just to change from disabling spawn chunks to control over its size. Removes disableSpawnChunks, adds spawnChunksSize. Fixes #192

src/main/java/carpet/CarpetSettings.java

@@ -5,13 +5,11 @@ import carpet.settings.Rule;
 import carpet.settings.SettingsManager;
 import carpet.settings.Validator;
 import carpet.utils.Messenger;
+import carpet.utils.SpawnChunks;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.command.ServerCommandSource;
 import net.minecraft.server.dedicated.DedicatedServer;
-import net.minecraft.server.world.ChunkTicketType;
-import net.minecraft.server.world.ServerChunkManager;
 import net.minecraft.server.world.ServerWorld;
-import net.minecraft.util.Unit;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Box;
 import net.minecraft.util.math.ChunkPos;
@@ -236,13 +234,6 @@ public class CarpetSettings
     @Rule( desc = "Pistons can push block entities, like hoppers, chests etc.", category = {EXPERIMENTAL, FEATURE} )
     public static boolean movableBlockEntities = false;
 
-    /*@Rule(
-            desc = "Orange stained glass behaves like slime, but doesn't stick to it",
-            extra = "Only available for 1.14. in 1.15 use honey instead",
-            category = {EXPERIMENTAL, FEATURE}
-    )
-    public static boolean honeySlime = false;*/
-
     @Rule( desc = "Saplings turn into dead shrubs in hot climates and no water access", category = FEATURE )
     public static boolean desertShrubs = false;
 
@@ -356,9 +347,6 @@ public class CarpetSettings
     @Rule(desc = "Pistons, Glass and Sponge can be broken faster with their appropriate tools", category = SURVIVAL)
     public static boolean missingTools = false;
 
-    //@Rule(desc = "Alternative, persistent caching strategy for nether portals", category = {SURVIVAL, CREATIVE})
-    //public static boolean portalCaching = false; // ineffective in 1.15
-
     @Rule(desc = "fill/clone/setblock and structure blocks cause block updates", category = CREATIVE)
     public static boolean fillUpdates = true;
 
@@ -509,13 +497,9 @@ public class CarpetSettings
     )
     public static int viewDistance = 0;
 
-    private static class DisableSpawnChunksValidator extends Validator<Boolean> {
-        @Override public Boolean validate(ServerCommandSource source, ParsedRule<Boolean> currentRule, Boolean newValue, String string) {
-            if (currentRule.get().booleanValue() == newValue.booleanValue())
-            {
-                //must been some startup thing
-                return newValue;
-            }
+    public static class ChangeSpawnChunksValidator extends Validator<Integer> {
+        public static void changeSpawnSize(int size)
+        {
             ServerWorld overworld = CarpetServer.minecraft_server.getWorld(DimensionType.OVERWORLD);
             if (overworld != null) {
                 ChunkPos centerChunk = new ChunkPos(new BlockPos(
@@ -523,40 +507,37 @@ public class CarpetSettings
                         overworld.getLevelProperties().getSpawnY(),
                         overworld.getLevelProperties().getSpawnZ()
                 ));
-                ServerChunkManager chunkManager = (ServerChunkManager) overworld.getChunkManager();
-
-                chunkManager.removeTicket(ChunkTicketType.START, centerChunk, 11, Unit.INSTANCE);
-                if (!newValue)
-                {
-                    chunkManager.addTicket(ChunkTicketType.START, centerChunk, 11, Unit.INSTANCE);
-                }
+                SpawnChunks.changeSpawnChunks(overworld.getChunkManager(), centerChunk, size);
+            }
+        }
+        @Override public Integer validate(ServerCommandSource source, ParsedRule<Integer> currentRule, Integer newValue, String string) {
+            if (newValue < 0 || newValue > 32)
+            {
+                Messenger.m(source, "r spawn chunk size has to be between 0 and 32");
+                return null;
+            }
+            if (currentRule.get().intValue() == newValue.intValue())
+            {
+                //must been some startup thing
+                return newValue;
+            }
+            ServerWorld currentOverworld = CarpetServer.minecraft_server.getWorld(DimensionType.OVERWORLD);
+            if (currentOverworld != null)
+            {
+                changeSpawnSize(newValue);
             }
             return newValue;
         }
     }
     @Rule(
-            desc = "Allows spawn chunks to unload",
+            desc = "Changes size of spawn chunks",
+            extra = {"Defines new radius", "setting it to 0 - disables spawn chunks"},
             category = CREATIVE,
-            validate = DisableSpawnChunksValidator.class
-    )
-    public static boolean disableSpawnChunks = false;
-
-    /*private static class KelpLimit extends Validator<Integer>
-    {
-        @Override public Integer validate(ServerCommandSource source, ParsedRule<Integer> currentRule, Integer newValue, String string) {
-            return (newValue>=0 && newValue <=25)?newValue:null;
-        }
-        @Override
-        public String description() { return "You must choose a value from 0 to 25. 25 and all natural kelp can grow 25 blocks, choose 0 to make all generated kelp not to grow";}
-    }
-    @Rule(
-            desc = "limits growth limit of newly naturally generated kelp to this amount of blocks",
-            options = {"0", "2", "25"},
-            category = FEATURE,
             strict = false,
-            validate = KelpLimit.class
+            options = {"0", "11"},
+            validate = ChangeSpawnChunksValidator.class
     )
-    public static int kelpGenerationGrowthLimit = 25;*/
+    public static int spawnChunksSize = 11;
 
