Expand on entity serialization API (#11807)

paper-api/src/main/java/io/papermc/paper/entity/EntitySerializationFlag.java

@@ -0,0 +1,38 @@
+package io.papermc.paper.entity;
+
+import org.bukkit.UnsafeValues;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+
+/**
+ * Represents flags for entity serialization.
+ *
+ * @see UnsafeValues#serializeEntity(Entity, EntitySerializationFlag... serializationFlags)
+ * @since 1.21.4
+ */
+public enum EntitySerializationFlag {
+
+    /**
+     * Serialize entities that wouldn't be serialized normally
+     * (e.g. dead, despawned, non-persistent, etc.).
+     *
+     * @see Entity#isValid()
+     * @see Entity#isPersistent()
+     */
+    FORCE,
+    /**
+     * Serialize misc non-saveable entities like lighting bolts, fishing bobbers, etc.
+     * <br>Note: players require a separate flag: {@link #PLAYER}.
+     */
+    MISC,
+    /**
+     * Include passengers in the serialized data.
+     */
+    PASSENGERS,
+    /**
+     * Allow serializing {@link Player}s.
+     * <p>Note: deserializing player data will always fail.
+     */
+    PLAYER
+
+}

paper-api/src/main/java/org/bukkit/UnsafeValues.java

@@ -1,6 +1,7 @@
 package org.bukkit;
 
 import com.google.common.collect.Multimap;
+import io.papermc.paper.entity.EntitySerializationFlag;
 import org.bukkit.advancement.Advancement;
 import org.bukkit.attribute.Attribute;
 import org.bukkit.attribute.AttributeModifier;
@@ -9,7 +10,9 @@ import org.bukkit.block.data.BlockData;
 import org.bukkit.damage.DamageEffect;
 import org.bukkit.damage.DamageSource;
 import org.bukkit.damage.DamageType;
+import org.bukkit.entity.Entity;
 import org.bukkit.entity.EntityType;
+import org.bukkit.event.entity.CreatureSpawnEvent;
 import org.bukkit.inventory.CreativeCategory;
 import org.bukkit.inventory.EquipmentSlot;
 import org.bukkit.inventory.ItemStack;
@@ -198,13 +201,81 @@ public interface UnsafeValues {
      */
     @NotNull ItemStack deserializeItemFromJson(@NotNull com.google.gson.JsonObject data) throws IllegalArgumentException;
 
-    byte[] serializeEntity(org.bukkit.entity.Entity entity);
+    /**
+     * Serializes the provided entity.
+     *
+     * @param entity entity
+     * @return serialized entity data
+     * @see #serializeEntity(Entity, EntitySerializationFlag...)
+     * @see #deserializeEntity(byte[], World, boolean, boolean)
+     * @throws IllegalArgumentException if couldn't serialize the entity
+     * @since 1.17.1
+     */
+    default byte @NotNull [] serializeEntity(@NotNull Entity entity) {
+        return serializeEntity(entity, new EntitySerializationFlag[0]);
+    }
 
-    default org.bukkit.entity.Entity deserializeEntity(byte[] data, World world) {
+    /**
+     * Serializes the provided entity.
+     *
+     * @param entity entity
+     * @param serializationFlags serialization flags
+     * @return serialized entity data
+     * @throws IllegalArgumentException if couldn't serialize the entity
+     * @see #deserializeEntity(byte[], World, boolean, boolean)
+     * @since 1.21.4
+     */
+    byte @NotNull [] serializeEntity(@NotNull Entity entity, @NotNull EntitySerializationFlag... serializationFlags);
+
+    /**
+     * Deserializes the entity from data.
+     * <br>The entity's {@link java.util.UUID} as well as passengers will not be preserved.
+     *
+     * @param data serialized entity data
+     * @param world world
+     * @return deserialized entity
+     * @throws IllegalArgumentException if invalid serialized entity data provided
+     * @see #deserializeEntity(byte[], World, boolean, boolean)
+     * @see #serializeEntity(Entity, EntitySerializationFlag...)
+     * @see Entity#spawnAt(Location, CreatureSpawnEvent.SpawnReason)
+     * @since 1.17.1
+     */
+    default @NotNull Entity deserializeEntity(byte @NotNull [] data, @NotNull World world) {
         return deserializeEntity(data, world, false);
     }
 
