Partial ViaVersion support

build.gradle.kts

@@ -18,6 +18,7 @@ java {
 
 repositories {
     mavenCentral()
+    maven("https://repo.viaversion.com")
     maven("https://s01.oss.sonatype.org/content/repositories/snapshots/")
     maven("https://jitpack.io")
     maven("https://repo.papermc.io/repository/maven-public/")
@@ -31,6 +32,9 @@ dependencies {
     // Zstd Compression Library
     implementation("com.github.luben:zstd-jni:1.5.5-4")
 
+    // ViaVersion support
+    compileOnly("com.viaversion:viaversion-api:4.9.4-SNAPSHOT")
+
     // WorldGuard support
     compileOnly("com.sk89q.worldguard:worldguard-bukkit:7.1.0-SNAPSHOT")
 

src/main/java/com/moulberry/axiom/AxiomPaper.java

@@ -36,6 +36,7 @@
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.io.FileReader;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -49,6 +50,7 @@ public class AxiomPaper extends JavaPlugin implements Listener {
     public final Set<UUID> activeAxiomPlayers = Collections.newSetFromMap(new ConcurrentHashMap<>());
     public final Map<UUID, RateLimiter> playerBlockBufferRateLimiters = new ConcurrentHashMap<>();
     public final Map<UUID, Restrictions> playerRestrictions = new ConcurrentHashMap<>();
+    public final Map<UUID, IdMapper<BlockState>> playerBlockRegistry = new ConcurrentHashMap<>();
     public Configuration configuration;
 
     public IdMapper<BlockState> allowedBlockRegistry = null;
@@ -265,6 +267,7 @@ public void afterInitChannel(@NonNull Channel channel) {
             activeAxiomPlayers.retainAll(stillActiveAxiomPlayers);
             playerBlockBufferRateLimiters.keySet().retainAll(stillActiveAxiomPlayers);
             playerRestrictions.keySet().retainAll(stillActiveAxiomPlayers);
+            playerBlockRegistry.keySet().retainAll(stillActiveAxiomPlayers);
         }, 20, 20);
 
         boolean sendMarkers = configuration.getBoolean("send-markers");
@@ -292,6 +295,14 @@ public boolean canUseAxiom(Player player) {
         return this.playerBlockBufferRateLimiters.get(uuid);
     }
 
+    public boolean hasCustomBlockRegistry(UUID uuid) {
+        return this.playerBlockRegistry.containsKey(uuid);
+    }
+
+    public IdMapper<BlockState> getBlockRegistry(UUID uuid) {
+        return this.playerBlockRegistry.getOrDefault(uuid, this.allowedBlockRegistry);
+    }
+
     private final WeakHashMap<World, ServerWorldPropertiesRegistry> worldProperties = new WeakHashMap<>();
 
     public @Nullable ServerWorldPropertiesRegistry getWorldPropertiesIfPresent(World world) {

src/main/java/com/moulberry/axiom/DisallowedBlocks.java

@@ -3,6 +3,7 @@
 import com.mojang.brigadier.StringReader;
 import com.mojang.datafixers.util.Either;
 import com.moulberry.axiom.buffer.BlockBuffer;
+import com.viaversion.viaversion.api.data.Mappings;
 import net.minecraft.commands.arguments.blocks.BlockPredicateArgument;
 import net.minecraft.commands.arguments.blocks.BlockStateParser;
 import net.minecraft.core.IdMapper;

src/main/java/com/moulberry/axiom/buffer/BlockBuffer.java

@@ -9,6 +9,7 @@
 import it.unimi.dsi.fastutil.shorts.Short2ObjectMap;
 import it.unimi.dsi.fastutil.shorts.Short2ObjectOpenHashMap;
 import net.minecraft.core.BlockPos;
+import net.minecraft.core.IdMapper;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.state.BlockState;
@@ -23,18 +24,16 @@ public class BlockBuffer {
 
     private final Long2ObjectMap<PalettedContainer<BlockState>> values;
 
