moved rest of the stuff. mixins needed still

src/main/java/carpet/commands/SpawnCommand.java

@@ -0,0 +1,261 @@
+package carpet.commands;
+
+import carpet.CarpetSettings;
+import carpet.helpers.HopperCounter;
+import carpet.helpers.TickSpeed;
+import carpet.utils.Messenger;
+import carpet.utils.SpawnReporter;
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.arguments.BoolArgumentType;
+import com.mojang.brigadier.builder.LiteralArgumentBuilder;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import net.minecraft.command.arguments.BlockPosArgumentType;
+import net.minecraft.command.arguments.DimensionArgumentType;
+import net.minecraft.entity.EntityCategory;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.DyeColor;
+import net.minecraft.server.command.ServerCommandSource;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.dimension.DimensionType;
+
+import java.util.Arrays;
+
+import static com.mojang.brigadier.arguments.IntegerArgumentType.getInteger;
+import static com.mojang.brigadier.arguments.IntegerArgumentType.integer;
+import static com.mojang.brigadier.arguments.StringArgumentType.getString;
+import static com.mojang.brigadier.arguments.StringArgumentType.string;
+import static com.mojang.brigadier.arguments.StringArgumentType.word;
+import static net.minecraft.server.command.CommandManager.argument;
+import static net.minecraft.server.command.CommandManager.literal;
+import static net.minecraft.server.command.CommandSource.suggestMatching;
+
+
+public class SpawnCommand
+{
+    public static void register(CommandDispatcher<ServerCommandSource> dispatcher)
+    {
+        LiteralArgumentBuilder<ServerCommandSource> literalargumentbuilder = literal("spawn").
+                requires((player) -> CarpetSettings.getBool("commandSpawn"));
+
+        literalargumentbuilder.
+                then(literal("list").
+                        then(argument("pos", BlockPosArgumentType.create()).
+                                executes( (c) -> listSpawns(c.getSource(), BlockPosArgumentType.getBlockPos(c, "pos"))))).
+                then(literal("tracking").
+                        executes( (c) -> printTrackingReport(c.getSource())).
+                        then(literal("start").
+                                executes( (c) -> startTracking(c.getSource(), null, null)).
+                                then(argument("from", BlockPosArgumentType.create()).
+                                        then(argument("to", BlockPosArgumentType.create()).
+                                                executes( (c) -> startTracking(
+                                                        c.getSource(),
+                                                        BlockPosArgumentType.getBlockPos(c, "from"),
+                                                        BlockPosArgumentType.getBlockPos(c, "to")))))).
+                        then(literal("stop").
+                                executes( (c) -> stopTracking(c.getSource()))).
+                        then(argument("type", word()).
+                                suggests( (c, b) -> suggestMatching(SpawnReporter.mob_groups,b)).
+                                executes( (c) -> recentSpawnsForType(c.getSource(), getString(c, "type"))))).
+                then(literal("test").
+                        executes( (c)-> runTest(c.getSource(), 72000, null)).
+                        then(argument("ticks", integer(10,720000)).
+                                executes( (c)-> runTest(
+                                        c.getSource(),
+                                        getInteger(c, "ticks"),
+                                        null)).
+                                then(argument("counter", word()).
+                                        suggests( (c, b) -> suggestMatching(Arrays.stream(DyeColor.values()).map(DyeColor::toString),b)).
+                                        executes((c)-> runTest(
+                                                c.getSource(),
+                                                getInteger(c, "ticks"),
+                                                getString(c, "counter")))))).
+                then(literal("mocking").
+                        then(argument("to do or not to do?", BoolArgumentType.bool()).
+                            executes( (c) -> toggleMocking(c.getSource(), BoolArgumentType.getBool(c, "to do or not to do?"))))).
+                then(literal("rates").
+                        executes( (c) -> generalMobcaps(c.getSource())).
+                        then(literal("reset").
+                                executes( (c) -> resetSpawnRates(c.getSource()))).
+                        then(argument("type", word()).
+                                suggests( (c, b) -> suggestMatching(SpawnReporter.mob_groups,b)).
+                                then(argument("rounds", integer(0)).
+                                        suggests( (c, b) -> suggestMatching(new String[]{"1"},b)).
+                                        executes( (c) -> setSpawnRates(
+                                                c.getSource(),
+                                                getString(c, "type"),
+                                                getInteger(c, "rounds")))))).
+                then(literal("mobcaps").
+                        executes( (c) -> generalMobcaps(c.getSource())).
+                        then(literal("set").
+                                then(argument("cap (hostile)", integer(1,1400)).
+                                        executes( (c) -> setMobcaps(c.getSource(), getInteger(c, "cap (hostile)"))))).
+                        then(argument("dimension", DimensionArgumentType.create()).
+                                executes( (c)-> mobcapsForDimension(c.getSource(), DimensionArgumentType.getDimensionArgument(c, "dimension"))))).
+                then(literal("entities").
+                        executes( (c) -> generalMobcaps(c.getSource()) ).