     @Rule(desc = "Coral structures will grow with bonemeal from coral plants", category = FEATURE)
     public static boolean renewableCoral = false;
@@ -573,13 +554,6 @@ public class CarpetSettings
 
     @Rule(desc = "Spawning requires much less CPU and Memory", category = OPTIMIZATION)
     public static boolean lagFreeSpawning = false;
-
-    //@Rule(
-    //        desc = "Prevents horses and other mobs to wander into the distance after dismounting",
-    //        extra = "Fixes issues with various Joergens wandering off and disappearing client-side",
-    //        category = BUGFIX
-    //)
-    //public static boolean horseWanderingFix = false;
     
     @Rule(
             desc = "Allows structure mobs to spawn in flat worlds",

src/main/java/carpet/fakes/ChunkTicketManagerInterface.java

@@ -0,0 +1,12 @@
+package carpet.fakes;
+
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import net.minecraft.server.world.ChunkTicket;
+import net.minecraft.util.SortedArraySet;
+import net.minecraft.util.math.ChunkPos;
+
+public interface ChunkTicketManagerInterface
+{
+    void changeSpawnChunks(ChunkPos pos, int distance);
+    Long2ObjectOpenHashMap<SortedArraySet<ChunkTicket<?>>> getTicketsByPosition();
+}

src/main/java/carpet/fakes/ServerChunkManagerInterface.java

@@ -0,0 +1,8 @@
+package carpet.fakes;
+
+import net.minecraft.server.world.ChunkTicketManager;
+
+public interface ServerChunkManagerInterface
+{
+    ChunkTicketManager getTicketManager();
+}

src/main/java/carpet/mixins/ChunkTicketManager_scarpetMixin.java

@@ -1,15 +1,23 @@
 package carpet.mixins;
 
+import carpet.fakes.ChunkTicketManagerInterface;
 import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
 import net.minecraft.server.world.ChunkTicket;
 import net.minecraft.server.world.ChunkTicketManager;
 import net.minecraft.util.SortedArraySet;
+import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.gen.Accessor;
+import org.spongepowered.asm.mixin.Shadow;
 
 @Mixin(ChunkTicketManager.class)
-public interface ChunkTicketManager_scarpetMixin
+public abstract class ChunkTicketManager_scarpetMixin implements ChunkTicketManagerInterface
 {
-    @Accessor
-    Long2ObjectOpenHashMap<SortedArraySet<ChunkTicket<?>>>  getTicketsByPosition();
+    @Shadow @Final private Long2ObjectOpenHashMap<SortedArraySet<ChunkTicket<?>>> ticketsByPosition;
+
+    @Override
+    public Long2ObjectOpenHashMap<SortedArraySet<ChunkTicket<?>>>  getTicketsByPosition()
+    {
+        return ticketsByPosition;
+    }
+
 }