-    org.bukkit.entity.Entity deserializeEntity(byte[] data, World world, boolean preserveUUID);
+    /**
+     * Deserializes the entity from data.
+     * <br>The entity's passengers will not be preserved.
+     *
+     * @param data serialized entity data
+     * @param world world
+     * @param preserveUUID whether to preserve the entity's uuid
+     * @return deserialized entity
+     * @throws IllegalArgumentException if invalid serialized entity data provided
+     * @see #deserializeEntity(byte[], World, boolean, boolean)
+     * @see #serializeEntity(Entity, EntitySerializationFlag...)
+     * @see Entity#spawnAt(Location, CreatureSpawnEvent.SpawnReason)
+     * @since 1.17.1
+     */
+    default @NotNull Entity deserializeEntity(byte @NotNull [] data, @NotNull World world, boolean preserveUUID) {
+        return deserializeEntity(data, world, preserveUUID, false);
+    }
+
+    /**
+     * Deserializes the entity from data.
+     *
+     * @param data serialized entity data
+     * @param world world
+     * @param preserveUUID whether to preserve uuids of the entity and its passengers
+     * @param preservePassengers whether to preserve passengers
+     * @return deserialized entity
+     * @throws IllegalArgumentException if invalid serialized entity data provided
+     * @see #serializeEntity(Entity, EntitySerializationFlag...)
+     * @see Entity#spawnAt(Location, CreatureSpawnEvent.SpawnReason)
+     * @since 1.21.4
+     */
+    @NotNull Entity deserializeEntity(byte @NotNull [] data, @NotNull World world, boolean preserveUUID, boolean preservePassengers);
 
     /**
      * Creates and returns the next EntityId available.

paper-api/src/main/java/org/bukkit/entity/Entity.java

@@ -14,6 +14,7 @@ import org.bukkit.World;
 import org.bukkit.block.BlockFace;
 import org.bukkit.block.PistonMoveReaction;
 import org.bukkit.command.CommandSender;
+import org.bukkit.event.entity.CreatureSpawnEvent;
 import org.bukkit.event.entity.EntityDamageEvent;
 import org.bukkit.event.player.PlayerTeleportEvent.TeleportCause;
 import org.bukkit.material.Directional;
@@ -1072,11 +1073,12 @@ public interface Entity extends Metadatable, CommandSender, Nameable, Persistent
      * <p>
      * Also, this method will fire the same events as a normal entity spawn.
      *
-     * @param location The location to spawn the entity at.
+     * @param location the location to spawn the entity at
-     * @return Whether the entity was successfully spawned.
+     * @return whether the entity was successfully spawned
+     * @since 1.17.1
      */
-    public default boolean spawnAt(@NotNull Location location) {
+    default boolean spawnAt(@NotNull Location location) {
-        return spawnAt(location, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DEFAULT);
+        return spawnAt(location, CreatureSpawnEvent.SpawnReason.DEFAULT);
     }
 
     /**
@@ -1086,11 +1088,12 @@ public interface Entity extends Metadatable, CommandSender, Nameable, Persistent
      * <p>
      * Also, this method will fire the same events as a normal entity spawn.
      *
-     * @param location The location to spawn the entity at.
+     * @param location the location to spawn the entity at
-     * @param reason   The reason for the entity being spawned.
+     * @param reason   the reason for the entity being spawned
-     * @return Whether the entity was successfully spawned.
+     * @return whether the entity was successfully spawned
+     * @since 1.17.1
      */
-    public boolean spawnAt(@NotNull Location location, @NotNull org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason reason);
+    boolean spawnAt(@NotNull Location location, @NotNull CreatureSpawnEvent.SpawnReason reason);
 
     /**
      * Check if entity is inside powdered snow.