+    private IdMapper<BlockState> registry;
     private PalettedContainer<BlockState> last = null;
     private long lastId = AxiomConstants.MIN_POSITION_LONG;
     private final Long2ObjectMap<Short2ObjectMap<CompressedBlockEntity>> blockEntities = new Long2ObjectOpenHashMap<>();
     private long totalBlockEntities = 0;
     private long totalBlockEntityBytes = 0;
 
-    public BlockBuffer() {
+    public BlockBuffer(IdMapper<BlockState> registry) {
         this.values = new Long2ObjectOpenHashMap<>();
-    }
-
-    public BlockBuffer(Long2ObjectMap<PalettedContainer<BlockState>> values) {
-        this.values = values;
+        this.registry = registry;
     }
 
     public void save(FriendlyByteBuf friendlyByteBuf) {
@@ -57,8 +56,9 @@ public void save(FriendlyByteBuf friendlyByteBuf) {
         friendlyByteBuf.writeLong(AxiomConstants.MIN_POSITION_LONG);
     }
 
-    public static BlockBuffer load(FriendlyByteBuf friendlyByteBuf, @Nullable RateLimiter rateLimiter, AtomicBoolean reachedRateLimit) {
-        BlockBuffer buffer = new BlockBuffer();
+    public static BlockBuffer load(FriendlyByteBuf friendlyByteBuf, @Nullable RateLimiter rateLimiter, AtomicBoolean reachedRateLimit,
+                                   IdMapper<BlockState> registry) {
+        BlockBuffer buffer = new BlockBuffer(registry);
 
         long totalBlockEntities = 0;
         long totalBlockEntityBytes = 0;
@@ -177,7 +177,7 @@ public PalettedContainer<BlockState> getOrCreateSectionForCoord(int x, int y, in
     public PalettedContainer<BlockState> getOrCreateSection(long id) {
         if (this.last == null || id != this.lastId) {
             this.lastId = id;
-            this.last = this.values.computeIfAbsent(id, k -> new PalettedContainer<>(AxiomPaper.PLUGIN.allowedBlockRegistry,
+            this.last = this.values.computeIfAbsent(id, k -> new PalettedContainer<>(this.registry,
                              EMPTY_STATE, PalettedContainer.Strategy.SECTION_STATES));
         }
 

src/main/java/com/moulberry/axiom/packet/AxiomBigPayloadHandler.java

@@ -62,8 +62,7 @@ protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) t
                     } else if (identifier.equals(UPLOAD_BLUEPRINT)) {
                         ServerPlayer player = connection.getPlayer();
                         if (AxiomPaper.PLUGIN.canUseAxiom(player.getBukkitEntity())) {
-                            player.getServer().execute(() -> uploadBlueprint.onReceive(player, buf));
-
+                            uploadBlueprint.onReceive(player, buf);
                             success = true;
                             in.skipBytes(in.readableBytes());
                             return;
@@ -74,8 +73,15 @@ protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) t
                             byte[] bytes = new byte[buf.writerIndex() - buf.readerIndex()];
                             buf.getBytes(buf.readerIndex(), bytes);
 
-                            player.getServer().execute(() -> requestChunkDataPacketListener.onPluginMessageReceived(
-                                identifier.toString(), player.getBukkitEntity(), bytes));
+                            player.getServer().execute(() -> {
+                                try {
+                                    requestChunkDataPacketListener.onPluginMessageReceived(
+                                            identifier.toString(), player.getBukkitEntity(), bytes);
+                                } catch (Throwable t) {
+                                    player.getBukkitEntity().kick(net.kyori.adventure.text.Component.text(
+                                            "An error occured while requesting chunk data: " + t.getMessage()));
+                                }
+                            });
 