src/main/java/carpet/mixins/ChunkTicketManager_spawnChunksMixin.java

@@ -0,0 +1,60 @@
+package carpet.mixins;
+
+import carpet.fakes.ChunkTicketManagerInterface;
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import net.minecraft.server.world.ChunkTicket;
+import net.minecraft.server.world.ChunkTicketManager;
+import net.minecraft.server.world.ChunkTicketType;
+import net.minecraft.util.SortedArraySet;
+import net.minecraft.util.Unit;
+import net.minecraft.util.math.ChunkPos;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import java.util.Iterator;
+
+@Mixin(ChunkTicketManager.class)
+public abstract class ChunkTicketManager_spawnChunksMixin implements ChunkTicketManagerInterface
+{
+
+    @Shadow protected abstract SortedArraySet<ChunkTicket<?>> getTicketSet(long position);
+
+    @Shadow @Final private Long2ObjectOpenHashMap<SortedArraySet<ChunkTicket<?>>> ticketsByPosition;
+
+    @Shadow public abstract <T> void removeTicket(ChunkTicketType<T> type, ChunkPos pos, int radius, T argument);
+
+    @Shadow protected abstract void removeTicket(long pos, ChunkTicket<?> ticket);
+
+    @Shadow public abstract <T> void addTicket(ChunkTicketType<T> type, ChunkPos pos, int radius, T argument);
+
+    @Override
+    public void changeSpawnChunks(ChunkPos chunkPos,  int distance)
+    {
+        long pos = chunkPos.toLong();
+        SortedArraySet<ChunkTicket<?>> set = ticketsByPosition.get(pos);
+        ChunkTicket existingTicket = null;
+        if (set != null)
+        {
+            Iterator<ChunkTicket<?>> iter = set.iterator();
+            while(iter.hasNext())
+            {
+                ChunkTicket ticket = iter.next();
+                if (ticket.getType() == ChunkTicketType.START)
+                {
+                    existingTicket = ticket;
+                    iter.remove();
+                }
+            }
+            set.add(existingTicket);
+        }
+        // the reason we are removing the ticket this way is that there are sideeffects of removal
+        if (existingTicket != null)
+        {
+            removeTicket(pos, existingTicket);
+        }
+        // set optionally new spawn ticket
+        if (distance > 0)
+            addTicket(ChunkTicketType.START, chunkPos, distance, Unit.INSTANCE);
+    }
+}

src/main/java/carpet/mixins/MinecraftServer_coreMixin.java

@@ -1,8 +1,10 @@
 package carpet.mixins;
 
 import carpet.CarpetServer;
+import carpet.CarpetSettings;
 import com.google.gson.JsonElement;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.WorldGenerationProgressListener;
 import net.minecraft.world.level.LevelGeneratorType;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
@@ -41,4 +43,11 @@ public abstract class MinecraftServer_coreMixin
     {
         CarpetServer.onServerClosed((MinecraftServer) (Object) this);
     }
+
+    @Inject(method = "prepareStartRegion", at = @At("RETURN"))
+    private void afterSpawnCreated(WorldGenerationProgressListener worldGenerationProgressListener, CallbackInfo ci)
+    {
+        if (CarpetSettings.spawnChunksSize != 11)
+            CarpetSettings.ChangeSpawnChunksValidator.changeSpawnSize(CarpetSettings.spawnChunksSize);
+    }
 }

src/main/java/carpet/mixins/ServerChunkManagerMixin.java

@@ -1,8 +1,10 @@
 package carpet.mixins;
 
+import carpet.fakes.ServerChunkManagerInterface;
 import carpet.utils.SpawnReporter;
 import it.unimi.dsi.fastutil.objects.Object2IntMap;
 import net.minecraft.entity.EntityCategory;
+import net.minecraft.server.world.ChunkTicketManager;
 import net.minecraft.server.world.ServerChunkManager;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.util.math.BlockPos;
@@ -24,12 +26,20 @@ import java.util.HashMap;
 import java.util.HashSet;
 
