docs: Add v4.9.2 MPDB converter warning

* Paper plugin support, save itemsToKeep if present, close #172

* Fixup wrong packages, suppress a warning

* Update docs, add settings for death saving, reorganise config slightly

* Improve default server name lookup

* docs: Add note on Unsupported Versions

* docs: Minor Sync Modes tweaks

build.gradle

@@ -77,7 +77,11 @@ subprojects {
         from '../LICENSE'
     }
 
-    if (['bukkit', 'plugin'].contains(project.name)) {
+    if (['paper'].contains(project.name)) {
+        compileJava.options.release.set 17
+    }
+
+    if (['bukkit', 'paper', 'plugin'].contains(project.name)) {
         shadowJar {
             destinationDirectory.set(file("$rootDir/target"))
             archiveClassifier.set('')

bukkit/build.gradle

@@ -7,13 +7,13 @@ dependencies {
     implementation 'net.william278:mapdataapi:1.0.3'
     implementation 'net.william278:andjam:1.0.2'
     implementation 'me.lucko:commodore:2.2'
-    implementation 'net.kyori:adventure-platform-bukkit:4.3.0'
-    implementation 'dev.triumphteam:triumph-gui:3.1.5'
+    implementation 'net.kyori:adventure-platform-bukkit:4.3.1'
+    implementation 'dev.triumphteam:triumph-gui:3.1.6'
     implementation 'space.arim.morepaperlib:morepaperlib:0.4.3'
     implementation 'de.tr7zw:item-nbt-api:2.12.0'
 
     compileOnly 'org.spigotmc:spigot-api:1.16.5-R0.1-SNAPSHOT'
-    compileOnly 'commons-io:commons-io:2.13.0'
+    compileOnly 'commons-io:commons-io:2.14.0'
     compileOnly 'org.json:json:20230618'
     compileOnly 'de.themoep:minedown-adventure:1.7.2-SNAPSHOT'
     compileOnly 'dev.dejvokep:boosted-yaml:1.3.1'

bukkit/src/main/java/net/william278/husksync/BukkitHuskSync.java

@@ -28,6 +28,7 @@ import net.william278.husksync.adapter.SnappyGsonAdapter;
 import net.william278.husksync.api.BukkitHuskSyncAPI;
 import net.william278.husksync.command.BukkitCommand;
 import net.william278.husksync.config.Locales;
+import net.william278.husksync.config.Server;
 import net.william278.husksync.config.Settings;
 import net.william278.husksync.data.BukkitSerializer;
 import net.william278.husksync.data.Data;
@@ -43,6 +44,7 @@ import net.william278.husksync.migrator.LegacyMigrator;
 import net.william278.husksync.migrator.Migrator;
 import net.william278.husksync.migrator.MpdbMigrator;
 import net.william278.husksync.redis.RedisManager;
+import net.william278.husksync.sync.DataSyncer;
 import net.william278.husksync.user.BukkitUser;
 import net.william278.husksync.user.ConsoleUser;
 import net.william278.husksync.user.OnlineUser;
@@ -64,6 +66,7 @@ import space.arim.morepaperlib.scheduling.RegionalScheduler;
 
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentSkipListSet;
 import java.util.logging.Level;
 import java.util.stream.Collectors;
 
@@ -82,8 +85,11 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
     private DataAdapter dataAdapter;
     private Map<Identifier, Serializer<? extends Data>> serializers;
     private Map<UUID, Map<Identifier, Data>> playerCustomDataStore;
+    private Set<UUID> lockedPlayers;
+    private DataSyncer dataSyncer;
     private Settings settings;
     private Locales locales;
+    private Server server;
     private List<Migrator> availableMigrators;
     private LegacyConverter legacyConverter;
     private Map<Integer, MapView> mapViews;
@@ -92,15 +98,18 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
     private AsynchronousScheduler asyncScheduler;
     private RegionalScheduler regionalScheduler;
     private Gson gson;
+    private boolean disabling;
 
     @Override
     public void onEnable() {
         // Initial plugin setup
+        this.disabling = false;
         this.gson = createGson();
         this.audiences = BukkitAudiences.create(this);
         this.paperLib = new MorePaperLib(this);
         this.availableMigrators = new ArrayList<>();
         this.serializers = new LinkedHashMap<>();
+        this.lockedPlayers = new ConcurrentSkipListSet<>();
         this.playerCustomDataStore = new ConcurrentHashMap<>();
         this.mapViews = new ConcurrentHashMap<>();
 
@@ -152,8 +161,14 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
             this.redisManager.initialize();
         });
 
+        // Prepare data syncer
+        initialize("data syncer", (plugin) -> {
+            dataSyncer = getSettings().getSyncMode().create(this);
+            dataSyncer.initialize();
+        });
+
         // Register events
-        initialize("events", (plugin) -> this.eventListener = new BukkitEventListener(this));
+        initialize("events", (plugin) -> this.eventListener = createEventListener());
 
         // Register commands
         initialize("commands", (plugin) -> BukkitCommand.Type.registerCommands(this));
@@ -176,6 +191,12 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
     @Override
     public void onDisable() {
         // Handle shutdown
+        this.disabling = true;
+
+        // Close the event listener / data syncer
+        if (this.dataSyncer != null) {
+            this.dataSyncer.terminate();
+        }
         if (this.eventListener != null) {
             this.eventListener.handlePluginDisable();
         }
@@ -188,6 +209,11 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
         log(Level.INFO, "Successfully disabled HuskSync v" + getPluginVersion());
     }
 
+    @NotNull
+    protected BukkitEventListener createEventListener() {
+        return new BukkitEventListener(this);
+    }
+
     @Override
     @NotNull
     public Set<OnlineUser> getOnlineUsers() {
@@ -226,6 +252,19 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
 
     @NotNull
     @Override
+    public DataSyncer getDataSyncer() {
+        return dataSyncer;
+    }
+
+    @Override
+    public void setDataSyncer(@NotNull DataSyncer dataSyncer) {
+        log(Level.INFO, String.format("Switching data syncer to %s", dataSyncer.getClass().getSimpleName()));
+        this.dataSyncer = dataSyncer;
+    }
+
+    @NotNull
+    @Override
+    @SuppressWarnings("unchecked")
     public Map<Identifier, Serializer<? extends Data>> getSerializers() {
         return serializers;
     }
@@ -258,6 +297,17 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
         this.settings = settings;
     }
 
+    @NotNull
+    @Override
+    public String getServerName() {
+        return server.getName();
+    }
+
+    @Override
+    public void setServer(@NotNull Server server) {
+        this.server = server;
+    }
+
     @Override
     @NotNull
     public Locales getLocales() {
@@ -328,7 +378,7 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
     @NotNull
     @Override
     public Set<UUID> getLockedPlayers() {
-        return this.eventListener.getLockedPlayers();
+        return lockedPlayers;
     }
 
     @NotNull
@@ -337,6 +387,11 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
         return gson;
     }
 
+    @Override
+    public boolean isDisabling() {
+        return disabling;
+    }
+
     @NotNull
     public Map<Integer, MapView> getMapViews() {
         return mapViews;

bukkit/src/main/java/net/william278/husksync/data/BukkitData.java

@@ -46,6 +46,7 @@ import org.jetbrains.annotations.Nullable;
 import java.util.*;
 import java.util.logging.Level;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 public abstract class BukkitData implements Data {
 
@@ -99,6 +100,10 @@ public abstract class BukkitData implements Data {
         }
 
         public void setContents(@NotNull ItemStack[] contents) {
+            // Ensure the array is the correct length for the inventory
+            if (contents.length != this.contents.length) {
+                contents = Arrays.copyOf(contents, this.contents.length);
+            }
             System.arraycopy(contents, 0, this.contents, 0, this.contents.length);
         }
 
@@ -588,30 +593,53 @@ public abstract class BukkitData implements Data {
         @NotNull
         public static BukkitData.Statistics from(@NotNull StatisticsMap stats) {
             return new BukkitData.Statistics(
-                    stats.genericStats().entrySet().stream().collect(Collectors.toMap(
-                            entry -> matchStatistic(entry.getKey()),
-                            Map.Entry::getValue
+                stats.genericStats().entrySet().stream()
+                    .flatMap(entry -> {
+                        Statistic statistic = matchStatistic(entry.getKey());
+                        return statistic != null ? Stream.of(new AbstractMap.SimpleEntry<>(statistic, entry.getValue())) : Stream.empty();
+                    })
+                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)),
+                stats.blockStats().entrySet().stream()
+                    .flatMap(entry -> {
+                        Statistic statistic = matchStatistic(entry.getKey());
+                        return statistic != null ? Stream.of(new AbstractMap.SimpleEntry<>(statistic, entry.getValue())) : Stream.empty();
+                    })
+                    .collect(Collectors.toMap(
+                        Map.Entry::getKey,
+                        entry -> entry.getValue().entrySet().stream()
+                            .flatMap(blockEntry -> {
+                                Material material = Material.matchMaterial(blockEntry.getKey());
+                                return material != null ? Stream.of(new AbstractMap.SimpleEntry<>(material, blockEntry.getValue())) : Stream.empty();
+                            })
+                            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue))
                     )),
-                    stats.blockStats().entrySet().stream().collect(Collectors.toMap(
-                            entry -> matchStatistic(entry.getKey()),
-                            entry -> entry.getValue().entrySet().stream().collect(Collectors.toMap(
-                                    blockEntry -> Material.matchMaterial(blockEntry.getKey()),
-                                    Map.Entry::getValue
-                            ))
+                stats.itemStats().entrySet().stream()
+                    .flatMap(entry -> {
+                        Statistic statistic = matchStatistic(entry.getKey());
+                        return statistic != null ? Stream.of(new AbstractMap.SimpleEntry<>(statistic, entry.getValue())) : Stream.empty();
+                    })
+                    .collect(Collectors.toMap(
+                        Map.Entry::getKey,
+                        entry -> entry.getValue().entrySet().stream()
+                            .flatMap(itemEntry -> {
+                                Material material = Material.matchMaterial(itemEntry.getKey());
+                                return material != null ? Stream.of(new AbstractMap.SimpleEntry<>(material, itemEntry.getValue())) : Stream.empty();
+                            })
+                            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue))
                     )),
-                    stats.itemStats().entrySet().stream().collect(Collectors.toMap(
-                            entry -> matchStatistic(entry.getKey()),
-                            entry -> entry.getValue().entrySet().stream().collect(Collectors.toMap(
-                                    itemEntry -> Material.matchMaterial(itemEntry.getKey()),
-                                    Map.Entry::getValue
-                            ))
-                    )),
-                    stats.entityStats().entrySet().stream().collect(Collectors.toMap(
-                            entry -> matchStatistic(entry.getKey()),
-                            entry -> entry.getValue().entrySet().stream().collect(Collectors.toMap(
-                                    entityEntry -> matchEntityType(entityEntry.getKey()),
-                                    Map.Entry::getValue
-                            ))
+                stats.entityStats().entrySet().stream()
+                    .flatMap(entry -> {
+                        Statistic statistic = matchStatistic(entry.getKey());
+                        return statistic != null ? Stream.of(new AbstractMap.SimpleEntry<>(statistic, entry.getValue())) : Stream.empty();
+                    })
+                    .collect(Collectors.toMap(
+                        Map.Entry::getKey,
+                        entry -> entry.getValue().entrySet().stream()
+                            .flatMap(itemEntry -> {
+                                EntityType entityType = matchEntityType(itemEntry.getKey());
+                                return entityType != null ? Stream.of(new AbstractMap.SimpleEntry<>(entityType, itemEntry.getValue())) : Stream.empty();
+                            })
+                            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue))
                     ))
             );
         }
@@ -633,20 +661,18 @@ public abstract class BukkitData implements Data {
             return new StatisticsMap(genericStats, blockStats, itemStats, entityStats);
         }
 
-        @NotNull
+        @Nullable
         private static Statistic matchStatistic(@NotNull String key) {
             return Arrays.stream(Statistic.values())
                     .filter(stat -> stat.getKey().toString().equals(key))
-                    .findFirst()
-                    .orElseThrow(() -> new IllegalArgumentException(String.format("Invalid statistic key: %s", key)));
+                    .findFirst().orElse(null);
         }
 
-        @NotNull
+        @Nullable
         private static EntityType matchEntityType(@NotNull String key) {
             return Arrays.stream(EntityType.values())
                     .filter(entityType -> entityType.getKey().toString().equals(key))
-                    .findFirst()
-                    .orElseThrow(() -> new IllegalArgumentException(String.format("Invalid entity type key: %s", key)));
+                    .findFirst().orElse(null);
         }
 
         @Override
@@ -708,7 +734,13 @@ public abstract class BukkitData implements Data {
         private <T extends Keyed> Map<String, Integer> convertStatistics(@NotNull Map<T, Integer> stats) {
             return stats.entrySet().stream().filter(entry -> entry.getKey() != null).collect(
                     TreeMap::new,
-                    (m, e) -> m.put(e.getKey().getKey().toString(), e.getValue()), TreeMap::putAll
+                    (m, e) -> {
+                        try {
+                            m.put(e.getKey().getKey().toString(), e.getValue());
+                        } catch (Throwable t) {
+                            // Ignore; skip elements with invalid keys (e.g., legacy materials)
+                        }
+                    }, TreeMap::putAll
             );
         }
 

bukkit/src/main/java/net/william278/husksync/listener/BukkitEventListener.java

@@ -43,6 +43,7 @@ import org.bukkit.event.player.PlayerCommandPreprocessEvent;
 import org.bukkit.event.player.PlayerDropItemEvent;
 import org.bukkit.event.player.PlayerInteractEntityEvent;
 import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.event.server.MapInitializeEvent;
 import org.bukkit.event.world.WorldSaveEvent;
 import org.jetbrains.annotations.NotNull;
 
@@ -115,6 +116,13 @@ public class BukkitEventListener extends EventListener implements BukkitJoinEven
                 .collect(Collectors.toList())));
     }
 
+    @EventHandler(ignoreCancelled = true)
+    public void onMapInitialize(@NotNull MapInitializeEvent event) {
+        if (plugin.getSettings().doPersistLockedMaps() && event.getMap().isLocked()) {
+            getPlugin().runAsync(() -> ((BukkitHuskSync) plugin).renderMapFromFile(event.getMap()));
+        }
+    }
+
 
     /*
      * Events to cancel if the player has not been set yet

bukkit/src/main/java/net/william278/husksync/migrator/LegacyMigrator.java

@@ -217,16 +217,16 @@ public class LegacyMigrator extends Migrator {
     @NotNull
     @Override
     public String getName() {
-        return "HuskSync v1.x --> v2.x Migrator";
+        return "HuskSync v1.x --> v3.x Migrator";
     }
 
     @NotNull
     @Override
     public String getHelpMenu() {
         return """
-                === HuskSync v1.x --> v2.x Migration Wizard =========
+                === HuskSync v1.x --> v3.x Migration Wizard =========
                 This will migrate all user data from HuskSync v1.x to
-                HuskSync v2.x's new format. To perform the migration,
+                HuskSync v3.x's new format. To perform the migration,
                 please follow the steps below carefully.
 
                 [!] Existing data in the database will be wiped. [!]

bukkit/src/main/java/net/william278/husksync/migrator/MpdbMigrator.java

@@ -221,6 +221,9 @@ public class MpdbMigrator extends Migrator {
     public String getHelpMenu() {
         return """
                 === MySQLPlayerDataBridge Migration Wizard ==========
+                NOTE: This migrator currently WORKS WITH MPDB version
+                v4.9.2 and below!
+                
                 This will migrate inventories, ender chests and XP
                 from the MySQLPlayerDataBridge plugin to HuskSync.
 
