase("disabled")
+                || newChunkSystemGenParallelism.equalsIgnoreCase("false")) {
+                useParallelGen = false;
+            } else {
+                throw new IllegalStateException("Invalid option for gen-parallelism: must be one of [on, off, enabled, disabled, true, false, default]");
+            }
+            FeatureHooks.initChunkTaskScheduler(useParallelGen);
         }
     }