+                        then(argument("type", string()).
+                                suggests( (c, b)->suggestMatching(SpawnReporter.mob_groups, b)).
+                                executes( (c) -> listEntitiesOfType(c.getSource(), getString(c, "type")))));
+
+        dispatcher.register(literalargumentbuilder);
+    }
+
+    private static int listSpawns(ServerCommandSource source, BlockPos pos)
+    {
+        Messenger.send(source, SpawnReporter.report(pos, source.getWorld()));
+        return 1;
+    }
+
+    private static int printTrackingReport(ServerCommandSource source)
+    {
+        Messenger.send(source, SpawnReporter.tracking_report(source.getWorld()));
+        return 1;
+    }
+
+    private static int startTracking(ServerCommandSource source, BlockPos a, BlockPos b)
+    {
+        if (SpawnReporter.track_spawns != 0L)
+        {
+            Messenger.m(source, "r You are already tracking spawning.");
+            return 0;
+        }
+        BlockPos lsl = null;
+        BlockPos usl = null;
+        if (a != null && b != null)
+        {
+            lsl = new BlockPos(
+                    Math.min(a.getX(), b.getX()),
+                    Math.min(a.getY(), b.getY()),
+                    Math.min(a.getZ(), b.getZ()) );
+            usl = new BlockPos(
+                    Math.max(a.getX(), b.getX()),
+                    Math.max(a.getY(), b.getY()),
+                    Math.max(a.getZ(), b.getZ()) );
+        }
+        SpawnReporter.reset_spawn_stats(false);
+        SpawnReporter.track_spawns = (long) source.getMinecraftServer().getTicks();
+        SpawnReporter.lower_spawning_limit = lsl;
+        SpawnReporter.upper_spawning_limit = usl;
+        Messenger.m(source, "gi Spawning tracking started.");
+        return 1;
+    }
+
+    private static int stopTracking(ServerCommandSource source)
+    {
+        Messenger.send(source, SpawnReporter.tracking_report(source.getWorld()));
+        SpawnReporter.reset_spawn_stats(false);
+        SpawnReporter.track_spawns = 0L;
+        SpawnReporter.lower_spawning_limit = null;
+        SpawnReporter.upper_spawning_limit = null;
+        Messenger.m(source, "gi Spawning tracking stopped.");
+        return 1;
+    }
+
+    private static int recentSpawnsForType(ServerCommandSource source, String mob_type)
+    {
+        if (!Arrays.asList(SpawnReporter.mob_groups).contains(mob_type))
+        {
+            Messenger.m(source, "r Wrong mob type: "+mob_type);
+            return 0;
+        }
+        Messenger.send(source, SpawnReporter.recent_spawns(source.getWorld(), mob_type));
+        return 1;
+    }
+
+    private static int runTest(ServerCommandSource source, int ticks, String counter)
+    {
+        //stop tracking
+        SpawnReporter.reset_spawn_stats(false);
+        //start tracking
+        SpawnReporter.track_spawns = (long) source.getMinecraftServer().getTicks();
+        //counter reset
+        if (counter == null)
+        {
+            HopperCounter.resetAll(source.getMinecraftServer());
+        }
+        else
+        {
+            HopperCounter hCounter = HopperCounter.getCounter(counter);
+            if (hCounter != null)
+                    hCounter.reset(source.getMinecraftServer());
+        }
+
+
+        // tick warp 0
+        TickSpeed.tickrate_advance(null, 0, null, null);
+        // tick warp given player
+        ServerCommandSource csource = null;
+        PlayerEntity player = null;
+        try
+        {
+            player = source.getPlayer();
+            csource = source;
+        }
+        catch (CommandSyntaxException ignored)
+        {
+        }
+        TickSpeed.tickrate_advance(player, ticks, null, csource);
+        Messenger.m(source, String.format("gi Started spawn test for %d ticks", ticks));
+        return 1;
+    }
+
+    private static int toggleMocking(ServerCommandSource source, boolean domock)
+    {
+        if (domock)
+        {
+            SpawnReporter.initialize_mocking();
+            Messenger.m(source, "gi Mock spawns started, Spawn statistics reset");
+        }
+        else
+        {
+            SpawnReporter.stop_mocking();
+            Messenger.m(source, "gi  Normal mob spawning, Spawn statistics reset");
+        }
+        return 1;
+    }
+
+    private static int generalMobcaps(ServerCommandSource source)
+    {
+        Messenger.send(source, SpawnReporter.printMobcapsForDimension(source.getWorld().getDimension().getType(), true));
+        return 1;
+    }
+
+    private static int resetSpawnRates(ServerCommandSource source)
+    {
+        for (String s: SpawnReporter.spawn_tries.keySet())
+        {
+            SpawnReporter.spawn_tries.put(s,1);
+        }
+        Messenger.m(source, "gi Spawn rates brought to 1 round per tick for all groups.");
+
+        return 1;
+    }
+
+    private static int setSpawnRates(ServerCommandSource source, String mobtype, int rounds)
+    {
+        String code = SpawnReporter.get_creature_code_from_string(mobtype);
+        SpawnReporter.spawn_tries.put(code, rounds);
+        Messenger.m(source, "gi "+mobtype+" mobs will now spawn "+rounds+" times per tick");
+        return 1;
+    }
+
+    private static int setMobcaps(ServerCommandSource source, int hostile_cap)
+    {
+        double desired_ratio = (double)hostile_cap/ EntityCategory.MONSTER.getSpawnCap();
+        SpawnReporter.mobcap_exponent = 4.0*Math.log(desired_ratio)/Math.log(2.0);
+        Messenger.m(source, String.format("gi Mobcaps for hostile mobs changed to %d, other groups will follow", hostile_cap));
+        return 1;
+    }
+
+    private static int mobcapsForDimension(ServerCommandSource source, DimensionType dim)
+    {
+        Messenger.send(source, SpawnReporter.printMobcapsForDimension(dim, true));
+        return 1;
+    }
+
+    private static int listEntitiesOfType(ServerCommandSource source, String mobtype)
+    {
+        Messenger.send(source, SpawnReporter.printEntitiesByType(mobtype, source.getWorld()));
+        return 1;
+    }
+}