@@ -254,6 +257,9 @@ public class MpdbMigrator extends Migrator {
 
                 STEP 4] To start the migration, please run:
                 "husksync migrate mpdb start"
+                
+                NOTE: This migrator currently WORKS WITH MPDB version
+                v4.9.2 and below!
                 """.replaceAll(Pattern.quote("%source_host%"), obfuscateDataString(sourceHost))
                 .replaceAll(Pattern.quote("%source_port%"), Integer.toString(sourcePort))
                 .replaceAll(Pattern.quote("%source_username%"), obfuscateDataString(sourceUsername))

bukkit/src/main/java/net/william278/husksync/util/BukkitMapPersister.java

@@ -22,6 +22,8 @@ package net.william278.husksync.util;
 import de.tr7zw.changeme.nbtapi.NBT;
 import de.tr7zw.changeme.nbtapi.iface.ReadWriteNBT;
 import de.tr7zw.changeme.nbtapi.iface.ReadableNBT;
+import net.querz.nbt.io.NBTUtil;
+import net.querz.nbt.tag.CompoundTag;
 import net.william278.husksync.HuskSync;
 import net.william278.mapdataapi.MapBanner;
 import net.william278.mapdataapi.MapData;
@@ -36,6 +38,7 @@ import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 import java.awt.*;
+import java.io.File;
 import java.util.List;
 import java.util.*;
 import java.util.function.Function;
@@ -175,11 +178,12 @@ public interface BukkitMapPersister {
                 return;
             }
 
-            // Add a renderer to the map with the data
+            // Add a renderer to the map with the data and save to file
             final MapView view = generateRenderedMap(canvasData);
             final String worldUid = getDefaultMapWorld().getUID().toString();
             meta.setMapView(view);
             map.setItemMeta(meta);
+            saveMapToFile(canvasData, view.getId());
 
             // Set the map view ID in NBT
             NBT.modify(map, editable -> {
@@ -192,6 +196,58 @@ public interface BukkitMapPersister {
         return map;
     }
 
+    default void renderMapFromFile(@NotNull MapView view) {
+        final File mapFile = new File(getMapCacheFolder(), view.getId() + ".dat");
+        if (!mapFile.exists()) {
+            return;
+        }
+
+        final MapData canvasData;
+        try {
+            canvasData = MapData.fromNbt(mapFile);
+        } catch (Throwable e) {
+            getPlugin().log(Level.WARNING, "Failed to deserialize map data from file", e);
+            return;
+        }
+
+        // Create a new map view renderer with the map data color at each pixel
+        view.getRenderers().clear();
+        view.addRenderer(new PersistentMapRenderer(canvasData));
+        view.setLocked(true);
+        view.setScale(MapView.Scale.NORMAL);
+        view.setTrackingPosition(false);
+        view.setUnlimitedTracking(false);
+
+        // Set the view to the map
+        setMapView(view);
+    }
+
+    default void saveMapToFile(@NotNull MapData data, int id) {
+        getPlugin().runAsync(() -> {
+            final File mapFile = new File(getMapCacheFolder(), id + ".dat");
+            if (mapFile.exists()) {
+                return;
+            }
+
+            try {
+                final CompoundTag rootTag = new CompoundTag();
+                rootTag.put("data", data.toNBT().getTag());
+                NBTUtil.write(rootTag, mapFile);
+            } catch (Throwable e) {
+                getPlugin().log(Level.WARNING, "Failed to serialize map data to file", e);
+            }
+        });
+    }
+
+    @NotNull
+    private File getMapCacheFolder() {
+        final File mapCache = new File(getPlugin().getDataFolder(), "maps");
+        if (!mapCache.exists() && !mapCache.mkdirs()) {
+            getPlugin().log(Level.WARNING, "Failed to create maps folder");
+        }
+        return mapCache;
+    }
+
     // Sets the renderer of a map, and returns the generated MapView
     @NotNull
     private MapView generateRenderedMap(@NotNull MapData canvasData) {

common/build.gradle

@@ -3,7 +3,7 @@ plugins {
 }
 
 dependencies {
-    api 'commons-io:commons-io:2.13.0'
+    api 'commons-io:commons-io:2.14.0'
     api 'org.apache.commons:commons-text:1.10.0'
     api 'de.themoep:minedown-adventure:1.7.2-SNAPSHOT'
     api 'net.kyori:adventure-api:4.14.0'

common/src/main/java/net/william278/husksync/HuskSync.java

@@ -28,6 +28,7 @@ import net.william278.desertwell.util.UpdateChecker;
 import net.william278.desertwell.util.Version;
 import net.william278.husksync.adapter.DataAdapter;
 import net.william278.husksync.config.Locales;
+import net.william278.husksync.config.Server;
 import net.william278.husksync.config.Settings;
 import net.william278.husksync.data.Data;
 import net.william278.husksync.data.Identifier;
@@ -36,6 +37,7 @@ import net.william278.husksync.database.Database;
 import net.william278.husksync.event.EventDispatcher;
 import net.william278.husksync.migrator.Migrator;
 import net.william278.husksync.redis.RedisManager;
+import net.william278.husksync.sync.DataSyncer;
 import net.william278.husksync.user.ConsoleUser;
 import net.william278.husksync.user.OnlineUser;
 import net.william278.husksync.util.LegacyConverter;
@@ -90,6 +92,11 @@ public interface HuskSync extends Task.Supplier, EventDispatcher {
     @NotNull
     RedisManager getRedisManager();
 
+    /**
+     * Returns the implementing adapter for serializing data
+     *
+     * @return the {@link DataAdapter}
+     */
     @NotNull
     DataAdapter getDataAdapter();
 
@@ -130,6 +137,21 @@ public interface HuskSync extends Task.Supplier, EventDispatcher {
         return getSerializers().keySet();
     }
 
+    /**
+     * Returns the data syncer implementation
+     *
+     * @return the {@link DataSyncer} implementation
+     */
+    @NotNull
+    DataSyncer getDataSyncer();
+
+    /**
+     * Set the data syncer implementation
+     *
+     * @param dataSyncer the {@link DataSyncer} implementation
+     */
+    void setDataSyncer(@NotNull DataSyncer dataSyncer);
+
     /**
      * Returns a list of available data {@link Migrator}s
      *
@@ -167,6 +189,11 @@ public interface HuskSync extends Task.Supplier, EventDispatcher {
 
     void setSettings(@NotNull Settings settings);
 
+    @NotNull
+    String getServerName();
+
+    void setServer(@NotNull Server server);
+
     /**
      * Returns the plugin {@link Locales}
      *
@@ -255,7 +282,7 @@ public interface HuskSync extends Task.Supplier, EventDispatcher {
     String getPlatformType();
 
     /**
-     * Returns the legacy data converter, if it exists
+     * Returns the legacy data converter if it exists
      *
      * @return the {@link LegacyConverter}
      */
@@ -267,7 +294,16 @@ public interface HuskSync extends Task.Supplier, EventDispatcher {
     default void loadConfigs() {
         try {
             // Load settings
-            setSettings(Annotaml.create(new File(getDataFolder(), "config.yml"), Settings.class).get());
+            setSettings(Annotaml.create(
+                    new File(getDataFolder(), "config.yml"),
+                    Settings.class
+            ).get());
+
+            // Load server name
+            setServer(Annotaml.create(
+                    new File(getDataFolder(), "server.yml"),
+                    Server.getDefault(this)
+            ).get());
 
             // Load locales from language preset default
             final Locales languagePresets = Annotaml.create(
@@ -305,12 +341,31 @@ public interface HuskSync extends Task.Supplier, EventDispatcher {
         }
     }
 
+    /**
+     * Get the set of UUIDs of "locked players", for which events will be canceled.
+     * </p>
+     * Players are locked while their items are being set (on join) or saved (on quit)
+     */
     @NotNull
     Set<UUID> getLockedPlayers();
 
+    default boolean isLocked(@NotNull UUID uuid) {
+        return getLockedPlayers().contains(uuid);
+    }
+
+    default void lockPlayer(@NotNull UUID uuid) {
+        getLockedPlayers().add(uuid);
+    }
+
+    default void unlockPlayer(@NotNull UUID uuid) {
+        getLockedPlayers().remove(uuid);
+    }
+
     @NotNull
     Gson getGson();
 
+    boolean isDisabling();
+
     @NotNull
     default Gson createGson() {
         return Converters.registerOffsetDateTime(new GsonBuilder()).create();

common/src/main/java/net/william278/husksync/api/HuskSyncAPI.java

@@ -26,6 +26,7 @@ import net.william278.husksync.data.Data;
 import net.william278.husksync.data.DataSnapshot;
 import net.william278.husksync.data.Identifier;
 import net.william278.husksync.data.Serializer;
+import net.william278.husksync.sync.DataSyncer;
 import net.william278.husksync.user.OnlineUser;
 import net.william278.husksync.user.User;
 import org.jetbrains.annotations.ApiStatus;
@@ -404,6 +405,7 @@ public abstract class HuskSyncAPI {
      * @param <T>        The type of the element
      * @return The deserialized element
      * @throws Serializer.DeserializationException If the element could not be deserialized
+     * @since 3.0
      */
     @NotNull
     public <T extends Adaptable> T deserializeData(@NotNull String serialized, Class<T> type)
@@ -418,6 +420,7 @@ public abstract class HuskSyncAPI {
      * @param <T>     The type of the element
      * @return The serialized JSON string
      * @throws Serializer.SerializationException If the element could not be serialized
+     * @since 3.0
      */
     @NotNull
     public <T extends Adaptable> String serializeData(@NotNull T element)
@@ -425,6 +428,16 @@ public abstract class HuskSyncAPI {
         return plugin.getDataAdapter().toJson(element);
     }
 
+    /**
+     * Set the {@link DataSyncer} to be used to sync data
+     *
+     * @param syncer The data syncer to use for synchronizing user data
+     * @since 3.1
+     */
+    public void setDataSyncer(@NotNull DataSyncer syncer) {
+        plugin.setDataSyncer(syncer);
+    }
+
     /**
      * <b>(Internal use only)</b> - Get the plugin instance
      *

common/src/main/java/net/william278/husksync/config/Locales.java

@@ -40,7 +40,7 @@ import java.util.Optional;
         ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
         ┣╸ See plugin about menu for international locale credits
         ┣╸ Formatted in MineDown: https://github.com/Phoenix616/MineDown
-        ┗╸ Translate HuskSync: https://william278.net/docs/husksync/Translations""")
+        ┗╸ Translate HuskSync: https://william278.net/docs/husksync/translations""")
 public class Locales {
 
     /**

common/src/main/java/net/william278/husksync/config/Server.java

@@ -0,0 +1,99 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync.config;
+
+import net.william278.annotaml.Annotaml;
+import net.william278.annotaml.YamlFile;
+import net.william278.annotaml.YamlKey;
+import net.william278.husksync.HuskSync;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.nio.file.Path;
+import java.util.List;
+
+/**
+ * Represents a server on a proxied network.
+ */
+@YamlFile(header = """
+        ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
+        ┃   HuskSync Server ID config  ┃
+        ┃    Developed by William278   ┃
+        ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
+        ┣╸ This file should contain the ID of this server as defined in your proxy config.
+        ┗╸ If you join it using /server alpha, then set it to 'alpha' (case-sensitive)""")
+public class Server {
+
+    @YamlKey("name")
+    private String serverName;
+
+    private Server(@NotNull String serverName) {
+        this.serverName = serverName;
+    }
+
+    @SuppressWarnings("unused")
+    private Server() {
+    }
+
+    @NotNull
+    public static Server getDefault(@NotNull HuskSync plugin) {
+        return new Server(getDefaultServerName(plugin));
+    }
+
+    /**
+     * Find a sensible default name for the server name property
+     */
+    @NotNull
+    private static String getDefaultServerName(@NotNull HuskSync plugin) {
+        try {
+            // Fetch server default from supported plugins if present
+            for (String s : List.of("HuskHomes", "HuskTowns")) {
+                final File serverFile = Path.of(plugin.getDataFolder().getParent(), s, "server.yml").toFile();
+                if (serverFile.exists()) {
+                    return Annotaml.create(serverFile, Server.class).get().getName();
+                }
+            }
+
+            // Fetch server default from user dir name
+            final Path serverDirectory = Path.of(System.getProperty("user.dir"));
+            return serverDirectory.getFileName().toString().trim();
+        } catch (Throwable e) {
+            return "server";
+        }
+    }
+
+    @Override
+    public boolean equals(@NotNull Object other) {
+        // If the name of this server matches another, the servers are the same.
+        if (other instanceof Server server) {
+            return server.getName().equalsIgnoreCase(this.getName());
+        }
+        return super.equals(other);
+    }
+
+    /**
+     * Proxy-defined name of this server.
+     */
+    @NotNull
+    public String getName() {
+        return serverName;
+    }
+
+}

common/src/main/java/net/william278/husksync/config/Settings.java

@@ -26,6 +26,7 @@ import net.william278.husksync.data.DataSnapshot;
 import net.william278.husksync.data.Identifier;
 import net.william278.husksync.database.Database;
 import net.william278.husksync.listener.EventListener;
+import net.william278.husksync.sync.DataSyncer;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
@@ -44,7 +45,7 @@ import java.util.*;
 public class Settings {
 
     // Top-level settings
-    @YamlComment("Locale of the default language file to use. Docs: https://william278.net/docs/huskhomes/translations")
+    @YamlComment("Locale of the default language file to use. Docs: https://william278.net/docs/husksync/translations")
     @YamlKey("language")
     private String language = "en-gb";
 
@@ -135,6 +136,11 @@ public class Settings {
 
 
     // Synchronization settings
+    @YamlComment("The mode of data synchronization to use (DELAY or LOCKSTEP). DELAY should be fine for most networks."
+            + " Docs: https://william278.net/docs/husksync/sync-modes")
+    @YamlKey("synchronization.mode")
+    private DataSyncer.Mode syncMode = DataSyncer.Mode.DELAY;
+
     @YamlComment("The number of data snapshot backups that should be kept at once per user")
     @YamlKey("synchronization.max_user_data_snapshots")
     private int maxUserDataSnapshots = 16;
@@ -150,7 +156,6 @@ public class Settings {
             DataSnapshot.SaveCause.INVENTORY_COMMAND.name(),
             DataSnapshot.SaveCause.ENDERCHEST_COMMAND.name(),
             DataSnapshot.SaveCause.BACKUP_RESTORE.name(),
-            DataSnapshot.SaveCause.CONVERTED_FROM_V2.name(),
             DataSnapshot.SaveCause.LEGACY_MIGRATION.name(),
             DataSnapshot.SaveCause.MPDB_MIGRATION.name()
     );
@@ -160,12 +165,21 @@ public class Settings {
     private boolean saveOnWorldSave = true;
 
     @YamlComment("Whether to create a snapshot for users when they die (containing their death drops)")
-    @YamlKey("synchronization.save_on_death")
+    @YamlKey("synchronization.save_on_death.enabled")
     private boolean saveOnDeath = false;
 
-    @YamlComment("Whether to save empty death drops for users when they die")
-    @YamlKey("synchronization.save_empty_drops_on_death")
-    private boolean saveEmptyDropsOnDeath = true;
+    @YamlComment("What items to save in death snapshots? (DROPS or ITEMS_TO_KEEP). "
+            + " Note that ITEMS_TO_KEEP (suggested for keepInventory servers) requires a Paper 1.19.4+ server.")
+    @YamlKey("synchronization.save_on_death.items_to_save")
+    private DeathItemsMode deathItemsMode = DeathItemsMode.DROPS;
+
+    @YamlComment("Should a death snapshot still be created even if the items to save on the player's death are empty?")
+    @YamlKey("synchronization.save_on_death.save_empty_items")
+    private boolean saveEmptyDeathItems = true;
+
+    @YamlComment("Whether dead players who log out and log in to a different server should have their items saved.")
+    @YamlKey("synchronization.save_on_death.sync_dead_players_changing_server")
+    private boolean synchronizeDeadPlayersChangingServer = true;
 
     @YamlComment("Whether to use the snappy data compression algorithm. Keep on unless you know what you're doing")
     @YamlKey("synchronization.compress_data")
@@ -183,12 +197,7 @@ public class Settings {
     @YamlKey("synchronization.synchronize_max_health")
     private boolean synchronizeMaxHealth = true;
 
-    @YamlComment("Whether dead players who log out and log in to a different server should have their items saved. "
-            + "You may need to modify this if you're using the keepInventory gamerule.")
-    @YamlKey("synchronization.synchronize_dead_players_changing_server")
-    private boolean synchronizeDeadPlayersChangingServer = true;
-
-    @YamlComment("How long, in milliseconds, this server should wait for a response from the redis server before "
+    @YamlComment("If using the DELAY sync method, how long should this server listen for Redis key data updates before "
             + "pulling data from the database instead (i.e., if the user did not change servers).")
     @YamlKey("synchronization.network_latency_milliseconds")
     private int networkLatencyMilliseconds = 500;
@@ -315,6 +324,11 @@ public class Settings {
         return redisUseSsl;
     }
 
+    @NotNull
+    public DataSyncer.Mode getSyncMode() {
+        return syncMode;
+    }
+
     public int getMaxUserDataSnapshots() {
         return maxUserDataSnapshots;
     }
@@ -331,8 +345,13 @@ public class Settings {
         return saveOnDeath;
     }
 
-    public boolean doSaveEmptyDropsOnDeath() {
-        return saveEmptyDropsOnDeath;
+    @NotNull
+    public DeathItemsMode getDeathItemsMode() {
+        return deathItemsMode;
+    }
+
+    public boolean doSaveEmptyDeathItems() {
+        return saveEmptyDeathItems;
     }
 
     public boolean doCompressData() {
@@ -387,6 +406,14 @@ public class Settings {
         }
     }
 
+    /**
+     * Represents the mode of saving items on death
+     */
+    public enum DeathItemsMode {
+        DROPS,
+        ITEMS_TO_KEEP
+    }
+
     /**
      * Represents the names of tables in the database
      */

common/src/main/java/net/william278/husksync/data/DataSnapshot.java

@@ -45,9 +45,9 @@ public class DataSnapshot {
 
     /*
      * Current version of the snapshot data format.
-     * HuskSync v3.0 uses v4; HuskSync v2.0 uses v1-v3
+     * HuskSync v3.1 uses v5, v3.0 uses v4; v2.0 uses v1-v3
      */
-    protected static final int CURRENT_FORMAT_VERSION = 4;
+    protected static final int CURRENT_FORMAT_VERSION = 5;
 