paper-server/patches/features/0017-Moonrise-optimisation-patches.patch

@@ -26719,7 +26719,7 @@ index 2f49dbc919f7f5eea9abce6106723c72f5ae45fb..87d4291a3944f706a694536da6de0f28
      }
  }
 diff --git a/net/minecraft/server/level/ServerEntity.java b/net/minecraft/server/level/ServerEntity.java
-index 70f6d068b3f3665b282d9750310c883839120ab2..870b9efd445ddadb3725e88351555ad986ce7c72 100644
+index da793ad12565c36fffb26eb771ff68c76632caf7..db06f966077928419bfe469260f04d7dfda69f28 100644
 --- a/net/minecraft/server/level/ServerEntity.java
 +++ b/net/minecraft/server/level/ServerEntity.java
 @@ -91,6 +91,11 @@ public class ServerEntity {
@@ -27496,7 +27496,7 @@ index 192977dd661ee795ada13db895db770293e9b402..95a4e37a3c93f9b3c56c7a7376ed521c
      }
  
 diff --git a/net/minecraft/server/level/ServerPlayer.java b/net/minecraft/server/level/ServerPlayer.java
-index ff5889f8fed0707a6654d9d21862e32e2ebc866d..e61fe83479f095e8addbd3e8f1d5179c998ae1eb 100644
+index 097ec55166b9e9269142be58992c29687122fe28..aeabb79512aabd7a9e8af1be72e1745f0e7eefe4 100644
 --- a/net/minecraft/server/level/ServerPlayer.java
 +++ b/net/minecraft/server/level/ServerPlayer.java
 @@ -178,7 +178,7 @@ import net.minecraft.world.scores.Team;
@@ -28372,7 +28372,7 @@ index 8cc5c0716392ba06501542ff5cbe71ee43979e5d..09fd99c9cbd23b5f3c899bfb00c9b896
 +    // Paper end - block counting
  }
 diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
-index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab6814aef9ee 100644
+index 189385600b9094291152035b17df869eaccc0428..25a1089a7376f0cbd96bb43b5c203640c88fc282 100644
 --- a/net/minecraft/world/entity/Entity.java
 +++ b/net/minecraft/world/entity/Entity.java
 @@ -135,7 +135,7 @@ import net.minecraft.world.scores.ScoreHolder;
@@ -28725,7 +28725,7 @@ index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab68
      }
  
      private static float[] collectCandidateStepUpHeights(AABB box, List<VoxelShape> colliders, float deltaY, float maxUpStep) {
-@@ -2664,23 +2812,110 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -2662,23 +2810,110 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
      }
  
      public boolean isInWall() {
@@ -28849,7 +28849,7 @@ index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab68
      }
  
      public InteractionResult interact(Player player, InteractionHand hand) {
-@@ -4104,15 +4339,17 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4102,15 +4337,17 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
      }
  
      public Iterable<Entity> getIndirectPassengers() {
@@ -28875,7 +28875,7 @@ index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab68
      }
  
      public int countPlayerPassengers() {
-@@ -4250,77 +4487,136 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4248,77 +4485,136 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
          return Mth.lerp(partialTick, this.yRotO, this.yRot);
      }
  
@@ -29066,7 +29066,7 @@ index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab68
  
      public boolean touchingUnloadedChunk() {
          AABB aabb = this.getBoundingBox().inflate(1.0);
-@@ -4473,6 +4769,15 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4471,6 +4767,15 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
          this.setPosRaw(x, y, z, false);
      }
      public final void setPosRaw(double x, double y, double z, boolean forceBoundingBoxUpdate) {
@@ -29082,7 +29082,7 @@ index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab68
          if (!checkPosition(this, x, y, z)) {
              return;
          }
-@@ -4603,6 +4908,12 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4601,6 +4906,12 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
  
      @Override
      public final void setRemoved(Entity.RemovalReason removalReason, org.bukkit.event.entity.EntityRemoveEvent.Cause cause) {
@@ -29095,7 +29095,7 @@ index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab68
          org.bukkit.craftbukkit.event.CraftEventFactory.callEntityRemoveEvent(this, cause);
          // CraftBukkit end
          final boolean alreadyRemoved = this.removalReason != null; // Paper - Folia schedulers
-@@ -4614,7 +4925,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4612,7 +4923,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
              this.stopRiding();
          }
  