src/main/java/carpet/fakes/PlayerListHudInterface.java

@@ -0,0 +1,6 @@
+package carpet.fakes;
+
+public interface PlayerListHudInterface
+{
+    boolean hasFooterOrHeader();
+}

src/main/java/carpet/helpers/CtrlQCrafting.javax

@@ -0,0 +1,48 @@
+package carpet.helpers;
+
+import net.minecraft.entity.LivingEntity LivingEntity;
+import net.minecraft.entity.player.PlayerEntity PlayerEntity;
+import net.minecraft.inventory. EntityEquipmentSlot;
+import net.minecraft.inventory.Slot;
+import net.minecraft.item.ItemStack;
+
+import java.util.List;
+
+public class CtrlQCrafting {
+
+    public static ItemStack dropAllCrafting(PlayerEntity playerIn, int index, List<Slot> invSlotParam)
+    {
+        ItemStack itemstack = ItemStack.EMPTY;
+        Slot slot = invSlotParam.get(index);
+
+        if (slot != null && slot.getHasStack())
+        {
+            ItemStack itemstack1 = slot.getStack();
+            itemstack = itemstack1.copy();
+            EntityEquipmentSlot entityequipmentslot = LivingEntity.getSlotForItemStack(itemstack);
+
+            if (index == 0)
+            {
+                playerIn.dropItem(itemstack, true);
+
+                itemstack1.setCount(0);
+
+                slot.onSlotChange(itemstack1, itemstack);
+            }
+
+            if (itemstack.getCount() == itemstack1.getCount())
+            {
+                return ItemStack.EMPTY;
+            }
+
+            ItemStack itemstack2 = slot.onTake(playerIn, itemstack1);
+
+            if (index == 0)
+            {
+                playerIn.dropItem(itemstack2, false);
+            }
+        }
+
+        return itemstack;
+    }
+}

src/main/java/carpet/mixins/InGameHudMixin.java

@@ -0,0 +1,28 @@
+package carpet.mixins;
+
+import carpet.fakes.PlayerListHudInterface;
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.gui.hud.InGameHud;
+import net.minecraft.client.gui.hud.PlayerListHud;
+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.Redirect;
+
+@Mixin(InGameHud.class)
+public abstract class InGameHudMixin
+{
+    @Shadow
+    @Final
+    private MinecraftClient client;
+
+    @Shadow @Final private PlayerListHud playerListHud;
+
+    @Redirect(method = "draw", at = @At(value = "INVOKE", target = "Lnet/minecraft/client/MinecraftClient;isInSingleplayer()Z"))
+    private boolean onDraw(MinecraftClient minecraftClient)
+    {
+        return this.client.isInSingleplayer() && !((PlayerListHudInterface) playerListHud).hasFooterOrHeader();
+    }
+
+}

src/main/java/carpet/mixins/PlayerListHudMixin.java

@@ -0,0 +1,19 @@
+package carpet.mixins;
+import carpet.fakes.PlayerListHudInterface;
+import net.minecraft.client.gui.hud.PlayerListHud;
+import net.minecraft.network.chat.Component;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(PlayerListHud.class)
+public abstract class PlayerListHudMixin implements PlayerListHudInterface
+{
+    @Shadow private Component footer;
+
+    @Shadow private Component header;
+
+    public boolean hasFooterOrHeader()
+    {
+        return footer != null || header != null;
+    }
+}

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

@@ -0,0 +1,53 @@
+package carpet.mixins;
+
+import carpet.CarpetSettings;
+import carpet.utils.SpawnReporter;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import net.minecraft.entity.EntityCategory;
+import net.minecraft.server.world.ServerChunkManager;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.dimension.DimensionType;
+import net.minecraft.world.level.LevelProperties;
+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.callback.CallbackInfo;
+import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
+
+@Mixin(ServerChunkManager.class)
+public abstract class ServerChunkManagerMixin
+{
+    @Shadow @Final private ServerWorld world;
+
+    @Inject(
+            method = "tickChunks",
+            locals = LocalCapture.CAPTURE_FAILHARD,
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lnet/minecraft/server/world/ThreadedAnvilChunkStorage;entryIterator()Lit/unimi/dsi/fastutil/objects/ObjectBidirectionalIterator;",
+                    shift = At.Shift.AFTER,
+                    ordinal = 0
+
+    ))
+    private void grabMobcaps(CallbackInfo ci,
+                             long long_1,
+                             long long_2,
+                             LevelProperties levelProperties_1,
+                             boolean boolean_1,
+                             boolean boolean_2,
+                             int int_1,
+                             BlockPos blockPos_1,
+                             boolean boolean_3,
+                             int int_2,
+                             EntityCategory[] entityCategorys_1,
+                             Object2IntMap object2IntMap_1)
+    {
+        DimensionType dim = this.world.dimension.getType();
+        SpawnReporter.mobCounts.put(dim, (Object2IntMap<EntityCategory>)object2IntMap_1);
+        SpawnReporter.chunkCounts.put(dim, int_2);
+    }
+
+}

