Merge remote-tracking branch 'upstream/master' into feature/blocky

.github/workflows/build.yml

@@ -23,25 +23,19 @@ jobs:
         with:
           submodules: recursive
 
+      - name: Validate Gradle Wrapper
+        uses: gradle/wrapper-validation-action@v1
+
       - uses: actions/setup-java@v3
         with:
           java-version: 17
           distribution: temurin
           
-      - name: Cache Gradle Packages
-        uses: actions/cache@v3
-        with:
-          path: | 
-            ~/.m2
-            ~/.gradle/caches
-            ~/.gradle/wrapper
-          key: ${{ github.ref_name }}-gradle-${{ hashFiles('*.gradle.kts', 'gradle.properties', 'gradlew', 'gradle/*', 'gradle/**/*', 'build-logic/*', 'build-logic/**/**/**/*', '**/*.gradle.kts', '**/**/*.gradle.kts') }}
-          restore-keys: ${{ github.ref_name }}-gradle-
-
       - name: Build
         uses: gradle/gradle-build-action@v2
         with:
-          arguments: build --no-daemon
+          arguments: build
+          gradle-home-cache-cleanup: true
           
       - name: Archive artifacts (Geyser Fabric)
         uses: actions/upload-artifact@v3
@@ -87,7 +81,7 @@ jobs:
           if-no-files-found: error
 
       - name: Publish to Maven Repository
-        if: ${{ job.status == 'success' && github.repository == 'GeyserMC/Geyser' && github.ref_name == 'master' }}
+        if: ${{ success() && github.repository == 'GeyserMC/Geyser' && github.ref_name == 'master' }}
         uses: gradle/gradle-build-action@v2
         env:
           ORG_GRADLE_PROJECT_geysermcUsername: ${{ vars.DEPLOY_USER }}
@@ -96,7 +90,7 @@ jobs:
           arguments: publish
 
       - name: Publish to Downloads API
-        if: ${{ github.ref_name == 'master' && job.status == 'success' && github.repository == 'GeyserMC/Geyser' }}
+        if: ${{ success() && github.repository == 'GeyserMC/Geyser' && github.ref_name == 'master' }}
         shell: bash
         env:
           DOWNLOADS_USERNAME: ${{ vars.DOWNLOADS_USERNAME }}
@@ -119,6 +113,15 @@ jobs:
           echo "{\"project\": \"$project\", \"version\": \"$version\", \"id\": $GITHUB_RUN_NUMBER, \"commit\": \"$GITHUB_SHA\"}" > metadata.json
           rsync -P -e "ssh -o StrictHostKeyChecking=no -i id_ecdsa" metadata.json $DOWNLOADS_USERNAME@$DOWNLOADS_SERVER_IP:~/uploads/$project/$GITHUB_RUN_NUMBER/
 
+      - name: Publish to Modrinth
+        uses: gradle/gradle-build-action@v2
+        if: ${{ success() && github.repository == 'GeyserMC/Geyser' && github.ref_name == 'master' }}
+        env:
+          MODRINTH_TOKEN: ${{ secrets.MODRINTH_TOKEN }}
+        with:
+          arguments: fabric:modrinth
+          gradle-home-cache-cleanup: true
+          
       - name: Notify Discord
         if: ${{ (success() || failure()) && github.repository == 'GeyserMC/Geyser' }}
         uses: Tim203/actions-git-discord-webhook@main

.github/workflows/publish.yml

@@ -1,31 +0,0 @@
-name: Publish
-on:
-  workflow_dispatch:
-  push:
-    paths-ignore:
-      - '.github/ISSUE_TEMPLATE/*.yml'
-      - '.github/actions/pullrequest.yml'
-      - '.idea/copyright/*.xml'
-      - '.gitignore'
-      - 'CONTRIBUTING.md'
-      - 'LICENSE'
-      - 'Jenkinsfile '
-      - 'README.md'
-      - 'licenseheader.txt'
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          submodules: recursive
-      - uses: gradle/wrapper-validation-action@v1
-      - uses: actions/setup-java@v3
-        with:
-          distribution: 'temurin'
-          java-version: 17
-      - name: Publish to Modrinth
-        env:
-          MODRINTH_TOKEN: ${{ secrets.MODRINTH_TOKEN }}
-        run: ./gradlew fabric:modrinth

bootstrap/fabric/build.gradle.kts

@@ -94,6 +94,7 @@ tasks {
 }
 
 modrinth {
+    token.set(System.getenv("MODRINTH_TOKEN")) // Even though this is the default value, apparently this prevents GitHub Actions caching the token?
     projectId.set("wKkoqHrH")
     versionNumber.set(project.version as String + "-" + System.getenv("GITHUB_RUN_NUMBER"))
     versionType.set("beta")

bootstrap/fabric/src/main/java/org/geysermc/geyser/platform/fabric/world/GeyserFabricWorldManager.java

@@ -25,6 +25,7 @@
 
 package org.geysermc.geyser.platform.fabric.world;
 
+import com.github.steveice10.mc.protocol.data.game.level.block.BlockEntityInfo;
 import com.nukkitx.math.vector.Vector3i;
 import com.nukkitx.nbt.NbtMap;
 import com.nukkitx.nbt.NbtMapBuilder;
@@ -40,16 +41,16 @@ import net.minecraft.world.item.WrittenBookItem;
 import net.minecraft.world.level.block.entity.BannerBlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.LecternBlockEntity;
+import net.minecraft.world.level.chunk.LevelChunk;
+import org.geysermc.erosion.util.LecternUtils;
 import org.geysermc.geyser.level.GeyserWorldManager;
 import org.geysermc.geyser.session.GeyserSession;
-import org.geysermc.geyser.translator.inventory.LecternInventoryTranslator;
 import org.geysermc.geyser.util.BlockEntityUtils;
 
 import javax.annotation.Nonnull;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.TimeUnit;
 
 public class GeyserFabricWorldManager extends GeyserWorldManager {
     private final MinecraftServer server;
@@ -59,69 +60,91 @@ public class GeyserFabricWorldManager extends GeyserWorldManager {
     }
 
     @Override
-    public boolean shouldExpectLecternHandled() {
+    public boolean shouldExpectLecternHandled(GeyserSession session) {
         return true;
     }
 
     @Override
-    public NbtMap getLecternDataAt(GeyserSession session, int x, int y, int z, boolean isChunkLoad) {
-        Runnable lecternGet = () -> {
-            // Mostly a reimplementation of Spigot lectern support
+    public void sendLecternData(GeyserSession session, int x, int z, List<BlockEntityInfo> blockEntityInfos) {
+        server.execute(() -> {
             ServerPlayer player = getPlayer(session);
-            if (player != null) {
-                BlockEntity blockEntity = player.level.getBlockEntity(new BlockPos(x, y, z));
-                if (!(blockEntity instanceof LecternBlockEntity lectern)) {
-                    return;
-                }
-
-                if (!lectern.hasBook()) {
-                    if (!isChunkLoad) {
-                        BlockEntityUtils.updateBlockEntity(session, LecternInventoryTranslator.getBaseLecternTag(x, y, z, 0).build(), Vector3i.from(x, y, z));
-                    }
-                    return;
-                }
-
-                ItemStack book = lectern.getBook();
-                int pageCount = WrittenBookItem.getPageCount(book);
-                boolean hasBookPages = pageCount > 0;
-                NbtMapBuilder lecternTag = LecternInventoryTranslator.getBaseLecternTag(x, y, z, hasBookPages ? pageCount : 1);
-                lecternTag.putInt("page", lectern.getPage() / 2);
-                NbtMapBuilder bookTag = NbtMap.builder()
-                        .putByte("Count", (byte) book.getCount())
-                        .putShort("Damage", (short) 0)
-                        .putString("Name", "minecraft:writable_book");
-                List<NbtMap> pages = new ArrayList<>(hasBookPages ? pageCount : 1);
-                if (hasBookPages && WritableBookItem.makeSureTagIsValid(book.getTag())) {
-                    ListTag listTag = book.getTag().getList("pages", 8);
-
-                    for (int i = 0; i < listTag.size(); i++) {
-                        String page = listTag.getString(i);
-                        NbtMapBuilder pageBuilder = NbtMap.builder()
-                                .putString("photoname", "")
-                                .putString("text", page);
-                        pages.add(pageBuilder.build());
-                    }
-                } else {
-                    // Empty page
-                    NbtMapBuilder pageBuilder = NbtMap.builder()
-                            .putString("photoname", "")
-                            .putString("text", "");
-                    pages.add(pageBuilder.build());
-                }
-
-                bookTag.putCompound("tag", NbtMap.builder().putList("pages", NbtType.COMPOUND, pages).build());
-                lecternTag.putCompound("book", bookTag.build());
-                NbtMap blockEntityTag = lecternTag.build();
-                BlockEntityUtils.updateBlockEntity(session, blockEntityTag, Vector3i.from(x, y, z));
+            if (player == null) {
+                return;
             }
-        };
-        if (isChunkLoad) {
-            // Hacky hacks to allow lectern loading to be delayed
-            session.scheduleInEventLoop(() -> server.execute(lecternGet), 1, TimeUnit.SECONDS);
-        } else {
-            server.execute(lecternGet);
+
+            LevelChunk chunk = player.getLevel().getChunk(x, z);
+            final int chunkBlockX = x << 4;
+            final int chunkBlockZ = z << 4;
+            for (int i = 0; i < blockEntityInfos.size(); i++) {
+                BlockEntityInfo blockEntityInfo = blockEntityInfos.get(i);
+                BlockEntity blockEntity = chunk.getBlockEntity(new BlockPos(chunkBlockX + blockEntityInfo.getX(),
+                        blockEntityInfo.getY(), chunkBlockZ + blockEntityInfo.getZ()));
+                sendLecternData(session, blockEntity, true);
+            }
+        });
+    }
+
+    @Override
+    public void sendLecternData(GeyserSession session, int x, int y, int z) {
+        server.execute(() -> {
+            ServerPlayer player = getPlayer(session);
+            if (player == null) {
+                return;
+            }
+
+            BlockEntity blockEntity = player.level.getBlockEntity(new BlockPos(x, y, z));
+            sendLecternData(session, blockEntity, false);
+        });
+    }
+
+    private void sendLecternData(GeyserSession session, BlockEntity blockEntity, boolean isChunkLoad) {
+        if (!(blockEntity instanceof LecternBlockEntity lectern)) {
+            return;
         }
-        return LecternInventoryTranslator.getBaseLecternTag(x, y, z, 0).build();
+
+        int x = blockEntity.getBlockPos().getX();
+        int y = blockEntity.getBlockPos().getY();
+        int z = blockEntity.getBlockPos().getZ();
+
+        if (!lectern.hasBook()) {
+            if (!isChunkLoad) {
+                BlockEntityUtils.updateBlockEntity(session, LecternUtils.getBaseLecternTag(x, y, z, 0).build(), Vector3i.from(x, y, z));
+            }
+            return;
+        }
+
+        ItemStack book = lectern.getBook();
+        int pageCount = WrittenBookItem.getPageCount(book);
+        boolean hasBookPages = pageCount > 0;
+        NbtMapBuilder lecternTag = LecternUtils.getBaseLecternTag(x, y, z, hasBookPages ? pageCount : 1);
+        lecternTag.putInt("page", lectern.getPage() / 2);
+        NbtMapBuilder bookTag = NbtMap.builder()
+                .putByte("Count", (byte) book.getCount())
+                .putShort("Damage", (short) 0)
+                .putString("Name", "minecraft:writable_book");
+        List<NbtMap> pages = new ArrayList<>(hasBookPages ? pageCount : 1);
+        if (hasBookPages && WritableBookItem.makeSureTagIsValid(book.getTag())) {
+            ListTag listTag = book.getTag().getList("pages", 8);
+
+            for (int i = 0; i < listTag.size(); i++) {
+                String page = listTag.getString(i);
+                NbtMapBuilder pageBuilder = NbtMap.builder()
+                        .putString("photoname", "")
+                        .putString("text", page);
+                pages.add(pageBuilder.build());
+            }
+        } else {
+            // Empty page
+            NbtMapBuilder pageBuilder = NbtMap.builder()
+                    .putString("photoname", "")
+                    .putString("text", "");
+            pages.add(pageBuilder.build());
+        }
+
+        bookTag.putCompound("tag", NbtMap.builder().putList("pages", NbtType.COMPOUND, pages).build());
+        lecternTag.putCompound("book", bookTag.build());
+        NbtMap blockEntityTag = lecternTag.build();
+        BlockEntityUtils.updateBlockEntity(session, blockEntityTag, Vector3i.from(x, y, z));
     }
 
     @Override

bootstrap/spigot/build.gradle.kts

@@ -1,5 +1,8 @@
 dependencies {
     api(projects.core)
+    api(libs.erosion.bukkit.common) {
+        isTransitive = false
+    }
 
     implementation(libs.adapters.spigot)
 
@@ -7,8 +10,8 @@ dependencies {
 
     implementation(libs.adventure.text.serializer.bungeecord)
     