@@ -29104,7 +29104,7 @@ index 45f69a914d5a0565196c4105d61541047301470f..f42bdae2f80805e5069212bd16e3ab68
          this.levelCallback.onRemove(removalReason);
          this.onRemoval(removalReason);
          // Paper start - Folia schedulers
-@@ -4648,7 +4959,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4646,7 +4957,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
      public boolean shouldBeSaved() {
          return (this.removalReason == null || this.removalReason.shouldSave())
              && !this.isPassenger()

paper-server/patches/sources/net/minecraft/world/entity/Entity.java.patch

@@ -706,52 +706,44 @@
  
      public void awardKillScore(Entity entity, DamageSource damageSource) {
          if (entity instanceof ServerPlayer) {
-@@ -1752,34 +_,70 @@
+@@ -1752,15 +_,22 @@
      }
  
      public boolean saveAsPassenger(CompoundTag compound) {
+-        if (this.removalReason != null && !this.removalReason.shouldSave()) {
 +        // CraftBukkit start - allow excluding certain data when saving
-+        return this.saveAsPassenger(compound, true);
++        // Paper start - Raw entity serialization API
++        return this.saveAsPassenger(compound, true, false, false);
 +    }
-+
++    public boolean saveAsPassenger(CompoundTag compound, boolean includeAll, boolean includeNonSaveable, boolean forceSerialization) {
-+    public boolean saveAsPassenger(CompoundTag compound, boolean includeAll) {
++        // Paper end - Raw entity serialization API
 +        // CraftBukkit end
-         if (this.removalReason != null && !this.removalReason.shouldSave()) {
++        if (this.removalReason != null && !this.removalReason.shouldSave() && !forceSerialization) { // Paper - Raw entity serialization API
              return false;
          } else {
-             String encodeId = this.getEncodeId();
+-            String encodeId = this.getEncodeId();
 -            if (encodeId == null) {
-+            if (!this.persist || encodeId == null) { // CraftBukkit - persist flag
++            String encodeId = this.getEncodeId(includeNonSaveable); // Paper - Raw entity serialization API
++            if ((!this.persist && !forceSerialization) || encodeId == null) { // CraftBukkit - persist flag // Paper - Raw entity serialization API
                  return false;
              } else {
                  compound.putString("id", encodeId);
 -                this.saveWithoutId(compound);
-+                this.saveWithoutId(compound, includeAll); // CraftBukkit - pass on includeAll
++                this.saveWithoutId(compound, includeAll, includeNonSaveable, forceSerialization); // CraftBukkit - pass on includeAll // Paper - Raw entity serialization API
                  return true;
              }
          }
-     }
+@@ -1771,15 +_,37 @@
-+
-+    // Paper start - Entity serialization api
-+    public boolean serializeEntity(CompoundTag compound) {
-+        List<Entity> pass = new java.util.ArrayList<>(this.getPassengers());
-+        this.passengers = ImmutableList.of();
-+        boolean result = save(compound);
-+        this.passengers = ImmutableList.copyOf(pass);
-+        return result;
-+    }
-+    // Paper end - Entity serialization api
- 
-     public boolean save(CompoundTag compound) {
-         return !this.isPassenger() && this.saveAsPassenger(compound);
      }
  
      public CompoundTag saveWithoutId(CompoundTag compound) {
 +        // CraftBukkit start - allow excluding certain data when saving
-+        return this.saveWithoutId(compound, true);
++        // Paper start - Raw entity serialization API
++        return this.saveWithoutId(compound, true, false, false);
 +    }
 +
-+    public CompoundTag saveWithoutId(CompoundTag compound, boolean includeAll) {
++    public CompoundTag saveWithoutId(CompoundTag compound, boolean includeAll, boolean includeNonSaveable, boolean forceSerialization) {
++        // Paper end - Raw entity serialization API
 +        // CraftBukkit end
          try {
 -            if (this.vehicle != null) {
@@ -827,7 +819,7 @@
                  for (Entity entity : this.getPassengers()) {
                      CompoundTag compoundTag = new CompoundTag();
 -                    if (entity.saveAsPassenger(compoundTag)) {
-+                    if (entity.saveAsPassenger(compoundTag, includeAll)) { // CraftBukkit - pass on includeAll
++                    if (entity.saveAsPassenger(compoundTag, includeAll, includeNonSaveable, forceSerialization)) { // CraftBukkit - pass on includeAll // Paper - Raw entity serialization API
                          listTag.add(compoundTag);
                      }
                  }
@@ -935,19 +927,30 @@
          } catch (Throwable var17) {
              CrashReport crashReport = CrashReport.forThrowable(var17, "Loading entity NBT");
              CrashReportCategory crashReportCategory = crashReport.addCategory("Entity being loaded");
-@@ -1949,6 +_,12 @@
+@@ -1944,10 +_,21 @@
-         return type.canSerialize() && key != null ? key.toString() : null;
-     }
  
