rework ContraptionData

src/main/java/com/simibubi/create/content/contraptions/AbstractContraptionEntity.java

@@ -18,13 +18,13 @@ import com.simibubi.create.AllItems;
 import com.simibubi.create.AllMovementBehaviours;
 import com.simibubi.create.AllPackets;
 import com.simibubi.create.AllSoundEvents;
-import com.simibubi.create.Create;
 import com.simibubi.create.content.contraptions.actors.psi.PortableStorageInterfaceMovement;
 import com.simibubi.create.content.contraptions.actors.seat.SeatBlock;
 import com.simibubi.create.content.contraptions.actors.seat.SeatEntity;
 import com.simibubi.create.content.contraptions.actors.trainControls.ControlsStopControllingPacket;
 import com.simibubi.create.content.contraptions.behaviour.MovementBehaviour;
 import com.simibubi.create.content.contraptions.behaviour.MovementContext;
+import com.simibubi.create.content.contraptions.data.ContraptionSyncLimiting;
 import com.simibubi.create.content.contraptions.elevator.ElevatorContraption;
 import com.simibubi.create.content.contraptions.glue.SuperGlueEntity;
 import com.simibubi.create.content.contraptions.mounted.MountedContraption;
@@ -615,11 +615,8 @@ public abstract class AbstractContraptionEntity extends Entity implements IEntit
 		CompoundTag compound = new CompoundTag();
 		writeAdditional(compound, true);
 
-		if (ContraptionData.isTooLargeForSync(compound)) {
-			String info = getContraption().getType().id + " @" + position() + " (" + getStringUUID() + ")";
-			Create.LOGGER.warn("Could not send Contraption Spawn Data (Packet too big): " + info);
-			compound = null;
-		}
+		if (ContraptionSyncLimiting.isTooLargeForSync(compound))
+			compound = null; // don't sync contraption data
 
 		buffer.writeNbt(compound);
 	}

src/main/java/com/simibubi/create/content/contraptions/ContraptionData.java

@@ -1,85 +0,0 @@
-package com.simibubi.create.content.contraptions;
-
-import com.simibubi.create.compat.Mods;
-import com.simibubi.create.foundation.mixin.accessor.NbtAccounterAccessor;
-import com.simibubi.create.infrastructure.config.AllConfigs;
-
-import io.netty.buffer.Unpooled;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.NbtAccounter;
-import net.minecraft.network.FriendlyByteBuf;
-import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
-
-public class ContraptionData {
-	/**
-	 * A sane, default maximum for contraption data size.
-	 */
-	public static final int DEFAULT_LIMIT = 2_000_000;
-	/**
-	 * Connectivity expands the NBT packet limit to 2 GB.
-	 */
-	public static final int CONNECTIVITY_LIMIT = Integer.MAX_VALUE;
-	/**
-	 * Packet Fixer expands the NBT packet limit to 200 MB.
-	 */
-	public static final int PACKET_FIXER_LIMIT = 209_715_200;
-	/**
-	 * XL Packets expands the NBT packet limit to 2 GB.
-	 */
-	public static final int XL_PACKETS_LIMIT = 2_000_000_000;
-	/**
-	 * Minecart item sizes are limited by the vanilla slot change packet ({@link ClientboundContainerSetSlotPacket}).
-	 * {@link #DEFAULT_LIMIT} is used as the default.
-	 * Connectivity, PacketFixer, and XL Packets expand the size limit.
-	 * If one of these mods is loaded, we take advantage of it and use the higher limit.
-	 */
-	public static final int PICKUP_LIMIT;
-
-	static {
-		int limit = DEFAULT_LIMIT;
-
-		// Check from largest to smallest to use the smallest limit if multiple mods are loaded.
-		// It is necessary to use the smallest limit because even if multiple mods are loaded,
-		// not all of their mixins may be applied. Therefore, it is safest to only assume that
-		// the mod with the smallest limit is actually active.
-		if (Mods.CONNECTIVITY.isLoaded()) {
-			limit = CONNECTIVITY_LIMIT;
-		}
-		if (Mods.XLPACKETS.isLoaded()) {
-			limit = XL_PACKETS_LIMIT;
-		}
-		if (Mods.PACKETFIXER.isLoaded()) {
-			limit = PACKET_FIXER_LIMIT;
-		}
-
-		PICKUP_LIMIT = limit;
-	}
-
-	/**
-	 * @return true if the given NBT is too large for a contraption to be synced to clients.
-	 */
-	public static boolean isTooLargeForSync(CompoundTag data) {
-		int max = AllConfigs.server().kinetics.maxDataSize.get();
-		return max != 0 && packetSize(data) > max;
-	}
-
-	/**
-	 * @return true if the given NBT is too large for a contraption to be picked up with a wrench.
-	 */
-	public static boolean isTooLargeForPickup(CompoundTag data) {
-		return packetSize(data) > PICKUP_LIMIT;
-	}
-
-	/**
-	 * @return the size of the given NBT when put through a packet, in bytes.
-	 */
-	public static long packetSize(CompoundTag data) {
-		FriendlyByteBuf test = new FriendlyByteBuf(Unpooled.buffer());
-		test.writeNbt(data);
-		NbtAccounter sizeTracker = new NbtAccounter(Long.MAX_VALUE);
-		test.readNbt(sizeTracker);
-		long size = ((NbtAccounterAccessor) sizeTracker).create$getUsage();
-		test.release();
-		return size;
-	}
-}