src/main/java/carpet/utils/HUDController.java

@@ -0,0 +1,117 @@
+package carpet.utils;
+
+import carpet.helpers.HopperCounter;
+import carpet.helpers.TickSpeed;
+import carpet.logging.LoggerRegistry;
+import carpet.logging.logHelpers.PacketCounter;
+import carpet.mixins.PlayerListHeaderS2CPacketMixin;
+import net.minecraft.entity.EntityCategory;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.client.network.packet.PlayerListHeaderS2CPacket;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.Pair;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.network.chat.BaseComponent;
+import net.minecraft.network.chat.TextComponent;
+import net.minecraft.world.dimension.DimensionType;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
+public class HUDController
+{
+    public static Map<PlayerEntity, List<BaseComponent>> player_huds = new HashMap<>();
+
+    public static void addMessage(PlayerEntity player, BaseComponent hudMessage)
+    {
+        if (!player_huds.containsKey(player))
+        {
+            player_huds.put(player, new ArrayList<>());
+        }
+        else
+        {
+            player_huds.get(player).add(new TextComponent("\n"));
+        }
+        player_huds.get(player).add(hudMessage);
+    }
+    public static void clear_player(PlayerEntity player)
+    {
+        PlayerListHeaderS2CPacket packet = new PlayerListHeaderS2CPacket();
+        ((PlayerListHeaderS2CPacketMixin)packet).setHeader(new TextComponent(""));
+        ((PlayerListHeaderS2CPacketMixin)packet).setFooter(new TextComponent(""));
+        ((ServerPlayerEntity)player).networkHandler.sendPacket(packet);
+    }
+
+
+    public static void update_hud(MinecraftServer server)
+    {
+        if(server.getTicks() % 20 != 0)
+            return;
+
+        player_huds.clear();
+
+        if (LoggerRegistry.__tps)
+            LoggerRegistry.getLogger("tps").log(()-> send_tps_display(server));
+
+        if (LoggerRegistry.__mobcaps)
+            LoggerRegistry.getLogger("mobcaps").log((option, player) -> {
+                DimensionType dim = player.dimension;
+                switch (option)
+                {
+                    case "overworld":
+                        dim = DimensionType.OVERWORLD;
+                        break;
+                    case "nether":
+                        dim = DimensionType.THE_NETHER;
+                        break;
+                    case "end":
+                        dim = DimensionType.THE_END;
+                        break;
+                }
+                return new BaseComponent[]{SpawnReporter.printMobcapsForDimension(dim, false).get(0)};
+            });
+
+        if(LoggerRegistry.__counter)
+            LoggerRegistry.getLogger("counter").log((option)->send_counter_info(server, option));
+
+        if (LoggerRegistry.__packets)
+            LoggerRegistry.getLogger("packets").log(()-> packetCounter());
+
+        for (PlayerEntity player: player_huds.keySet())
+        {
+            PlayerListHeaderS2CPacket packet = new PlayerListHeaderS2CPacket();
+            ((PlayerListHeaderS2CPacketMixin)packet).setHeader(new TextComponent(""));
+            ((PlayerListHeaderS2CPacketMixin)packet).setFooter(Messenger.c(player_huds.get(player).toArray(new Object[0])));
+            ((ServerPlayerEntity)player).networkHandler.sendPacket(packet);
+        }
+    }
+    private static BaseComponent [] send_tps_display(MinecraftServer server)
+    {
+        double MSPT = MathHelper.average(server.lastTickLengths) * 1.0E-6D;
+        double TPS = 1000.0D / Math.max((TickSpeed.time_warp_start_time != 0)?0.0:TickSpeed.mspt, MSPT);
+        String color = Messenger.heatmap_color(MSPT,TickSpeed.mspt);
+        return new BaseComponent[]{Messenger.c(
+                "g TPS: ", String.format(Locale.US, "%s %.1f",color, TPS),
+                "g  MSPT: ", String.format(Locale.US,"%s %.1f", color, MSPT))};
+    }
+
+    private static BaseComponent [] send_counter_info(MinecraftServer server, String color)
+    {
+        HopperCounter counter = HopperCounter.getCounter(color);
+        List <BaseComponent> res = counter == null ? Collections.emptyList() : counter.format(server, false, true);
+        return new BaseComponent[]{ Messenger.c(res.toArray(new Object[0]))};
+    }
+    private static BaseComponent [] packetCounter()
+    {
+        BaseComponent [] ret =  new BaseComponent[]{
+                Messenger.c("w I/" + PacketCounter.totalIn + " O/" + PacketCounter.totalOut),
+        };
+        PacketCounter.reset();
+        return ret;
+    }
+}

src/main/java/carpet/utils/Messenger.java

@@ -80,7 +80,8 @@ public class Messenger
     }
     public static String heatmap_color(double actual, double reference)
     {
-        String color = "e";
+        String color = "g";
+        if (actual >= 0.0D) color = "e";
         if (actual > 0.5D*reference) color = "y";
         if (actual > 0.8D*reference) color = "r";
         if (actual > reference) color = "m";