-    // Both paper-api and paper-mojangapi only provide Java 17 versions for 1.19
-    compileOnly(libs.paper.api) {
+    // Both folia-api and paper-mojangapi only provide Java 17 versions for 1.19
+    compileOnly(libs.folia.api) {
         attributes {
             attribute(TargetJvmVersion.TARGET_JVM_VERSION_ATTRIBUTE, 17)
         }

bootstrap/spigot/src/main/java/org/geysermc/geyser/platform/spigot/GeyserPaperPingPassthrough.java

@@ -59,13 +59,13 @@ public final class GeyserPaperPingPassthrough implements IGeyserPingPassthrough
             // runtime because we still have to shade in our own Adventure class. For now.
             PaperServerListPingEvent event;
             if (OLD_CONSTRUCTOR != null) {
-                // Approximately pre-1.19
+                // 1.19, removed in 1.19.4
                 event = OLD_CONSTRUCTOR.newInstance(new GeyserStatusClient(inetSocketAddress),
                         Bukkit.getMotd(), Bukkit.getOnlinePlayers().size(),
                         Bukkit.getMaxPlayers(), Bukkit.getVersion(), GameProtocol.getJavaProtocolVersion(), null);
             } else {
                 event = new PaperServerListPingEvent(new GeyserStatusClient(inetSocketAddress),
-                        Bukkit.getMotd(), Bukkit.shouldSendChatPreviews(), Bukkit.getOnlinePlayers().size(),
+                        Bukkit.getMotd(), Bukkit.getOnlinePlayers().size(),
                         Bukkit.getMaxPlayers(), Bukkit.getVersion(), GameProtocol.getJavaProtocolVersion(), null);
             }
             Bukkit.getPluginManager().callEvent(event);

bootstrap/spigot/src/main/java/org/geysermc/geyser/platform/spigot/GeyserSpigotPingPassthrough.java

@@ -66,7 +66,7 @@ public class GeyserSpigotPingPassthrough implements IGeyserPingPassthrough {
     private static class GeyserPingEvent extends ServerListPingEvent {
 
         public GeyserPingEvent(InetAddress address, String motd, int numPlayers, int maxPlayers) {
-            super(address, motd, Bukkit.shouldSendChatPreviews(), numPlayers, maxPlayers);
+            super("", address, motd, numPlayers, maxPlayers);
         }
 
         @Override

bootstrap/spigot/src/main/java/org/geysermc/geyser/platform/spigot/ReflectedNames.java

@@ -60,16 +60,16 @@ public final class ReflectedNames {
     }
 
     static Constructor<PaperServerListPingEvent> getOldPaperPingConstructor() {
-        if (getConstructor(PaperServerListPingEvent.class, StatusClient.class, String.class, boolean.class, int.class,
+        if (getConstructor(PaperServerListPingEvent.class, StatusClient.class, String.class, int.class,
                 int.class, String.class, int.class, CachedServerIcon.class) != null) {
-            // @NotNull StatusClient client, @NotNull String motd, boolean shouldSendChatPreviews, int numPlayers, int maxPlayers,
+            // @NotNull StatusClient client, @NotNull String motd, int numPlayers, int maxPlayers,
             //            @NotNull String version, int protocolVersion, @Nullable CachedServerIcon favicon
             // New constructor is present
             return null;
         }
-        // @NotNull StatusClient client, @NotNull String motd, int numPlayers, int maxPlayers,
+        // @NotNull StatusClient client, @NotNull String motd, boolean shouldSendChatPreviews, int numPlayers, int maxPlayers,
         //            @NotNull String version, int protocolVersion, @Nullable CachedServerIcon favicon
-        return getConstructor(PaperServerListPingEvent.class, StatusClient.class, String.class, int.class, int.class,
+        return getConstructor(PaperServerListPingEvent.class, StatusClient.class, String.class, boolean.class, int.class, int.class,
                 String.class, int.class, CachedServerIcon.class);
     }
 

bootstrap/spigot/src/main/java/org/geysermc/geyser/platform/spigot/world/GeyserPistonListener.java

@@ -27,8 +27,8 @@ package org.geysermc.geyser.platform.spigot.world;
 
 import com.github.steveice10.mc.protocol.data.game.level.block.value.PistonValueType;
 import com.nukkitx.math.vector.Vector3i;
+import it.unimi.dsi.fastutil.objects.Object2IntArrayMap;
 import it.unimi.dsi.fastutil.objects.Object2IntMap;
-import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.World;
@@ -85,7 +85,7 @@ public class GeyserPistonListener implements Listener {
         PistonValueType type = isExtend ? PistonValueType.PUSHING : PistonValueType.PULLING;
         boolean sticky = event.isSticky();
 
-        Object2IntMap<Vector3i> attachedBlocks = new Object2IntOpenHashMap<>();
+        Object2IntMap<Vector3i> attachedBlocks = new Object2IntArrayMap<>();
         boolean blocksFilled = false;
 
         for (Map.Entry<UUID, GeyserSession> entry : geyser.getSessionManager().getSessions().entrySet()) {

bootstrap/spigot/src/main/java/org/geysermc/geyser/platform/spigot/world/manager/GeyserSpigotWorldManager.java

@@ -25,33 +25,28 @@
 
 package org.geysermc.geyser.platform.spigot.world.manager;
 
+import com.github.steveice10.mc.protocol.data.game.level.block.BlockEntityInfo;
 import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
-import com.github.steveice10.opennbt.tag.builtin.ListTag;
-import com.github.steveice10.opennbt.tag.builtin.Tag;
-import com.nukkitx.math.vector.Vector3i;
 import com.nukkitx.nbt.NbtMap;
-import com.nukkitx.nbt.NbtMapBuilder;
-import com.nukkitx.nbt.NbtType;
 import org.bukkit.Bukkit;
+import org.bukkit.Chunk;
 import org.bukkit.World;
-import org.bukkit.block.*;
-import org.bukkit.block.banner.Pattern;
+import org.bukkit.block.Block;
 import org.bukkit.entity.Player;
-import org.bukkit.inventory.ItemStack;
-import org.bukkit.inventory.meta.BookMeta;
 import org.bukkit.plugin.Plugin;
+import org.geysermc.erosion.bukkit.BukkitLecterns;
+import org.geysermc.erosion.bukkit.BukkitUtils;
+import org.geysermc.erosion.bukkit.PickBlockUtils;
+import org.geysermc.erosion.bukkit.SchedulerUtils;
 import org.geysermc.geyser.level.GameRule;
 import org.geysermc.geyser.level.WorldManager;
 import org.geysermc.geyser.level.block.BlockStateValues;
 import org.geysermc.geyser.registry.BlockRegistries;
 import org.geysermc.geyser.session.GeyserSession;
-import org.geysermc.geyser.translator.inventory.LecternInventoryTranslator;
-import org.geysermc.geyser.translator.inventory.item.nbt.BannerTranslator;
 import org.geysermc.geyser.util.BlockEntityUtils;
 import org.jetbrains.annotations.Nullable;
 
 import javax.annotation.Nonnull;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 
@@ -60,9 +55,11 @@ import java.util.concurrent.CompletableFuture;
  */
 public class GeyserSpigotWorldManager extends WorldManager {
     private final Plugin plugin;
+    private final BukkitLecterns lecterns;
 
     public GeyserSpigotWorldManager(Plugin plugin) {
         this.plugin = plugin;
+        this.lecterns = new BukkitLecterns(plugin);
     }
 
     @Override
@@ -81,6 +78,12 @@ public class GeyserSpigotWorldManager extends WorldManager {
     }
 
     public int getBlockNetworkId(Block block) {
+        if (SchedulerUtils.FOLIA && !Bukkit.isOwnedByCurrentRegion(block)) {
+            // Terrible behavior, but this is basically what's always been happening behind the scenes anyway.
+            CompletableFuture<String> blockData = new CompletableFuture<>();
+            Bukkit.getRegionScheduler().execute(this.plugin, block.getLocation(), () -> blockData.complete(block.getBlockData().getAsString()));
+            return BlockRegistries.JAVA_IDENTIFIERS.getOrDefault(blockData.join(), BlockStateValues.JAVA_AIR_ID);
+        }
         return BlockRegistries.JAVA_IDENTIFIERS.getOrDefault(block.getBlockData().getAsString(), BlockStateValues.JAVA_AIR_ID);
     }
 
@@ -90,71 +93,64 @@ public class GeyserSpigotWorldManager extends WorldManager {
     }
 
     @Override
-    public NbtMap getLecternDataAt(GeyserSession session, int x, int y, int z, boolean isChunkLoad) {
-        // Run as a task to prevent async issues
-        Runnable lecternInfoGet = () -> {
-            Player bukkitPlayer;
-            if ((bukkitPlayer = Bukkit.getPlayer(session.getPlayerEntity().getUsername())) == null) {
-                return;
-            }
-
-            Block block = bukkitPlayer.getWorld().getBlockAt(x, y, z);
-            if (!(block.getState() instanceof Lectern lectern)) {
-                session.getGeyser().getLogger().error("Lectern expected at: " + Vector3i.from(x, y, z).toString() + " but was not! " + block.toString());
-                return;
-            }
-
-            ItemStack itemStack = lectern.getInventory().getItem(0);
-            if (itemStack == null || !(itemStack.getItemMeta() instanceof BookMeta bookMeta)) {
-                if (!isChunkLoad) {
-                    // We need to update the lectern since it's not going to be updated otherwise
-                    BlockEntityUtils.updateBlockEntity(session, LecternInventoryTranslator.getBaseLecternTag(x, y, z, 0).build(), Vector3i.from(x, y, z));
-                }
-                // We don't care; return
-                return;
-            }
-
-            // On the count: allow the book to show/open even there are no pages. We know there is a book here, after all, and this matches Java behavior
-            boolean hasBookPages = bookMeta.getPageCount() > 0;
-            NbtMapBuilder lecternTag = LecternInventoryTranslator.getBaseLecternTag(x, y, z, hasBookPages ? bookMeta.getPageCount() : 1);
-            lecternTag.putInt("page", lectern.getPage() / 2);
-            NbtMapBuilder bookTag = NbtMap.builder()
-                    .putByte("Count", (byte) itemStack.getAmount())
-                    .putShort("Damage", (short) 0)
-                    .putString("Name", "minecraft:writable_book");
-            List<NbtMap> pages = new ArrayList<>(bookMeta.getPageCount());
-            if (hasBookPages) {
-                for (String page : bookMeta.getPages()) {
-                    NbtMapBuilder pageBuilder = NbtMap.builder()
-                            .putString("photoname", "")
-                            .putString("text", page);
-                    pages.add(pageBuilder.build());
-                }
-            } else {
-                // Empty page
-                NbtMapBuilder pageBuilder = NbtMap.builder()
-                        .putString("photoname", "")
-                        .putString("text", "");
-                pages.add(pageBuilder.build());
-            }
-            
-            bookTag.putCompound("tag", NbtMap.builder().putList("pages", NbtType.COMPOUND, pages).build());
-            lecternTag.putCompound("book", bookTag.build());
-            NbtMap blockEntityTag = lecternTag.build();
-            BlockEntityUtils.updateBlockEntity(session, blockEntityTag, Vector3i.from(x, y, z));
-        };
-
-        if (isChunkLoad) {
-            // Delay to ensure the chunk is sent first, and then the lectern data
-            Bukkit.getScheduler().runTaskLater(this.plugin, lecternInfoGet, 5);
-        } else {
-            Bukkit.getScheduler().runTask(this.plugin, lecternInfoGet);
+    public void sendLecternData(GeyserSession session, int x, int y, int z) {
+        Player bukkitPlayer;
+        if ((bukkitPlayer = Bukkit.getPlayer(session.getPlayerEntity().getUsername())) == null) {
+            return;
+        }
+
+        Block block = bukkitPlayer.getWorld().getBlockAt(x, y, z);
+        // Run as a task to prevent async issues
+        SchedulerUtils.runTask(this.plugin, () -> sendLecternData(session, block, false), block);
+    }
+
+    public void sendLecternData(GeyserSession session, int x, int z, List<BlockEntityInfo> blockEntityInfos) {
+        Player bukkitPlayer;
+        if ((bukkitPlayer = Bukkit.getPlayer(session.getPlayerEntity().getUsername())) == null) {
+            return;
+        }
+        if (SchedulerUtils.FOLIA) {
+            Chunk chunk = getChunk(bukkitPlayer.getWorld(), x, z);
+            if (chunk == null) {
+                return;
+            }
+            Bukkit.getRegionScheduler().execute(this.plugin, bukkitPlayer.getWorld(), x, z, () ->
+                sendLecternData(session, chunk, blockEntityInfos));
+        } else {
+            Bukkit.getScheduler().runTask(this.plugin, () -> {
+                Chunk chunk = getChunk(bukkitPlayer.getWorld(), x, z);
+                if (chunk == null) {
+                    return;
+                }
+                sendLecternData(session, chunk, blockEntityInfos);
+            });
+        }
+    }
+
+    private Chunk getChunk(World world, int x, int z) {
+        if (!world.isChunkLoaded(x, z)) {
+            return null;
+        }
+        return world.getChunkAt(x, z);
+    }
+
+    private void sendLecternData(GeyserSession session, Chunk chunk, List<BlockEntityInfo> blockEntityInfos) {
+        for (int i = 0; i < blockEntityInfos.size(); i++) {
+            BlockEntityInfo info = blockEntityInfos.get(i);
+            Block block = chunk.getBlock(info.getX(), info.getY(), info.getZ());
+            sendLecternData(session, block, true);
+        }
+    }
+
+    private void sendLecternData(GeyserSession session, Block block, boolean isChunkLoad) {
+        NbtMap blockEntityTag = this.lecterns.getLecternData(block, isChunkLoad);
+        if (blockEntityTag != null) {
+            BlockEntityUtils.updateBlockEntity(session, blockEntityTag, BukkitUtils.getVector(block.getLocation()));
         }
-        return LecternInventoryTranslator.getBaseLecternTag(x, y, z, 0).build(); // Will be updated later
     }
 