     @SerializedName("id")
     protected UUID id;
@@ -61,6 +61,9 @@ public class DataSnapshot {
     @SerializedName("save_cause")
     protected SaveCause saveCause;
 
+    @SerializedName("server_name")
+    protected String serverName;
+
     @SerializedName("minecraft_version")
     protected String minecraftVersion;
 
@@ -74,12 +77,13 @@ public class DataSnapshot {
     protected Map<String, String> data;
 
     private DataSnapshot(@NotNull UUID id, boolean pinned, @NotNull OffsetDateTime timestamp,
-                         @NotNull SaveCause saveCause, @NotNull Map<String, String> data,
+                         @NotNull SaveCause saveCause, @NotNull String serverName, @NotNull Map<String, String> data,
                          @NotNull Version minecraftVersion, @NotNull String platformType, int formatVersion) {
         this.id = id;
         this.pinned = pinned;
         this.timestamp = timestamp;
         this.saveCause = saveCause;
+        this.serverName = serverName;
         this.data = data;
         this.minecraftVersion = minecraftVersion.toStringWithoutMetadata();
         this.platformType = platformType;
@@ -114,7 +118,7 @@ public class DataSnapshot {
                             "Please ensure each server is running the latest version of HuskSync.",
                     snapshot.getFormatVersion(), CURRENT_FORMAT_VERSION));
         }
-        if (snapshot.getFormatVersion() < CURRENT_FORMAT_VERSION) {
+        if (snapshot.getFormatVersion() < 4) {
             if (plugin.getLegacyConverter().isPresent()) {
                 return plugin.getLegacyConverter().get().convert(
                         data,
@@ -195,13 +199,26 @@ public class DataSnapshot {
         return saveCause;
     }
 
+    /**
+     * Get the server the snapshot was created on.
+     * <p>
+     * Note that snapshots generated before v3.1 will return {@code "N/A"}
+     *
+     * @return The server name
+     * @since 3.1
+     */
+    @NotNull
+    public String getServerName() {
+        return Optional.ofNullable(serverName).orElse("N/A");
+    }
+
     /**
      * Set why the snapshot was created
      *
      * @param saveCause The {@link SaveCause data save cause} of the snapshot
      * @since 3.0
      */
-    public void setSaveCause(SaveCause saveCause) {
+    public void setSaveCause(@NotNull SaveCause saveCause) {
         this.saveCause = saveCause;
     }
 
@@ -256,9 +273,9 @@ public class DataSnapshot {
     public static class Packed extends DataSnapshot implements Adaptable {
 
         protected Packed(@NotNull UUID id, boolean pinned, @NotNull OffsetDateTime timestamp,
-                         @NotNull SaveCause saveCause, @NotNull Map<String, String> data,
+                         @NotNull SaveCause saveCause, @NotNull String serverName, @NotNull Map<String, String> data,
                          @NotNull Version minecraftVersion, @NotNull String platformType, int formatVersion) {
-            super(id, pinned, timestamp, saveCause, data, minecraftVersion, platformType, formatVersion);
+            super(id, pinned, timestamp, saveCause, serverName, data, minecraftVersion, platformType, formatVersion);
         }
 
         @SuppressWarnings("unused")
@@ -282,8 +299,8 @@ public class DataSnapshot {
         @NotNull
         public Packed copy() {
             return new Packed(
-                    UUID.randomUUID(), pinned, OffsetDateTime.now(), saveCause, data,
-                    getMinecraftVersion(), platformType, formatVersion
+                    UUID.randomUUID(), pinned, OffsetDateTime.now(), saveCause, serverName,
+                    data, getMinecraftVersion(), platformType, formatVersion
             );
         }
 
@@ -307,7 +324,7 @@ public class DataSnapshot {
         @NotNull
         public DataSnapshot.Unpacked unpack(@NotNull HuskSync plugin) {
             return new Unpacked(
-                    id, pinned, timestamp, saveCause, data,
+                    id, pinned, timestamp, saveCause, serverName, data,
                     getMinecraftVersion(), platformType, formatVersion, plugin
             );
         }
@@ -325,17 +342,17 @@ public class DataSnapshot {
         private final Map<Identifier, Data> deserialized;
 
         private Unpacked(@NotNull UUID id, boolean pinned, @NotNull OffsetDateTime timestamp,
-                         @NotNull SaveCause saveCause, @NotNull Map<String, String> data,
+                         @NotNull SaveCause saveCause, @NotNull String serverName, @NotNull Map<String, String> data,
                          @NotNull Version minecraftVersion, @NotNull String platformType, int formatVersion,
                          @NotNull HuskSync plugin) {
-            super(id, pinned, timestamp, saveCause, data, minecraftVersion, platformType, formatVersion);
+            super(id, pinned, timestamp, saveCause, serverName, data, minecraftVersion, platformType, formatVersion);
             this.deserialized = deserializeData(plugin);
         }
 
         private Unpacked(@NotNull UUID id, boolean pinned, @NotNull OffsetDateTime timestamp,
-                         @NotNull SaveCause saveCause, @NotNull Map<Identifier, Data> data,
+                         @NotNull SaveCause saveCause, @NotNull String serverName, @NotNull Map<Identifier, Data> data,
                          @NotNull Version minecraftVersion, @NotNull String platformType, int formatVersion) {
-            super(id, pinned, timestamp, saveCause, Map.of(), minecraftVersion, platformType, formatVersion);
+            super(id, pinned, timestamp, saveCause, serverName, Map.of(), minecraftVersion, platformType, formatVersion);
             this.deserialized = data;
         }
 
@@ -384,7 +401,7 @@ public class DataSnapshot {
         @ApiStatus.Internal
         public DataSnapshot.Packed pack(@NotNull HuskSync plugin) {
             return new DataSnapshot.Packed(
-                    id, pinned, timestamp, saveCause, serializeData(plugin),
+                    id, pinned, timestamp, saveCause, serverName, serializeData(plugin),
                     getMinecraftVersion(), platformType, formatVersion
             );
         }
@@ -402,6 +419,7 @@ public class DataSnapshot {
         private final HuskSync plugin;
         private UUID id;
         private SaveCause saveCause;
+        private String serverName;
         private boolean pinned;
         private OffsetDateTime timestamp;
         private final Map<Identifier, Data> data;
@@ -412,6 +430,7 @@ public class DataSnapshot {
             this.data = new HashMap<>();
             this.timestamp = OffsetDateTime.now();
             this.id = UUID.randomUUID();
+            this.serverName = plugin.getServerName();
         }
 
         /**
@@ -441,6 +460,19 @@ public class DataSnapshot {
             return this;
         }
 
+        /**
+         * Set the name of the server where this snapshot was created
+         *
+         * @param serverName The server name
+         * @return The builder
+         * @since 3.1
+         */
+        @NotNull
+        public Builder serverName(@NotNull String serverName) {
+            this.serverName = serverName;
+            return this;
+        }
+
         /**
          * Set whether the data should be pinned
          *
@@ -686,6 +718,7 @@ public class DataSnapshot {
                     pinned || plugin.getSettings().doAutoPin(saveCause),
                     timestamp,
                     saveCause,
+                    serverName,
                     data,
                     plugin.getMinecraftVersion(),
                     plugin.getPlatformType(),

common/src/main/java/net/william278/husksync/listener/EventListener.java

@@ -23,13 +23,12 @@ import net.william278.husksync.HuskSync;
 import net.william278.husksync.data.Data;
 import net.william278.husksync.data.DataSnapshot;
 import net.william278.husksync.user.OnlineUser;
-import net.william278.husksync.util.Task;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.*;
-import java.util.concurrent.atomic.AtomicLong;
-import java.util.concurrent.atomic.AtomicReference;
-import java.util.logging.Level;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
 
 /**
  * Handles what should happen when events are fired
@@ -39,22 +38,8 @@ public abstract class EventListener {
     // The plugin instance
     protected final HuskSync plugin;
 
-    /**
-     * Set of UUIDs of "locked players", for which events will be canceled.
-     * </p>
-     * Players are locked while their items are being set (on join) or saved (on quit)
-     */
-    private final Set<UUID> lockedPlayers;
-
-    /**
-     * Whether the plugin is currently being disabled
-     */
-    private boolean disabling;
-
     protected EventListener(@NotNull HuskSync plugin) {
         this.plugin = plugin;
-        this.lockedPlayers = new HashSet<>();
-        this.disabling = false;
     }
 
     /**
@@ -66,51 +51,8 @@ public abstract class EventListener {
         if (user.isNpc()) {
             return;
         }
-        lockedPlayers.add(user.getUuid());
-
-        plugin.runAsyncDelayed(() -> {
-            // Fetch from the database if the user isn't changing servers
-            if (!plugin.getRedisManager().getUserServerSwitch(user)) {
-                this.setUserFromDatabase(user);
-                return;
-            }
-
-            // Set the user as soon as the source server has set the data to redis
-            final long MAX_ATTEMPTS = 16L;
-            final AtomicLong timesRun = new AtomicLong(0L);
-            final AtomicReference<Task.Repeating> task = new AtomicReference<>();
-            final Runnable runnable = () -> {
-                if (user.isOffline()) {
-                    task.get().cancel();
-                    return;
-                }
-                if (disabling || timesRun.getAndIncrement() > MAX_ATTEMPTS) {
-                    task.get().cancel();
-                    this.setUserFromDatabase(user);
-                    return;
-                }
-
-                plugin.getRedisManager().getUserData(user).ifPresent(redisData -> {
-                    task.get().cancel();
-                    user.applySnapshot(redisData, DataSnapshot.UpdateCause.SYNCHRONIZED);
-                });
-            };
-            task.set(plugin.getRepeatingTask(runnable, 10));
-            task.get().run();
-
-        }, Math.max(0, plugin.getSettings().getNetworkLatencyMilliseconds() / 50L));
-    }
-
-    /**
-     * Set a user's data from the database
-     *
-     * @param user The user to set the data for
-     */
-    private void setUserFromDatabase(@NotNull OnlineUser user) {
-        plugin.getDatabase().getLatestSnapshot(user).ifPresentOrElse(
-                snapshot -> user.applySnapshot(snapshot, DataSnapshot.UpdateCause.SYNCHRONIZED),
-                () -> user.completeSync(true, DataSnapshot.UpdateCause.NEW_USER, plugin)
-        );
+        plugin.lockPlayer(user.getUuid());
+        plugin.getDataSyncer().setUserData(user);
     }
 
     /**
@@ -119,27 +61,11 @@ public abstract class EventListener {
      * @param user The {@link OnlineUser} to handle
      */
     protected final void handlePlayerQuit(@NotNull OnlineUser user) {
-        // Players quitting have their data manually saved when the plugin is disabled
-        if (disabling) {
+        if (user.isNpc() || plugin.isDisabling() || plugin.isLocked(user.getUuid())) {
             return;
         }
-
-        // Don't sync players awaiting synchronization
-        if (lockedPlayers.contains(user.getUuid()) || user.isNpc()) {
-            return;
-        }
-
-        // Handle disconnection
-        try {
-            lockedPlayers.add(user.getUuid());
-            plugin.getRedisManager().setUserServerSwitch(user).thenRun(() -> {
-                final DataSnapshot.Packed data = user.createSnapshot(DataSnapshot.SaveCause.DISCONNECT);
-                plugin.getRedisManager().setUserData(user, data);
-                plugin.getDatabase().addSnapshot(user, data);
-            });
-        } catch (Throwable e) {
-            plugin.log(Level.SEVERE, "An exception occurred handling a player disconnection", e);
-        }
+        plugin.lockPlayer(user.getUuid());
+        plugin.runAsync(() -> plugin.getDataSyncer().saveUserData(user));
     }
 
     /**
@@ -148,11 +74,11 @@ public abstract class EventListener {
      * @param usersInWorld a list of users in the world that is being saved
      */
     protected final void saveOnWorldSave(@NotNull List<OnlineUser> usersInWorld) {
-        if (disabling || !plugin.getSettings().doSaveOnWorldSave()) {
+        if (plugin.isDisabling() || !plugin.getSettings().doSaveOnWorldSave()) {
             return;
         }
         usersInWorld.stream()
-                .filter(user -> !lockedPlayers.contains(user.getUuid()) && !user.isNpc())
+                .filter(user -> !plugin.isLocked(user.getUuid()) && !user.isNpc())
                 .forEach(user -> plugin.getDatabase().addSnapshot(
                         user, user.createSnapshot(DataSnapshot.SaveCause.WORLD_SAVE)
                 ));
@@ -162,16 +88,16 @@ public abstract class EventListener {
      * Handles the saving of data when a player dies
      *
      * @param user  The user who died
-     * @param drops The items that this user would have dropped
+     * @param items The items that should be saved for this user on their death
      */
-    protected void saveOnPlayerDeath(@NotNull OnlineUser user, @NotNull Data.Items drops) {
-        if (disabling || !plugin.getSettings().doSaveOnDeath() || lockedPlayers.contains(user.getUuid()) || user.isNpc()
-                || (!plugin.getSettings().doSaveEmptyDropsOnDeath() && drops.isEmpty())) {
+    protected void saveOnPlayerDeath(@NotNull OnlineUser user, @NotNull Data.Items items) {
+        if (plugin.isDisabling() || !plugin.getSettings().doSaveOnDeath() || plugin.isLocked(user.getUuid())
+                || user.isNpc() || (!plugin.getSettings().doSaveEmptyDeathItems() && items.isEmpty())) {
             return;
         }
 
         final DataSnapshot.Packed snapshot = user.createSnapshot(DataSnapshot.SaveCause.DEATH);
-        snapshot.edit(plugin, (data -> data.getInventory().ifPresent(inventory -> inventory.setContents(drops))));
+        snapshot.edit(plugin, (data -> data.getInventory().ifPresent(inventory -> inventory.setContents(items))));
         plugin.getDatabase().addSnapshot(user, snapshot);
     }
 
@@ -182,20 +108,18 @@ public abstract class EventListener {
      * @return Whether the event should be canceled
      */
     protected final boolean cancelPlayerEvent(@NotNull UUID userUuid) {
-        return disabling || lockedPlayers.contains(userUuid);
+        return plugin.isDisabling() || plugin.isLocked(userUuid);
     }
 
     /**
      * Handle the plugin disabling
      */
     public final void handlePluginDisable() {
-        disabling = true;
-
-        // Save data for all online users
+        // Save for all online players
         plugin.getOnlineUsers().stream()
-                .filter(user -> !lockedPlayers.contains(user.getUuid()) && !user.isNpc())
+                .filter(user -> !plugin.isLocked(user.getUuid()) && !user.isNpc())
                 .forEach(user -> {
-                    lockedPlayers.add(user.getUuid());
+                    plugin.lockPlayer(user.getUuid());
                     plugin.getDatabase().addSnapshot(user, user.createSnapshot(DataSnapshot.SaveCause.SERVER_SHUTDOWN));
                 });
 
@@ -204,10 +128,6 @@ public abstract class EventListener {
         plugin.getRedisManager().terminate();
     }
 
-    public final Set<UUID> getLockedPlayers() {
-        return this.lockedPlayers;
-    }
-
     /**
      * Represents priorities for events that HuskSync listens to
      */

common/src/main/java/net/william278/husksync/redis/RedisKeyType.java

@@ -24,9 +24,9 @@ import org.jetbrains.annotations.NotNull;
 import java.util.Locale;
 
 public enum RedisKeyType {
-    CACHE(60 * 60 * 24),
     DATA_UPDATE(10),
-    SERVER_SWITCH(10);
+    SERVER_SWITCH(10),
+    DATA_CHECKOUT(60 * 60 * 24 * 7 * 52);
 
     private final int timeToLive;
 

common/src/main/java/net/william278/husksync/redis/RedisManager.java

@@ -92,7 +92,7 @@ public class RedisManager extends JedisPubSub {
         try (Jedis jedis = jedisPool.getResource()) {
             jedis.subscribe(
                     this,
-                    Arrays.stream(RedisMessageType.values())
+                    Arrays.stream(RedisMessage.Type.values())
                             .map(type -> type.getMessageChannel(clusterId))
                             .toArray(String[]::new)
             );
@@ -101,7 +101,7 @@ public class RedisManager extends JedisPubSub {
 
     @Override
     public void onMessage(@NotNull String channel, @NotNull String message) {
-        final RedisMessageType messageType = RedisMessageType.getTypeFromChannel(channel, clusterId).orElse(null);
+        final RedisMessage.Type messageType = RedisMessage.Type.getTypeFromChannel(channel, clusterId).orElse(null);
         if (messageType == null) {
             return;
         }
@@ -118,7 +118,7 @@ public class RedisManager extends JedisPubSub {
                     user -> RedisMessage.create(
                             UUID.fromString(new String(redisMessage.getPayload(), StandardCharsets.UTF_8)),
                             user.createSnapshot(DataSnapshot.SaveCause.INVENTORY_COMMAND).asBytes(plugin)
-                    ).dispatch(plugin, RedisMessageType.RETURN_USER_DATA)
+                    ).dispatch(plugin, RedisMessage.Type.RETURN_USER_DATA)
             );
             case RETURN_USER_DATA -> {
                 final CompletableFuture<Optional<DataSnapshot.Packed>> future = pendingRequests.get(
@@ -142,7 +142,7 @@ public class RedisManager extends JedisPubSub {
     public void sendUserDataUpdate(@NotNull User user, @NotNull DataSnapshot.Packed data) {
         plugin.runAsync(() -> {
             final RedisMessage redisMessage = RedisMessage.create(user.getUuid(), data.asBytes(plugin));
-            redisMessage.dispatch(plugin, RedisMessageType.UPDATE_USER_DATA);
+            redisMessage.dispatch(plugin, RedisMessage.Type.UPDATE_USER_DATA);
         });
     }
 