src/main/java/carpet/utils/SpawnReporter.java

@@ -0,0 +1,526 @@
+
+package carpet.utils;
+
+import java.util.List;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+import carpet.mixins.WeightedPickerEntryMixin;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import net.minecraft.entity.SpawnType;
+import net.minecraft.entity.mob.MobEntity;
+import net.minecraft.server.world.ServerChunkManager;
+import net.minecraft.structure.OceanMonumentGenerator;
+import net.minecraft.util.Pair;
+import net.minecraft.util.registry.Registry;
+import net.minecraft.network.chat.BaseComponent;
+import net.minecraft.world.World;
+import net.minecraft.util.math.BlockPos;
+
+import net.minecraft.util.DyeColor;
+
+import net.minecraft.entity.EntityCategory;
+import net.minecraft.world.biome.Biome;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.dimension.DimensionType;
+import net.minecraft.world.SpawnHelper;
+import net.minecraft.entity.SpawnRestriction;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.Entity;
+
+import net.minecraft.entity.passive.OcelotEntity;
+import net.minecraft.world.Heightmap;
+import net.minecraft.world.gen.chunk.ChunkGenerator;
+
+import java.lang.Math;
+
+public class SpawnReporter
+{
+    public static String [] mob_groups = {"hostile","passive","water","ambient"};
+    public static boolean mock_spawns = false;
+    
+    public static Long track_spawns = 0L;
+    public static final HashMap<DimensionType, Object2IntMap<EntityCategory>> mobCounts = new HashMap<>();
+    public static final HashMap<DimensionType, Integer> chunkCounts = new HashMap<>();
+
+    public static final HashMap<String, HashMap<String,Long>> spawn_stats = new HashMap<String, HashMap<String,Long>>();
+    public static double mobcap_exponent = 0.0D;
+    
+    public static final HashMap<String, Long> spawn_attempts = new HashMap<String, Long>();
+    public static final HashMap<String, Long> overall_spawn_ticks = new HashMap<String, Long>();
+    public static final HashMap<String, Long> spawn_ticks_full = new HashMap<String, Long>();
+    public static final HashMap<String, Long> spawn_ticks_fail = new HashMap<String, Long>();
+    public static final HashMap<String, Long> spawn_ticks_succ = new HashMap<String, Long>();
+    public static final HashMap<String, Long> spawn_ticks_spawns = new HashMap<String, Long>();
+    public static final HashMap<String, Long> spawn_cap_count = new HashMap<String, Long>();
+    public static class SpawnPos
+    {
+        public String mob;
+        public BlockPos pos;
+        public SpawnPos(String mob, BlockPos pos)
+        {
+            this.mob = mob;
+            this.pos = pos;
+        }
+    }
+    public static final HashMap<String, EvictingQueue<SpawnPos, Integer>> spawned_mobs = new HashMap<>();
+    public static final HashMap<String, Integer> spawn_tries = new HashMap<>();
+    public static BlockPos lower_spawning_limit = null;
+    public static BlockPos upper_spawning_limit = null;
+
+    static {
+        reset_spawn_stats(true);
+    }
+
+    public static void registerSpawn(LivingEntity el, String type, String mob, BlockPos pos) { registerSpawn(el, type, mob, pos, 1L);}
+    public static void registerSpawn(LivingEntity el, String type, String mob, BlockPos pos, long value)
+    {
+        if (lower_spawning_limit != null)
+        {
+            if (!( (lower_spawning_limit.getX() <= pos.getX() && pos.getX() <= upper_spawning_limit.getX()) &&
+                 (lower_spawning_limit.getY() <= pos.getY() && pos.getY() <= upper_spawning_limit.getY()) && 
+                 (lower_spawning_limit.getZ() <= pos.getZ() && pos.getZ() <= upper_spawning_limit.getZ())
+               ))
+            {
+                return;
+            }
+        }
+        
+        long count = spawn_stats.get(type).getOrDefault(mob, 0L);
+        spawn_stats.get(type).put(mob, count + value);
+        spawned_mobs.get(type).put(new SpawnPos(mob, new BlockPos(el)), 1);
+    }
+
+
+    public static List<BaseComponent> printMobcapsForDimension(DimensionType dim, boolean multiline)
+    {
+        String name = dim.toString();
+        List<BaseComponent> lst = new ArrayList<>();
+        if (multiline)
+            lst.add(Messenger.s(String.format("Mobcaps for %s:",name)));
+        Object2IntMap<EntityCategory> dimCounts = mobCounts.get(dim);
+        int chunkcount = chunkCounts.getOrDefault(dim, -1);
+        if (dimCounts == null || chunkcount < 0)
+        {
+            lst.add(Messenger.c("g   --UNAVAILABLE--"));
+            return lst;
+        }
+
+        List<String> shortCodes = new ArrayList<>();
+        for (EntityCategory enumcreaturetype : EntityCategory.values())
+        {
+            String type_code = String.format("%s", enumcreaturetype);
+            int cur = dimCounts.getOrDefault(enumcreaturetype, -1);
+            int max = chunkcount * enumcreaturetype.getSpawnCap() / (int)Math.pow(17.0D, 2.0D); // from ServerChunkManager.CHUNKS_ELIGIBLE_FOR_SPAWNING
+            String color = Messenger.heatmap_color(cur, max);
+            String mobColor = Messenger.creatureTypeColor(enumcreaturetype);
+            if (multiline)
+            {
+                int rounds = spawn_tries.get(type_code);
+                lst.add(Messenger.c(String.format("w   %s: ", type_code),
+                        (cur < 0) ? "g -" : (color + " " + cur), "g  / ", mobColor + " " + max,
+                        (rounds == 1) ? "w " : String.format("fi  (%d rounds/tick)", spawn_tries.get(type_code))
