Add FeatureFlag API (#8952)

* Add FeatureFlag API * switch to index & move method * fix test
2024-12-28 23:38:25 +01:00 · 2024-09-07 13:35:11 -07:00 · 2024-09-07 13:35:11 -07:00 · fc2cdc7db9
commit fc2cdc7db9
parent b91a342aa2
4 changed files with 757 additions and 5 deletions
--- a/patches/api/Add-FeatureFlag-API.patch
+++ b/patches/api/Add-FeatureFlag-API.patch
@ -0,0 +1,333 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jake Potrebic <jake.m.potrebic@gmail.com>
+Date: Thu, 9 Mar 2023 11:24:43 -0800
+Subject: [PATCH] Add FeatureFlag API
+
+
+diff --git a/src/main/java/io/papermc/paper/world/flag/FeatureDependant.java b/src/main/java/io/papermc/paper/world/flag/FeatureDependant.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/java/io/papermc/paper/world/flag/FeatureDependant.java
+@@ -0,0 +0,0 @@
+package io.papermc.paper.world.flag;
+
+import java.util.Set;
+import org.bukkit.FeatureFlag;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Unmodifiable;
+
+/**
+ * Implemented by types in built-in registries that are controlled by {@link FeatureFlag FeatureFlags}.
+ * Types in data-driven registries that are controlled by feature flags just will not exist in that registry.
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface FeatureDependant {
+
+    /**
+     * Gets the set of required feature flags for this
+     * to be enabled.
+     *
+     * @return the immutable set of feature flags
+     */
+    default @Unmodifiable @NonNull Set<FeatureFlag> requiredFeatures() {
+        return FeatureFlagProvider.provider().requiredFeatures(this);
+    }
+}
+diff --git a/src/main/java/io/papermc/paper/world/flag/FeatureFlagProvider.java b/src/main/java/io/papermc/paper/world/flag/FeatureFlagProvider.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/java/io/papermc/paper/world/flag/FeatureFlagProvider.java
+@@ -0,0 +0,0 @@
+package io.papermc.paper.world.flag;
+
+import java.util.Optional;
+import java.util.ServiceLoader;
+import java.util.Set;
+import org.bukkit.FeatureFlag;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+interface FeatureFlagProvider {
+
+    Optional<FeatureFlagProvider> PROVIDER = ServiceLoader.load(FeatureFlagProvider.class).findFirst();
+
+    static FeatureFlagProvider provider() {
+        return PROVIDER.orElseThrow();
+    }
+
+    Set<FeatureFlag> requiredFeatures(FeatureDependant dependant);
+}
+diff --git a/src/main/java/io/papermc/paper/world/flag/FeatureFlagSetHolder.java b/src/main/java/io/papermc/paper/world/flag/FeatureFlagSetHolder.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/java/io/papermc/paper/world/flag/FeatureFlagSetHolder.java
+@@ -0,0 +0,0 @@
+package io.papermc.paper.world.flag;
+
+import java.util.Set;
+import org.bukkit.FeatureFlag;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Unmodifiable;
+
+/**
+ * Implemented by types that hold {@link FeatureFlag FeatureFlags} like
+ * {@link org.bukkit.generator.WorldInfo} and {@link org.bukkit.RegionAccessor}.
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface FeatureFlagSetHolder {
+
+    /**
+     * Checks if this is enabled based on the loaded feature flags.
+     *
+     * @return true if enabled
+     */
+    default boolean isEnabled(final @NonNull FeatureDependant featureDependant) {
+        return this.getFeatureFlags().containsAll(featureDependant.requiredFeatures());
+    }
+
+    /**
+     * Get all {@link FeatureFlag FeatureFlags} enabled in this world.
+     *
+     * @return all enabled {@link FeatureFlag FeatureFlags}
+     */
+    @Unmodifiable @NonNull Set<FeatureFlag> getFeatureFlags();
+}
+diff --git a/src/main/java/org/bukkit/FeatureFlag.java b/src/main/java/org/bukkit/FeatureFlag.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/FeatureFlag.java
+++ b/src/main/java/org/bukkit/FeatureFlag.java
+@@ -0,0 +0,0 @@
+ package org.bukkit;
+ 
+// Paper start - overhaul FeatureFlag API
+import com.google.common.base.Preconditions;
+import java.util.List;
+import net.kyori.adventure.key.Key;
+import net.kyori.adventure.util.Index;
+import org.intellij.lang.annotations.Subst;
+// Paper end - overhaul FeatureFlag API
+ import org.jetbrains.annotations.ApiStatus;
+ 
+ /**
+  * This represents a Feature Flag for a World.
+- * <br>
+- * Flags which are unavailable in the current version will be null and/or
+- * removed.
+  */
+ @ApiStatus.Experimental
+ public interface FeatureFlag extends Keyed {
+ 
+-    public static final FeatureFlag VANILLA = Bukkit.getUnsafe().getFeatureFlag(NamespacedKey.minecraft("vanilla"));
+    // Paper start - overhaul FeatureFlag API
+    /**
+     * The {@code vanilla} feature flag.