 @Mixin(ServerChunkManager.class)
-public abstract class ServerChunkManagerMixin
+public abstract class ServerChunkManagerMixin implements ServerChunkManagerInterface
 {
     @Shadow @Final private ServerWorld world;
 
     @Shadow @Final private static int CHUNKS_ELIGIBLE_FOR_SPAWNING;
 
+    @Shadow @Final private ChunkTicketManager ticketManager;
+
+    @Override // shared between scarpet and spawnChunks setting
+    public ChunkTicketManager getTicketManager()
+    {
+        return ticketManager;
+    }
+
     @Inject(
             method = "tickChunks",
             locals = LocalCapture.CAPTURE_FAILHARD,

src/main/java/carpet/mixins/ServerChunkManager_scarpetMixin.java

@@ -1,13 +0,0 @@
-package carpet.mixins;
-
-import net.minecraft.server.world.ChunkTicketManager;
-import net.minecraft.server.world.ServerChunkManager;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-@Mixin(ServerChunkManager.class)
-public interface ServerChunkManager_scarpetMixin
-{
-    @Accessor
-    ChunkTicketManager getTicketManager();
-}

src/main/java/carpet/mixins/ServerWorld_spawnChunksMixin.java

@@ -0,0 +1,17 @@
+package carpet.mixins;
+
+import carpet.CarpetSettings;
+import net.minecraft.server.world.ServerWorld;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.Constant;
+import org.spongepowered.asm.mixin.injection.ModifyConstant;
+
+@Mixin(ServerWorld.class)
+public class ServerWorld_spawnChunksMixin
+{
+    @ModifyConstant(method = "setSpawnPos", constant = @Constant(intValue = 11), expect = 2)
+    private int pushLimit(int original)
+    {
+        return CarpetSettings.spawnChunksSize;
+    }
+}

src/main/java/carpet/script/CarpetExpression.java

@@ -1,14 +1,14 @@
 package carpet.script;
 
 import carpet.CarpetServer;
+import carpet.fakes.ChunkTicketManagerInterface;
 import carpet.fakes.MinecraftServerInterface;
 import carpet.fakes.BiomeArrayInterface;
+import carpet.fakes.ServerChunkManagerInterface;
 import carpet.fakes.StatTypeInterface;
 import carpet.fakes.ThreadedAnvilChunkStorageInterface;
 import carpet.helpers.FeatureGenerator;
-import carpet.mixins.ChunkTicketManager_scarpetMixin;
 import carpet.mixins.PointOfInterest_scarpetMixin;
-import carpet.mixins.ServerChunkManager_scarpetMixin;
 import carpet.script.Fluff.TriFunction;
 import carpet.script.bundled.Module;
 import carpet.CarpetSettings;
@@ -708,7 +708,7 @@ public class CarpetExpression
         {
             ServerWorld world = ((CarpetContext) c).s.getWorld();
             Long2ObjectOpenHashMap<SortedArraySet<ChunkTicket<?>>> levelTickets = (
-                    (ChunkTicketManager_scarpetMixin) ((ServerChunkManager_scarpetMixin) world.getChunkManager())
+                    (ChunkTicketManagerInterface) ((ServerChunkManagerInterface) world.getChunkManager())
                             .getTicketManager()
             ).getTicketsByPosition();
             List<Value> res = new ArrayList<>();

src/main/java/carpet/utils/SpawnChunks.java

@@ -0,0 +1,16 @@
+package carpet.utils;
+
+import carpet.fakes.ChunkTicketManagerInterface;
+import carpet.fakes.ServerChunkManagerInterface;
+import net.minecraft.server.world.ChunkTicketManager;
+import net.minecraft.server.world.ServerChunkManager;
+import net.minecraft.util.math.ChunkPos;
+
+public class SpawnChunks
+{
+    public static void changeSpawnChunks(ServerChunkManager chunkManager, ChunkPos pos, int size)
+    {
+        ChunkTicketManager ticketManager = ((ServerChunkManagerInterface)chunkManager).getTicketManager();
+        ((ChunkTicketManagerInterface)ticketManager).changeSpawnChunks(pos, size);
+    }
+}