src/main/java/com/simibubi/create/content/contraptions/data/ContraptionPickupLimiting.java

@@ -0,0 +1,55 @@
+package com.simibubi.create.content.contraptions.data;
+
+import com.simibubi.create.compat.Mods;
+import com.simibubi.create.foundation.mixin.accessor.NbtAccounterAccessor;
+
+import io.netty.buffer.Unpooled;
+import net.minecraft.Util;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtAccounter;
+import net.minecraft.network.FriendlyByteBuf;
+
+public class ContraptionPickupLimiting {
+	/// The default NBT limit, defined by {@link FriendlyByteBuf#readNbt()}.
+	public static final int NBT_LIMIT = 2_097_152;
+
+	// increased nbt limits provided by other mods.
+	public static final int PACKET_FIXER_LIMIT = NBT_LIMIT * 100;
+	public static final int XL_PACKETS_LIMIT = Integer.MAX_VALUE;
+
+	// leave some space for the rest of the packet.
+	public static final int BUFFER = 20_000;
+
+	// the actual limit to be used
+	public static final int LIMIT = Util.make(() -> {
+		// the smallest limit needs to be used, as we can't guarantee that all mixins are applied if multiple are present.
+		if (Mods.PACKETFIXER.isLoaded()) {
+			return PACKET_FIXER_LIMIT;
+		} else if (Mods.XLPACKETS.isLoaded()) {
+			return XL_PACKETS_LIMIT;
+		}
+
+		// none are present, use vanilla default
+		return NBT_LIMIT;
+	}) - BUFFER;
+
+	/**
+	 * @return true if the given NBT is too large for a contraption to be picked up with a wrench.
+	 */
+	public static boolean isTooLargeForPickup(CompoundTag data) {
+		return nbtSize(data) > LIMIT;
+	}
+
+	/**
+	 * @return the size of the given NBT when read by the client according to {@link NbtAccounter}
+	 */
+	private static long nbtSize(CompoundTag data) {
+		FriendlyByteBuf test = new FriendlyByteBuf(Unpooled.buffer());
+		test.writeNbt(data);
+		NbtAccounter sizeTracker = new NbtAccounter(Long.MAX_VALUE);
+		test.readNbt(sizeTracker);
+		long size = ((NbtAccounterAccessor) sizeTracker).create$getUsage();
+		test.release();
+		return size;
+	}
+}

src/main/java/com/simibubi/create/content/contraptions/data/ContraptionSyncLimiting.java