@@ -162,7 +162,7 @@ public class RedisManager extends JedisPubSub {
                     user.getUuid(),
                     requestId.toString().getBytes(StandardCharsets.UTF_8)
             );
-            redisMessage.dispatch(plugin, RedisMessageType.REQUEST_USER_DATA);
+            redisMessage.dispatch(plugin, RedisMessage.Type.REQUEST_USER_DATA);
         });
         return future.orTimeout(
                         plugin.getSettings().getNetworkLatencyMilliseconds(),
@@ -180,44 +180,96 @@ public class RedisManager extends JedisPubSub {
      * @param user the user to set data for
      * @param data the user's data to set
      */
+    @Blocking
     public void setUserData(@NotNull User user, @NotNull DataSnapshot.Packed data) {
-        plugin.runAsync(() -> {
-            try (Jedis jedis = jedisPool.getResource()) {
-                jedis.setex(
-                        getKey(RedisKeyType.DATA_UPDATE, user.getUuid(), clusterId),
-                        RedisKeyType.DATA_UPDATE.getTimeToLive(),
-                        data.asBytes(plugin)
+        try (Jedis jedis = jedisPool.getResource()) {
+            jedis.setex(
+                    getKey(RedisKeyType.DATA_UPDATE, user.getUuid(), clusterId),
+                    RedisKeyType.DATA_UPDATE.getTimeToLive(),
+                    data.asBytes(plugin)
+            );
+            plugin.debug(String.format("[%s] Set %s key to redis at: %s", user.getUsername(),
+                    RedisKeyType.DATA_UPDATE.name(), new SimpleDateFormat("mm:ss.SSS").format(new Date())));
+        } catch (Throwable e) {
+            plugin.log(Level.SEVERE, "An exception occurred setting a user's server switch", e);
+        }
+    }
+
+    @Blocking
+    public void setUserCheckedOut(@NotNull User user, boolean checkedOut) {
+        try (Jedis jedis = jedisPool.getResource()) {
+            if (checkedOut) {
+                jedis.set(
+                        getKey(RedisKeyType.DATA_CHECKOUT, user.getUuid(), clusterId),
+                        plugin.getServerName().getBytes(StandardCharsets.UTF_8)
                 );
-                plugin.debug(String.format("[%s] Set %s key to redis at: %s", user.getUsername(),
-                        RedisKeyType.DATA_UPDATE.name(), new SimpleDateFormat("mm:ss.SSS").format(new Date())));
-            } catch (Throwable e) {
-                plugin.log(Level.SEVERE, "An exception occurred setting a user's server switch", e);
+            } else {
+                jedis.del(getKey(RedisKeyType.DATA_CHECKOUT, user.getUuid(), clusterId));
             }
-        });
+            plugin.debug(String.format("[%s] %s %s key to redis at: %s",
+                    checkedOut ? "set" : "removed", user.getUsername(), RedisKeyType.DATA_CHECKOUT.name(),
+                    new SimpleDateFormat("mm:ss.SSS").format(new Date())));
+        } catch (Throwable e) {
+            plugin.log(Level.SEVERE, "An exception occurred setting a user's server switch", e);
+        }
+    }
+
+    @Blocking
+    public Optional<String> getUserCheckedOut(@NotNull User user) {
+        try (Jedis jedis = jedisPool.getResource()) {
+            final byte[] key = getKey(RedisKeyType.DATA_CHECKOUT, user.getUuid(), clusterId);
+            final byte[] readData = jedis.get(key);
+            if (readData != null) {
+                plugin.debug("[" + user.getUsername() + "] Successfully read "
+                        + RedisKeyType.DATA_CHECKOUT.name() + " key from redis at: " +
+                        new SimpleDateFormat("mm:ss.SSS").format(new Date()));
+                return Optional.of(new String(readData, StandardCharsets.UTF_8));
+            }
+        } catch (Throwable e) {
+            plugin.log(Level.SEVERE, "An exception occurred fetching a user's checkout key from redis", e);
+        }
+        plugin.debug("[" + user.getUsername() + "] Could not read " +
+                RedisKeyType.DATA_CHECKOUT.name() + " key from redis at: " +
+                new SimpleDateFormat("mm:ss.SSS").format(new Date()));
+        return Optional.empty();
+    }
+
+    @Blocking
+    public void clearUsersCheckedOutOnServer() {
+        final String keyFormat = String.format("%s*", RedisKeyType.DATA_CHECKOUT.getKeyPrefix(clusterId));
+        try (Jedis jedis = jedisPool.getResource()) {
+            final Set<String> keys = jedis.keys(keyFormat);
+            if (keys == null) {
+                plugin.log(Level.WARNING, "Checkout key set returned null from jedis during clearing");
+                return;
+            }
+            for (String key : keys) {
+                if (jedis.get(key).equals(plugin.getServerName())) {
+                    jedis.del(key);
+                }
+            }
+        } catch (Throwable e) {
+            plugin.log(Level.SEVERE, "An exception occurred clearing users checked out on this server", e);
+        }
     }
 
     /**
      * Set a user's server switch to the Redis server
      *
      * @param user the user to set the server switch for
-     * @return a future returning void when complete
      */
-    public CompletableFuture<Void> setUserServerSwitch(@NotNull User user) {
-        final CompletableFuture<Void> future = new CompletableFuture<>();
-        plugin.runAsync(() -> {
-            try (Jedis jedis = jedisPool.getResource()) {
-                jedis.setex(
-                        getKey(RedisKeyType.SERVER_SWITCH, user.getUuid(), clusterId),
-                        RedisKeyType.SERVER_SWITCH.getTimeToLive(), new byte[0]
-                );
-                future.complete(null);
-                plugin.debug(String.format("[%s] Set %s key to redis at: %s", user.getUsername(),
-                        RedisKeyType.SERVER_SWITCH.name(), new SimpleDateFormat("mm:ss.SSS").format(new Date())));
-            } catch (Throwable e) {
-                plugin.log(Level.SEVERE, "An exception occurred setting a user's server switch", e);
-            }
-        });
-        return future;
+    @Blocking
+    public void setUserServerSwitch(@NotNull User user) {
+        try (Jedis jedis = jedisPool.getResource()) {
+            jedis.setex(
+                    getKey(RedisKeyType.SERVER_SWITCH, user.getUuid(), clusterId),
+                    RedisKeyType.SERVER_SWITCH.getTimeToLive(), new byte[0]
+            );
+            plugin.debug(String.format("[%s] Set %s key to redis at: %s", user.getUsername(),
+                    RedisKeyType.SERVER_SWITCH.name(), new SimpleDateFormat("mm:ss.SSS").format(new Date())));
+        } catch (Throwable e) {
+            plugin.log(Level.SEVERE, "An exception occurred setting a user's server switch", e);
+        }
     }
 
     /**
@@ -226,6 +278,7 @@ public class RedisManager extends JedisPubSub {
      * @param user The user to fetch data for
      * @return The user's data, if it's present on the database. Otherwise, an empty optional.
      */
+    @Blocking
     public Optional<DataSnapshot.Packed> getUserData(@NotNull User user) {
         try (Jedis jedis = jedisPool.getResource()) {
             final byte[] key = getKey(RedisKeyType.DATA_UPDATE, user.getUuid(), clusterId);
@@ -251,6 +304,7 @@ public class RedisManager extends JedisPubSub {
         }
     }
 
+    @Blocking
     public boolean getUserServerSwitch(@NotNull User user) {
         try (Jedis jedis = jedisPool.getResource()) {
             final byte[] key = getKey(RedisKeyType.SERVER_SWITCH, user.getUuid(), clusterId);
@@ -274,6 +328,7 @@ public class RedisManager extends JedisPubSub {
         }
     }
 
+    @Blocking
     public void terminate() {
         if (jedisPool != null) {
             if (!jedisPool.isClosed()) {

common/src/main/java/net/william278/husksync/redis/RedisMessage.java

@@ -25,6 +25,9 @@ import net.william278.husksync.HuskSync;
 import net.william278.husksync.adapter.Adaptable;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.Optional;
 import java.util.UUID;
 
 public class RedisMessage implements Adaptable {
@@ -53,7 +56,7 @@ public class RedisMessage implements Adaptable {
         return plugin.getGson().fromJson(json, RedisMessage.class);
     }
 
-    public void dispatch(@NotNull HuskSync plugin, @NotNull RedisMessageType type) {
+    public void dispatch(@NotNull HuskSync plugin, @NotNull Type type) {
         plugin.runAsync(() -> plugin.getRedisManager().sendMessage(
                 type.getMessageChannel(plugin.getSettings().getClusterId()),
                 plugin.getGson().toJson(this)
@@ -77,4 +80,27 @@ public class RedisMessage implements Adaptable {
         this.payload = payload;
     }
 
+    public enum Type {
+
+        UPDATE_USER_DATA,
+        REQUEST_USER_DATA,
+        RETURN_USER_DATA;
+
+        @NotNull
+        public String getMessageChannel(@NotNull String clusterId) {
+            return String.format(
+                    "%s:%s:%s",
+                    RedisManager.KEY_NAMESPACE.toLowerCase(Locale.ENGLISH),
+                    clusterId.toLowerCase(Locale.ENGLISH),
+                    name().toLowerCase(Locale.ENGLISH)
+            );
+        }
+
+        public static Optional<Type> getTypeFromChannel(@NotNull String channel, @NotNull String clusterId) {
+            return Arrays.stream(values())
+                    .filter(messageType -> messageType.getMessageChannel(clusterId).equalsIgnoreCase(channel))
+                    .findFirst();
+        }
+
+    }
 }

common/src/main/java/net/william278/husksync/redis/RedisMessageType.java

@@ -1,50 +0,0 @@
-/*
- * This file is part of HuskSync, licensed under the Apache License 2.0.
- *
- *  Copyright (c) William278 <will27528@gmail.com>
- *  Copyright (c) contributors
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- */
-
-package net.william278.husksync.redis;
-
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Arrays;
-import java.util.Locale;
-import java.util.Optional;
-
-public enum RedisMessageType {
-
-    UPDATE_USER_DATA,
-    REQUEST_USER_DATA,
-    RETURN_USER_DATA;
-
-    @NotNull
-    public String getMessageChannel(@NotNull String clusterId) {
-        return String.format(
-                "%s:%s:%s",
-                RedisManager.KEY_NAMESPACE.toLowerCase(Locale.ENGLISH),
-                clusterId.toLowerCase(Locale.ENGLISH),
-                name().toLowerCase(Locale.ENGLISH)
-        );
-    }
-
-    public static Optional<RedisMessageType> getTypeFromChannel(@NotNull String channel, @NotNull String clusterId) {
-        return Arrays.stream(values())
-                .filter(messageType -> messageType.getMessageChannel(clusterId).equalsIgnoreCase(channel))
-                .findFirst();
-    }
-
-}

common/src/main/java/net/william278/husksync/sync/DataSyncer.java

@@ -0,0 +1,152 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync.sync;
+
+import net.william278.husksync.HuskSync;
+import net.william278.husksync.api.HuskSyncAPI;
+import net.william278.husksync.data.DataSnapshot;
+import net.william278.husksync.user.OnlineUser;
+import net.william278.husksync.util.Task;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+/**
+ * Handles the synchronization of data when a player changes servers or logs in
+ *
+ * @since 3.1
+ */
+public abstract class DataSyncer {
+    private static final long BASE_LISTEN_ATTEMPTS = 16;
+    private static final long LISTEN_DELAY = 10;
+
+    protected final HuskSync plugin;
+    private final long maxListenAttempts;
+
+    @ApiStatus.Internal
+    protected DataSyncer(@NotNull HuskSync plugin) {
+        this.plugin = plugin;
+        this.maxListenAttempts = getMaxListenAttempts();
+    }
+
+    /**
+     * API-exposed constructor for a {@link DataSyncer}
+     *
+     * @param api instance of the {@link HuskSyncAPI}
+     */
+    @SuppressWarnings("unused")
+    public DataSyncer(@NotNull HuskSyncAPI api) {
+        this(api.getPlugin());
+    }
+
+    /**
+     * Called when the plugin is enabled
+     */
+    public void initialize() {
+    }
+
+    /**
+     * Called when the plugin is disabled
+     */
+    public void terminate() {
+    }
+
+    /**
+     * Called when a user's data should be fetched and applied to them
+     *
+     * @param user the user to fetch data for
+     */
+    public abstract void setUserData(@NotNull OnlineUser user);
+
+    /**
+     * Called when a user's data should be serialized and saved
+     *
+     * @param user the user to save
+     */
+    public abstract void saveUserData(@NotNull OnlineUser user);
+
+    // Calculates the max attempts the system should listen for user data for based on the latency value
+    private long getMaxListenAttempts() {
+        return BASE_LISTEN_ATTEMPTS + (
+                (Math.max(100, plugin.getSettings().getNetworkLatencyMilliseconds()) / 1000) * 20 / LISTEN_DELAY
+        );
+    }
+
+    // Set a user's data from the database, or set them as a new user
+    @ApiStatus.Internal
+    protected void setUserFromDatabase(@NotNull OnlineUser user) {
+        plugin.getDatabase().getLatestSnapshot(user).ifPresentOrElse(
+                snapshot -> user.applySnapshot(snapshot, DataSnapshot.UpdateCause.SYNCHRONIZED),
+                () -> user.completeSync(true, DataSnapshot.UpdateCause.NEW_USER, plugin)
+        );
+    }
+
+    // Continuously listen for data from Redis
+    @ApiStatus.Internal
+    protected void listenForRedisData(@NotNull OnlineUser user, @NotNull Supplier<Boolean> completionSupplier) {
+        final AtomicLong timesRun = new AtomicLong(0L);
+        final AtomicReference<Task.Repeating> task = new AtomicReference<>();
+        final Runnable runnable = () -> {
+            if (user.isOffline()) {
+                task.get().cancel();
+                return;
+            }
+            if (plugin.isDisabling() || timesRun.getAndIncrement() > maxListenAttempts) {
+                task.get().cancel();
+                setUserFromDatabase(user);
+                return;
+            }
+
+            if (completionSupplier.get()) {
+                task.get().cancel();
+            }
+        };
+        task.set(plugin.getRepeatingTask(runnable, LISTEN_DELAY));
+        task.get().run();
+    }
+
+    /**
+     * Represents the different available default modes of {@link DataSyncer}
+     *
+     * @since 3.1
+     */
+    public enum Mode {
+        DELAY(DelayDataSyncer::new),
+        LOCKSTEP(LockstepDataSyncer::new);
+
+        private final Function<HuskSync, ? extends DataSyncer> supplier;
+
+        Mode(@NotNull Function<HuskSync, ? extends DataSyncer> supplier) {
+            this.supplier = supplier;
+        }
+
+        @NotNull
+        public DataSyncer create(@NotNull HuskSync plugin) {
+            return supplier.apply(plugin);
+        }
+
+    }
+
+
+}

common/src/main/java/net/william278/husksync/sync/DelayDataSyncer.java

@@ -0,0 +1,69 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync.sync;
+
+import net.william278.husksync.HuskSync;
+import net.william278.husksync.data.DataSnapshot;
+import net.william278.husksync.user.OnlineUser;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * A data syncer which applies a network delay before checking the presence of user data
+ */
+public class DelayDataSyncer extends DataSyncer {
+
+    public DelayDataSyncer(@NotNull HuskSync plugin) {
+        super(plugin);
+    }
+
+    @Override
+    public void setUserData(@NotNull OnlineUser user) {
+        plugin.runAsyncDelayed(
+                () -> {
+                    // Fetch from the database if the user isn't changing servers
+                    if (!plugin.getRedisManager().getUserServerSwitch(user)) {
+                        this.setUserFromDatabase(user);
+                        return;
+                    }
+
+                    // Listen for the data to be updated
+                    this.listenForRedisData(
+                            user,
+                            () -> plugin.getRedisManager().getUserData(user).map(data -> {
+                                user.applySnapshot(data, DataSnapshot.UpdateCause.SYNCHRONIZED);
+                                return true;
+                            }).orElse(false)
+                    );
+                },
+                Math.max(0, plugin.getSettings().getNetworkLatencyMilliseconds() / 50L)
+        );
+    }
+
+    @Override
+    public void saveUserData(@NotNull OnlineUser user) {
+        plugin.runAsync(() -> {
+            plugin.getRedisManager().setUserServerSwitch(user);
+            final DataSnapshot.Packed data = user.createSnapshot(DataSnapshot.SaveCause.DISCONNECT);
+            plugin.getRedisManager().setUserData(user, data);
+            plugin.getDatabase().addSnapshot(user, data);
+        });
+    }
+
+}