+     @Nullable
+     public final String getEncodeId() {
++        // Paper start - Raw entity serialization API
++        return getEncodeId(false);
++    }
++    public final @Nullable String getEncodeId(boolean includeNonSaveable) {
++        // Paper end - Raw entity serialization API
+         EntityType<?> type = this.getType();
+         ResourceLocation key = EntityType.getKey(type);
+-        return type.canSerialize() && key != null ? key.toString() : null;
+-    }
++        return (type.canSerialize() || includeNonSaveable) && key != null ? key.toString() : null; // Paper - Raw entity serialization API
++    }
++
 +    // CraftBukkit start - allow excluding certain data when saving
 +    protected void addAdditionalSaveData(CompoundTag tag, boolean includeAll) {
 +        this.addAdditionalSaveData(tag);
 +    }
 +    // CraftBukkit end
-+
+ 
      protected abstract void readAdditionalSaveData(CompoundTag tag);
  
-     protected abstract void addAdditionalSaveData(CompoundTag tag);
 @@ -1990,11 +_,61 @@
  
      @Nullable

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java

@@ -46,6 +46,7 @@ import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Player;
 import org.bukkit.entity.Pose;
 import org.bukkit.entity.SpawnCategory;
+import org.bukkit.event.entity.CreatureSpawnEvent;
 import org.bukkit.event.entity.EntityDamageEvent;
 import org.bukkit.event.entity.EntityRemoveEvent;
 import org.bukkit.event.player.PlayerTeleportEvent.TeleportCause;
@@ -955,7 +956,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
     @Override
     public String getAsString() {
         CompoundTag tag = new CompoundTag();
-        if (!this.getHandle().saveAsPassenger(tag, false)) {
+        if (!this.getHandle().saveAsPassenger(tag, false, false, false)) {
             return null;
         }
 
@@ -988,7 +989,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
 
     private Entity copy(net.minecraft.world.level.Level level) {
         CompoundTag compoundTag = new CompoundTag();
-        this.getHandle().saveAsPassenger(compoundTag, false);
+        this.getHandle().saveAsPassenger(compoundTag, false, true, true);
 
         return net.minecraft.world.entity.EntityType.loadEntityRecursive(compoundTag, level, EntitySpawnReason.LOAD, java.util.function.Function.identity());
     }
@@ -1224,17 +1225,19 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
     }
     // Paper end - tracked players API
 
-    // Paper start - raw entity serialization API
     @Override
-    public boolean spawnAt(Location location, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason reason) {
+    public boolean spawnAt(Location location, CreatureSpawnEvent.SpawnReason reason) {
         Preconditions.checkNotNull(location, "location cannot be null");
         Preconditions.checkNotNull(reason, "reason cannot be null");
         this.entity.setLevel(((CraftWorld) location.getWorld()).getHandle());
         this.entity.setPos(location.getX(), location.getY(), location.getZ());
         this.entity.setRot(location.getYaw(), location.getPitch());
-        return !this.entity.valid && this.entity.level().addFreshEntity(this.entity, reason);
+        final boolean spawned = !this.entity.valid && this.entity.level().addFreshEntity(this.entity, reason);
+        if (!spawned) return false; // Do not attempt to spawn rest if root was not spawned in
+        // Like net.minecraft.world.level.ServerLevelAccessor.addFreshEntityWithPassengers(net.minecraft.world.entity.Entity, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason)
+        this.entity.getIndirectPassengers().forEach(e -> e.level().addFreshEntity(e, reason));
+        return true;
     }
-    // Paper end - raw entity serialization API
 