     @Override
-    public boolean shouldExpectLecternHandled() {
+    public boolean shouldExpectLecternHandled(GeyserSession session) {
         return true;
     }
 
@@ -184,42 +180,18 @@ public class GeyserSpigotWorldManager extends WorldManager {
     @Override
     public CompletableFuture<@Nullable CompoundTag> getPickItemNbt(GeyserSession session, int x, int y, int z, boolean addNbtData) {
         CompletableFuture<@Nullable CompoundTag> future = new CompletableFuture<>();
+        Player bukkitPlayer;
+        if ((bukkitPlayer = Bukkit.getPlayer(session.getPlayerEntity().getUuid())) == null) {
+            future.complete(null);
+            return future;
+        }
+        Block block = bukkitPlayer.getWorld().getBlockAt(x, y, z);
         // Paper 1.19.3 complains about async access otherwise.
         // java.lang.IllegalStateException: Tile is null, asynchronous access?
-        Bukkit.getScheduler().runTask(this.plugin, () -> {
-            Player bukkitPlayer;
-            if ((bukkitPlayer = Bukkit.getPlayer(session.getPlayerEntity().getUuid())) == null) {
-                future.complete(null);
-                return;
-            }
-
-            Block block = bukkitPlayer.getWorld().getBlockAt(x, y, z);
-            BlockState state = block.getState();
-            if (state instanceof Banner banner) {
-                ListTag list = new ListTag("Patterns");
-                for (int i = 0; i < banner.numberOfPatterns(); i++) {
-                    Pattern pattern = banner.getPattern(i);
-                    list.add(BannerTranslator.getJavaPatternTag(pattern.getPattern().getIdentifier(), pattern.getColor().ordinal()));
-                }
-
-                CompoundTag root = addToBlockEntityTag(list);
-
-                future.complete(root);
-                return;
-            }
-            future.complete(null);
-        });
+        SchedulerUtils.runTask(this.plugin, () -> future.complete(PickBlockUtils.pickBlock(block)), block);
         return future;
     }
 
-    private CompoundTag addToBlockEntityTag(Tag tag) {
-        CompoundTag compoundTag = new CompoundTag("");
-        CompoundTag blockEntityTag = new CompoundTag("BlockEntityTag");
-        blockEntityTag.put(tag);
-        compoundTag.put(blockEntityTag);
-        return compoundTag;
-    }
-
     /**
      * This should be set to true if we are post-1.13 but before the latest version, and we should convert the old block state id
      * to the current one.

bootstrap/spigot/src/main/resources/plugin.yml

@@ -5,6 +5,7 @@ website: ${url}
 version: ${version}
 softdepend: ["ViaVersion", "floodgate"]
 api-version: 1.13
+folia-supported: true
 commands:
   geyser:
     description: The main command for Geyser.

core/build.gradle.kts

@@ -49,6 +49,10 @@ dependencies {
     // Adventure text serialization
     api(libs.bundles.adventure)
 
+    api(libs.erosion.common) {
+        isTransitive = false
+    }
+
     // Test
     testImplementation(libs.junit)
 

core/src/main/java/org/geysermc/geyser/GeyserImpl.java

@@ -50,6 +50,7 @@ import org.geysermc.api.Geyser;
 import org.geysermc.common.PlatformType;
 import org.geysermc.cumulus.form.Form;
 import org.geysermc.cumulus.form.util.FormBuilder;
+import org.geysermc.erosion.packet.Packets;
 import org.geysermc.floodgate.crypto.AesCipher;
 import org.geysermc.floodgate.crypto.AesKeyProducer;
 import org.geysermc.floodgate.crypto.Base64Topping;
@@ -67,6 +68,7 @@ import org.geysermc.geyser.api.network.RemoteServer;
 import org.geysermc.geyser.command.GeyserCommandManager;
 import org.geysermc.geyser.configuration.GeyserConfiguration;
 import org.geysermc.geyser.entity.EntityDefinitions;
+import org.geysermc.geyser.erosion.UnixSocketClientListener;
 import org.geysermc.geyser.event.GeyserEventBus;
 import org.geysermc.geyser.extension.GeyserExtensionManager;
 import org.geysermc.geyser.level.WorldManager;
@@ -140,6 +142,8 @@ public class GeyserImpl implements GeyserApi {
     private FloodgateSkinUploader skinUploader;
     private NewsHandler newsHandler;
 
+    private UnixSocketClientListener erosionUnixListener;
+
     private volatile boolean shuttingDown = false;
 
     private ScheduledExecutorService scheduledThread;
@@ -293,6 +297,14 @@ public class GeyserImpl implements GeyserApi {
 
         this.newsHandler = new NewsHandler(BRANCH, this.buildNumber());
 
+        Packets.initGeyser();
+
+        if (Epoll.isAvailable()) {
+            this.erosionUnixListener = new UnixSocketClientListener();
+        } else {
+            logger.debug("Epoll is not available; Erosion's Unix socket handling will not work.");
+        }
+
         CooldownUtils.setDefaultShowCooldown(config.getShowCooldown());
         DimensionUtils.changeBedrockNetherId(config.isAboveBedrockNetherBuilding()); // Apply End dimension ID workaround to Nether
 
@@ -570,6 +582,10 @@ public class GeyserImpl implements GeyserApi {
         newsHandler.shutdown();
         this.commandManager().getCommands().clear();
 
+        if (this.erosionUnixListener != null) {
+            this.erosionUnixListener.close();
+        }
+
         ResourcePack.PACKS.clear();
 
         this.eventBus.fire(new GeyserShutdownEvent(this.extensionManager, this.eventBus));

core/src/main/java/org/geysermc/geyser/entity/EntityDefinitions.java

@@ -148,6 +148,7 @@ public final class EntityDefinitions {
     public static final EntityDefinition<AbstractSkeletonEntity> STRAY;
     public static final EntityDefinition<StriderEntity> STRIDER;
     public static final EntityDefinition<TadpoleEntity> TADPOLE;
+    public static final EntityDefinition<TextDisplayEntity> TEXT_DISPLAY;
     public static final EntityDefinition<TNTEntity> TNT;
     public static final EntityDefinition<MinecartEntity> TNT_MINECART;
     public static final EntityDefinition<TraderLlamaEntity> TRADER_LLAMA;
@@ -295,6 +296,28 @@ public final class EntityDefinitions {
                     .addTranslator(MetadataType.INT, TNTEntity::setFuseLength)
                     .build();
 
+            EntityDefinition<Entity> displayBase = EntityDefinition.inherited(entityBase.factory(), entityBase)
+                    .addTranslator(null) // Interpolation start ticks
+                    .addTranslator(null) // Interpolation duration ID
+                    .addTranslator(null) // Translation
+                    .addTranslator(null) // Scale
+                    .addTranslator(null) // Left rotation
+                    .addTranslator(null) // Right rotation
+                    .addTranslator(null) // Billboard render constraints
+                    .addTranslator(null) // Brightness override
+                    .addTranslator(null) // View range
+                    .addTranslator(null) // Shadow radius
+                    .addTranslator(null) // Shadow strength
+                    .addTranslator(null) // Width
+                    .addTranslator(null) // Height
+                    .addTranslator(null) // Glow color override
+                    .build();
+            TEXT_DISPLAY = EntityDefinition.inherited(TextDisplayEntity::new, displayBase)
+                    .type(EntityType.TEXT_DISPLAY)
+                    .identifier("minecraft:armor_stand")
+                    .addTranslator(MetadataType.CHAT, TextDisplayEntity::setText)
+                    .build();
+
             EntityDefinition<FireballEntity> fireballBase = EntityDefinition.inherited(FireballEntity::new, entityBase)
                     .addTranslator(null) // Item
                     .build();

core/src/main/java/org/geysermc/geyser/entity/type/FishingHookEntity.java

@@ -30,12 +30,11 @@ import com.nukkitx.math.vector.Vector3f;
 import com.nukkitx.protocol.bedrock.data.entity.EntityData;
 import com.nukkitx.protocol.bedrock.packet.PlaySoundPacket;
 import lombok.Getter;
+import org.geysermc.erosion.util.BlockPositionIterator;
 import org.geysermc.geyser.entity.EntityDefinitions;
 import org.geysermc.geyser.entity.type.player.PlayerEntity;
-import org.geysermc.geyser.level.block.BlockPositionIterator;
 import org.geysermc.geyser.level.block.BlockStateValues;
 import org.geysermc.geyser.level.physics.BoundingBox;
-import org.geysermc.geyser.registry.BlockRegistries;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.collision.BlockCollision;
 import org.geysermc.geyser.util.BlockUtils;

core/src/main/java/org/geysermc/geyser/entity/type/ItemEntity.java

@@ -40,11 +40,12 @@ import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.inventory.item.ItemTranslator;
 
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 
 public class ItemEntity extends ThrowableEntity {
     protected ItemData item;
 
-    private int waterLevel = -1;
+    private CompletableFuture<Integer> waterLevel = CompletableFuture.completedFuture(-1);
 
     public ItemEntity(GeyserSession session, int entityId, long geyserId, UUID uuid, EntityDefinition<?> definition, Vector3f position, Vector3f motion, float yaw, float pitch, float headYaw) {
         super(session, entityId, geyserId, uuid, definition, position, motion, yaw, pitch, headYaw);
@@ -111,15 +112,15 @@ public class ItemEntity extends ThrowableEntity {
     @Override
     protected void moveAbsoluteImmediate(Vector3f position, float yaw, float pitch, float headYaw, boolean isOnGround, boolean teleported) {
         float offset = definition.offset();
-        if (waterLevel == 0) { // Item is in a full block of water
+        if (waterLevel.join() == 0) { // Item is in a full block of water
             // Move the item entity down so it doesn't float above the water
             offset = -definition.offset();
         }
         super.moveAbsoluteImmediate(position.add(0, offset, 0), 0, 0, 0, isOnGround, teleported);
         this.position = position;
 
-        int block = session.getGeyser().getWorldManager().getBlockAt(session, position.toInt());
-        waterLevel = BlockStateValues.getWaterLevel(block);
+        waterLevel = session.getGeyser().getWorldManager().getBlockAtAsync(session, position.getFloorX(), position.getFloorY(), position.getFloorZ())
+                .thenApply(BlockStateValues::getWaterLevel);
     }
 
     @Override
@@ -144,6 +145,6 @@ public class ItemEntity extends ThrowableEntity {
 
     @Override
     protected boolean isInWater() {
-        return waterLevel != -1;
+        return waterLevel.join() != -1;
     }
 }

core/src/main/java/org/geysermc/geyser/entity/type/TextDisplayEntity.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2019-2023 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.entity.type;
+
+import com.github.steveice10.mc.protocol.data.game.entity.metadata.EntityMetadata;
+import com.nukkitx.math.vector.Vector3f;
+import com.nukkitx.protocol.bedrock.data.entity.EntityData;
+import net.kyori.adventure.text.Component;
+import org.geysermc.geyser.entity.EntityDefinition;
+import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.geyser.translator.text.MessageTranslator;
+
+import java.util.UUID;
+
+// Note: 1.19.4 requires that the billboard is set to something in order to show, on Java Edition
+public class TextDisplayEntity extends Entity {
+    public TextDisplayEntity(GeyserSession session, int entityId, long geyserId, UUID uuid, EntityDefinition<?> definition, Vector3f position, Vector3f motion, float yaw, float pitch, float headYaw) {
+        super(session, entityId, geyserId, uuid, definition, position, motion, yaw, pitch, headYaw);
+    }
+
+    @Override
+    protected void initializeMetadata() {
+        super.initializeMetadata();
+        // Remove armor stand body
+        this.dirtyMetadata.put(EntityData.SCALE, 0f);
+        this.dirtyMetadata.put(EntityData.NAMETAG_ALWAYS_SHOW, (byte) 1);
+    }
+
+    public void setText(EntityMetadata<Component, ?> entityMetadata) {
+        this.dirtyMetadata.put(EntityData.NAMETAG, MessageTranslator.convertMessage(entityMetadata.getValue()));
+    }
+}

core/src/main/java/org/geysermc/geyser/entity/type/living/SquidEntity.java

@@ -34,12 +34,13 @@ import org.geysermc.geyser.level.block.BlockStateValues;
 import org.geysermc.geyser.session.GeyserSession;
 