common/src/main/java/net/william278/husksync/sync/LockstepDataSyncer.java

@@ -0,0 +1,69 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync.sync;
+
+import net.william278.husksync.HuskSync;
+import net.william278.husksync.data.DataSnapshot;
+import net.william278.husksync.user.OnlineUser;
+import org.jetbrains.annotations.NotNull;
+
+public class LockstepDataSyncer extends DataSyncer {
+
+    public LockstepDataSyncer(@NotNull HuskSync plugin) {
+        super(plugin);
+    }
+
+    @Override
+    public void initialize() {
+        plugin.getRedisManager().clearUsersCheckedOutOnServer();
+    }
+
+    @Override
+    public void terminate() {
+        plugin.getRedisManager().clearUsersCheckedOutOnServer();
+    }
+
+    // Consume their data when they are checked in
+    @Override
+    public void setUserData(@NotNull OnlineUser user) {
+        this.listenForRedisData(user, () -> {
+            if (plugin.getRedisManager().getUserCheckedOut(user).isEmpty()) {
+                plugin.getRedisManager().setUserCheckedOut(user, true);
+                plugin.getRedisManager().getUserData(user).ifPresentOrElse(
+                        data -> user.applySnapshot(data, DataSnapshot.UpdateCause.SYNCHRONIZED),
+                        () -> this.setUserFromDatabase(user)
+                );
+                return true;
+            }
+            return false;
+        });
+    }
+
+    @Override
+    public void saveUserData(@NotNull OnlineUser user) {
+        plugin.runAsync(() -> {
+            final DataSnapshot.Packed data = user.createSnapshot(DataSnapshot.SaveCause.DISCONNECT);
+            plugin.getRedisManager().setUserData(user, data);
+            plugin.getRedisManager().setUserCheckedOut(user, false);
+            plugin.getDatabase().addSnapshot(user, data);
+        });
+    }
+
+}

common/src/main/java/net/william278/husksync/user/OnlineUser.java

@@ -158,7 +158,7 @@ public abstract class OnlineUser extends User implements CommandUser, UserDataHo
             }
             plugin.fireEvent(
                     plugin.getSyncCompleteEvent(this),
-                    (event) -> plugin.getLockedPlayers().remove(getUuid())
+                    (event) -> plugin.unlockPlayer(getUuid())
             );
         } else {
             cause.getFailedLocale(plugin).ifPresent(this::sendMessage);

common/src/main/java/net/william278/husksync/util/DataSnapshotOverview.java

@@ -70,6 +70,8 @@ public class DataSnapshotOverview {
         }
         locales.getLocale("data_manager_cause", snapshot.getSaveCause().getDisplayName())
                 .ifPresent(user::sendMessage);
+        locales.getLocale("data_manager_server", snapshot.getServerName())
+                .ifPresent(user::sendMessage);
 
         // User status data, if present in the snapshot
         final Optional<Data.Health> health = snapshot.getHealth();

common/src/main/resources/locales/bg-bg.yml

@@ -11,6 +11,7 @@ data_manager_title: '[Преглеждане потребителският сн
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Клеймо на Версията:\n&8Когато данните са били запазени)'
 data_manager_pinned: '[※ Закачен снапшот](#d8ff2b show_text=&7Закачен:\n&8Снапшота на този потребител няма да бъде автоматично завъртан.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Причина на Запазване:\n&8Какво е накарало данните да бъдат запазени)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Точки кръв)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Точки глад)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7Ниво опит)   [🏹 %5%](dark_aqua show_text=&7Режим на игра)'
 data_manager_advancements_statistics: '[⭐ Напредъци: %1%](color=#ffc43b-#f5c962 show_text=&7Напредъци, в които имате прогрес:\n&8%2%)   [⌛ Изиграно Време: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7Изиграно време в играта\n&8⚠ Базирано на статистики от играта)\n'

common/src/main/resources/locales/de-de.yml

@@ -11,6 +11,7 @@ data_manager_title: '[Du siehst den Nutzerdaten-Schnappschuss](#00fb9a) [%1%](#0
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Versions-Zeitstempel:\n&8Zeitpunkt der Speicherung der Daten)'
 data_manager_pinned: '[※ Schnappschuss angeheftet](#d8ff2b show_text=&7Angeheftet:\n&8Dieser Nutzerdaten-Schnappschuss wird nicht automatisch rotiert.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Speicherungsgrund:\n&8Der Grund für das Speichern der Daten)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Lebenspunkte)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Hungerpunkte)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7XP-Level)   [🏹 %5%](dark_aqua show_text=&7Spielmodus)'
 data_manager_advancements_statistics: '[⭐ Erfolge: %1%](color=#ffc43b-#f5c962 show_text=&7Erfolge in denen du Fortschritt gemacht hast:\n&8%2%)   [⌛ Spielzeit: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7Deine verbrachte Zeit im Spiel\n&8⚠ Basierend auf Spielstatistiken)\n'

common/src/main/resources/locales/en-gb.yml

@@ -11,6 +11,7 @@ data_manager_title: '[Viewing user data snapshot](#00fb9a) [%1%](#00fb9a show_te
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Version timestamp:\n&8When the data was saved)'
 data_manager_pinned: '[※ Snapshot pinned](#d8ff2b show_text=&7Pinned:\n&8This user data snapshot won''t be automatically rotated.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Save cause:\n&8What caused the data to be saved)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Health points)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Hunger points)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7XP level)   [🏹 %5%](dark_aqua show_text=&7Game mode)'
 data_manager_advancements_statistics: '[⭐ Advancements: %1%](color=#ffc43b-#f5c962 show_text=&7Advancements you have progress in:\n&8%2%)   [⌛ Play Time: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7In-game play time\n&8⚠ Based on in-game statistics)\n'

common/src/main/resources/locales/es-es.yml

@@ -11,6 +11,7 @@ data_manager_title: '[Viendo una snapshot sobre la informacion del jugador](#00f
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Version del registro:\n&8Cuando los datos se han guardado)'
 data_manager_pinned: '[※ Snapshot anclada](#d8ff2b show_text=&Anclado:\n&8La informacion de este jugador no se rotará automaticamente.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Motivo del guardado:\n&8Lo que ha causado que se guarde)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Puntos de vida)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Puntos de hambre)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7Nivel de exp)   [🏹 %5%](dark_aqua show_text=&7Gamemode)'
 data_manager_advancements_statistics: '[⭐ Logros: %1%](color=#ffc43b-#f5c962 show_text=&7Logros que has conseguido:\n&8%2%)   [⌛ Tiempo de juego: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7In-game play time\n&8⚠ Based on in-game statistics)\n'

common/src/main/resources/locales/it-it.yml

@@ -11,6 +11,7 @@ data_manager_title: '[Stai vedendo l''istantanea](#00fb9a) [%1%](#00fb9a show_te
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7:\n&8Quando i dati sono stati salvati)'
 data_manager_pinned: '[※ Istantanea fissata](#d8ff2b show_text=&7Pinned:\n&8Quest''istantanea non sarà cancellata automaticamente.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Causa di salvataggio:\n&8Cosa ha causato il salvataggio dei dati)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Peso dell''istantanea:\n&8Peso stimato del file (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Vita)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Fame)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7Livello di XP)   [🏹 %5%](dark_aqua show_text=&7Modalità di gioco)'
 data_manager_advancements_statistics: '[⭐ Progressi: %1%](color=#ffc43b-#f5c962 show_text=&7Progressi compiuti in:\n&8%2%)   [⌛ Tempo di gioco: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7Tempo di gioco\n&8⚠ Basato sulle statistiche di gioco)\n'

common/src/main/resources/locales/ja-jp.yml

@@ -1,49 +1,50 @@
 synchronization_complete: '[⏵データが同期されました！](#00fb9a)'
-synchronization_failed: '[⏵ Failed to synchronize your data! Please contact an administrator.](#ff7e5e)'
-inventory_viewer_menu_title: '&0%1%''s Inventory'
-ender_chest_viewer_menu_title: '&0%1%''s Ender Chest'
-inventory_viewer_opened: '[Viewing snapshot of](#00fb9a) [%1%](#00fb9a bold)[''s inventory as of ⌚ %2%](#00fb9a)'
-ender_chest_viewer_opened: '[Viewing snapshot of](#00fb9a) [%1%](#00fb9a bold)[''s Ender Chest as of ⌚ %2%](#00fb9a)'
-data_update_complete: '[🔔 Your data has been updated!](#00fb9a)'
-data_update_failed: '[🔔 Failed to update your data! Please contact an administrator.](#ff7e5e)'
-user_registration_complete: '[⭐ User registration complete!](#00fb9a)'
-data_manager_title: '[Viewing user data snapshot](#00fb9a) [%1%](#00fb9a show_text=&7Version UUID:\n&8%2%) [for](#00fb9a) [%3%](#00fb9a bold show_text=&7Player UUID:\n&8%4%)[:](#00fb9a)'
-data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Version timestamp:\n&8When the data was saved)'
-data_manager_pinned: '[※ Snapshot pinned](#d8ff2b show_text=&7Pinned:\n&8This user data snapshot won''t be automatically rotated.)'
-data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Save cause:\n&8What caused the data to be saved)'
-data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
-data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Health points)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Hunger points)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7XP level)   [🏹 %5%](dark_aqua show_text=&7Game mode)'
-data_manager_advancements_statistics: '[⭐ Advancements: %1%](color=#ffc43b-#f5c962 show_text=&7Advancements you have progress in:\n&8%2%)   [⌛ Play Time: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7In-game play time\n&8⚠ Based on in-game statistics)\n'
-data_manager_item_buttons: '[View:](gray) [[🪣 Inventory…]](color=#a17b5f-#f5b98c show_text=&7Click to view run_command=/inventory %1% %2%)   [[⌀ Ender Chest…]](#b649c4-#d254ff show_text=&7Click to view run_command=/enderchest %1% %2%)'
-data_manager_management_buttons: '[Manage:](gray) [[❌ Delete…]](#ff3300 show_text=&7Click to delete this snapshot of user data.\n&8This will not affect the user''s current data.\n&#ff3300&⚠ This cannot be undone! suggest_command=/husksync:userdata delete %1% %2%)   [[⏪ Restore…]](#00fb9a show_text=&7Click to restore this user data.\n&8This will set the user''s data to this snapshot.\n&#ff3300&⚠ %1%''s current data will be overwritten! suggest_command=/husksync:userdata restore %1% %2%)   [[※ Pin/Unpin…]](#d8ff2b show_text=&7Click to pin or unpin this user data snapshot\n&8Pinned snapshots won''t be automatically rotated run_command=/userdata pin %1% %2%)'
-data_manager_system_buttons: '[System:](gray) [[⏷ File Dump…]](dark_gray show_text=&7Click to dump this raw user data snapshot to a file.\n&8Data dumps can be found in ~/plugins/HuskSync/dumps/ run_command=/husksync:userdata dump %1% %2% file)   [[☂ Web Dump…]](dark_gray show_text=&7Click to dump this raw user data snapshot to the mc-logs service\n&8You will be provided with a URL containing the data. run_command=/husksync:userdata dump %1% %2% web)'
-data_manager_advancements_preview_remaining: 'and %1% more…'
-data_list_title: '[%1%''s user data snapshots:](#00fb9a) [(%2%-%3% of](#00fb9a) [%4%](#00fb9a bold)[)](#00fb9a)\n'
-data_list_item: '[%1%](gray show_text=&7User Data Snapshot for %2%&8⚡ %4% run_command=/userdata view %2% %3%) [%5%](#d8ff2b show_text=&7Pinned:\n&8Pinned snapshots won''t be automatically rotated. run_command=/userdata view %2% %3%) [%6%](color=#ffc43b-#f5c962 show_text=&7Version timestamp:&7\n&8When the data was saved\n&8%7% run_command=/userdata view %2% %3%)   [⚑ %8%](#23a825-#36f539 show_text=&7Save cause:\n&8What caused the data to be saved run_command=/userdata view %2% %3%)   [⏏ %9%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:&7\n&8Estimated file size of the snapshot (in KiB) run_command=/userdata view %2% %3%)'
-data_deleted: '[❌ Successfully deleted user data snapshot](#00fb9a) [%1%](#00fb9a show_text=&7Version UUID:\n&8%2%) [for](#00fb9a) [%3%.](#00fb9a show_text=&7Player UUID:\n&8%4%)'
-data_restored: '[⏪ Successfully restored](#00fb9a) [%1%](#00fb9a show_text=&7Player UUID:\n&8%2%)[''s current user data from snapshot](#00fb9a) [%3%.](#00fb9a show_text=&7Version UUID:\n&8%4%)'
-data_pinned: '[※ Successfully pinned user data snapshot](#00fb9a) [%1%](#00fb9a show_text=&7Version UUID:\n&8%2%) [for](#00fb9a) [%3%.](#00fb9a show_text=&7Player UUID:\n&8%4%)'
-data_unpinned: '[※ Successfully unpinned user data snapshot](#00fb9a) [%1%](#00fb9a show_text=&7Version UUID:\n&8%2%) [for](#00fb9a) [%3%.](#00fb9a show_text=&7Player UUID:\n&8%4%)'
-data_dumped: '[☂ Successfully dumped the user data snapshot %1% for %2% to:](#00fb9a) &7%3%'
-list_footer: '\n%1%[Page](#00fb9a) [%2%](#00fb9a)/[%3%](#00fb9a)%4%   %5%'
-list_previous_page_button: '[◀](white show_text=&7View previous page run_command=%2% %1%) '
-list_next_page_button: ' [▶](white show_text=&7View next page run_command=%2% %1%)'
+synchronization_failed: '[⏵ データの同期に失敗しました！管理者に連絡してください。](#ff7e5e)'
+inventory_viewer_menu_title: '&0%1%のインベントリ'
+ender_chest_viewer_menu_title: '&0%1%のエンダーチェスト'
+inventory_viewer_opened: '[⌚ %2%](#00fb9a) [%1%](#00fb9a bold) [のインベントリのスナップショットを閲覧する](#00fb9a)'
+ender_chest_viewer_opened: '[⌚ %2%](#00fb9a) [%1%](#00fb9a bold) [のエンダーチェストのスナップショットを閲覧する](#00fb9a)'
+data_update_complete: '[🔔 データが更新されました！](#00fb9a)'
+data_update_failed: '[🔔 データの更新に失敗しました！管理者に連絡してください。](#ff7e5e)'
+user_registration_complete: '[⭐ ユーザー登録が完了しました！](#00fb9a)'
+data_manager_title: '[%3%](#00fb9a bold show_text=&7プレイヤーUUID:\n&8%4%) [のユーザーデータスナップショット](#00fb9a)[%1%](#00fb9a show_text=&7バージョンUUID:\n&8%2%)[を表示:](#00fb9a)'
+data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7バージョンタイムスタンプ:\n&8データの保存時期)'
+data_manager_pinned: '[※ ピン留めされたスナップショット](#d8ff2b show_text=&7ピン留め:\n&8このユーザーデータのスナップショットは自動的にローテーションされません。)'
+data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7保存理由:\n&8データが保存された理由)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
+data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7スナップショットサイズ:\n&8スナップショットの推定ファイルサイズ（単位:KiB）)\n'
+data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7体力)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7空腹度)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7経験値レベル)   [🏹 %5%](dark_aqua show_text=&7ゲームモード)'
+data_manager_advancements_statistics: '[⭐ 進捗: %1%](color=#ffc43b-#f5c962 show_text=&7達成した進捗:\n&8%2%)   [⌛ プレイ時間: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7ゲーム内のプレイ時間\n&8⚠ ゲーム内の統計に基づく)\n'
+data_manager_item_buttons: '[表示:](gray) [[🪣 インベントリ…]](color=#a17b5f-#f5b98c show_text=&7クリックで表示 run_command=/husksync:inventory %1% %2%)   [[⌀ エンダーチェスト…]](#b649c4-#d254ff show_text=&7クリックで表示 run_command=/husksync:enderchest %1% %2%)'
+data_manager_management_buttons: '[管理:](gray) [[❌ 消去…]](#ff3300 show_text=&7クリックでこのユーザーデータのスナップショットを消去します。\n&8これはユーザーの現在のデータには影響しません。\n&#ff3300&⚠ この操作は元に戻せません！ suggest_command=/husksync:userdata delete %1% %2%)   [[⏪ 復元…]](#00fb9a show_text=&7クリックでこのユーザーデータを復元します。\n&8これにより、ユーザーデータはこのスナップショットに設定されます。\n&#ff3300&⚠ %1% の現在のデータは上書きされます！ suggest_command=/husksync:userdata restore %1% %2%)   [[※ ピン留め/ピン外し…]](#d8ff2b show_text=&7クリックでこのユーザーデータのスナップショットをピン留め、若しくはピンを外します。\n&8ピン留めされたスナップショットは自動的にローテーションしません。 run_command=/userdata pin %1% %2%)'
+data_manager_system_buttons: '[システム:](gray) [[⏷ ファイルダンプ…]](dark_gray show_text=&7クリックで未加工のユーザーデータスナップショットをダンプファイルにします。\n&8データダンプの場所は ~/plugins/HuskSync/dumps/ です run_command=/husksync:userdata dump %1% %2% file)   [[☂ Webダンプ…]](dark_gray show_text=&7クリックでユーザーデータスナップショットをmc-logsサービスにダンプします。\n&8データを含むURLが提供されます。 run_command=/husksync:userdata dump %1% %2% web)'
+data_manager_advancements_preview_remaining: 'さらに %1% 件…'
+data_list_title: '[%1% のユーザーデータスナップショット:](#00fb9a) [(%4%件中](#00fb9a bold) [%2%-%3%件](#00fb9a)[)](#00fb9a)\n'
+data_list_item: '[%1%](gray show_text=&7%2% のユーザーデータスナップショット&8⚡ %4% run_command=/husksync:userdata view %2% %3%) [%5%](#d8ff2b show_text=&7ピン留め:\n&8ピン留めされたスナップショットは自動的にローテーションしません。 run_command=/husksync:userdata view %2% %3%) [%6%](color=#ffc43b-#f5c962 show_text=&7バージョンタイムスタンプ:&7\n&8データの保存時期\n&8%7% run_command=/userdata view %2% %3%)   [⚑ %8%](#23a825-#36f539 show_text=&7保存理由:\n&8データが保存された理由 run_command=/userdata view %2% %3%)   [⏏ %9%](color=#62a9f5-#7ab8fa show_text=&7スナップショットサイズ:&7\n&8スナップショットの推定ファイルサイズ (単位:KiB) run_command=/userdata view %2% %3%)'
+data_deleted: '[❌](#00fb9a) [%3%](#00fb9a show_text=&7Player UUID:\n&8%4%) [のユーザーデータスナップショット](#00fb9a) [%1%](#00fb9a show_text=&7Version UUID:\n&8%2%) [の消去に成功しました。](#00fb9a)'
+data_restored: '[⏪](#00fb9a) [スナップショット](#00fb9a) [%3%](#00fb9a show_text=&7Version UUID:\n&8%4%) [から](#00fb9a) [%1%](#00fb9a show_text=&7Player UUID:\n&8%2%) [の現在のユーザーデータの復元に成功しました。](#00fb9a)'
+data_pinned: '[※](#00fb9a) [%3%](#00fb9a show_text=&7Player UUID:\n&8%4%) [のユーザーデータスナップショット](#00fb9a) [%1%](#00fb9a show_text=&7Version UUID:\n&8%2%) [のピン留めに成功しました。](#00fb9a)'
+data_unpinned: '[※](#00fb9a) [%3%](#00fb9a show_text=&7Player UUID:\n&8%4%) [のユーザーデータスナップショット](#00fb9a) [%1%](#00fb9a show_text=&7Version UUID:\n&8%2%) [のピン外しに成功しました。](#00fb9a)'
+data_dumped: '[☂ %2% のユーザーデータスナップショット %1% のダンプに成功:](#00fb9a) &7%3%'
+list_footer: '\n%1%[ページ](#00fb9a) [%2%](#00fb9a)/[%3%](#00fb9a)%4%   %5%'
+list_previous_page_button: '[◀](white show_text=&7前のページへ run_command=%2% %1%) '
+list_next_page_button: ' [▶](white show_text=&7次のページへ run_command=%2% %1%)'
 list_page_jumpers: '(%1%)'
-list_page_jumper_button: '[%1%](show_text=&7Jump to page %1% run_command=%2% %1%)'
+list_page_jumper_button: '[%1%](show_text=&7%1% ページ目へ run_command=%2% %1%)'
 list_page_jumper_current_page: '[%1%](#00fb9a)'
 list_page_jumper_separator: ' '
 list_page_jumper_group_separator: '…'
 up_to_date: '[HuskSync](#00fb9a bold) [| HuskSyncの最新バージョンを実行しています(v%1%).](#00fb9a)'
-update_available: '[HuskSync](#ff7e5e bold) [| HuskSyncの最新バージョンが更新されています: v%1% (running: v%2%).](#ff7e5e)'
-reload_complete: '[HuskSync](#00fb9a bold) [| 設定ファイルとメッセージファイルを再読み込みしました。](#00fb9a)\n[⚠ Ensure config files are up-to-date on all servers!](#00fb9a)\n[A restart is needed for config changes to take effect.](#00fb9a italic)'
-error_invalid_syntax: '[Error:](#ff3300) [構文が正しくありません。使用法:](#ff7e5e) [%1%](#ff7e5e italic show_text=&#ff7e5e&Click to suggest suggest_command=%1%)'
+update_available: '[HuskSync](#ff7e5e bold) [| HuskSyncの最新バージョンが更新されています: v%1% (実行中: v%2%).](#ff7e5e)'
+reload_complete: '[HuskSync](#00fb9a bold) [| 設定ファイルとメッセージファイルを再読み込みしました。](#00fb9a)\n[⚠ すべてのサーバーで設定ファイルが最新であることを確認してください！](#00fb9a)\n[設定の変更を有効にするには再起動が必要です。](#00fb9a italic)'
+error_invalid_syntax: '[Error:](#ff3300) [構文が正しくありません。使用法:](#ff7e5e) [%1%](#ff7e5e italic show_text=&#ff7e5e&クリックでサジェスト suggest_command=%1%)'
 error_invalid_player: '[Error:](#ff3300) [そのプレイヤーは見つかりませんでした](#ff7e5e)'
 error_no_permission: '[Error:](#ff3300) [このコマンドを実行する権限がありません](#ff7e5e)'
 error_console_command_only: '[Error:](#ff3300) [そのコマンドは%1%コンソールからのみ実行できます](#ff7e5e)'
-error_in_game_command_only: 'Error: That command can only be used in-game.'
-error_no_data_to_display: '[Error:](#ff3300) [Could not find any user data to display.](#ff7e5e)'
-error_invalid_version_uuid: '[Error:](#ff3300) [Could not find any user data for that version UUID.](#ff7e5e)'
-husksync_command_description: 'Manage the HuskSync plugin'
-userdata_command_description: 'View, manage & restore player userdata'
-inventory_command_description: 'View & edit a player''s inventory'
-enderchest_command_description: 'View & edit a player''s Ender Chest'
+error_in_game_command_only: 'Error: そのコマンドはゲーム内でしか使えません。'
+error_no_data_to_display: '[Error:](#ff3300) [表示するユーザーデータが見つかりませんでした。](#ff7e5e)'
+error_invalid_version_uuid: '[Error:](#ff3300) [そのバージョンUUIDのユーザーデータが見つかりませんでした。](#ff7e5e)'
+husksync_command_description: 'HuskSyncプラグインを管理する'
+userdata_command_description: 'プレーヤーのユーザーデータを表示・管理・復元する'
+inventory_command_description: 'プレイヤーのインベントリを閲覧・編集する'
+enderchest_command_description: 'プレイヤーのエンダーチェストを閲覧・編集する'