     // Paper start - entity powdered snow API
     @Override

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftEntitySnapshot.java

@@ -66,7 +66,7 @@ public class CraftEntitySnapshot implements EntitySnapshot {
 
     public static CraftEntitySnapshot create(CraftEntity entity) {
         CompoundTag tag = new CompoundTag();
-        if (!entity.getHandle().saveAsPassenger(tag, false)) {
+        if (!entity.getHandle().saveAsPassenger(tag, false, false, false)) {
             return null;
         }
 

paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.util;
 
+import ca.spottedleaf.moonrise.common.PlatformHooks;
 import com.google.common.base.Charsets;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Multimap;
@@ -13,24 +14,34 @@ import com.mojang.serialization.Dynamic;
 import com.mojang.serialization.JsonOps;
 import java.io.File;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.EnumSet;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import java.util.stream.Stream;
+import io.papermc.paper.entity.EntitySerializationFlag;
 import net.minecraft.SharedConstants;
 import net.minecraft.advancements.AdvancementHolder;
 import net.minecraft.commands.Commands;
 import net.minecraft.commands.arguments.item.ItemParser;
 import net.minecraft.core.registries.BuiltInRegistries;
 import net.minecraft.core.registries.Registries;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
 import net.minecraft.nbt.NbtOps;
 import net.minecraft.nbt.StringTag;
 import net.minecraft.nbt.Tag;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerLevel;
 import net.minecraft.util.datafix.DataFixers;
 import net.minecraft.util.datafix.fixes.References;
+import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.alchemy.Potion;
 import net.minecraft.world.level.block.Block;
@@ -43,6 +54,7 @@ import org.bukkit.Material;
 import org.bukkit.NamespacedKey;
 import org.bukkit.Registry;
 import org.bukkit.UnsafeValues;
+import org.bukkit.World;
 import org.bukkit.advancement.Advancement;
 import org.bukkit.attribute.Attribute;
 import org.bukkit.attribute.AttributeModifier;
@@ -51,10 +63,12 @@ import org.bukkit.block.data.BlockData;
 // import org.bukkit.craftbukkit.CraftFeatureFlag; // Paper
 import org.bukkit.craftbukkit.CraftRegistry;
 import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.craftbukkit.block.CraftBiome;
 import org.bukkit.craftbukkit.block.data.CraftBlockData;
 import org.bukkit.craftbukkit.damage.CraftDamageEffect;
 import org.bukkit.craftbukkit.damage.CraftDamageSourceBuilder;
+import org.bukkit.craftbukkit.entity.CraftEntity;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.craftbukkit.legacy.CraftLegacy;
 import org.bukkit.craftbukkit.legacy.FieldRename;
@@ -513,7 +527,7 @@ public final class CraftMagicNumbers implements UnsafeValues {
         Preconditions.checkNotNull(item, "null cannot be serialized");
         Preconditions.checkArgument(item.getType() != Material.AIR, "air cannot be serialized");
 
-        return serializeNbtToBytes((net.minecraft.nbt.CompoundTag) (item instanceof CraftItemStack ? ((CraftItemStack) item).handle : CraftItemStack.asNMSCopy(item)).save(MinecraftServer.getServer().registryAccess()));
+        return serializeNbtToBytes((CompoundTag) (item instanceof CraftItemStack ? ((CraftItemStack) item).handle : CraftItemStack.asNMSCopy(item)).save(MinecraftServer.getServer().registryAccess()));
     }
 
     @Override
@@ -521,9 +535,9 @@ public final class CraftMagicNumbers implements UnsafeValues {
         Preconditions.checkNotNull(data, "null cannot be deserialized");
         Preconditions.checkArgument(data.length > 0, "cannot deserialize nothing");
 