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 
 public class SquidEntity extends WaterEntity implements Tickable {
     private float targetPitch;
     private float targetYaw;
 
-    private boolean inWater;
+    private CompletableFuture<Boolean> inWater = CompletableFuture.completedFuture(Boolean.FALSE);
 
     public SquidEntity(GeyserSession session, int entityId, long geyserId, UUID uuid, EntityDefinition<?> definition, Vector3f position, Vector3f motion, float yaw, float pitch, float headYaw) {
         super(session, entityId, geyserId, uuid, definition, position, motion, yaw, pitch, headYaw);
@@ -50,7 +51,7 @@ public class SquidEntity extends WaterEntity implements Tickable {
         boolean pitchChanged;
         boolean yawChanged;
         float oldPitch = pitch;
-        if (inWater) {
+        if (inWater.join()) {
             float oldYaw = yaw;
             pitch += (targetPitch - pitch) * 0.1f;
             yaw += (targetYaw - yaw) * 0.1f;
@@ -93,7 +94,7 @@ public class SquidEntity extends WaterEntity implements Tickable {
     @Override
     public void setYaw(float yaw) {
         // Let the Java server control yaw when the squid is out of water
-        if (!inWater) {
+        if (!inWater.join()) {
             this.yaw = yaw;
         }
     }
@@ -127,10 +128,10 @@ public class SquidEntity extends WaterEntity implements Tickable {
 
     private void checkInWater() {
         if (getFlag(EntityFlag.RIDING)) {
-            inWater = false;
+            inWater = CompletableFuture.completedFuture(false);
         } else {
-            int block = session.getGeyser().getWorldManager().getBlockAt(session, position.toInt());
-            inWater = BlockStateValues.getWaterLevel(block) != -1;
+            inWater = session.getGeyser().getWorldManager().getBlockAtAsync(session, position.toInt())
+                    .thenApply(block -> BlockStateValues.getWaterLevel(block) != -1);
         }
     }
 }

core/src/main/java/org/geysermc/geyser/entity/type/living/monster/ShulkerEntity.java

@@ -43,6 +43,15 @@ public class ShulkerEntity extends GolemEntity {
         super(session, entityId, geyserId, uuid, definition, position, motion, yaw, pitch, headYaw);
         // Indicate that invisibility should be fixed through the resource pack
         setFlag(EntityFlag.BRIBED, true);
+
+    }
+
+    @Override
+    protected void initializeMetadata() {
+        super.initializeMetadata();
+        // As of 1.19.4, it seems Java no longer sends the shulker color if it's the default color on initial spawn
+        // We still need the special case for 16 color in setShulkerColor though as it will send it for an entity metadata update
+        dirtyMetadata.put(EntityData.VARIANT, 16);
     }
 
     public void setAttachedFace(EntityMetadata<Direction, ?> entityMetadata) {

core/src/main/java/org/geysermc/geyser/erosion/AbstractGeyserboundPacketHandler.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2019-2023 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.erosion;
+
+import org.geysermc.erosion.packet.geyserbound.*;
+import org.geysermc.geyser.session.GeyserSession;
+import org.jetbrains.annotations.Nullable;
+
+public abstract class AbstractGeyserboundPacketHandler implements GeyserboundPacketHandler {
+    protected final GeyserSession session;
+
+    public AbstractGeyserboundPacketHandler(GeyserSession session) {
+        this.session = session;
+    }
+
+    @Override
+    public void handleBatchBlockId(GeyserboundBatchBlockIdPacket packet) {
+        illegalPacket(packet);
+    }
+
+    @Override
+    public void handleBlockEntity(GeyserboundBlockEntityPacket packet) {
+        illegalPacket(packet);
+    }
+
+    @Override
+    public void handleBlockId(GeyserboundBlockIdPacket packet) {
+        illegalPacket(packet);
+    }
+
+    @Override
+    public void handleBlockLookupFail(GeyserboundBlockLookupFailPacket packet) {
+        illegalPacket(packet);
+    }
+
+    @Override
+    public void handleBlockPlace(GeyserboundBlockPlacePacket packet) {
+        illegalPacket(packet);
+    }
+
+    @Override
+    public void handlePistonEvent(GeyserboundPistonEventPacket packet) {
+        illegalPacket(packet);
+    }
+
+    @Override
+    public void handlePickBlock(GeyserboundPickBlockPacket packet) {
+        illegalPacket(packet);
+    }
+
+    /**
+     * Is this handler actually listening to any packets?
+     */
+    public abstract boolean isActive();
+
+    @Nullable
+    public abstract GeyserboundPacketHandlerImpl getAsActive();
+
+    public void close() {
+    }
+
+    protected final void illegalPacket(GeyserboundPacket packet) {
+        session.getGeyser().getLogger().warning("Illegal packet sent from backend server! " + packet);
+    }
+}

core/src/main/java/org/geysermc/geyser/erosion/GeyserErosionPacketSender.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2019-2023 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.erosion;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import org.geysermc.erosion.Constants;
+import org.geysermc.erosion.packet.ErosionPacketSender;
+import org.geysermc.erosion.packet.Packets;
+import org.geysermc.erosion.packet.backendbound.BackendboundPacket;
+import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.geyser.util.PluginMessageUtils;
+
+import java.io.IOException;
+
+public record GeyserErosionPacketSender(GeyserSession session) implements ErosionPacketSender<BackendboundPacket> {
+
+    @Override
+    public void sendPacket(BackendboundPacket packet) {
+        ByteBuf buf = Unpooled.buffer();
+        try {
+            Packets.encode(buf, packet);
+            byte[] bytes = new byte[buf.readableBytes()];
+            buf.readBytes(bytes);
+            PluginMessageUtils.sendMessage(session, Constants.PLUGIN_MESSAGE, bytes);
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            buf.release();
+        }
+    }
+
+    @Override
+    public void setChannel(Channel channel) {
+    }
+}

core/src/main/java/org/geysermc/geyser/erosion/GeyserboundHandshakePacketHandler.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2019-2023 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.erosion;
+
+import io.netty.channel.Channel;
+import org.geysermc.erosion.netty.NettyPacketSender;
+import org.geysermc.erosion.packet.ErosionPacketHandler;
+import org.geysermc.erosion.packet.geyserbound.GeyserboundHandshakePacket;
+import org.geysermc.geyser.session.GeyserSession;
+import org.jetbrains.annotations.Nullable;
+
+public final class GeyserboundHandshakePacketHandler extends AbstractGeyserboundPacketHandler {
+
+    public GeyserboundHandshakePacketHandler(GeyserSession session) {
+        super(session);
+    }
+
+    @Override
+    public void handleHandshake(GeyserboundHandshakePacket packet) {
+        boolean useTcp = packet.getTransportType().getSocketAddress() == null;
+        GeyserboundPacketHandlerImpl handler = new GeyserboundPacketHandlerImpl(session, useTcp ? new GeyserErosionPacketSender(session) : new NettyPacketSender<>());
+        session.setErosionHandler(handler);
+        if (!useTcp) {
+            if (session.getGeyser().getErosionUnixListener() == null) {
+                session.disconnect("Erosion configurations using Unix socket handling are not supported on this hardware!");
+                return;
+            }
+            session.getGeyser().getErosionUnixListener().createClient(handler, packet.getTransportType().getSocketAddress());
+        } else {
+            handler.onConnect();
+        }
+        session.ensureInEventLoop(() -> session.getChunkCache().clear());
+    }
+
+    @Override
+    public boolean isActive() {
+        return false;
+    }
+
+    @Override
+    public @Nullable GeyserboundPacketHandlerImpl getAsActive() {
+        return null;
+    }
+
+    @Override
+    public ErosionPacketHandler setChannel(Channel channel) {
+        return null;
+    }
+}

core/src/main/java/org/geysermc/geyser/erosion/GeyserboundPacketHandlerImpl.java

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2019-2023 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.erosion;
+
+import com.github.steveice10.mc.protocol.data.game.level.block.value.PistonValueType;
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import com.nukkitx.math.vector.Vector3i;
+import com.nukkitx.nbt.NbtMap;
+import com.nukkitx.protocol.bedrock.data.SoundEvent;
+import com.nukkitx.protocol.bedrock.packet.LevelSoundEventPacket;
+import io.netty.channel.Channel;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMaps;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.ints.IntArrays;
+import it.unimi.dsi.fastutil.objects.Object2IntArrayMap;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import lombok.Getter;
+import lombok.Setter;
+import org.geysermc.erosion.packet.ErosionPacketHandler;
+import org.geysermc.erosion.packet.ErosionPacketSender;
+import org.geysermc.erosion.packet.backendbound.BackendboundInitializePacket;
+import org.geysermc.erosion.packet.backendbound.BackendboundPacket;
+import org.geysermc.erosion.packet.geyserbound.*;
+import org.geysermc.geyser.level.block.BlockStateValues;
+import org.geysermc.geyser.level.physics.Direction;
+import org.geysermc.geyser.network.GameProtocol;
+import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.geyser.session.cache.PistonCache;
+import org.geysermc.geyser.translator.level.block.entity.PistonBlockEntity;
+import org.geysermc.geyser.util.BlockEntityUtils;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public final class GeyserboundPacketHandlerImpl extends AbstractGeyserboundPacketHandler {
+    private final ErosionPacketSender<BackendboundPacket> packetSender;
+    @Setter
+    private CompletableFuture<Integer> pendingLookup = null;
+    @Getter
+    private final Int2ObjectMap<CompletableFuture<Integer>> asyncPendingLookups = Int2ObjectMaps.synchronize(new Int2ObjectOpenHashMap<>(4));
+    @Setter
+    private CompletableFuture<int[]> pendingBatchLookup = null;
+    @Setter
+    private CompletableFuture<CompoundTag> pickBlockLookup = null;
+
+    private final AtomicInteger nextTransactionId = new AtomicInteger(1);
+
+    public GeyserboundPacketHandlerImpl(GeyserSession session, ErosionPacketSender<BackendboundPacket> packetSender) {
+        super(session);
+        this.packetSender = packetSender;
+    }
+
+    @Override
+    public void handleBatchBlockId(GeyserboundBatchBlockIdPacket packet) {
+        if (this.pendingBatchLookup != null) {
+            this.pendingBatchLookup.complete(packet.getBlocks());
+        } else {
+            session.getGeyser().getLogger().warning("Batch block ID packet received with no future to complete.");
+        }
+    }
+
+    @Override
+    public void handleBlockEntity(GeyserboundBlockEntityPacket packet) {
+        NbtMap nbt = packet.getNbt();
+        BlockEntityUtils.updateBlockEntity(session, nbt, Vector3i.from(nbt.getInt("x"), nbt.getInt("y"), nbt.getInt("z")));
+    }
+
+    @Override
+    public void handleBlockId(GeyserboundBlockIdPacket packet) {
+        if (packet.getTransactionId() == 0) {
+            if (this.pendingLookup != null) {
+                this.pendingLookup.complete(packet.getBlockId());
+                return;
+            }
+        }
+        CompletableFuture<Integer> future = this.asyncPendingLookups.remove(packet.getTransactionId());
+        if (future != null) {
+            future.complete(packet.getBlockId());
+            return;
+        }
+        session.getGeyser().getLogger().warning("Block ID packet received with no future to complete.");
+    }
+
+    @Override
+    public void handleBlockLookupFail(GeyserboundBlockLookupFailPacket packet) {
+        if (packet.getTransactionId() == 0) {
+            if (this.pendingBatchLookup != null) {
+                this.pendingBatchLookup.complete(null);
+                return;
+            }
+        }
+        int transactionId = packet.getTransactionId() - 1;
+        if (transactionId == 0) {
+            if (this.pendingLookup != null) {
+                this.pendingLookup.complete(0);
+            }
+        }
+        CompletableFuture<Integer> future = this.asyncPendingLookups.remove(transactionId);
+        if (future != null) {
+            future.complete(BlockStateValues.JAVA_AIR_ID);
+        }
+    }
+
+    @Override
+    public void handleBlockPlace(GeyserboundBlockPlacePacket packet) {
+        LevelSoundEventPacket placeBlockSoundPacket = new LevelSoundEventPacket();
+        placeBlockSoundPacket.setSound(SoundEvent.PLACE);
+        placeBlockSoundPacket.setPosition(packet.getPos().toFloat());
+        placeBlockSoundPacket.setBabySound(false);
+        placeBlockSoundPacket.setExtraData(session.getBlockMappings().getBedrockBlockId(packet.getBlockId()));
+        placeBlockSoundPacket.setIdentifier(":");
+        session.sendUpstreamPacket(placeBlockSoundPacket);
+        session.setLastBlockPlacePosition(null);
+        session.setLastBlockPlacedId(null);
+    }
+
+    @Override
+    public void handlePickBlock(GeyserboundPickBlockPacket packet) {
+        if (this.pickBlockLookup != null) {
+            this.pickBlockLookup.complete(packet.getTag());
+        }
+    }
+
+    @Override
+    public void handlePistonEvent(GeyserboundPistonEventPacket packet) {
+        Direction orientation = BlockStateValues.getPistonOrientation(packet.getBlockId());
+        Vector3i position = packet.getPos();
+        boolean isExtend = packet.isExtend();
+
+        var stream = packet.getAttachedBlocks()
+                .object2IntEntrySet()
+                .stream()
+                .filter(entry -> BlockStateValues.canPistonMoveBlock(entry.getIntValue(), isExtend));
+        Object2IntMap<Vector3i> attachedBlocks = new Object2IntArrayMap<>();
+        stream.forEach(entry -> attachedBlocks.put(entry.getKey(), entry.getIntValue()));
+
+        session.executeInEventLoop(() -> {
+            PistonCache pistonCache = session.getPistonCache();
+            PistonBlockEntity blockEntity = pistonCache.getPistons().computeIfAbsent(position, pos ->
+                    new PistonBlockEntity(session, position, orientation, packet.isSticky(), !isExtend));
+            blockEntity.setAction(isExtend ? PistonValueType.PUSHING : PistonValueType.PULLING, attachedBlocks);
+        });
+    }
+
+    @Override
+    public void handleHandshake(GeyserboundHandshakePacket packet) {
+        this.close();
+        var handler = new GeyserboundHandshakePacketHandler(this.session);
+        session.setErosionHandler(handler);
+        handler.handleHandshake(packet);
+    }
+
+    @Override
+    public boolean isActive() {
+        return true;
+    }
+
+    @Override
+    public GeyserboundPacketHandlerImpl getAsActive() {
+        return this;
+    }
+
+    @Override
+    public void onConnect() {
+        sendPacket(new BackendboundInitializePacket(session.getPlayerEntity().getUuid(), GameProtocol.getJavaProtocolVersion()));
+    }
+
+    public void sendPacket(BackendboundPacket packet) {
+        this.packetSender.sendPacket(packet);
+    }
+
+    public void close() {
+        this.packetSender.close();
+    }
+
+    public int getNextTransactionId() {
+        return nextTransactionId.getAndIncrement();
+    }
+
+    @Override
+    public ErosionPacketHandler setChannel(Channel channel) {
+        this.packetSender.setChannel(channel);
+        return this;
+    }
+}