common/src/main/resources/locales/nl-nl.yml

@@ -0,0 +1,50 @@
+synchronization_complete: '[⏵ Data gesynchroniseerd!](#00fb9a)'
+synchronization_failed: '[⏵ Synchroniseren van jouw gegevens is niet gelukt! Neem contact op met een beheerder.](#ff7e5e)'
+inventory_viewer_menu_title: '&0%1%''s Inventaris'
+ender_chest_viewer_menu_title: '&0%1%''s Enderkist'
+inventory_viewer_opened: '[Momentopname bekijken van](#00fb9a) [%1%](#00fb9a bold)[''s inventaris per ⌚ %2%](#00fb9a)'
+ender_chest_viewer_opened: '[Momentopname bekijken van](#00fb9a) [%1%](#00fb9a bold)[''s Enderkist per ⌚ %2%](#00fb9a)'
+data_update_complete: '[🔔 Jouw gegevens zijn bijgewerkt!](#00fb9a)'
+data_update_failed: '[🔔 Het is niet gelukt om jouw gegevens bij te werken! Neem contact op met een beheerder.](#ff7e5e)'
+user_registration_complete: '[⭐ Gebruikersregistratie voltooid!](#00fb9a)'
+data_manager_title: '[Momentopname van gebruikersgegevens bekijken](#00fb9a) [%1%](#00fb9a show_text=&7Versie UUID:\n&8%2%) [voor](#00fb9a) [%3%](#00fb9a bold show_text=&7Speler UUID:\n&8%4%)[:](#00fb9a)'
+data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Versie tijdmarkering:\n&8Toen de gegevens werden opgeslagen)'
+data_manager_pinned: '[※ Momentopname vastgezet](#d8ff2b show_text=&7Vastgezet:\n&8Deze momentopname van gebruikersgegevens wordt niet automatisch gerouleerd.)'
+data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Reden opslaan:\n&8Waarom de data is opgeslagen)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
+data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Grootte van momentopname:\n&8Geschatte bestandsgrootte van de momentopname (in KiB))\n'
+data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Gezondheids punten)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Honger punten)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7XP level)   [🏹 %5%](dark_aqua show_text=&7Speltype)'
+data_manager_advancements_statistics: '[⭐ Advancements: %1%](color=#ffc43b-#f5c962 show_text=&7Advancements waarin je voortgang hebt:\n&8%2%)   [⌛ Speeltijd: %3%uren](color=#62a9f5-#7ab8fa show_text=&7In-game speeltijd\n&8⚠ Gebaseerd op in-game statistieken)\n'
+data_manager_item_buttons: '[View:](gray) [[🪣 Inventaris…]](color=#a17b5f-#f5b98c show_text=&7Klikken om te bekijken run_command=/inventory %1% %2%)   [[⌀ Enderkist…]](#b649c4-#d254ff show_text=&7Klikken om te bekijken run_command=/enderchest %1% %2%)'
+data_manager_management_buttons: '[Beheren:](gray) [[❌ Verwijderen…]](#ff3300 show_text=&7Klik om deze momentopname van gebruikersgegevens te verwijderen.\n&8Dit heeft geen invloed op de huidige gegevens van de gebruiker.\n&#ff3300&⚠ Dit kan niet ongedaan gemaakt worden! suggest_command=/husksync:userdata delete %1% %2%)   [[⏪ Herstellen…]](#00fb9a show_text=&7Klik om deze gebruikersgegevens te herstellen.\n&8Hierdoor worden de gegevens van de gebruiker ingesteld op deze momentopname.\n&#ff3300&⚠ %1%''s huidige gegevens worden overschreven! suggest_command=/husksync:userdata restore %1% %2%)   [[※ Vastzetten/losmaken…]](#d8ff2b show_text=&7Klik om deze momentopname van gebruikersgegevens vast te zetten of los te maken\n&8Vastgezette momentopnamen worden niet automatisch gerouleerd run_command=/userdata pin %1% %2%)'
+data_manager_system_buttons: '[Systeem:](gray) [[⏷ Bestandsdump…]](dark_gray show_text=&7Klik om deze ruwe gebruikersgegevenssnapshot naar een bestand te dumperen.\n&8Gegevensdumps zijn te vinden in ~/plugins/HuskSync/dumps/ run_command=/husksync:userdata dump %1% %2% file)   [[☂ Webdump…]](dark_gray show_text=&7Klik om deze ruwe gebruikersgegevenssnapshot naar de mc-logs-service te dumpen\n&8Je ontvangt een URL met de gegevens. run_command=/husksync:userdata dump %1% %2% web)'
+data_manager_advancements_preview_remaining: 'en %1% meer…'
+data_list_title: '[%1%''s momentopnamen van gebruikersgegevens:](#00fb9a) [(%2%-%3% van](#00fb9a) [%4%](#00fb9a bold)[)](#00fb9a)\n'
+data_list_item: '[%1%](gray show_text=&7Gebruikersgegevens momentopname voor %2%&8⚡ %4% run_command=/userdata view %2% %3%) [%5%](#d8ff2b show_text=&7Vastgezet:\n&8Vastgezette momentopnamen worden niet automatisch gerouleerd. run_command=/userdata view %2% %3%) [%6%](color=#ffc43b-#f5c962 show_text=&7Versie tijdmarkering:&7\n&8Wanneer de data was opgeslagen\n&8%7% run_command=/userdata view %2% %3%)   [⚑ %8%](#23a825-#36f539 show_text=&7Reden opslaan:\n&8Waarom de data is opgeslagen run_command=/userdata view %2% %3%)   [⏏ %9%](color=#62a9f5-#7ab8fa show_text=&7Grootte van momentopname:&7\n&8Geschatte bestandsgrootte van de momentopname (in KiB) run_command=/userdata view %2% %3%)'
+data_deleted: '[❌ Momentopname van gebruikersgegevens is verwijderd](#00fb9a) [%1%](#00fb9a show_text=&7Versie UUID:\n&8%2%) [voor](#00fb9a) [%3%.](#00fb9a show_text=&7Speler UUID:\n&8%4%)'
+data_restored: '[⏪ Succesvol hersteld](#00fb9a) [%1%](#00fb9a show_text=&7Speler UUID:\n&8%2%)[''s huidige gebruikersgegevens uit momentopname](#00fb9a) [%3%.](#00fb9a show_text=&7Versie UUID:\n&8%4%)'
+data_pinned: '[※ Momentopname van gebruikersgegevens is vastgezet](#00fb9a) [%1%](#00fb9a show_text=&7Versie UUID:\n&8%2%) [voor](#00fb9a) [%3%.](#00fb9a show_text=&7Speler UUID:\n&8%4%)'
+data_unpinned: '[※ Momentopname van gebruikersgegevens is losgemaakt](#00fb9a) [%1%](#00fb9a show_text=&7Versie UUID:\n&8%2%) [voor](#00fb9a) [%3%.](#00fb9a show_text=&7Speler UUID:\n&8%4%)'
+data_dumped: '[☂ De momentopname van gebruikersgegevens %1% voor %2% is met succes gedumpt naar:](#00fb9a) &7%3%'
+list_footer: '\n%1%[Pagina](#00fb9a) [%2%](#00fb9a)/[%3%](#00fb9a)%4%   %5%'
+list_previous_page_button: '[◀](white show_text=&7Bekijk vorige pagina run_command=%2% %1%) '
+list_next_page_button: ' [▶](white show_text=&7Bekijk volgende pagina run_command=%2% %1%)'
+list_page_jumpers: '(%1%)'
+list_page_jumper_button: '[%1%](show_text=&7Ga naar pagina %1% run_command=%2% %1%)'
+list_page_jumper_current_page: '[%1%](#00fb9a)'
+list_page_jumper_separator: ' '
+list_page_jumper_group_separator: '…'
+up_to_date: '[HuskSync](#00fb9a bold) [| Je gebruikt de nieuwste versie van HuskSync (v%1%).](#00fb9a)'
+update_available: '[HuskSync](#ff7e5e bold) [| Er is een nieuwe versie van HuskSync beschikbaar: v%1% (huidige versie: v%2%).](#ff7e5e)'
+reload_complete: '[HuskSync](#00fb9a bold) [| Configuratie- en berichtbestanden opnieuw geladen.](#00fb9a)\n[⚠ Controleer of de configuratiebestanden up-to-date zijn op alle servers!](#00fb9a)\n[Een herstart is nodig voor de configuratiewijzigingen van kracht te laten worden.](#00fb9a italic)'
+error_invalid_syntax: '[Error:](#ff3300) [Onjuiste syntaxis. Gebruik:](#ff7e5e) [%1%](#ff7e5e italic show_text=&#ff7e5e&Click to suggest suggest_command=%1%)'
+error_invalid_player: '[Error:](#ff3300) [Kan geen speler met die naam vinden.](#ff7e5e)'
+error_no_permission: '[Error:](#ff3300) [Je hebt geen toestemming om deze opdracht uit te voeren](#ff7e5e)'
+error_console_command_only: '[Error:](#ff3300) [Dat command kan alleen via de console worden uitgevoerd](#ff7e5e)'
+error_in_game_command_only: 'Error: Dat command kan alleen in-game worden gebruikt.'
+error_no_data_to_display: '[Error:](#ff3300) [Kon geen gebruikersgegevens vinden om weer te geven.](#ff7e5e)'
+error_invalid_version_uuid: '[Error:](#ff3300) [Kon geen gebruikersgegevens vinden voor dat versie-UUID.](#ff7e5e)'
+husksync_command_description: 'Beheer de HuskSync plugin'
+userdata_command_description: 'Bekijk, beheer en herstel de gebruikersgegevens van spelers'
+inventory_command_description: 'Bekijk en bewerk de inventaris van een speler'
+enderchest_command_description: 'Bekijk en bewerk de Enderkist van een speler'