-        net.minecraft.nbt.CompoundTag compound = deserializeNbtFromBytes(data);
+        CompoundTag compound = deserializeNbtFromBytes(data);
         final int dataVersion = compound.getInt("DataVersion");
-        compound = ca.spottedleaf.moonrise.common.PlatformHooks.get().convertNBT(References.ITEM_STACK, MinecraftServer.getServer().fixerUpper, compound, dataVersion, this.getDataVersion()); // Paper - possibly use dataconverter
+        compound = PlatformHooks.get().convertNBT(References.ITEM_STACK, MinecraftServer.getServer().fixerUpper, compound, dataVersion, this.getDataVersion()); // Paper - possibly use dataconverter
         return CraftItemStack.asCraftMirror(net.minecraft.world.item.ItemStack.parse(MinecraftServer.getServer().registryAccess(), compound).orElseThrow());
     }
 
@@ -558,32 +572,98 @@ public final class CraftMagicNumbers implements UnsafeValues {
     }
 
     @Override
-    public byte[] serializeEntity(org.bukkit.entity.Entity entity) {
+    public byte[] serializeEntity(org.bukkit.entity.Entity entity, EntitySerializationFlag... serializationFlags) {
         Preconditions.checkNotNull(entity, "null cannot be serialized");
-        Preconditions.checkArgument(entity instanceof org.bukkit.craftbukkit.entity.CraftEntity, "only CraftEntities can be serialized");
+        Preconditions.checkArgument(entity instanceof CraftEntity, "Only CraftEntities can be serialized");
 
-        net.minecraft.nbt.CompoundTag compound = new net.minecraft.nbt.CompoundTag();
+        Set<EntitySerializationFlag> flags = Set.of(serializationFlags);
-        ((org.bukkit.craftbukkit.entity.CraftEntity) entity).getHandle().serializeEntity(compound);
+        final boolean serializePassangers = flags.contains(EntitySerializationFlag.PASSENGERS);
+        final boolean forceSerialization = flags.contains(EntitySerializationFlag.FORCE);
+        final boolean allowPlayerSerialization = flags.contains(EntitySerializationFlag.PLAYER);
+        final boolean allowMiscSerialization = flags.contains(EntitySerializationFlag.MISC);
+        final boolean includeNonSaveable = allowPlayerSerialization || allowMiscSerialization;
+
+        net.minecraft.world.entity.Entity nmsEntity = ((CraftEntity) entity).getHandle();
+        (serializePassangers ? nmsEntity.getSelfAndPassengers() : Stream.of(nmsEntity)).forEach(e -> {
+            // Ensure force flag is not needed
+            Preconditions.checkArgument(
+                (e.getBukkitEntity().isValid() && e.getBukkitEntity().isPersistent()) || forceSerialization,
+                "Cannot serialize invalid or non-persistent entity %s(%s) without the FORCE flag",
+                e.getType().toShortString(),
+                e.getStringUUID()
+            );
+
+            if (e instanceof Player) {
+                // Ensure player flag is not needed
+                Preconditions.checkArgument(
+                    allowPlayerSerialization,
+                    "Cannot serialize player(%s) without the PLAYER flag",
+                    e.getStringUUID()
+                );
+            } else {
+                // Ensure player flag is not needed
+                Preconditions.checkArgument(
+                    nmsEntity.getType().canSerialize() || allowMiscSerialization,
+                    "Cannot serialize misc non-saveable entity %s(%s) without the MISC flag",
+                    e.getType().toShortString(),
+                    e.getStringUUID()
+                );
+            }
+        });
+
+        CompoundTag compound = new CompoundTag();
+        if (serializePassangers) {
+            if (!nmsEntity.saveAsPassenger(compound, true, includeNonSaveable, forceSerialization)) {
+                throw new IllegalArgumentException("Couldn't serialize entity");
+            }
+        } else {
+            List<net.minecraft.world.entity.Entity> pass = new ArrayList<>(nmsEntity.getPassengers());
+            nmsEntity.passengers = com.google.common.collect.ImmutableList.of();
+            boolean serialized = nmsEntity.saveAsPassenger(compound, true, includeNonSaveable, forceSerialization);
+            nmsEntity.passengers = com.google.common.collect.ImmutableList.copyOf(pass);
+            if (!serialized) {
+                throw new IllegalArgumentException("Couldn't serialize entity");
+            }
+        }
         return serializeNbtToBytes(compound);
     }
 