@@ -0,0 +1,52 @@
+package com.simibubi.create.content.contraptions.data;
+
+import com.simibubi.create.compat.Mods;
+
+import io.netty.buffer.Unpooled;
+import net.minecraft.Util;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.FriendlyByteBuf;
+
+public class ContraptionSyncLimiting {
+	/**
+	 * Contraption entity sync is limited by the clientbound custom payload limit, since that's what Forge's
+	 * extended spawn packet uses. The NBT limit is irrelevant since it's bypassed on deserialization.
+	 */
+	public static final int SIZE_LIMIT = 1_048_576;
+
+	// increased packet limits provided by other mods.
+	public static final int PACKET_FIXER_LIMIT = SIZE_LIMIT * 100;
+	public static final int XL_PACKETS_LIMIT = Integer.MAX_VALUE;
+
+	// leave some room for the rest of the packet.
+	public static final int BUFFER = 20_000;
+
+	// the actual limit to be used
+	public static final int LIMIT = Util.make(() -> {
+		// the smallest limit needs to be used, as we can't guarantee that all mixins are applied if multiple are present.
+		if (Mods.PACKETFIXER.isLoaded()) {
+			return PACKET_FIXER_LIMIT;
+		} else if (Mods.XLPACKETS.isLoaded()) {
+			return XL_PACKETS_LIMIT;
+		}
+
+		// none are present, use vanilla default
+		return SIZE_LIMIT;
+	}) - BUFFER;
+
+	/**
+	 * @return true if the given NBT is too large for a contraption to be synced to clients.
+	 */
+	public static boolean isTooLargeForSync(CompoundTag data) {
+		return byteSize(data) > LIMIT;
+	}
+
+	/**
+	 * @return the size of the given NBT when encoded, in bytes
+	 */
+	private static long byteSize(CompoundTag data) {
+		FriendlyByteBuf test = new FriendlyByteBuf(Unpooled.buffer());
+		test.writeNbt(data);
+		return test.writerIndex();
+	}
+}

src/main/java/com/simibubi/create/content/contraptions/data/README.md

@@ -0,0 +1,37 @@
+# Data Limiting
+This pair of classes prevents clients from getting chunkbanned when contraptions are too large.
+
+This information is up-to-date as of 1.20.1.
+
+There's a few different packet limits in play:
+- the NBT limit: `2_097_152`, enforced by `FriendlyByteBuf.readNbt()`
+- the clientbound custom payload limit: `1_048_576` bytes, applies to `ClientboundCustomPayloadPacket`
+- the serverbound custom payload limit: `32767` bytes, applies to `ServerboundCustomPayloadPacket`
+- the packet limit: `8_388_608` bytes, applies to all packets
+
+# NBT Size vs Bytes
+There's two units in play as well - NBT Size and Bytes. The NBT limit uses NBT size, while the other
+three use bytes. I'm (TropheusJ) not sure what exactly an NBT Size unit is - it's not bits, but it's
+close.
+
+Because of this discrepancy, the NBT limit is actually much lower than it seems. It will usually be
+the first limit hit.
+
+Bytes are found by writing a tag to a buffer and getting its `writerIndex`. NBT Size is found using
+an `NbtAccounter`.
+
+# Sync
+Sync is pretty straightforward.
+
+The only limit relevant here is the clientbound custom payload limit. The NBT limit would be relevant, but
+client-side deserialization bypasses it.
+
+Sync is much less of an issue compared to pickup, since a lot of data can be skipped when syncing.
+
+# Pickup
+Two limits are relevant for pickup: the NBT limit and the packet limit.
+
+The NBT limit is hit way sooner, and is usually the limiting factor. Other mods may increase it, in
+which case the packet limit may become relevant.
+
+The custom payload limit is not relevant since item sync goes through the vanilla `ClientboundContainerSetSlotPacket`.