+                ));
+            }
+            else
+            {
+                shortCodes.add(color+" "+((cur<0)?"-":cur));
+                shortCodes.add("g /");
+                shortCodes.add(mobColor+" "+max);
+                shortCodes.add("g ,");
+            }
+        }
+        if (!multiline)
+        {
+            if (shortCodes.size()>0)
+            {
+                shortCodes.remove(shortCodes.size() - 1);
+                lst.add(Messenger.c(shortCodes.toArray(new Object[0])));
+            }
+            else
+            {
+                lst.add(Messenger.c("g   --UNAVAILABLE--"));
+            }
+
+        }
+        return lst;
+    }
+    
+    public static List<BaseComponent> recent_spawns(World world, String creature_type_code)
+    {
+        
+        EntityCategory creature_type = get_creature_type_from_code(creature_type_code);
+        List<BaseComponent> lst = new ArrayList<>();
+        if ((track_spawns == 0L))
+        {
+            lst.add(Messenger.s("Spawn tracking not started"));
+            return lst;
+        }
+        if (creature_type == null)
+        {
+            lst.add(Messenger.s(String.format("Incorrect creature type: %s",creature_type_code)));
+            return lst;
+        }
+
+        String type_code = get_type_string(creature_type);
+        
+        lst.add(Messenger.s(String.format("Recent %s spawns:",type_code)));
+        for (SpawnPos entry: spawned_mobs.get(type_code).keySet())
+        {
+            lst.add( Messenger.c(String.format("w  - %s ",entry.mob), Messenger.tp("wb",entry.pos)));
+        }
+        
+        if (lst.size()==1)
+        {
+            lst.add(Messenger.s(" - Nothing spawned yet, sorry."));
+        }
+        return lst;
+
+    }
+    
+    public static List<BaseComponent> show_mobcaps(BlockPos pos, World worldIn)
+    {
+        DyeColor under = WoolTool.getWoolColorAtPosition(worldIn, pos.down());
+        if (under == null)
+        {
+            if (track_spawns > 0L)
+            {
+                return tracking_report(worldIn);
+            }
+            else
+            {
+                //return print_general_mobcaps(worldIn);
+            }
+        }
+        String creature_type = get_type_code_from_wool_code(under);
+        if (creature_type != null)
+        {
+            if (track_spawns > 0L)
+            {
+                return recent_spawns(worldIn, creature_type);
+            }
+            else
+            {
+                return printEntitiesByType(creature_type, worldIn);
+                
+            }
+            
+        }
+        if (track_spawns > 0L)
+        {
+            return tracking_report(worldIn);
+        }
+        else
+        {
+            return tracking_report(worldIn);
+            //// TODO
+            //return print_general_mobcaps(worldIn);
+        }
+        
+    }
+    
+    public static String get_type_code_from_wool_code(DyeColor color)
+    {
+        switch (color)
+        {
+            case RED:
+                return "hostile";
+            case GREEN:
+                return "passive";
+            case BLUE:
+                return "water";
+            case BROWN:
+                return "ambient";
+        }
+        return null;
+    }
+    
+    public static EntityCategory get_creature_type_from_code(String type_code)
+    {
+        if ("hostile".equalsIgnoreCase(type_code))
+        {
+            return EntityCategory.MONSTER;
+        }
+        else if ("passive".equalsIgnoreCase(type_code))
+        {
+            return EntityCategory.CREATURE;
+        }
+        else if ("water".equalsIgnoreCase(type_code))
+        {
+            return EntityCategory.WATER_CREATURE;
+        }
+        else if ("ambient".equalsIgnoreCase(type_code))
+        {
+            return EntityCategory.AMBIENT;
+        }
+        return null;
+    }
+    
+    
+    public static String get_type_string(EntityCategory type)
+    {
+        return String.format("%s", type);
+    }
+    
+    public static String get_creature_code_from_string(String str)
+    {
+        return get_type_string(get_creature_type_from_code(str));
+    }
+    
+    public static List<BaseComponent> printEntitiesByType(String creature_type_code, World worldIn) //Class<?> entityType)
+    {
+        EntityCategory typ = get_creature_type_from_code(creature_type_code);
+        List<BaseComponent> lst = new ArrayList<>();
+        if (typ == null)
+        {
+            lst.add(Messenger.c(String.format("r Incorrect creature type: %s",creature_type_code)));
+            return lst;
+        }
+        Class<?> cls = typ.getDeclaringClass();// getBaseClass();// getCreatureClass();
+        lst.add( Messenger.s(String.format("Loaded entities for %s class:", get_type_string(typ))));
+
+        lst.add(Messenger.s(" <sorry, this list will be populated, once M figures out what counts>"));
+        //for (Entity entity : ((ServerWorld)worldIn).getEntities(...))
+        //{
+        //    if ((!(entity instanceof LivingEntity) || !((LivingEntity)entity).isNoDespawnRequired()) && cls.isAssignableFrom(entity.getClass()))
+        //    {
+        //        lst.add(Messenger.c("w  - ",
+        //                Messenger.tp("w", entity.posX, entity.posY, entity.posZ),"w  : "+EntityType.getId(entity.getType())));
+        //    }
+        //}
+        if (lst.size()==1)
+        {
+            lst.add(Messenger.s(" - Empty."));
+        }