     @Override
-    public org.bukkit.entity.Entity deserializeEntity(byte[] data, org.bukkit.World world, boolean preserveUUID) {
+    public org.bukkit.entity.Entity deserializeEntity(byte[] data, World world, boolean preserveUUID, boolean preservePassengers) {
         Preconditions.checkNotNull(data, "null cannot be deserialized");
-        Preconditions.checkArgument(data.length > 0, "cannot deserialize nothing");
+        Preconditions.checkArgument(data.length > 0, "Cannot deserialize empty data");
 
-        net.minecraft.nbt.CompoundTag compound = deserializeNbtFromBytes(data);
+        CompoundTag compound = deserializeNbtFromBytes(data);
         int dataVersion = compound.getInt("DataVersion");
-        compound = ca.spottedleaf.moonrise.common.PlatformHooks.get().convertNBT(References.ENTITY, MinecraftServer.getServer().fixerUpper, compound, dataVersion, this.getDataVersion()); // Paper - possibly use dataconverter
+        compound = PlatformHooks.get().convertNBT(References.ENTITY, MinecraftServer.getServer().fixerUpper, compound, dataVersion, this.getDataVersion()); // Paper - possibly use dataconverter
-        if (!preserveUUID) {
+        if (!preservePassengers) {
-            // Generate a new UUID so we don't have to worry about deserializing the same entity twice
+            compound.remove("Passengers");
-            compound.remove("UUID");
         }
-        return net.minecraft.world.entity.EntityType.create(compound, ((org.bukkit.craftbukkit.CraftWorld) world).getHandle(), net.minecraft.world.entity.EntitySpawnReason.LOAD)
+        net.minecraft.world.entity.Entity nmsEntity = deserializeEntity(compound, ((CraftWorld) world).getHandle(), preserveUUID);
-            .orElseThrow(() -> new IllegalArgumentException("An ID was not found for the data. Did you downgrade?")).getBukkitEntity();
+        return nmsEntity.getBukkitEntity();
     }
 
-    private byte[] serializeNbtToBytes(net.minecraft.nbt.CompoundTag compound) {
+    private net.minecraft.world.entity.Entity deserializeEntity(CompoundTag compound, ServerLevel world, boolean preserveUUID) {
+        if (!preserveUUID) {
+            // Generate a new UUID, so we don't have to worry about deserializing the same entity twice
+            compound.remove("UUID");
+        }
+        net.minecraft.world.entity.Entity nmsEntity = net.minecraft.world.entity.EntityType.create(compound, world, net.minecraft.world.entity.EntitySpawnReason.LOAD)
+            .orElseThrow(() -> new IllegalArgumentException("An ID was not found for the data. Did you downgrade?"));
+        if (compound.contains("Passengers", Tag.TAG_LIST)) {
+            ListTag passengersCompound = compound.getList("Passengers", Tag.TAG_COMPOUND);
+            for (Tag tag : passengersCompound) {
+                if (!(tag instanceof CompoundTag serializedPassenger)) {
+                    continue;
+                }
+                net.minecraft.world.entity.Entity passengerEntity = deserializeEntity(serializedPassenger, world, preserveUUID);
+                passengerEntity.startRiding(nmsEntity, true);
+            }
+        }
+        return nmsEntity;
+    }
+
+    private byte[] serializeNbtToBytes(CompoundTag compound) {
         compound.putInt("DataVersion", getDataVersion());
         java.io.ByteArrayOutputStream outputStream = new java.io.ByteArrayOutputStream();
         try {
@@ -597,8 +677,8 @@ public final class CraftMagicNumbers implements UnsafeValues {
         return outputStream.toByteArray();
     }
 
-    private net.minecraft.nbt.CompoundTag deserializeNbtFromBytes(byte[] data) {
+    private CompoundTag deserializeNbtFromBytes(byte[] data) {
-        net.minecraft.nbt.CompoundTag compound;
+        CompoundTag compound;
         try {
             compound = net.minecraft.nbt.NbtIo.readCompressed(
                 new java.io.ByteArrayInputStream(data), net.minecraft.nbt.NbtAccounter.unlimitedHeap()