common/src/main/resources/locales/pt-br.yml

@@ -11,6 +11,7 @@ data_manager_title: '[Visualizando snapshot dos dados do usuário](#00fb9a) [%1%
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Version timestamp:\n&8Quando os dados foram salvos)'
 data_manager_pinned: '[※ Snapshot marcada](#d8ff2b show_text=&7Marcada:\n&8Essa snapshot de dados do usuário não será girada automaticamente.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Causa do salvamento:\n&8O motivo para que os dados fossem salvos)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Pontos de Vida)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Pontos de vida)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7XP level)   [🏹 %5%](dark_aqua show_text=&7Game mode)'
 data_manager_advancements_statistics: '[⭐ Progressos: %1%](color=#ffc43b-#f5c962 show_text=&7Progressos que você tem realizado em:\n&8%2%)   [⌛ Tempo de jogo: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7Tempo de jogo dentro do jogo\n&8⚠ Com base em estatísticas dentro do jogo)\n'

common/src/main/resources/locales/uk-ua.yml

@@ -11,6 +11,7 @@ data_manager_title: '[Viewing user data snapshot](#00fb9a) [%1%](#00fb9a show_te
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7Version timestamp:\n&8When the data was saved)'
 data_manager_pinned: '[※ Snapshot pinned](#d8ff2b show_text=&7Pinned:\n&8This user data snapshot won''t be automatically rotated.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7Save cause:\n&8What caused the data to be saved)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7Health points)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7Hunger points)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7XP level)   [🏹 %5%](dark_aqua show_text=&7Game mode)'
 data_manager_advancements_statistics: '[⭐ Advancements: %1%](color=#ffc43b-#f5c962 show_text=&7Advancements you have progress in:\n&8%2%)   [⌛ Play Time: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7In-game play time\n&8⚠ Based on in-game statistics)\n'

common/src/main/resources/locales/zh-cn.yml

@@ -11,6 +11,7 @@ data_manager_title: '[正在查看玩家](#00fb9a) [%3%](#00fb9a bold show_text=
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7备份时间:\n&7何时保存了此数据)'
 data_manager_pinned: '[※ 置顶备份](#d8ff2b show_text=&7置顶:\n&8此数据备份不会按照备份时间自动排序.)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7备份原因:\n&7为何保存了此数据)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7血量)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7饱食度)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7经验等级)   [🏹 %5%](dark_aqua show_text=&7游戏模式)'
 data_manager_advancements_statistics: '[⭐ 成就: %1%](color=#ffc43b-#f5c962 show_text=&7%2%)   [⌛ 游玩时间: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7⚠ 基于游戏内的统计)\n'

common/src/main/resources/locales/zh-tw.yml

@@ -11,6 +11,7 @@ data_manager_title: '[查看](#00fb9a) [%3%](#00fb9a bold show_text=&7玩家 UUI
 data_manager_timestamp: '[⌚ %1%](#ffc43b-#f5c962 show_text=&7快照時間:\n&8何時保存的資料)'
 data_manager_pinned: '[※ 被標記的快照](#d8ff2b show_text=&7標記:\n&8此快照資料不會自動輪換更新)'
 data_manager_cause: '[⚑ %1%](#23a825-#36f539 show_text=&7保存原因:\n&8保存此快照的原因)'
+data_manager_server: '[Ⓢ %1%](#ff87b3-#f5538e show_text=&7Server:\n&8Name of the server the data was saved on)'
 data_manager_size: '[⏏ %1%](color=#62a9f5-#7ab8fa show_text=&7Snapshot size:\n&8Estimated file size of the snapshot (in KiB))\n'
 data_manger_status: '[%1%](red)[/](gray)[%2%](red)[×](gray)[❤](red show_text=&7血量)   [%3%](yellow)[×](gray)[🍖](yellow show_text=&7飽食度)   [ʟᴠ](green)[.](gray)[%4%](green show_text=&7經驗等級)   [🏹 %5%](dark_aqua show_text=&7遊戲模式)'
 data_manager_advancements_statistics: '[⭐ 成就: %1%](color=#ffc43b-#f5c962 show_text=&7已獲得的成就:\n&8%2%)   [⌛ 遊戲時間: %3%ʜʀs](color=#62a9f5-#7ab8fa show_text=&7遊戲內的遊玩時間\n&8⚠ 根據遊戲內統計)\n'

docs/Config-File.md

@@ -1,6 +1,12 @@
-This page contains the configuration file reference for HuskSync. The config file is located in `/plugins/HuskSync/config.yml`
+This page contains the configuration structure for HuskSync.
 
-## Example config
+## Configuration structure
+📁 `plugins/HuskSync/`
+- 📄 `config.yml`: General plugin configuration
+- 📄 `server.yml`: Server ID configuration
+- 📄 `messages-xx-xx.yml`: Plugin locales, formatted in MineDown (see [[Translations]])
+
+## Example files
 <details>
 <summary>config.yml</summary>
 
@@ -12,7 +18,7 @@ This page contains the configuration file reference for HuskSync. The config fil
 # ┣╸ Information: https://william278.net/project/husksync
 # ┣╸ Config Help: https://william278.net/docs/husksync/config-file/
 # ┗╸ Documentation: https://william278.net/docs/husksync
-# Locale of the default language file to use. Docs: https://william278.net/docs/huskhomes/translations
+# Locale of the default language file to use. Docs: https://william278.net/docs/husksync/translations
 language: en-gb
 # Whether to automatically check for plugin updates on startup
 check_for_updates: true
@@ -54,6 +60,8 @@ redis:
     password: ''
   use_ssl: false
 synchronization:
+  # The mode of data synchronization to use (DELAY or LOCKSTEP). DELAY should be fine for most networks. Docs: https://william278.net/docs/husksync/sync-modes
+  mode: DELAY
   # The number of data snapshot backups that should be kept at once per user
   max_user_data_snapshots: 16
   # Number of hours between new snapshots being saved as backups (Use "0" to backup all snapshots)
@@ -63,15 +71,19 @@ synchronization:
     - INVENTORY_COMMAND
     - ENDERCHEST_COMMAND
     - BACKUP_RESTORE
-    - CONVERTED_FROM_V2
     - LEGACY_MIGRATION
     - MPDB_MIGRATION
   # Whether to create a snapshot for users on a world when the server saves that world
   save_on_world_save: true
-  # Whether to create a snapshot for users when they die (containing their death drops)
-  save_on_death: false
-  # Whether to save empty death drops for users when they die
-  save_empty_drops_on_death: true
+  save_on_death:
+    # Whether to create a snapshot for users when they die (containing their death drops)
+    enabled: true
+    # What items to save in death snapshots? (DROPS or ITEMS_TO_KEEP). Note that ITEMS_TO_KEEP (suggested for keepInventory servers) requires a Paper 1.19.4+ server
+    items_to_save: DROPS
+    # Should a death snapshot still be created even if the items to save on the player's death are empty?
+    save_empty_items: false
+    # Whether dead players who log out and log in to a different server should have their items saved.
+    sync_dead_players_changing_server: true
   # Whether to use the snappy data compression algorithm. Keep on unless you know what you're doing
   compress_data: true
   # Where to display sync notifications (ACTION_BAR, CHAT, TOAST or NONE)
@@ -80,9 +92,7 @@ synchronization:
   persist_locked_maps: true
   # Whether to synchronize player max health (requires health syncing to be enabled)
   synchronize_max_health: true
-  # Whether dead players who log out and log in to a different server should have their items saved. You may need to modify this if you're using the keepInventory gamerule.
-  synchronize_dead_players_changing_server: true
-  # How long, in milliseconds, this server should wait for a response from the redis server before pulling data from the database instead (i.e., if the user did not change servers).
+  # If using the DELAY sync method, how long should this server listen for Redis key data updates before pulling data from the database instead (i.e., if the user did not change servers).
   network_latency_milliseconds: 500
   # Which data types to synchronize (Docs: https://william278.net/docs/husksync/sync-features)
   features:
@@ -109,5 +119,17 @@ synchronization:
 
 </details>
 
-## Messages files
-You can customize the plugin locales, too, by editing your `messages-xx-xx.yml` file. This file is formatted using [MineDown syntax](https://github.com/Phoenix616/MineDown). For more information, see [[Translations]].
+<details>
+<summary>server.yml</summary>
+
+```yaml
+# ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
+# ┃   HuskSync Server ID config  ┃
+# ┃    Developed by William278   ┃
+# ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
+# ┣╸ This file should contain the ID of this server as defined in your proxy config.
+# ┗╸ If you join it using /server alpha, then set it to 'alpha' (case-sensitive)
+name: beta
+```
+
+</details>

docs/Custom-Data-API.md

@@ -4,6 +4,8 @@ To do this, you create and register an implementation of a platform `Data` class
 
 > **Note:** Before you begin, consider if this is what you'd like to do. For simpler/smaller data sync tasks you may wish to consider using the PersistentDataContainer API format instead, which is a bit more portable if you decide to exit the HuskSync ecosystem.
 
+If you'd like to have a look at an example of a data extension for HuskSync that provides serializers for Pixelmon data when running the plugin on Arclight, check out [PokeSync by GsTio86](https://github.com/GsTio86/PokeSync)!
+
 ## Table of Contents
 1. [Extending the BukkitData Class](#1-extending-the-bukkitdata-class)
    1. [Implementing Adaptable](#11-implementing-adaptable) 

docs/Data-Snapshot-API.md

@@ -307,7 +307,7 @@ huskSyncAPI.editCurrentInventory(user, inventory -> {
     // Get the player's inventory contents
     ItemStack[] inventoryContents = ((BukkitData.Items.Inventory) inventory).getContents();
     
-    // The array of ItemStacks is a copy of the player's inventory contents (in 1.20.1, this is an array of length 42)
+    // The array of ItemStacks is a copy of the player's inventory contents (Typically an array of length 42)
     inventoryContents[0] = new ItemStack(Material.DIAMOND_SWORD);
     inventoryContents[1] = null; // null = an empty slot
     

docs/Dumping-UserData.md

@@ -23,7 +23,8 @@ The name of the generated .json file will match the following format: `<username
   "pinned": false,
   "timestamp": "2023-09-15T17:27:08.6768038+01:00",
   "save_cause": "DISCONNECT",
-  "minecraft_version": "1.20.1",
+  "server": "alpha",
+  "minecraft_version": "1.20.2",
   "platform_type": "bukkit",
   "format_version": 4,
   "data": {

docs/FAQs.md

@@ -33,9 +33,7 @@ HuskSync requires Redis to operate (for reasons demonstrated below). Redis is an
 <details>
 <summary>&nbsp;<b>How does the plugin synchronize data?</b></summary>
 
-![System diagram](https://raw.githubusercontent.com/WiIIiam278/HuskSync/master/images/system-diagram.png)
-
-HuskSync makes use of both MySQL and Redis for optimal data synchronization.
+HuskSync makes use of both MySQL and Redis for optimal data synchronization. You have the option of using one of two [[Sync Modes]], which synchronize data between servers (`DELAY` or `LOCKSTEP`)
 
 When a user changes servers, in addition to data being saved to MySQL, it is also cached via the Redis server with a temporary expiry key. When changing servers, the receiving server detects the key and sets the user data from Redis. When a player rejoins the network, the system fetches the last-saved data snapshot from the MySQL Database.
 

docs/Home.md

@@ -14,6 +14,7 @@ Welcome! This is the plugin documentation for HuskSync v3.x+. Please click throu
 ## Documentation
 * 🖥️ [[Commands]]
 * ✅ [[Sync Features]]
+* ⚙️ [[Sync Modes]]
 * 🟩 [[Plan Hook]]
 * ☂️ [[Dumping UserData]]
 * 📋 [[Event Priorities]]

docs/Keep-Inventory.md

@@ -8,22 +8,26 @@ HuskSync has some special handling when players die, to account for scenarios wh
 * **Snapshot creation on death**—HuskSync can create a special snapshot for backup purposes when a player dies, formed by taking their drops and setting this to their inventory. When `keepInventory` is enabled, the player drops are empty, so this creates an inaccurate snapshot. This option is disabled by default.
 
 ## How can this be fixed?
-You will need to set the `synchronization.save_on_death` (which controls making snapshots on death), `save_empty_drops_on_death` (which controls whether snapshots of players who have no items to drop should be created), and `synchronization.synchronize_dead_players_changing_server` (which controls whether to sync dead players when they change servers) options to `false` in `config.yml`.
+You should change the `items_to_save` mode to `ITEMS_TO_KEEP` instead of drops. Also, ensure `save_empty_items` and `sync_dead_players_changing_server` are enabled.
 
 <details>
-  <summary>Example in config.yml</summary>
-  
-  ```yml
-     synchronization:
-       # ...
-       save_on_death: false # <-- Set this to false
-       save_empty_drops_on_death: false # <-- Set this to false
-       # ...
-       synchronize_dead_players_changing_server: false # <-- Set this to false
-  ```
-  
-</details>
+<summary>Example in config.yml</summary>
 
+```yml
+ synchronization:
+   #...
+   save_on_death:
+     # Whether to create a snapshot for users when they die (containing their death drops)
+     enabled: true
+     # What items to save in death snapshots? (DROPS or ITEMS_TO_KEEP). Note that ITEMS_TO_KEEP (suggested for keepInventory servers) requires a Paper 1.19.4+ server
+     items_to_save: ITEMS_TO_KEEP
+     # Should a death snapshot still be created even if the items to save on the player's death are empty?
+     save_empty_items: true
+     # Whether dead players who log out and log in to a different server should have their items saved.
+     sync_dead_players_changing_server: true
+   #...
+```
+</details>
 
 ## Troubleshooting with custom keepInventory setups
 If the above doesn't work for you, you may need to do more things to get this to work properly.

docs/Legacy-Migration.md

@@ -1,4 +1,4 @@
-This guide will walk you through how to upgrade from HuskSync v1.4.x to HuskSync v2.x or v3.x. Data from HuskSync v2.x will automatically be imported into HuskSync v3.x.
+This guide will walk you through how to upgrade from HuskSync v1.4.x to HuskSync v3.x. Data from HuskSync v2.x will automatically be imported into HuskSync v3.x.
 
 ## Requirements
 - MySQL Database with HuskSync v1.4.x data
@@ -9,15 +9,15 @@ This guide will walk you through how to upgrade from HuskSync v1.4.x to HuskSync
 ### 1. Uninstall HuskSync v1.x from all servers
 - Switch off all servers and your proxy
 - Delete the .jar file from your `~/plugins/` folders on your Spigot servers
-- Also delete the .jar file from your `~/plugins/` folders on your Proxy. HuskSync v2.x no longer requires a proxy plugin.
-- Delete (or make a copy and delete) all HuskSync config data folders (`~/plugins/HuskSync/`). HuskSync 2.x has a new config and messages file.
+- Also delete the .jar file from your `~/plugins/` folders on your Proxy. HuskSync v3.x no longer requires a proxy plugin.
+- Delete (or make a copy and delete) all HuskSync config data folders (`~/plugins/HuskSync/`). HuskSync v3.x has new `config.yml`, `messages-xx-xx.yml` and `server.yml` files.
 
-### 2. Install HuskSync v2.x on all Spigot servers
-- HuskSync v2.x must only be installed on your Spigot servers, not your proxy.
+### 2. Install HuskSync v3.x on all Spigot servers
+- HuskSync v3.x must only be installed on your Spigot servers, not your proxy.
 - Follow the setup instructions [here](Setup).
 
 ### 3. Configure the migrator
-- With your servers back on and correctly configured to run HuskSync v2.x, ensure nobody is online.
+- With your servers back on and correctly configured to run HuskSync v3.x, ensure nobody is online.
 - Use the console on one of your Spigot servers to enter: `husksync migrate legacy`
 - Carefully read the migration configuration instructions. In most cases, you won't have to change the settings, but if you do need to adjust them, use `husksync migrate legacy set <setting> <value>`.
 - Migration will be carried out *from* the database you specify with the settings in console *to* the database configured in `config.yml`. If you're migrating from multiple clusters, ensure you run the migrator on the correct servers corresponding to the migrator.

docs/MPDB-Migration.md

@@ -1,5 +1,7 @@
 This guide will walk you through how to migrate from MySQLPlayerDataBridge (MPDB) to HuskSync v2.x.
 
+> **Warning:** Please note that due to MPDB changes, HuskSync only supports migrating from MySQLPlayerDataBridge `<= v4.9.2`. Support for newer versions will be added in the future.
+
 ## Requirements
 - Spigot servers with MySQLPlayerDataBridge *still installed*
 

docs/Setup.md

@@ -1,6 +1,8 @@
 This will walk you through installing HuskSync on your network of Spigot servers.
 