+        return lst;
+    }
+    
+    public static void initialize_mocking()
+    {
+        reset_spawn_stats(false);
+        mock_spawns = true;
+        
+    }
+    public static void stop_mocking()
+    {
+        reset_spawn_stats(false);
+        mock_spawns = false;
+        
+    }
+    public static void reset_spawn_stats(boolean full)
+    {
+        spawn_stats.clear();
+        spawned_mobs.clear();
+        for (EntityCategory enumcreaturetype : EntityCategory.values())
+        {
+            String type_code = String.format("%s", enumcreaturetype);
+            if (full)
+            {
+                spawn_tries.put(type_code, 1);
+            }
+            for (String suffix: new String[] {""," (N)"," (E)"})
+            {
+                String code = type_code+suffix;
+                overall_spawn_ticks.put(code, 0L);
+                spawn_attempts.put(code, 0L);
+                spawn_ticks_full.put(code, 0L);
+                spawn_ticks_fail.put(code, 0L);
+                spawn_ticks_succ.put(code, 0L);
+                spawn_ticks_spawns.put(code, 0L);
+                spawn_cap_count.put(code, 0L);
+            }
+            
+            spawn_stats.put(type_code, new HashMap<>());
+            spawned_mobs.put(type_code, new EvictingQueue<>());
+        }
+        track_spawns = 0L;
+    }
+    
+    public static List<BaseComponent> tracking_report(World worldIn)
+    {
+        List<BaseComponent> report = new ArrayList<>();
+        if (track_spawns == 0L)
+        {
+            report.add(Messenger.c(
+                    "w Spawn tracking disabled, type '",
+                    "wi /spawn tracking start","/spawn tracking start",
+                    "w ' to enable"));
+            return report;
+        }
+        Long duration = (long) worldIn.getServer().getTicks() - track_spawns;
+        report.add(Messenger.c("bw --------------------"));
+        String simulated = mock_spawns?"[SIMULATED] ":"";
+        String location = (lower_spawning_limit != null)?String.format("[in (%d, %d, %d)x(%d, %d, %d)]",
+                lower_spawning_limit.getX(),lower_spawning_limit.getY(),lower_spawning_limit.getZ(),
+                upper_spawning_limit.getX(),upper_spawning_limit.getY(),upper_spawning_limit.getZ() ):"";
+        report.add(Messenger.s(String.format("%sSpawn statistics %s: for %.1f min", simulated, location, (duration/72000.0)*60)));
+        for (EntityCategory enumcreaturetype : EntityCategory.values())
+        {
+            String type_code = String.format("%s", enumcreaturetype);
+            boolean there_are_mobs_to_list = false;
+            for (String world_code: new String[] {"", " (N)", " (E)"})  
+            {
+                String code = type_code+world_code;
+                if (spawn_ticks_spawns.get(code) > 0L)
+                {
+                    there_are_mobs_to_list = true;
+                    double hours = overall_spawn_ticks.get(code)/72000.0;
+                    report.add(Messenger.s(String.format(" > %s (%.1f min), %.1f m/t, {%.1f%%F / %.1f%%- / %.1f%%+}; %.2f s/att",
+                        code,
+                        60*hours,
+                        (1.0D*spawn_cap_count.get(code))/ spawn_attempts.get(code),
+                        (100.0D*spawn_ticks_full.get(code))/ spawn_attempts.get(code),
+                        (100.0D*spawn_ticks_fail.get(code))/ spawn_attempts.get(code),
+                        (100.0D*spawn_ticks_succ.get(code))/ spawn_attempts.get(code),
+                        (1.0D*spawn_ticks_spawns.get(code))/(spawn_ticks_fail.get(code)+spawn_ticks_succ.get(code))
+                    )));
+                }
+            }
+            if (there_are_mobs_to_list)
+            {
+                for (String creature_name : spawn_stats.get(type_code).keySet())
+                {
+                    report.add(Messenger.s(String.format("   - %s: %d spawns, %d per hour",
+                            creature_name,
+                            spawn_stats.get(type_code).get(creature_name),
+                            (72000 * spawn_stats.get(type_code).get(creature_name)/duration ))));
+                }
+            }
+        }
+        return report;
+    }
+
+    
+
+    public static void killEntity(LivingEntity entity)
+    {
+        if (entity.hasVehicle())
+        {
+            entity.getVehicle().remove();
+        }
+        if (entity.hasPassengers())
+        {
+            for (Entity e: entity.getPassengerList())
+            {
+                e.remove();
+            }
+        }
+        if (entity instanceof OcelotEntity)
+        {
+            for (Entity e: entity.getEntityWorld().getEntities(OcelotEntity.class, entity.getBoundingBox()))
+            {
+                e.remove();
+            }
+        }
+        entity.remove();
+    }
+
+    public static List<BaseComponent> report(BlockPos pos, World worldIn)
+    {
+        List<BaseComponent> rep = new ArrayList<>();
+        int x = pos.getX(); int y = pos.getY(); int z = pos.getZ();
+        Chunk chunk = worldIn.getChunk(pos);
+        int lc = chunk.sampleHeightmap(Heightmap.Type.WORLD_SURFACE, x, z) + 1;
+        String where = String.format((y >= lc) ? "%d blocks above it." : "%d blocks below it.",  MathHelper.abs(y-lc));
+        if (y == lc) where = "right at it.";
+        rep.add(Messenger.s(String.format("Maximum spawn Y value for (%+d, %+d) is %d. You are "+where, x, z, lc )));
+        rep.add(Messenger.s("Spawns:"));