                             success = true;
                             in.skipBytes(in.readableBytes());

src/main/java/com/moulberry/axiom/packet/HelloPacketListener.java

@@ -1,15 +1,17 @@
 package com.moulberry.axiom.packet;
 
 import com.google.common.util.concurrent.RateLimiter;
-import com.moulberry.axiom.AxiomConstants;
-import com.moulberry.axiom.AxiomPaper;
-import com.moulberry.axiom.View;
-import com.moulberry.axiom.WorldExtension;
+import com.moulberry.axiom.*;
 import com.moulberry.axiom.blueprint.ServerBlueprintManager;
 import com.moulberry.axiom.event.AxiomHandshakeEvent;
 import com.moulberry.axiom.persistence.ItemStackDataType;
 import com.moulberry.axiom.persistence.UUIDDataType;
+import com.moulberry.axiom.viaversion.ViaVersionHelper;
 import com.moulberry.axiom.world_properties.server.ServerWorldPropertiesRegistry;
+import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.data.*;
+import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
+import com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag;
 import io.netty.buffer.Unpooled;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
@@ -52,18 +54,52 @@ public void onPluginMessageReceived(@NotNull String channel, @NotNull Player pla
 
         int serverDataVersion = SharedConstants.getCurrentVersion().getDataVersion().getVersion();
         if (dataVersion != serverDataVersion) {
-            Component text = Component.text("Axiom: Incompatible data version detected (client " + dataVersion +
-                ", server " + serverDataVersion  + "), are you using ViaVersion?");
+            if (!Bukkit.getPluginManager().isPluginEnabled("ViaVersion")) {
+                Component text = Component.text("Axiom: Incompatible data version detected (client " + dataVersion +
+                    ", server " + serverDataVersion  + ")");
+
+                String incompatibleDataVersion = plugin.configuration.getString("incompatible-data-version");
+                if (incompatibleDataVersion == null) incompatibleDataVersion = "kick";
+                if (incompatibleDataVersion.equals("warn")) {
+                    player.sendMessage(text.color(NamedTextColor.RED));
+                    return;
+                } else if (!incompatibleDataVersion.equals("ignore")) {
+                    player.kick(text);
+                    return;
+                }
+            } else {
+//                int playerVersion = Via.getAPI().getPlayerVersion(player.getUniqueId());
+//                if (ProtocolVersion.isRegistered(playerVersion)) {
+//                    ProtocolVersion version = ProtocolVersion.getProtocol(playerVersion);
+//                    String name = version.getName().split("/")[0];
+//
+//
+//                }
+
+                CompoundTag tag = MappingDataLoader.loadNBT("mappings-1.20.2to1.20.3.nbt");
+
+                if (tag == null) {
+                    player.kick(Component.text("Axiom+ViaVersion: Failed to load mappings (1.20.2 <-> 1.20.3)"));
+                    return;
+                }
+
+                Mappings mappings = MappingDataLoader.loadMappings(tag, "blockstates");
+
+                if (mappings == null) {
+                    player.kick(Component.text("Axiom+ViaVersion: Failed to load mapped blockstates (1.20.2 <-> 1.20.3"));
+                    return;
+                }
+
+                this.plugin.playerBlockRegistry.put(player.getUniqueId(), ViaVersionHelper.applyMappings(this.plugin.allowedBlockRegistry,
+                        BiMappings.of(mappings).inverse()));
 
-            String incompatibleDataVersion = plugin.configuration.getString("incompatible-data-version");
-            if (incompatibleDataVersion == null) incompatibleDataVersion = "kick";
-            if (incompatibleDataVersion.equals("warn")) {
+                Component text = Component.text("Axiom: Warning, client and server versions don't match. " +
+                        "Axiom will try to use ViaVersion conversions, but this process may cause problems");
                 player.sendMessage(text.color(NamedTextColor.RED));
-                return;
-            } else if (!incompatibleDataVersion.equals("ignore")) {
-                player.kick(text);
-                return;
             }
+//            inverse.getNewIdOrDefault()
+
+
         }
 