 ## Requirements
+> **Note:** If the plugin fails to load, please check that you are not running an [incompatible version combination](Unsupported-Versions)
+
 * A MySQL Database (v8.0+)
 * A Redis Database (v5.0+) — see [[FAQs]] for more details.
 * Any number of Spigot servers, connected by a BungeeCord or Velocity-based proxy (Minecraft v1.16.5+, running Java 16+)
@@ -17,8 +19,11 @@ This will walk you through installing HuskSync on your network of Spigot servers
 - Navigate to the HuskSync config file on each server (`~/plugins/HuskSync/config.yml`)
 - Under `credentials` in the `database` section, enter the credentials of your MySQL Database. You shouldn't touch the `connection_pool` properties.
 - Under `credentials` in the `redis` section, enter the credentials of your Redis Database. If your Redis server doesn't have a password, leave the password blank as it is.
-- Unless you want to have multiple clusters of servers within your network, each with separate user data, do not change the value of `cluster_id`.
-### 4. Start every server again
+- Unless you want to have multiple clusters of servers within your network, each with separate user data, you should not change the value of `cluster_id`.
+### 4. Set server names in server.yml files
+- Navigate to the HuskSync server name file on each server (`~/plugins/HuskSync/server.yml`)
+- Set the `name:` of the server in this file to the ID of this server as defined in the config of your proxy (e.g., if this is the "hub" server you access with `/server hub`, put `'hub'` here)
+### 5. Start every server again
 - Provided your MySQL and Redis credentials were correct, synchronization should begin as soon as you start your servers again.
 - If you need to import data from HuskSync v1.x or MySQLPlayerDataBridge, please see the guides below:
   - [[Legacy Migration]]

docs/Sync-Modes.md

@@ -0,0 +1,45 @@
+HuskSync offers two built-in **synchronization modes** that utilise Redis and MySQL to optimally sync data as users change servers (illustrated below). These sync modes change the way data is synced between servers, and can be changed in the `config.yml` file.
+
+![Overall architecture of the synchronisation systems](https://raw.githubusercontent.com/WiIIiam278/HuskSync/master/images/system-diagram.png)
+
+## Available Modes
+* The `DELAY` sync mode is the default sync mode, that use the `network_latency_miliseconds` value to apply a delay before listening to Redis data
+* The `LOCKSTEP` sync mode uses a data checkout system to ensure that all servers are in sync regardless of network latency or tick rate fluctuations. This mode was introduced in HuskSync v3.1
+
+You can change which sync mode you are using by editing the `sync_mode` setting under `synchronization` in `config.yml`. 
+
+> **Warning:** Please note that you must use the same sync mode on all servers (at least within a cluster).
+
+<details>
+<summary>Changing the sync mode (config.yml)</summary>
+
+```yaml
+synchronization:
+  # The mode of data synchronization to use (DELAY or LOCKSTEP). DELAY should be fine for most networks. Docs: https://william278.net/docs/husksync/sync-modes
+  mode: DELAY
+```
+</details>
+
+## Delay
+The `DELAY` sync mode works as described below:
+* When a user disconnects from a server, a `SERVER_SWITCH` key is immediately set on Redis, followed by a `DATA_UPDATE` key which contains the user's packed and serialized Data Snapshot.
+* When the user connects to a server, they are marked as locked (unable to break blocks, use containers, etc.)
+* The server asynchronously waits for the `network_latency_miliseconds` value (default: 500ms) to allow the source server time to serialize & set their key.
+* After waiting, the server checks for the `SERVER_SWITCH` key. 
+  * If present, it will continuously attempt to read for a `DATA_UPDATE` key; when read, their data will be set from the snapshot deserialized from Redis.
+  * If not present, their data will be pulled from the database (as though they joined the network)
+
+`DELAY` has been the default sync mode since HuskSync v2.0. In HuskSync v3.1, `LOCKSTEP` was introduced. Since the delay mode has been tested and deployed for the longest, it is still the default, though note this may change in the future.
+
+However, if your network has a fluctuating tick rate or significant latency (especially if you have servers on different hardware/locations), you may wish to use `LOCKSTEP` instead for a more reliable sync system.
+
+## Lockstep
+The `LOCKSTEP` sync mode works as described below:
+* When a user connects to a server, the server will continuously asynchronously check if a `DATA_CHECKOUT` key is present. 
+  * If, or when, the key is not present, the plugin will set a new `DATA_CHECKOUT` key.
+* After this, the plugin will check Redis for the presence of a `DATA_UPDATE` key. 
+  * If a `DATA_UPDATE` key is present, the user's data will be set from the snapshot deserialized from Redis contained within that key.
+  * Otherwise, their data will be pulled from the database.
+* When a user disconnects from a server, their data is serialized and set to Redis with a `DATA_UPDATE` key. After this key has been set, the user's current `DATA_CHECKOUT` key will be removed from Redis.
+
+Additionally, note that `DATA_CHECKOUT` keys are set with the server ID of the server which "checked out" the data (taken from the `server.yml` config file). On both shutdown and startup, the plugin will clear all `DATA_CHECKOUT` keys for the current server ID (to prevent stale keys in the event of a server crash for instance)

docs/Translations.md

@@ -3,10 +3,10 @@ HuskSync supports a number of community-sourced translations of the plugin local
 You can change which preset language option to use by changing the top-level `language` setting in the plugin config.yml file. You must change this to one of the supported language codes. You can [view a list of the supported languages](https://github.com/WiIIiam278/HuskSync/tree/master/common/src/main/resources/locales) by looking at the locales source folder.
 
 ## Contributing Locales
-You can contribute locales by submitting a pull request with a yaml file containing translations of the [default locales](https://github.com/WiIIiam278/HuskSync/blob/master/common/src/main/resources/locales/en-gb.yml) into your language. Here's a few pointers for doing this: 
-* Do not translate the locale keys themselves (e.g. `teleporting_offline_player`)
+You can contribute locales by submitting a pull request with a yaml file containing translations of the [default locales](https://github.com/WiIIiam278/HuskSync/blob/master/common/src/main/resources/locales/en-gb.yml) into your language. Here are a few pointers for doing this: 
+* Do not translate the locale keys themselves (e.g. `synchronization_complete`)
 * Your pull request should be for a file in the [locales folder](https://github.com/WiIIiam278/HuskSync/tree/master/common/src/main/resources/locales)
-* Do not translate the [MineDown](https://github.com/Phoenix616/MineDown) markdown syntax itself or commands and their parameters; only the english interface text
+* Do not translate the [MineDown](https://github.com/Phoenix616/MineDown) Markdown syntax itself or commands and their parameters; only the english interface text
 * Each locale should be on one line, and the header should be removed.
 * Use the correct ISO 639-1 [locale code](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes) for your language and dialect
 * If you are able to, you can add your name to the `AboutMenu` translators credit list yourself, otherwise this can be done for you

docs/Unsupported-Versions.md

@@ -0,0 +1,10 @@
+This plugin does not support the following software-Minecraft version combinations. The plugin will fail to load if you attempt to run it with these versions. Apologies for the inconvenience.
+
+## Incompatibility table
+| Minecraft Versions | Server Software                           | Notes                                  |
+|--------------------|-------------------------------------------|----------------------------------------|
+| 1.19.4             | Only: `Purpur, Pufferfish`†        | Older Paper builds also not supported. |
+| 1.19.3             | Only: `Paper, Purpur, Pufferfish`† | Upgrade to 1.19.4 or use Spigot        |
+| below 1.16.5       | _All_                                     | Upgrade to 1.16.5                      |
+
+†Further downstream forks of this server software are also affected.

docs/_Sidebar.md

@@ -11,6 +11,7 @@
 ## Documentation
 * 🖥️ [[Commands]]
 * ✅ [[Sync Features]]
+* ⚙️ [[Sync Modes]]
 * 🟩 [[Plan Hook]]
 * ☂️ [[Dumping UserData]]
 * 📋 [[Event Priorities]]

gradle.properties

@@ -3,7 +3,7 @@ org.gradle.jvmargs='-Dfile.encoding=UTF-8'
 org.gradle.daemon=true
 javaVersion=16
 
-plugin_version=3.0.2
+plugin_version=3.1
 plugin_archive=husksync
 plugin_description=A modern, cross-server player data synchronization system
 

paper/build.gradle

@@ -0,0 +1,41 @@
+dependencies {
+    implementation project(':bukkit')
+    compileOnly project(':common')
+
+    compileOnly 'io.papermc.paper:paper-api:1.19.4-R0.1-SNAPSHOT'
+}
+
+shadowJar {
+    dependencies {
+        exclude(dependency('com.mojang:brigadier'))
+    }
+
+    relocate 'org.apache.commons.io', 'net.william278.husksync.libraries.commons.io'
+    relocate 'org.apache.commons.text', 'net.william278.husksync.libraries.commons.text'
+    relocate 'org.apache.commons.lang3', 'net.william278.husksync.libraries.commons.lang3'
+    relocate 'com.google.gson', 'net.william278.husksync.libraries.gson'
+    relocate 'org.json', 'net.william278.husksync.libraries.json'
+    relocate 'com.fatboyindustrial', 'net.william278.husksync.libraries'
+    relocate 'de.themoep', 'net.william278.husksync.libraries'
+    relocate 'net.kyori', 'net.william278.husksync.libraries'
+    relocate 'org.jetbrains', 'net.william278.husksync.libraries'
+    relocate 'org.intellij', 'net.william278.husksync.libraries'
+    relocate 'com.zaxxer', 'net.william278.husksync.libraries'
+    relocate 'dev.dejvokep', 'net.william278.husksync.libraries'
+    relocate 'net.william278.desertwell', 'net.william278.husksync.libraries.desertwell'
+    relocate 'net.william278.paginedown', 'net.william278.husksync.libraries.paginedown'
+    relocate 'net.william278.mapdataapi', 'net.william278.husksync.libraries.mapdataapi'
+    relocate 'net.william278.andjam', 'net.william278.husksync.libraries.andjam'
+    relocate 'net.querz', 'net.william278.husksync.libraries.nbtparser'
+    relocate 'net.roxeez', 'net.william278.husksync.libraries'
+
+    relocate 'me.lucko.commodore', 'net.william278.husksync.libraries.commodore'
+    relocate 'net.byteflux.libby', 'net.william278.husksync.libraries.libby'
+    relocate 'org.bstats', 'net.william278.husksync.libraries.bstats'
+    relocate 'dev.triumphteam.gui', 'net.william278.husksync.libraries.triumphgui'
+    relocate 'net.william278.mpdbconverter', 'net.william278.husksync.libraries.mpdbconverter'
+    relocate 'net.william278.hslmigrator', 'net.william278.husksync.libraries.hslconverter'
+    relocate 'net.william278.annotaml', 'net.william278.husksync.libraries.annotaml'
+    relocate 'space.arim.morepaperlib', 'net.william278.husksync.libraries.paperlib'
+    relocate 'de.tr7zw.changeme.nbtapi', 'net.william278.husksync.libraries.nbtapi'
+}

paper/src/main/java/net/william278/husksync/PaperHuskSync.java

@@ -0,0 +1,35 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync;
+
+import net.william278.husksync.listener.BukkitEventListener;
+import net.william278.husksync.listener.PaperEventListener;
+import org.jetbrains.annotations.NotNull;
+
+@SuppressWarnings("unused")
+public class PaperHuskSync extends BukkitHuskSync {
+
+    @NotNull
+    @Override
+    protected BukkitEventListener createEventListener() {
+        return new PaperEventListener(this);
+    }
+
+}

paper/src/main/java/net/william278/husksync/PaperHuskSyncLoader.java

@@ -0,0 +1,82 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync;
+
+import io.papermc.paper.plugin.loader.PluginClasspathBuilder;
+import io.papermc.paper.plugin.loader.PluginLoader;
+import io.papermc.paper.plugin.loader.library.impl.MavenLibraryResolver;
+import net.william278.annotaml.Annotaml;
+import net.william278.annotaml.YamlFile;
+import net.william278.annotaml.YamlKey;
+import org.eclipse.aether.artifact.DefaultArtifact;
+import org.eclipse.aether.graph.Dependency;
+import org.eclipse.aether.repository.RemoteRepository;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.InputStream;
+import java.util.List;
+import java.util.Objects;
+
+@SuppressWarnings({"UnstableApiUsage", "unused"})
+public class PaperHuskSyncLoader implements PluginLoader {
+
+    @Override
+    public void classloader(@NotNull PluginClasspathBuilder classpathBuilder) {
+        MavenLibraryResolver resolver = new MavenLibraryResolver();
+
+        resolveLibraries(classpathBuilder).stream()
+                .map(DefaultArtifact::new)
+                .forEach(artifact -> resolver.addDependency(new Dependency(artifact, null)));
+        resolver.addRepository(new RemoteRepository.Builder(
+                "maven", "default", "https://repo.maven.apache.org/maven2/"
+        ).build());
+
+        classpathBuilder.addLibrary(resolver);
+    }
+
+    @NotNull
+    private static List<String> resolveLibraries(@NotNull PluginClasspathBuilder classpathBuilder) {
+        try (InputStream input = getLibraryListFile()) {
+            return Annotaml.create(PaperLibraries.class, Objects.requireNonNull(input)).get().libraries;
+        } catch (Exception e) {
+            classpathBuilder.getContext().getLogger().error("Failed to resolve libraries", e);
+        }
+        return List.of();
+    }
+
+    @Nullable
+    private static InputStream getLibraryListFile() {
+        return PaperHuskSyncLoader.class.getClassLoader().getResourceAsStream("paper-libraries.yml");
+    }
+
+    @YamlFile(header = "Dependencies for HuskSync on Paper")
+    public static class PaperLibraries {
+
+        @YamlKey("libraries")
+        private List<String> libraries;
+
+        @SuppressWarnings("unused")
+        private PaperLibraries() {
+        }
+
+    }
+
+}

paper/src/main/java/net/william278/husksync/listener/PaperEventListener.java

@@ -0,0 +1,65 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync.listener;
+
+import net.william278.husksync.BukkitHuskSync;
+import net.william278.husksync.data.BukkitData;
+import net.william278.husksync.user.BukkitUser;
+import net.william278.husksync.user.OnlineUser;
+import org.bukkit.event.entity.PlayerDeathEvent;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public class PaperEventListener extends BukkitEventListener {
+
+    public PaperEventListener(@NotNull BukkitHuskSync plugin) {
+        super(plugin);
+    }
+
+    @Override
+    public void handlePlayerDeath(@NotNull PlayerDeathEvent event) {
+        // If the player is locked or the plugin disabling, clear their drops
+        final OnlineUser user = BukkitUser.adapt(event.getEntity(), plugin);
+        if (cancelPlayerEvent(user.getUuid())) {
+            event.getDrops().clear();
+            event.getItemsToKeep().clear();
+            return;
+        }
+
+        // Handle saving player data snapshots on death
+        if (!plugin.getSettings().doSaveOnDeath()) {
+            return;
+        }
+
+        // Paper - support saving the player's items to keep if enabled
+        final int maxInventorySize = BukkitData.Items.Inventory.INVENTORY_SLOT_COUNT;
+        final List<ItemStack> itemsToSave = switch (plugin.getSettings().getDeathItemsMode()) {
+            case DROPS -> event.getDrops();
+            case ITEMS_TO_KEEP -> event.getItemsToKeep();
+        };
+        if (itemsToSave.size() > maxInventorySize) {
+            itemsToSave.subList(maxInventorySize, itemsToSave.size()).clear();
+        }
+        super.saveOnPlayerDeath(user, BukkitData.Items.ItemArray.adapt(itemsToSave));
+    }
+
+}

paper/src/main/resources/paper-libraries.yml

@@ -0,0 +1,6 @@
+# Dependencies for HuskSync on Paper
+libraries:
+  - 'redis.clients:jedis:${jedis_version}'
+  - 'com.mysql:mysql-connector-j:${mysql_driver_version}'
+  - 'org.mariadb.jdbc:mariadb-java-client:${mariadb_driver_version}'
+  - 'org.xerial.snappy:snappy-java:${snappy_version}'

paper/src/main/resources/paper-plugin.yml

@@ -0,0 +1,18 @@
+name: 'HuskSync'
+description: '${description}'
+author: 'William278'
+website: 'https://william278.net/'
+main: 'net.william278.husksync.PaperHuskSync'
+loader: 'net.william278.husksync.PaperHuskSyncLoader'
+version: '${version}'
+api-version: '1.19'
+dependencies:
+  server:
+    MysqlPlayerDataBridge:
+      required: false
+      load: BEFORE
+      join-classpath: true
+    Plan:
+      required: false
+      load: BEFORE
+      join-classpath: true

plugin/build.gradle

@@ -1,3 +1,4 @@
 dependencies {
     implementation project(path: ':bukkit', configuration: 'shadow')
+    runtimeOnly project(path: ':paper')
 }

settings.gradle

@@ -5,7 +5,9 @@ pluginManagement {
 }
 
 rootProject.name = 'HuskSync'
-
-include 'common'
-include 'bukkit'
-include 'plugin'
+include(
+        'common',
+        'bukkit',
+        'paper',
+        'plugin'
+)

test/requirements.txt

@@ -4,4 +4,4 @@ colorama==0.4.6
 idna==3.4
 requests==2.31.0
 tqdm==4.66.1
-urllib3==2.0.4
+urllib3==2.0.6

test/spin_network.py

@@ -13,7 +13,7 @@ from tqdm import tqdm
 class Parameters:
     root_dir = './servers/'
     proxy_version = "1.20"
-    minecraft_version = '1.20.1'
+    minecraft_version = '1.20.2'
     eula_agreement = 'true'
 
     backend_names = ['alpha', 'beta']