core/src/main/java/org/geysermc/geyser/erosion/UnixSocketClientListener.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2019-2023 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.erosion;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.epoll.EpollDomainSocketChannel;
+import io.netty.channel.epoll.EpollEventLoopGroup;
+import org.geysermc.erosion.netty.impl.AbstractUnixSocketListener;
+import org.geysermc.erosion.packet.geyserbound.GeyserboundPacketHandler;
+
+import java.net.SocketAddress;
+
+public final class UnixSocketClientListener extends AbstractUnixSocketListener {
+    private EventLoopGroup eventLoopGroup;
+
+    public void initializeEventLoopGroup() {
+        if (this.eventLoopGroup == null) {
+            this.eventLoopGroup = new EpollEventLoopGroup();
+        }
+    }
+
+    public void createClient(GeyserboundPacketHandler handler, SocketAddress address) {
+        initializeEventLoopGroup();
+        (new Bootstrap()
+                .channel(EpollDomainSocketChannel.class)
+                .handler(new ChannelInitializer<Channel>() {
+                    @Override
+                    protected void initChannel(Channel ch) {
+                        initPipeline(ch, handler);
+                    }
+                })
+                .group(this.eventLoopGroup.next())
+                .connect(address))
+                .syncUninterruptibly()
+                .channel();
+    }
+
+    @Override
+    public void close() {
+        if (this.eventLoopGroup != null) {
+            this.eventLoopGroup.shutdownGracefully();
+        }
+    }
+}

core/src/main/java/org/geysermc/geyser/level/GeyserWorldManager.java

@@ -25,19 +25,63 @@
 
 package org.geysermc.geyser.level;
 
+import com.github.steveice10.mc.protocol.data.game.level.block.BlockEntityInfo;
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import com.nukkitx.math.vector.Vector3i;
 import com.nukkitx.nbt.NbtMap;
 import com.nukkitx.nbt.NbtMapBuilder;
 import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
 import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+import org.geysermc.erosion.packet.backendbound.*;
+import org.geysermc.erosion.util.BlockPositionIterator;
+import org.geysermc.erosion.util.LecternUtils;
 import org.geysermc.geyser.session.GeyserSession;
-import org.geysermc.geyser.translator.inventory.LecternInventoryTranslator;
+import org.geysermc.geyser.util.BlockEntityUtils;
+import org.jetbrains.annotations.Nullable;
+
+import javax.annotation.Nonnull;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
 
 public class GeyserWorldManager extends WorldManager {
     private final Object2ObjectMap<String, String> gameruleCache = new Object2ObjectOpenHashMap<>();
 
     @Override
     public int getBlockAt(GeyserSession session, int x, int y, int z) {
-        return session.getChunkCache().getBlockAt(x, y, z);
+        var erosionHandler = session.getErosionHandler().getAsActive();
+        if (erosionHandler == null) {
+            return session.getChunkCache().getBlockAt(x, y, z);
+        }
+        CompletableFuture<Integer> future = new CompletableFuture<>(); // Boxes
+        erosionHandler.setPendingLookup(future);
+        erosionHandler.sendPacket(new BackendboundBlockRequestPacket(0, Vector3i.from(x, y, z)));
+        return future.join();
+    }
+
+    @Override
+    public CompletableFuture<Integer> getBlockAtAsync(GeyserSession session, int x, int y, int z) {
+        var erosionHandler = session.getErosionHandler().getAsActive();
+        if (erosionHandler == null) {
+            return super.getBlockAtAsync(session, x, y, z);
+        }
+        CompletableFuture<Integer> future = new CompletableFuture<>(); // Boxes
+        int transactionId = erosionHandler.getNextTransactionId();
+        erosionHandler.getAsyncPendingLookups().put(transactionId, future);
+        erosionHandler.sendPacket(new BackendboundBlockRequestPacket(transactionId, Vector3i.from(x, y, z)));
+        return future;
+    }
+
+    @Override
+    public int[] getBlocksAt(GeyserSession session, BlockPositionIterator iter) {
+        var erosionHandler = session.getErosionHandler().getAsActive();
+        if (erosionHandler == null) {
+            return super.getBlocksAt(session, iter);
+        }
+        CompletableFuture<int[]> future = new CompletableFuture<>();
+        erosionHandler.setPendingBatchLookup(future);
+        erosionHandler.sendPacket(new BackendboundBatchBlockRequestPacket(iter));
+        return future.join();
     }
 
     @Override
@@ -47,10 +91,31 @@ public class GeyserWorldManager extends WorldManager {
     }
 
     @Override
-    public NbtMap getLecternDataAt(GeyserSession session, int x, int y, int z, boolean isChunkLoad) {
+    public void sendLecternData(GeyserSession session, int x, int z, List<BlockEntityInfo> blockEntityInfos) {
+        var erosionHandler = session.getErosionHandler().getAsActive();
+        if (erosionHandler == null) {
+            // No-op - don't send any additional information other than what the chunk has already sent
+            return;
+        }
+        List<Vector3i> vectors = new ObjectArrayList<>(blockEntityInfos.size());
+        for (int i = 0; i < blockEntityInfos.size(); i++) {
+            BlockEntityInfo info = blockEntityInfos.get(i);
+            vectors.add(Vector3i.from(info.getX(), info.getY(), info.getZ()));
+        }
+        erosionHandler.sendPacket(new BackendboundBatchBlockEntityPacket(x, z, vectors));
+    }
+
+    @Override
+    public void sendLecternData(GeyserSession session, int x, int y, int z) {
+        var erosionHandler = session.getErosionHandler().getAsActive();
+        if (erosionHandler != null) {
+            erosionHandler.sendPacket(new BackendboundBlockEntityPacket(Vector3i.from(x, y, z)));
+            return;
+        }
+
         // Without direct server access, we can't get lectern information on-the-fly.
         // I should have set this up so it's only called when there is a book in the block state. - Camotoy
-        NbtMapBuilder lecternTag = LecternInventoryTranslator.getBaseLecternTag(x, y, z, 1);
+        NbtMapBuilder lecternTag = LecternUtils.getBaseLecternTag(x, y, z, 1);
         lecternTag.putCompound("book", NbtMap.builder()
                 .putByte("Count", (byte) 1)
                 .putShort("Damage", (short) 0)
@@ -61,12 +126,12 @@ public class GeyserWorldManager extends WorldManager {
                         .build())
                 .build());
         lecternTag.putInt("page", -1); // I'm surprisingly glad this exists - it forces Bedrock to stop reading immediately. Usually.
-        return lecternTag.build();
+        BlockEntityUtils.updateBlockEntity(session, lecternTag.build(), Vector3i.from(x, y, z));
     }
 
     @Override
-    public boolean shouldExpectLecternHandled() {
-        return false;
+    public boolean shouldExpectLecternHandled(GeyserSession session) {
+        return session.getErosionHandler().isActive();
     }
 
     @Override
@@ -99,4 +164,17 @@ public class GeyserWorldManager extends WorldManager {
     public boolean hasPermission(GeyserSession session, String permission) {
         return false;
     }
+
+    @Nonnull
+    @Override
+    public CompletableFuture<@Nullable CompoundTag> getPickItemNbt(GeyserSession session, int x, int y, int z, boolean addNbtData) {
+        var erosionHandler = session.getErosionHandler().getAsActive();
+        if (erosionHandler == null) {
+            return super.getPickItemNbt(session, x, y, z, addNbtData);
+        }
+        CompletableFuture<CompoundTag> future = new CompletableFuture<>();
+        erosionHandler.setPickBlockLookup(future);
+        erosionHandler.sendPacket(new BackendboundPickBlockPacket(Vector3i.from(x, y, z)));
+        return future;
+    }
 }

core/src/main/java/org/geysermc/geyser/level/WorldManager.java

@@ -26,14 +26,16 @@
 package org.geysermc.geyser.level;
 
 import com.github.steveice10.mc.protocol.data.game.entity.player.GameMode;
+import com.github.steveice10.mc.protocol.data.game.level.block.BlockEntityInfo;
 import com.github.steveice10.mc.protocol.data.game.setting.Difficulty;
 import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
 import com.nukkitx.math.vector.Vector3i;
-import com.nukkitx.nbt.NbtMap;
+import org.geysermc.erosion.util.BlockPositionIterator;
 import org.geysermc.geyser.session.GeyserSession;
 import org.jetbrains.annotations.Nullable;
 
 import javax.annotation.Nonnull;
+import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.CompletableFuture;
 
@@ -68,6 +70,23 @@ public abstract class WorldManager {
      */
     public abstract int getBlockAt(GeyserSession session, int x, int y, int z);
 
+    public final CompletableFuture<Integer> getBlockAtAsync(GeyserSession session, Vector3i vector) {
+        return this.getBlockAtAsync(session, vector.getX(), vector.getY(), vector.getZ());
+    }
+
+    public CompletableFuture<Integer> getBlockAtAsync(GeyserSession session, int x, int y, int z) {
+        return CompletableFuture.completedFuture(this.getBlockAt(session, x, y, z));
+    }
+
+    public int[] getBlocksAt(GeyserSession session, BlockPositionIterator iter) {
+        int[] blocks = new int[iter.getMaxIterations()];
+        for (; iter.hasNext(); iter.next()) {
+            int networkId = this.getBlockAt(session, iter.getX(), iter.getY(), iter.getZ());
+            blocks[iter.getIteration()] = networkId;
+        }
+        return blocks;
+    }
+
     /**
      * Checks whether or not this world manager requires a separate chunk cache/has access to more block data than the chunk cache.
      * <p>
@@ -89,20 +108,28 @@ public abstract class WorldManager {
      * We solve this problem by querying all loaded lecterns, where possible, and sending their information in a block entity
      * tag.
      *
+     * Note that the lectern data may be sent asynchronously.
+     *
      * @param session the session of the player
      * @param x the x coordinate of the lectern
      * @param y the y coordinate of the lectern
      * @param z the z coordinate of the lectern
-     * @param isChunkLoad if this is called during a chunk load or not. Changes behavior in certain instances.
-     * @return the Bedrock lectern block entity tag. This may not be the exact block entity tag - for example, Spigot's
-     * block handled must be done on the server thread, so we send the tag manually there.
      */
-    public abstract NbtMap getLecternDataAt(GeyserSession session, int x, int y, int z, boolean isChunkLoad);
+    public abstract void sendLecternData(GeyserSession session, int x, int y, int z);
+
+    /**
+     * {@link #sendLecternData(GeyserSession, int, int, int)} but batched for chunks.
+     *
+     * @param x chunk x
+     * @param z chunk z
+     * @param blockEntityInfos a list of coordinates (chunk local) to grab lecterns from.
+     */
+    public abstract void sendLecternData(GeyserSession session, int x, int z, List<BlockEntityInfo> blockEntityInfos);
 