         if (apiVersion != AxiomConstants.API_VERSION) {

src/main/java/com/moulberry/axiom/packet/RequestChunkDataPacketListener.java

@@ -5,6 +5,7 @@
 import com.moulberry.axiom.VersionHelper;
 import com.moulberry.axiom.buffer.CompressedBlockEntity;
 import com.moulberry.axiom.integration.plotsquared.PlotSquaredIntegration;
+import com.viaversion.viaversion.api.Via;
 import io.netty.buffer.Unpooled;
 import it.unimi.dsi.fastutil.longs.*;
 import net.minecraft.core.BlockPos;
@@ -46,7 +47,7 @@ public void onPluginMessageReceived(@NotNull String channel, @NotNull Player buk
         FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.wrappedBuffer(message));
         long id = friendlyByteBuf.readLong();
 
-        if (!this.plugin.canUseAxiom(bukkitPlayer)) {
+        if (!this.plugin.canUseAxiom(bukkitPlayer) || this.plugin.hasCustomBlockRegistry(bukkitPlayer.getUniqueId())) {
             // We always send an 'empty' response in order to make the client happy
             sendEmptyResponse(player, id);
             return;

src/main/java/com/moulberry/axiom/packet/SetBlockBufferPacketListener.java

@@ -85,7 +85,7 @@ public void onReceive(ServerPlayer player, FriendlyByteBuf friendlyByteBuf) {
         byte type = friendlyByteBuf.readByte();
         if (type == 0) {
             AtomicBoolean reachedRateLimit = new AtomicBoolean(false);
-            BlockBuffer buffer = BlockBuffer.load(friendlyByteBuf, rateLimiter, reachedRateLimit);
+            BlockBuffer buffer = BlockBuffer.load(friendlyByteBuf, rateLimiter, reachedRateLimit, this.plugin.getBlockRegistry(player.getUUID()));
             if (reachedRateLimit.get()) {
                 player.sendSystemMessage(Component.literal("[Axiom] Exceeded server rate-limit of " + (int)rateLimiter.getRate() + " sections per second")
                     .withStyle(ChatFormatting.RED));

src/main/java/com/moulberry/axiom/packet/SetBlockPacketListener.java

@@ -7,6 +7,7 @@
 import io.netty.buffer.Unpooled;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Holder;
+import net.minecraft.core.IdMapper;
 import net.minecraft.core.SectionPos;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.server.level.ServerLevel;
@@ -79,8 +80,9 @@ public void onPluginMessageReceived(@NotNull String channel, @NotNull Player buk
         // Read packet
         FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.wrappedBuffer(message));
         IntFunction<Map<BlockPos, BlockState>> mapFunction = FriendlyByteBuf.limitValue(Maps::newLinkedHashMapWithExpectedSize, 512);
+        IdMapper<BlockState> registry = this.plugin.getBlockRegistry(bukkitPlayer.getUniqueId());
         Map<BlockPos, BlockState> blocks = friendlyByteBuf.readMap(mapFunction,
-                FriendlyByteBuf::readBlockPos, buf -> buf.readById(this.plugin.allowedBlockRegistry));
+                FriendlyByteBuf::readBlockPos, buf -> buf.readById(registry));
         boolean updateNeighbors = friendlyByteBuf.readBoolean();
 
         int reason = friendlyByteBuf.readVarInt();
@@ -129,6 +131,10 @@ public void onPluginMessageReceived(@NotNull String channel, @NotNull Player buk
                 BlockPos blockPos = entry.getKey();
                 BlockState blockState = entry.getValue();
 
+                if (blockState == null) {
+                    continue;
+                }
+
                 // Disallow in unloaded chunks
                 if (!player.level().isLoaded(blockPos)) {
                     continue;
@@ -154,6 +160,10 @@ public void onPluginMessageReceived(@NotNull String channel, @NotNull Player buk
                 BlockPos blockPos = entry.getKey();
                 BlockState blockState = entry.getValue();
 