+        for (EntityCategory enumcreaturetype : EntityCategory.values())
+        {
+            String type_code = String.format("%s", enumcreaturetype).substring(0, 3);
+            List<Biome.SpawnEntry> lst = ((ChunkGenerator)worldIn.getChunkManager().getChunkGenerator()).getEntitySpawnList(enumcreaturetype, pos);
+            if (lst != null && !lst.isEmpty())
+            {
+                for (Biome.SpawnEntry spawnEntry : lst)
+                {
+                    boolean canspawn = SpawnHelper.canSpawn(SpawnRestriction.getLocation(spawnEntry.type), worldIn, pos, spawnEntry.type);
+                    int will_spawn = -1;
+                    boolean fits = false;
+                    boolean fits1 = false;
+                    
+                    MobEntity mob;
+                    try
+                    {
+                        mob = (MobEntity) spawnEntry.type.create(worldIn);
+                    }
+                    catch (Exception exception)
+                    {
+                        exception.printStackTrace();
+                        return rep;
+                    }
+                    
+                    boolean fits_true = false;
+                    boolean fits_false = false;
+                    
+                    if (canspawn)
+                    {
+                        will_spawn = 0;
+                        for (int attempt = 0; attempt < 50; ++attempt)
+                        {
+                            float f = (float)x + 0.5F;
+                            float f1 = (float)z + 0.5F;
+                            mob.setPositionAndAngles((double)f, (double)y, (double)f1, worldIn.random.nextFloat() * 360.0F, 0.0F);
+                            fits1 = worldIn.doesNotCollide(mob);
+                            
+                            for (int i = 0; i < 20; ++i)
+                            {
+                                if (mob.canSpawn(worldIn, SpawnType.NATURAL))
+                                {
+                                    will_spawn += 1;
+                                }
+                            }
+                            mob.initialize(worldIn, worldIn.getLocalDifficulty(new BlockPos(mob)), SpawnType.NATURAL, null, null);
+                            // the code invokes onInitialSpawn after getCanSpawHere
+                            fits = fits1 && worldIn.doesNotCollide(mob);
+                            if (fits)
+                            {
+                                fits_true = true;
+                            }
+                            else
+                            {
+                                fits_false = true;
+                            }
+                            
+                            killEntity(mob);
+                            
+                            try
+                            {
+                                mob = (MobEntity) spawnEntry.type.create(worldIn);
+                            }
+                            catch (Exception exception)
+                            {
+                                exception.printStackTrace();
+                                return rep;
+                            }
+                        }
+                    }
+                    
+                    String creature_name = Registry.ENTITY_TYPE.getId(mob.getType()).toString().replaceFirst("minecraft:","");
+                    String pack_size = String.format("%d", mob.getLimitPerChunk());//String.format("%d-%d", animal.minGroupCount, animal.maxGroupCount);
+                    int weight = ((WeightedPickerEntryMixin) spawnEntry).getWeight();
+                    if (canspawn)
+                    {
+                        String c = (fits_true && will_spawn>0)?"e":"gi";
+                        rep.add(Messenger.c(
+                                String.format("%s %s: %s (%d:%d-%d/%d), can: ",c,type_code,creature_name,weight,spawnEntry.minGroupSize, spawnEntry.maxGroupSize,  mob.getLimitPerChunk()),
+                                "l YES",
+                                c+" , fit: ",
+                                ((fits_true && fits_false)?"y YES and NO":(fits_true?"l YES":"r NO")),
+                                c+" , will: ",
+                                ((will_spawn>0)?"l ":"r ")+Math.round((double)will_spawn)/10+"%"
+                        ));
+                    }
+                    else
+                    {
+                        rep.add(Messenger.c(String.format("gi %s: %s (%d:%d-%d/%d), can: ",type_code,creature_name,weight,spawnEntry.minGroupSize, spawnEntry.maxGroupSize, mob.getLimitPerChunk()), "n NO"));
+                    }
+                    killEntity(mob);
+                }
+            }
+        }
+        return rep;
+    }
+}

src/main/resources/carpet.mixins.json

@@ -3,10 +3,23 @@
   "package": "carpet.mixins",
   "compatibilityLevel": "JAVA_8",
   "mixins": [
-    "CommandManagerMixin"
+    "CommandManagerMixin",
+    "MinecraftServerMixin",
+    "PlayerListHeaderS2CPacketMixin",
+    "WeightedPickerEntryMixin",
+    "ExperienceOrbEntityMixin",
+    "PlayerActionC2SPacketMixin",
+    "ServerPlayerEntityMixin",
+    "ServerChunkManagerMixin"
   ],
   "client": [
-    "CommandManagerMixin"
+    "MinecraftClientMixin",
+    "IntegratedServerMixin",
+    "InGameHudMixin",
+    "PlayerListHudMixin"
+  ],
+  "server": [
+    "MinecraftDedicatedServerMixin"
   ],
   "injectors": {
     "defaultRequire": 1