src/main/java/com/simibubi/create/content/contraptions/mounted/MinecartContraptionItem.java

@@ -10,11 +10,11 @@ import com.simibubi.create.AllItems;
 import com.simibubi.create.AllMovementBehaviours;
 import com.simibubi.create.content.contraptions.AbstractContraptionEntity;
 import com.simibubi.create.content.contraptions.Contraption;
-import com.simibubi.create.content.contraptions.ContraptionData;
 import com.simibubi.create.content.contraptions.ContraptionMovementSetting;
 import com.simibubi.create.content.contraptions.OrientedContraptionEntity;
 import com.simibubi.create.content.contraptions.actors.psi.PortableStorageInterfaceMovement;
 import com.simibubi.create.content.contraptions.behaviour.MovementContext;
+import com.simibubi.create.content.contraptions.data.ContraptionPickupLimiting;
 import com.simibubi.create.content.kinetics.deployer.DeployerFakePlayer;
 import com.simibubi.create.foundation.advancement.AllAdvancements;
 import com.simibubi.create.foundation.utility.CreateLang;
@@ -249,7 +249,7 @@ public class MinecartContraptionItem extends Item {
 
 		ItemStack generatedStack = create(type, oce).setHoverName(entity.getCustomName());
 
-		if (ContraptionData.isTooLargeForPickup(generatedStack.serializeNBT())) {
+		if (ContraptionPickupLimiting.isTooLargeForPickup(generatedStack.serializeNBT())) {
 			MutableComponent message = CreateLang.translateDirect("contraption.minecart_contraption_too_big")
 					.withStyle(ChatFormatting.RED);
 			player.displayClientMessage(message, true);

src/main/java/com/simibubi/create/infrastructure/config/CKinetics.java

@@ -1,6 +1,5 @@
 package com.simibubi.create.infrastructure.config;
 
-import com.simibubi.create.content.contraptions.ContraptionData;
 import com.simibubi.create.content.contraptions.ContraptionMovementSetting;
 
 import net.createmod.catnip.config.ConfigBase;
@@ -32,8 +31,6 @@ public class CKinetics extends ConfigBase {
 
 	public final ConfigGroup contraptions = group(1, "contraptions", "Moving Contraptions");
 	public final ConfigInt maxBlocksMoved = i(2048, 1, "maxBlocksMoved", Comments.maxBlocksMoved);
-	public final ConfigInt maxDataSize =
-		i(ContraptionData.DEFAULT_LIMIT, 0, "maxDataSize", Comments.bytes, Comments.maxDataDisable, Comments.maxDataSize, Comments.maxDataSize2);
 	public final ConfigInt maxChassisRange = i(16, 1, "maxChassisRange", Comments.maxChassisRange);
 	public final ConfigInt maxPistonPoles = i(64, 1, "maxPistonPoles", Comments.maxPistonPoles);
 	public final ConfigInt maxRopeLength = i(384, 1, "maxRopeLength", Comments.maxRopeLength);
@@ -86,9 +83,6 @@ public class CKinetics extends ConfigBase {
 			"multiplier used for calculating exhaustion from speed when a crank is turned.";
 		static String maxBlocksMoved =
 			"Maximum amount of blocks in a structure movable by Pistons, Bearings or other means.";
-		static String maxDataSize = "Maximum amount of data a contraption can have before it can't be synced with players.";
-		static String maxDataSize2 = "Un-synced contraptions will not be visible and will not have collision.";
-		static String maxDataDisable = "[0 to disable this limit]";
 		static String maxChassisRange = "Maximum value of a chassis attachment range.";
 		static String maxPistonPoles = "Maximum amount of extension poles behind a Mechanical Piston.";
 		static String maxRopeLength = "Max length of rope available off a Rope Pulley.";