+                if (blockState == null) {
+                    continue;
+                }
+
                 // Disallow in unloaded chunks
                 if (!player.level().isLoaded(blockPos)) {
                     continue;

src/main/java/com/moulberry/axiom/packet/UploadBlueprintPacketListener.java

@@ -47,25 +47,34 @@ public void onReceive(ServerPlayer serverPlayer, FriendlyByteBuf friendlyByteBuf
             return;
         }
 
-        Path path = this.plugin.blueprintFolder.resolve(relative);
-
-        // Write file
-        try {
-            Files.createDirectories(path.getParent());
-        } catch (IOException e) {
-            return;
-        }
-        try (OutputStream outputStream = new BufferedOutputStream(Files.newOutputStream(path))) {
-            BlueprintIo.writeRaw(outputStream, rawBlueprint);
-        } catch (IOException e) {
-            return;
-        }
-
-        // Update registry
-        registry.blueprints().put("/" + pathStr.substring(0, pathStr.length()-3), rawBlueprint);
-
-        // Resend manifest
-        ServerBlueprintManager.sendManifest(serverPlayer.getServer().getPlayerList().getPlayers());
+        String pathName = pathStr.substring(0, pathStr.length()-3);
+
+        serverPlayer.getServer().execute(() -> {
+            try {
+                Path path = this.plugin.blueprintFolder.resolve(relative);
+
+                // Write file
+                try {
+                    Files.createDirectories(path.getParent());
+                } catch (IOException e) {
+                    return;
+                }
+                try (OutputStream outputStream = new BufferedOutputStream(Files.newOutputStream(path))) {
+                    BlueprintIo.writeRaw(outputStream, rawBlueprint);
+                } catch (IOException e) {
+                    return;
+                }
+
+                // Update registry
+                registry.blueprints().put("/" + pathName, rawBlueprint);
+
+                // Resend manifest
+                ServerBlueprintManager.sendManifest(serverPlayer.getServer().getPlayerList().getPlayers());
+            } catch (Throwable t) {
+                serverPlayer.getBukkitEntity().kick(net.kyori.adventure.text.Component.text(
+                        "An error occured while uploading blueprint: " + t.getMessage()));
+            }
+        });
     }
 
 }

src/main/java/com/moulberry/axiom/viaversion/ViaVersionHelper.java

@@ -1,2 +1,42 @@
-package com.moulberry.axiom.viaversion;public class ViaVersionHelper {
+package com.moulberry.axiom.viaversion;
+
+import com.moulberry.axiom.buffer.BlockBuffer;
+import com.viaversion.viaversion.api.data.BiMappings;
+import com.viaversion.viaversion.api.data.Mappings;
+import net.minecraft.core.IdMapper;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.state.BlockState;
+
+public class ViaVersionHelper {
+
+    public static IdMapper<BlockState> applyMappings(IdMapper<BlockState> registry, BiMappings mappings) {
+        IdMapper<BlockState> newBlockRegistry = new IdMapper<>();
+
+        // Add empty mappings for non-existent blocks
+        int size = mappings.mappedSize();
+        for (int i = 0; i < size; i++) {
+            newBlockRegistry.addMapping(BlockBuffer.EMPTY_STATE, i);
+        }
+
+        // Map blocks
+        for (int i = 0; i < registry.size(); i++) {
+            BlockState blockState = registry.byId(i);
+
+            if (blockState != null) {
+                int newId = mappings.getNewId(i);
+                if (newId >= 0) {
+                    newBlockRegistry.addMapping(blockState, newId);
+                }
+            }
+        }
+
+        // Ensure block -> id is correct for the empty state
+        int newEmptyStateId = mappings.getNewId(registry.getId(BlockBuffer.EMPTY_STATE));
+        if (newEmptyStateId >= 0) {
+            newBlockRegistry.addMapping(BlockBuffer.EMPTY_STATE, newEmptyStateId);
+        }
+
+        return newBlockRegistry;
+    }
+
 }