     /**
      * @return whether we should expect lectern data to update, or if we have to fall back on a workaround.
      */
-    public abstract boolean shouldExpectLecternHandled();
+    public abstract boolean shouldExpectLecternHandled(GeyserSession session);
 
     /**
      * Updates a gamerule value on the Java server

core/src/main/java/org/geysermc/geyser/level/block/BlockPositionIterator.java

@@ -1,80 +0,0 @@
-/*
- * Copyright (c) 2019-2022 GeyserMC. http://geysermc.org
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @author GeyserMC
- * @link https://github.com/GeyserMC/Geyser
- */
-
-package org.geysermc.geyser.level.block;
-
-import com.nukkitx.network.util.Preconditions;
-
-public class BlockPositionIterator {
-    private final int minX;
-    private final int minY;
-    private final int minZ;
-
-    private final int sizeX;
-    private final int sizeZ;
-
-    private int i = 0;
-    private final int maxI;
-
-    public BlockPositionIterator(int minX, int minY, int minZ, int maxX, int maxY, int maxZ) {
-        Preconditions.checkArgument(maxX >= minX, "maxX is not greater than or equal to minX");
-        Preconditions.checkArgument(maxY >= minY, "maxY is not greater than or equal to minY");
-        Preconditions.checkArgument(maxZ >= minZ, "maxZ is not greater than or equal to minZ");
-
-        this.minX = minX;
-        this.minY = minY;
-        this.minZ = minZ;
-
-        this.sizeX = maxX - minX + 1;
-        int sizeY = maxY - minY + 1;
-        this.sizeZ = maxZ - minZ + 1;
-        this.maxI = sizeX * sizeY * sizeZ;
-    }
-
-    public boolean hasNext() {
-        return i < maxI;
-    }
-
-    public void next() {
-        // Iterate in zxy order
-        i++;
-    }
-
-    public void reset() {
-        i = 0;
-    }
-
-    public int getX() {
-        return ((i / sizeZ) % sizeX) + minX;
-    }
-
-    public int getY() {
-        return (i / sizeZ / sizeX) + minY;
-    }
-
-    public int getZ() {
-        return (i % sizeZ) + minZ;
-    }
-}

core/src/main/java/org/geysermc/geyser/level/physics/CollisionManager.java

@@ -33,10 +33,10 @@ import com.nukkitx.protocol.bedrock.data.entity.EntityFlag;
 import com.nukkitx.protocol.bedrock.packet.MovePlayerPacket;
 import lombok.Getter;
 import lombok.Setter;
+import org.geysermc.erosion.util.BlockPositionIterator;
 import org.geysermc.geyser.entity.EntityDefinitions;
 import org.geysermc.geyser.entity.type.Entity;
 import org.geysermc.geyser.entity.type.player.PlayerEntity;
-import org.geysermc.geyser.level.block.BlockPositionIterator;
 import org.geysermc.geyser.level.block.BlockStateValues;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.session.cache.PistonCache;
@@ -215,7 +215,7 @@ public class CollisionManager {
         int minCollisionZ = (int) Math.floor(position.getZ() - ((box.getSizeZ() / 2) + COLLISION_TOLERANCE + pistonExpand));
         int maxCollisionZ = (int) Math.floor(position.getZ() + (box.getSizeZ() / 2) + COLLISION_TOLERANCE + pistonExpand);
 
-        return new BlockPositionIterator(minCollisionX, minCollisionY, minCollisionZ, maxCollisionX, maxCollisionY, maxCollisionZ);
+        return BlockPositionIterator.fromMinMax(minCollisionX, minCollisionY, minCollisionZ, maxCollisionX, maxCollisionY, maxCollisionZ);
     }
 
     public BlockPositionIterator playerCollidableBlocksIterator() {
@@ -235,8 +235,9 @@ public class CollisionManager {
 
         // Used when correction code needs to be run before the main correction
         BlockPositionIterator iter = session.getCollisionManager().playerCollidableBlocksIterator();
-        for (; iter.hasNext(); iter.next()) {
-            BlockCollision blockCollision = BlockUtils.getCollisionAt(session, iter.getX(), iter.getY(), iter.getZ());
+        int[] blocks = session.getGeyser().getWorldManager().getBlocksAt(session, iter);
+        for (iter.reset(); iter.hasNext(); iter.next()) {
+            BlockCollision blockCollision = BlockUtils.getCollision(blocks[iter.getIteration()]);
             if (blockCollision != null) {
                 blockCollision.beforeCorrectPosition(iter.getX(), iter.getY(), iter.getZ(), playerBoundingBox);
             }
@@ -244,7 +245,7 @@ public class CollisionManager {
 
         // Main correction code
         for (iter.reset(); iter.hasNext(); iter.next()) {
-            BlockCollision blockCollision = BlockUtils.getCollisionAt(session, iter.getX(), iter.getY(), iter.getZ());
+            BlockCollision blockCollision = BlockUtils.getCollision(blocks[iter.getIteration()]);
             if (blockCollision != null) {
                 if (!blockCollision.correctPosition(session, iter.getX(), iter.getY(), iter.getZ(), playerBoundingBox)) {
                     return false;

core/src/main/java/org/geysermc/geyser/pack/ResourcePack.java

@@ -108,7 +108,14 @@ public class ResourcePack {
                 try (ZipFile zip = new ZipFile(file);
                      Stream<? extends ZipEntry> stream = zip.stream()) {
                     stream.forEach((x) -> {
-                        if (x.getName().contains("manifest.json")) {
+                        String name = x.getName();
+                        if (name.length() >= 80) {
+                            GeyserImpl.getInstance().getLogger().warning("The resource pack " + file.getName()
+                                    + " has a file in it that meets or exceeds 80 characters in its path (" + name
+                                    + ", " + name.length() + " characters long). This will cause problems on some Bedrock platforms." +
+                                    " Please rename it to be shorter, or reduce the amount of folders needed to get to the file.");
+                        }
+                        if (name.contains("manifest.json")) {
                             try {
                                 ResourcePackManifest manifest = FileUtils.loadJson(zip.getInputStream(x), ResourcePackManifest.class);
                                 // Sometimes a pack_manifest file is present and not in a valid format,

core/src/main/java/org/geysermc/geyser/session/GeyserSession.java

@@ -112,6 +112,8 @@ import org.geysermc.geyser.entity.type.Entity;
 import org.geysermc.geyser.entity.type.ItemFrameEntity;
 import org.geysermc.geyser.entity.type.Tickable;
 import org.geysermc.geyser.entity.type.player.SessionPlayerEntity;
+import org.geysermc.geyser.erosion.AbstractGeyserboundPacketHandler;
+import org.geysermc.geyser.erosion.GeyserboundHandshakePacketHandler;
 import org.geysermc.geyser.inventory.Inventory;
 import org.geysermc.geyser.inventory.PlayerInventory;
 import org.geysermc.geyser.inventory.recipe.GeyserRecipe;
@@ -136,6 +138,7 @@ import org.geysermc.geyser.translator.text.MessageTranslator;
 import org.geysermc.geyser.util.ChunkUtils;
 import org.geysermc.geyser.util.DimensionUtils;
 import org.geysermc.geyser.util.LoginEncryptionUtils;
+import org.jetbrains.annotations.NotNull;
 
 import java.net.ConnectException;
 import java.net.InetSocketAddress;
@@ -168,6 +171,10 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
     @Setter
     private JsonNode certChainData;
 
+    @NotNull
+    @Setter
+    private AbstractGeyserboundPacketHandler erosionHandler;
+
     @Accessors(fluent = true)
     @Setter
     private RemoteServer remoteServer;
@@ -255,7 +262,7 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
 
     /**
      * Stores a list of all lectern locations and their block entity tags.
-     * See {@link WorldManager#getLecternDataAt(GeyserSession, int, int, int, boolean)}
+     * See {@link WorldManager#sendLecternData(GeyserSession, int, int, int)}
      * for more information.
      */
     private final Set<Vector3i> lecternCache;
@@ -557,6 +564,8 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
         this.upstream = new UpstreamSession(bedrockServerSession);
         this.eventLoop = eventLoop;
 
+        this.erosionHandler = new GeyserboundHandshakePacketHandler(this);
+
         this.advancementsCache = new AdvancementsCache(this);
         this.bookEditCache = new BookEditCache(this);
         this.chunkCache = new ChunkCache(this);
@@ -585,7 +594,7 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
         this.spawned = false;
         this.loggedIn = false;
 
-        if (geyser.getWorldManager().shouldExpectLecternHandled()) {
+        if (geyser.getWorldManager().shouldExpectLecternHandled(this)) {
             // Unneeded on these platforms
             this.lecternCache = null;
         } else {
@@ -1094,6 +1103,8 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
             tickThread.cancel(false);
         }
 
+        erosionHandler.close();
+
         closed = true;
     }
 

core/src/main/java/org/geysermc/geyser/translator/inventory/LecternInventoryTranslator.java

@@ -35,6 +35,7 @@ import com.nukkitx.nbt.NbtMap;
 import com.nukkitx.nbt.NbtMapBuilder;
 import com.nukkitx.nbt.NbtType;
 import com.nukkitx.protocol.bedrock.data.inventory.ItemData;
+import org.geysermc.erosion.util.LecternUtils;
 import org.geysermc.geyser.inventory.GeyserItemStack;
 import org.geysermc.geyser.inventory.Inventory;
 import org.geysermc.geyser.inventory.LecternContainer;
@@ -110,13 +111,13 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
             Vector3i position = session.getLastInteractionBlockPosition();
             // If shouldExpectLecternHandled returns true, this is already handled for us
             // shouldRefresh means that we should boot out the client on our side because their lectern GUI isn't updated yet
-            boolean shouldRefresh = !session.getGeyser().getWorldManager().shouldExpectLecternHandled() && !session.getLecternCache().contains(position);
+            boolean shouldRefresh = !session.getGeyser().getWorldManager().shouldExpectLecternHandled(session) && !session.getLecternCache().contains(position);
 
             NbtMap blockEntityTag;
             if (tag != null) {
                 int pagesSize = ((ListTag) tag.get("pages")).size();
                 ItemData itemData = book.getItemData(session);
-                NbtMapBuilder lecternTag = getBaseLecternTag(position.getX(), position.getY(), position.getZ(), pagesSize);
+                NbtMapBuilder lecternTag = LecternUtils.getBaseLecternTag(position.getX(), position.getY(), position.getZ(), pagesSize);
                 lecternTag.putCompound("book", NbtMap.builder()
                         .putByte("Count", (byte) itemData.getCount())
                         .putShort("Damage", (short) 0)
@@ -127,7 +128,7 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
                 blockEntityTag = lecternTag.build();
             } else {
                 // There is *a* book here, but... no NBT.
-                NbtMapBuilder lecternTag = getBaseLecternTag(position.getX(), position.getY(), position.getZ(), 1);
+                NbtMapBuilder lecternTag = LecternUtils.getBaseLecternTag(position.getX(), position.getY(), position.getZ(), 1);
                 NbtMapBuilder bookTag = NbtMap.builder()
                         .putByte("Count", (byte) 1)
                         .putShort("Damage", (short) 0)
@@ -162,20 +163,4 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
     public Inventory createInventory(String name, int windowId, ContainerType containerType, PlayerInventory playerInventory) {
         return new LecternContainer(name, windowId, this.size, containerType, playerInventory);
     }
-
-    public static NbtMapBuilder getBaseLecternTag(int x, int y, int z, int totalPages) {
-        NbtMapBuilder builder = NbtMap.builder()
-                .putInt("x", x)
-                .putInt("y", y)
-                .putInt("z", z)
-                .putString("id", "Lectern");
-        if (totalPages != 0) {
-            builder.putByte("hasBook", (byte) 1);
-            builder.putInt("totalPages", totalPages);
-        } else {
-            // Not usually needed, but helps with kicking out Bedrock players from reading the UI
-            builder.putByte("hasBook", (byte) 0);
-        }
-        return builder;
-    }
 }

core/src/main/java/org/geysermc/geyser/translator/inventory/item/PotionTranslator.java

@@ -48,15 +48,23 @@ public class PotionTranslator extends ItemTranslator {
         if (itemStack.getNbt() == null) return super.translateToBedrock(itemStack, mapping, mappings);
         Tag potionTag = itemStack.getNbt().get("Potion");
         if (potionTag instanceof StringTag) {
-            Potion potion = Potion.getByJavaIdentifier(((StringTag) potionTag).getValue());
-            if (potion != null) {
+            int customItemId = CustomItemTranslator.getCustomItem(itemStack.getNbt(), mapping);
+            if (customItemId == -1) {
+                Potion potion = Potion.getByJavaIdentifier(((StringTag) potionTag).getValue());
+                if (potion != null) {
+                    return ItemData.builder()
+                            .id(mapping.getBedrockId())
+                            .damage(potion.getBedrockId())
+                            .count(itemStack.getAmount())
+                            .tag(translateNbtToBedrock(itemStack.getNbt()));
+                }
+                GeyserImpl.getInstance().getLogger().debug("Unknown Java potion: " + potionTag.getValue());
+            } else {
                 return ItemData.builder()
-                        .id(mapping.getBedrockId())
-                        .damage(potion.getBedrockId())
+                        .id(customItemId)
                         .count(itemStack.getAmount())
                         .tag(translateNbtToBedrock(itemStack.getNbt()));
             }
-            GeyserImpl.getInstance().getLogger().debug("Unknown Java potion: " + potionTag.getValue());
         }
         return super.translateToBedrock(itemStack, mapping, mappings);
     }

core/src/main/java/org/geysermc/geyser/translator/inventory/item/nbt/BannerTranslator.java

@@ -40,6 +40,8 @@ import javax.annotation.Nonnull;
 import java.util.*;
 import java.util.stream.Collectors;
 
+import static org.geysermc.erosion.util.BannerUtils.getJavaPatternTag;
+
 @ItemRemapper
 public class BannerTranslator extends NbtItemStackTranslator {
     /**
@@ -66,15 +68,6 @@ public class BannerTranslator extends NbtItemStackTranslator {
         OMINOUS_BANNER_PATTERN.add(getJavaPatternTag("bo", 15));
     }
 
-    public static CompoundTag getJavaPatternTag(String pattern, int color) {
-        StringTag patternType = new StringTag("Pattern", pattern);
-        IntTag colorTag = new IntTag("Color", color);
-        CompoundTag tag = new CompoundTag("");
-        tag.put(patternType);
-        tag.put(colorTag);
-        return tag;
-    }
-
     public BannerTranslator() {
         appliedItems = Arrays.stream(Registries.ITEMS.forVersion(GameProtocol.DEFAULT_BEDROCK_CODEC.getProtocolVersion()).getItems())
                 .filter(entry -> entry.getJavaIdentifier().endsWith("banner"))
@@ -117,7 +110,7 @@ public class BannerTranslator extends NbtItemStackTranslator {
      * @return The Java edition format pattern nbt
      */
     public static CompoundTag getJavaBannerPattern(NbtMap pattern) {
-        return BannerTranslator.getJavaPatternTag(pattern.getString("Pattern"), 15 - pattern.getInt("Color"));
+        return getJavaPatternTag(pattern.getString("Pattern"), 15 - pattern.getInt("Color"));
     }
 
     /**

core/src/main/java/org/geysermc/geyser/translator/level/block/entity/PistonBlockEntity.java

@@ -224,7 +224,7 @@ public class PistonBlockEntity {
         int blockId = session.getGeyser().getWorldManager().getBlockAt(session, blockInFront);
         if (BlockStateValues.isPistonHead(blockId)) {
             ChunkUtils.updateBlock(session, BlockStateValues.JAVA_AIR_ID, blockInFront);
-        } else if (session.getGeyser().getPlatformType() == PlatformType.SPIGOT && blockId == BlockStateValues.JAVA_AIR_ID) {
+        } else if ((session.getGeyser().getPlatformType() == PlatformType.SPIGOT || session.getErosionHandler().isActive()) && blockId == BlockStateValues.JAVA_AIR_ID) {
             // Spigot removes the piston head from the cache, but we need to send the block update ourselves
             ChunkUtils.updateBlock(session, BlockStateValues.JAVA_AIR_ID, blockInFront);
         }

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/BedrockBlockPickRequestTranslator.java

@@ -71,30 +71,28 @@ public class BedrockBlockPickRequestTranslator extends PacketTranslator<BlockPic
         boolean addNbtData = packet.isAddUserData() && blockMapping.isBlockEntity(); // Holding down CTRL
         if (BlockStateValues.getBannerColor(blockToPick) != -1 || addNbtData) {
             session.getGeyser().getWorldManager().getPickItemNbt(session, vector.getX(), vector.getY(), vector.getZ(), addNbtData)
-                    .whenComplete((tag, ex) -> {
+                    .whenComplete((tag, ex) -> session.ensureInEventLoop(() -> {
                         if (tag == null) {
                             pickItem(session, blockMapping);
                             return;
                         }
 
-                        session.ensureInEventLoop(() -> {
-                            if (addNbtData) {
-                                ListTag lore = new ListTag("Lore");
-                                lore.add(new StringTag("", "\"(+NBT)\""));
-                                CompoundTag display = tag.get("display");
-                                if (display == null) {
-                                    display = new CompoundTag("display");
-                                    tag.put(display);
-                                }
-                                display.put(lore);
+                        if (addNbtData) {
+                            ListTag lore = new ListTag("Lore");
+                            lore.add(new StringTag("", "\"(+NBT)\""));
+                            CompoundTag display = tag.get("display");
+                            if (display == null) {
+                                display = new CompoundTag("display");
+                                tag.put(display);
                             }
-                            // I don't really like this... I'd rather get an ID from the block mapping I think
-                            ItemMapping mapping = session.getItemMappings().getMapping(blockMapping.getPickItem());
+                            display.put(lore);
+                        }
+                        // I don't really like this... I'd rather get an ID from the block mapping I think
+                        ItemMapping mapping = session.getItemMappings().getMapping(blockMapping.getPickItem());
 
-                            ItemStack itemStack = new ItemStack(mapping.getJavaId(), 1, tag);
-                            InventoryUtils.findOrCreateItem(session, itemStack);
-                        });
-                    });
+                        ItemStack itemStack = new ItemStack(mapping.getJavaId(), 1, tag);
+                        InventoryUtils.findOrCreateItem(session, itemStack);
+                    }));
             return;
         }
 

core/src/main/java/org/geysermc/geyser/translator/protocol/java/JavaCustomPayloadTranslator.java

@@ -35,10 +35,13 @@ import io.netty.buffer.Unpooled;
 import org.geysermc.cumulus.Forms;
 import org.geysermc.cumulus.form.Form;
 import org.geysermc.cumulus.form.util.FormType;
+import org.geysermc.erosion.Constants;
+import org.geysermc.erosion.packet.ErosionPacket;
+import org.geysermc.erosion.packet.Packets;
+import org.geysermc.erosion.packet.geyserbound.GeyserboundPacket;
 import org.geysermc.floodgate.pluginmessage.PluginMessageChannels;
 import org.geysermc.geyser.GeyserImpl;
 import org.geysermc.geyser.GeyserLogger;
-import org.geysermc.geyser.api.network.AuthType;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
 import org.geysermc.geyser.translator.protocol.Translator;
@@ -51,82 +54,96 @@ public class JavaCustomPayloadTranslator extends PacketTranslator<ClientboundCus
 
     @Override
     public void translate(GeyserSession session, ClientboundCustomPayloadPacket packet) {
-        // The only plugin messages it has to listen for are Floodgate plugin messages
-        if (session.remoteServer().authType() != AuthType.FLOODGATE) {
+        String channel = packet.getChannel();
+
+        if (channel.equals(Constants.PLUGIN_MESSAGE)) {
+            ByteBuf buf = Unpooled.wrappedBuffer(packet.getData());
+            ErosionPacket<?> erosionPacket = Packets.decode(buf);
+            ((GeyserboundPacket) erosionPacket).handle(session.getErosionHandler());
             return;
         }
 
-        String channel = packet.getChannel();
-
         if (channel.equals(PluginMessageChannels.FORM)) {
-            byte[] data = packet.getData();
+            session.ensureInEventLoop(() -> {
+                byte[] data = packet.getData();
 
-            // receive: first byte is form type, second and third are the id, remaining is the form data
-            // respond: first and second byte id, remaining is form response data
+                // receive: first byte is form type, second and third are the id, remaining is the form data
+                // respond: first and second byte id, remaining is form response data
 
-            FormType type = FormType.fromOrdinal(data[0]);
-            if (type == null) {
-                throw new NullPointerException("Got type " + data[0] + " which isn't a valid form type!");
-            }
-
-            String dataString = new String(data, 3, data.length - 3, Charsets.UTF_8);
-
-            Form form = Forms.fromJson(dataString, type, (ignored, response) -> {
-                byte[] finalData;
-                if (response == null) {
-                    // Response data can be null as of 1.19.20 (same behaviour as empty response data)
-                    // Only need to send the form id
-                    finalData = new byte[]{data[1], data[2]};
-                } else {
-                    byte[] raw = response.getBytes(StandardCharsets.UTF_8);
-                    finalData = new byte[raw.length + 2];
-
-                    finalData[0] = data[1];
-                    finalData[1] = data[2];
-                    System.arraycopy(raw, 0, finalData, 2, raw.length);
+                FormType type = FormType.fromOrdinal(data[0]);
+                if (type == null) {
+                    throw new NullPointerException("Got type " + data[0] + " which isn't a valid form type!");
                 }
 
-                session.sendDownstreamPacket(new ServerboundCustomPayloadPacket(channel, finalData));
+                String dataString = new String(data, 3, data.length - 3, Charsets.UTF_8);
+
+                Form form = Forms.fromJson(dataString, type, (ignored, response) -> {
+                    byte[] finalData;
+                    if (response == null) {
+                        // Response data can be null as of 1.19.20 (same behaviour as empty response data)
+                        // Only need to send the form id
+                        finalData = new byte[]{data[1], data[2]};
+                    } else {
+                        byte[] raw = response.getBytes(StandardCharsets.UTF_8);
+                        finalData = new byte[raw.length + 2];
+
+                        finalData[0] = data[1];
+                        finalData[1] = data[2];
+                        System.arraycopy(raw, 0, finalData, 2, raw.length);
+                    }
+
+                    session.sendDownstreamPacket(new ServerboundCustomPayloadPacket(channel, finalData));
+                });
+                session.sendForm(form);
             });
-            session.sendForm(form);
 
         } else if (channel.equals(PluginMessageChannels.TRANSFER)) {
-            byte[] data = packet.getData();
+            session.ensureInEventLoop(() -> {
+                byte[] data = packet.getData();
 
-            // port (4 bytes), address (remaining data)
-            if (data.length < 5) {
-                throw new NullPointerException("Transfer data should be at least 5 bytes long");
-            }
+                // port (4 bytes), address (remaining data)
+                if (data.length < 5) {
+                    throw new NullPointerException("Transfer data should be at least 5 bytes long");
+                }
 
-            int port = data[0] << 24 | (data[1] & 0xFF) << 16 | (data[2] & 0xFF) << 8 | data[3] & 0xFF;
-            String address = new String(data, 4, data.length - 4);
+                int port = data[0] << 24 | (data[1] & 0xFF) << 16 | (data[2] & 0xFF) << 8 | data[3] & 0xFF;
+                String address = new String(data, 4, data.length - 4);
 
-            if (logger.isDebug()) {
-                logger.info("Transferring client to: " + address + ":" + port);
-            }
+                if (logger.isDebug()) {
+                    logger.info("Transferring client to: " + address + ":" + port);
+                }
 
-            TransferPacket transferPacket = new TransferPacket();
-            transferPacket.setAddress(address);
-            transferPacket.setPort(port);
-            session.sendUpstreamPacket(transferPacket);
+                TransferPacket transferPacket = new TransferPacket();
+                transferPacket.setAddress(address);
+                transferPacket.setPort(port);
+                session.sendUpstreamPacket(transferPacket);
+            });
 
         } else if (channel.equals(PluginMessageChannels.PACKET)) {
-            logger.debug("A packet has been sent using the Floodgate api");
-            byte[] data = packet.getData();
+            session.ensureInEventLoop(() -> {
+                logger.debug("A packet has been sent using the Floodgate api");
+                byte[] data = packet.getData();
 
-            // packet id, packet data
-            if (data.length < 2) {
-                throw new IllegalStateException("Packet data should be at least 2 bytes long");
-            }
+                // packet id, packet data
+                if (data.length < 2) {
+                    throw new IllegalStateException("Packet data should be at least 2 bytes long");
+                }
 
-            int packetId = data[0] & 0xFF;
-            ByteBuf packetData = Unpooled.wrappedBuffer(data, 1, data.length - 1);
+                int packetId = data[0] & 0xFF;
+                ByteBuf packetData = Unpooled.wrappedBuffer(data, 1, data.length - 1);
 
-            var toSend = new UnknownPacket();
-            toSend.setPacketId(packetId);
-            toSend.setPayload(packetData);
+                var toSend = new UnknownPacket();
+                toSend.setPacketId(packetId);
+                toSend.setPayload(packetData);
 
-            session.sendUpstreamPacket(toSend);
+                session.sendUpstreamPacket(toSend);
+            });
         }
     }
+
+    @Override
+    public boolean shouldExecuteInEventLoop() {
+        // For Erosion packets
+        return false;
+    }
 }

core/src/main/java/org/geysermc/geyser/translator/protocol/java/JavaLoginTranslator.java

@@ -36,6 +36,7 @@ import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import org.geysermc.floodgate.pluginmessage.PluginMessageChannels;
 import org.geysermc.geyser.api.network.AuthType;
 import org.geysermc.geyser.entity.type.player.SessionPlayerEntity;
+import org.geysermc.geyser.erosion.GeyserboundHandshakePacketHandler;
 import org.geysermc.geyser.level.JavaDimension;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.text.TextDecoration;
@@ -57,6 +58,11 @@ public class JavaLoginTranslator extends PacketTranslator<ClientboundLoginPacket
         SessionPlayerEntity entity = session.getPlayerEntity();
         entity.setEntityId(packet.getEntityId());
 
+        if (session.getErosionHandler().isActive()) {
+            session.getErosionHandler().close();
+            session.setErosionHandler(new GeyserboundHandshakePacketHandler(session));
+        }
+
         Map<String, JavaDimension> dimensions = session.getDimensions();
         dimensions.clear();
 
@@ -129,6 +135,10 @@ public class JavaLoginTranslator extends PacketTranslator<ClientboundLoginPacket
 
         session.sendDownstreamPacket(new ServerboundCustomPayloadPacket("minecraft:brand", PluginMessageUtils.getGeyserBrandData()));
 
+        // TODO don't send two packets
+//        if (true) {
+//            session.sendDownstreamPacket(new ServerboundCustomPayloadPacket("minecraft:register", Constants.PLUGIN_MESSAGE.getBytes(StandardCharsets.UTF_8)));
+//        }
         // register the plugin messaging channels used in Floodgate
         if (session.remoteServer().authType() == AuthType.FLOODGATE) {
             session.sendDownstreamPacket(new ServerboundCustomPayloadPacket("minecraft:register", PluginMessageChannels.getFloodgateRegisterData()));

core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockEventTranslator.java

@@ -58,15 +58,16 @@ public class JavaBlockEventTranslator extends PacketTranslator<ClientboundBlockE
             blockEventPacket.setEventType(1);
             session.sendUpstreamPacket(blockEventPacket);
         } else if (packet.getValue() instanceof NoteBlockValue) {
-            int blockState = session.getGeyser().getWorldManager().getBlockAt(session, position);
-            blockEventPacket.setEventData(BlockStateValues.getNoteblockPitch(blockState));
-            session.sendUpstreamPacket(blockEventPacket);
+            session.getGeyser().getWorldManager().getBlockAtAsync(session, position).thenAccept(blockState -> {
+                blockEventPacket.setEventData(BlockStateValues.getNoteblockPitch(blockState));
+                session.sendUpstreamPacket(blockEventPacket);
+            });
         } else if (packet.getValue() instanceof PistonValue pistonValue) {
             PistonValueType action = (PistonValueType) packet.getType();
             Direction direction = Direction.fromPistonValue(pistonValue.getDirection());
             PistonCache pistonCache = session.getPistonCache();
 
-            if (session.getGeyser().getPlatformType() == PlatformType.SPIGOT) {
+            if (session.getGeyser().getPlatformType() == PlatformType.SPIGOT || session.getErosionHandler().isActive()) {
                 // Mostly handled in the GeyserPistonEvents class
                 // Retracting sticky pistons is an exception, since the event is not called on Spigot from 1.13.2 - 1.17.1
                 // See https://github.com/PaperMC/Paper/blob/6fa1983e9ce177a4a412d5b950fd978620174777/patches/server/0304-Fire-BlockPistonRetractEvent-for-all-empty-pistons.patch

core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockUpdateTranslator.java

@@ -43,7 +43,7 @@ public class JavaBlockUpdateTranslator extends PacketTranslator<ClientboundBlock
     public void translate(GeyserSession session, ClientboundBlockUpdatePacket packet) {
         Vector3i pos = packet.getEntry().getPosition();
         boolean updatePlacement = session.getGeyser().getPlatformType() != PlatformType.SPIGOT && // Spigot simply listens for the block place event
-                session.getGeyser().getWorldManager().getBlockAt(session, pos) != packet.getEntry().getBlock();
+                !session.getErosionHandler().isActive() && session.getGeyser().getWorldManager().getBlockAt(session, pos) != packet.getEntry().getBlock();
         session.getWorldCache().updateServerCorrectBlockState(pos, packet.getEntry().getBlock());
         if (updatePlacement) {
             this.checkPlace(session, packet);

core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaForgetLevelChunkTranslator.java

@@ -52,7 +52,7 @@ public class JavaForgetLevelChunkTranslator extends PacketTranslator<Clientbound
         }
         removedSkulls.forEach(session.getSkullCache()::removeSkull);
 
-        if (!session.getGeyser().getWorldManager().shouldExpectLecternHandled()) {
+        if (!session.getGeyser().getWorldManager().shouldExpectLecternHandled(session)) {
             // Do the same thing with lecterns
             Iterator<Vector3i> iterator = session.getLecternCache().iterator();
             while (iterator.hasNext()) {

core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java

@@ -38,6 +38,7 @@ import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
 import com.nukkitx.math.vector.Vector3i;
 import com.nukkitx.nbt.NBTOutputStream;
 import com.nukkitx.nbt.NbtMap;
+import com.nukkitx.nbt.NbtMapBuilder;
 import com.nukkitx.nbt.NbtUtils;
 import com.nukkitx.protocol.bedrock.packet.LevelChunkPacket;
 import io.netty.buffer.ByteBuf;
@@ -49,6 +50,7 @@ import it.unimi.dsi.fastutil.ints.IntImmutableList;
 import it.unimi.dsi.fastutil.ints.IntList;
 import it.unimi.dsi.fastutil.ints.IntLists;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+import org.geysermc.erosion.util.LecternUtils;
 import org.geysermc.geyser.entity.type.ItemFrameEntity;
 import org.geysermc.geyser.level.BedrockDimension;
 import org.geysermc.geyser.level.block.BlockStateValues;
@@ -95,6 +97,7 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
 
         final BlockEntityInfo[] blockEntities = packet.getBlockEntities();
         final List<NbtMap> bedrockBlockEntities = new ObjectArrayList<>(blockEntities.length);
+        final List<BlockEntityInfo> lecterns = new ObjectArrayList<>();
 
         BitSet waterloggedPaletteIds = new BitSet();
         BitSet bedrockOnlyBlockEntityIds = new BitSet();
@@ -328,7 +331,9 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                 extendedCollisionNextSection = thisExtendedCollisionNextSection;
             }
 
-            session.getChunkCache().addToCache(packet.getX(), packet.getZ(), javaChunks);
+            if (!session.getErosionHandler().isActive()) {
+                session.getChunkCache().addToCache(packet.getX(), packet.getZ(), javaChunks);
+            }
 
             final int chunkBlockX = packet.getX() << 4;
             final int chunkBlockZ = packet.getZ() << 4;
@@ -350,8 +355,15 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
 
                 if (type == BlockEntityType.LECTERN && BlockStateValues.getLecternBookStates().get(blockState)) {
                     // If getLecternBookStates is false, let's just treat it like a normal block entity
-                    bedrockBlockEntities.add(session.getGeyser().getWorldManager().getLecternDataAt(
-                            session, x + chunkBlockX, y, z + chunkBlockZ, true));
+                    // Fill in tag with a default value
+                    NbtMapBuilder lecternTag = LecternUtils.getBaseLecternTag(x + chunkBlockX, y, z + chunkBlockZ, 1);
+                    lecternTag.putCompound("book", NbtMap.builder()
+                                    .putByte("Count", (byte) 1)
+                                    .putShort("Damage", (short) 0)
+                                    .putString("Name", "minecraft:written_book").build());
+                    lecternTag.putInt("page", -1);
+                    bedrockBlockEntities.add(lecternTag.build());
+                    lecterns.add(blockEntity);
                     continue;
                 }
 
@@ -455,6 +467,10 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
         levelChunkPacket.setData(payload);
         session.sendUpstreamPacket(levelChunkPacket);
 
+        if (!lecterns.isEmpty()) {
+            session.getGeyser().getWorldManager().sendLecternData(session, packet.getX(), packet.getZ(), lecterns);
+        }
+
         for (Map.Entry<Vector3i, ItemFrameEntity> entry : session.getItemFrameCache().entrySet()) {
             Vector3i position = entry.getKey();
             if ((position.getX() >> 4) == packet.getX() && (position.getZ() >> 4) == packet.getZ()) {

core/src/main/java/org/geysermc/geyser/util/collection/LecternHasBookMap.java

@@ -27,9 +27,9 @@ package org.geysermc.geyser.util.collection;
 
 import com.nukkitx.math.vector.Vector3i;
 import com.nukkitx.nbt.NbtMap;
+import org.geysermc.erosion.util.LecternUtils;
 import org.geysermc.geyser.level.WorldManager;
 import org.geysermc.geyser.session.GeyserSession;
-import org.geysermc.geyser.translator.inventory.LecternInventoryTranslator;
 import org.geysermc.geyser.util.BlockEntityUtils;
 
 /**
@@ -47,27 +47,24 @@ public class LecternHasBookMap extends FixedInt2BooleanMap {
         int offset = blockState - this.start;
         if (offset < 0 || offset >= this.value.length) {
             // Block state is out of bounds of this map - lectern has been destroyed, if it existed
-            if (!worldManager.shouldExpectLecternHandled()) {
+            if (!worldManager.shouldExpectLecternHandled(session)) {
                 session.getLecternCache().remove(position);
             }
             return;
         }
 
         boolean newLecternHasBook;
-        if (worldManager.shouldExpectLecternHandled()) {
-            // As of right now, no tag can be added asynchronously
-            worldManager.getLecternDataAt(session, position.getX(), position.getY(), position.getZ(), false);
+        if (worldManager.shouldExpectLecternHandled(session)) {
+            worldManager.sendLecternData(session, position.getX(), position.getY(), position.getZ());
         } else if ((newLecternHasBook = this.value[offset]) != this.get(worldManager.getBlockAt(session, position))) {
-            // If the lectern block was updated, or it previously had a book
-            NbtMap newLecternTag;
             // newLecternHasBook = the new lectern block state's "has book" toggle.
             if (newLecternHasBook) {
-                newLecternTag = worldManager.getLecternDataAt(session, position.getX(), position.getY(), position.getZ(), false);
+                worldManager.sendLecternData(session, position.getX(), position.getY(), position.getZ());
             } else {
                 session.getLecternCache().remove(position);
-                newLecternTag = LecternInventoryTranslator.getBaseLecternTag(position.getX(), position.getY(), position.getZ(), 0).build();
+                NbtMap newLecternTag = LecternUtils.getBaseLecternTag(position.getX(), position.getY(), position.getZ(), 0).build();
+                BlockEntityUtils.updateBlockEntity(session, newLecternTag, position);
             }
-            BlockEntityUtils.updateBlockEntity(session, newLecternTag, position);
         }
     }
 }

gradle/libs.versions.toml

@@ -1,6 +1,7 @@
 [versions]
 base-api = "1.0.0-SNAPSHOT"
 cumulus = "1.1.1"
+erosion = "1.0-20230330.170602-3"
 events = "1.0-SNAPSHOT"
 jackson = "2.14.0"
 fastutil = "8.5.2"
@@ -19,9 +20,9 @@ checkerframework = "3.19.0"
 log4j = "2.17.1"
 jline = "3.21.0"
 terminalconsoleappender = "1.2.0"
-paper = "1.19-R0.1-SNAPSHOT"
+folia = "1.19.4-R0.1-SNAPSHOT"
 viaversion = "4.0.0"
-adapters = "1.6-SNAPSHOT"
+adapters = "1.7-SNAPSHOT"
 commodore = "2.2"
 bungeecord = "a7c6ede"
 velocity = "3.0.0"
@@ -35,6 +36,9 @@ base-api = { group = "org.geysermc.api", name = "base-api", version.ref = "base-
 cumulus = { group = "org.geysermc.cumulus", name = "cumulus", version.ref = "cumulus" }
 events = { group = "org.geysermc.event", name = "events", version.ref = "events" }
 
+erosion-bukkit-common = { group = "org.geysermc.erosion", name = "bukkit-common", version.ref = "erosion" }
+erosion-common = { group = "org.geysermc.erosion", name = "common", version.ref = "erosion" }
+
 jackson-annotations = { group = "com.fasterxml.jackson.core", name = "jackson-annotations", version.ref = "jackson" }
 jackson-core = { group = "com.fasterxml.jackson.core", name = "jackson-databind", version.ref = "jackson" }
 jackson-dataformat-yaml = { group = "com.fasterxml.jackson.dataformat", name = "jackson-dataformat-yaml", version.ref = "jackson" }
@@ -66,8 +70,8 @@ jline-terminal = { group = "org.jline", name = "jline-terminal", version.ref = "
 jline-terminal-jna = { group = "org.jline", name = "jline-terminal-jna", version.ref = "jline" }
 jline-reader = { group = "org.jline", name = "jline-reader", version.ref = "jline" }
 
-paper-api = { group = "io.papermc.paper", name = "paper-api", version.ref = "paper" }
-paper-mojangapi = { group = "io.papermc.paper", name = "paper-mojangapi", version.ref = "paper" }
+folia-api = { group = "dev.folia", name = "folia-api", version.ref = "folia" }
+paper-mojangapi = { group = "io.papermc.paper", name = "paper-mojangapi", version.ref = "folia" }
 
 # check these on https://modmuss50.me/fabric.html
 fabric-minecraft = { group = "com.mojang", name = "minecraft", version.ref = "fabric-minecraft" }