+     */
+    FeatureFlag VANILLA = create("vanilla");
+ 
+    /**
+     * The {@code bundle} feature flag.
+     */
+     @ApiStatus.Experimental // Paper - add missing annotation
+-    public static final FeatureFlag BUNDLE = Bukkit.getUnsafe().getFeatureFlag(NamespacedKey.minecraft("bundle"));
+    FeatureFlag BUNDLE = create("bundle");
+ 
+     /**
+-     * <strong>AVAILABLE BETWEEN VERSIONS:</strong> 1.19 - 1.19.4
+-     *
+-     * @deprecated not available since 1.20
+     * The {@code trade_rebalance} feature flag.
+      */
+-    @Deprecated
+-    public static final FeatureFlag UPDATE_1_20 = Bukkit.getUnsafe().getFeatureFlag(NamespacedKey.minecraft("update_1_20"));
+-
+     @ApiStatus.Experimental // Paper - add missing annotation
+-    public static final FeatureFlag TRADE_REBALANCE = Bukkit.getUnsafe().getFeatureFlag(NamespacedKey.minecraft("trade_rebalance"));
+    FeatureFlag TRADE_REBALANCE = create("trade_rebalance");
+
+    @Deprecated(since = "1.20")
+    FeatureFlag UPDATE_1_20 = deprecated("update_1_20");
+
+    @Deprecated(since = "1.21")
+    FeatureFlag UPDATE_121 = deprecated("update_1_21");
+ 
+     /**
+-     * <strong>AVAILABLE BETWEEN VERSIONS:</strong> 1.20.5 - 1.20.6
+-     *
+-     * @deprecated not available since 1.21
+     * An index of all feature flags.
+      */
+-    @Deprecated
+-    public static final FeatureFlag UPDATE_121 = Bukkit.getUnsafe().getFeatureFlag(NamespacedKey.minecraft("update_1_21"));
+    Index<Key, FeatureFlag> ALL_FLAGS = Index.create(FeatureFlag::key, List.copyOf(FeatureFlagImpl.ALL_FLAGS));
+
+    private static FeatureFlag create(@Subst("vanilla") final String name) {
+        final FeatureFlag flag = new FeatureFlagImpl(NamespacedKey.minecraft(name));
+        Preconditions.checkState(FeatureFlagImpl.ALL_FLAGS.add(flag), "Tried to add duplicate feature flag: " + name);
+        return flag;
+    }
+
+    private static FeatureFlag deprecated(@Subst("vanilla") final String name) {
+        return new FeatureFlagImpl.Deprecated(NamespacedKey.minecraft(name));
+    }
+    // Paper end - overhaul FeatureFlag API
+ }
+diff --git a/src/main/java/org/bukkit/FeatureFlagImpl.java b/src/main/java/org/bukkit/FeatureFlagImpl.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/java/org/bukkit/FeatureFlagImpl.java
+@@ -0,0 +0,0 @@
+package org.bukkit;
+
+import java.util.HashSet;
+import java.util.Set;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+@DefaultQualifier(NonNull.class)
+record FeatureFlagImpl(NamespacedKey key) implements FeatureFlag {
+
+    static final Set<FeatureFlag> ALL_FLAGS = new HashSet<>();
+
+    @Override
+    public NamespacedKey getKey() {
+        return this.key;
+    }
+
+    @ApiStatus.Internal
+    @DefaultQualifier(NonNull.class)
+    record Deprecated(NamespacedKey key) implements FeatureFlag {
+
+        @Override
+        public NamespacedKey getKey() {
+            return this.key;
+        }
+    }
+}
+diff --git a/src/main/java/org/bukkit/RegionAccessor.java b/src/main/java/org/bukkit/RegionAccessor.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/RegionAccessor.java
+++ b/src/main/java/org/bukkit/RegionAccessor.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.Nullable;
+  * A RegionAccessor gives access to getting, modifying and spawning {@link Biome}, {@link BlockState} and {@link Entity},
+  * as well as generating some basic structures.
+  */
+-public interface RegionAccessor extends Keyed { // Paper
+public interface RegionAccessor extends Keyed, io.papermc.paper.world.flag.FeatureFlagSetHolder { // Paper - feature flag API
+ 
+     /**
+      * Gets the {@link Biome} at the given {@link Location}.
+diff --git a/src/main/java/org/bukkit/UnsafeValues.java b/src/main/java/org/bukkit/UnsafeValues.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/UnsafeValues.java
+++ b/src/main/java/org/bukkit/UnsafeValues.java
+@@ -0,0 +0,0 @@ public interface UnsafeValues {
+ 
+     String getTranslationKey(Attribute attribute);
+ 
+-    @Nullable
+-    FeatureFlag getFeatureFlag(@NotNull NamespacedKey key);
+    // Paper - replace with better system
+ 
+     /**
+      * Do not use, method will get removed, and the plugin won't run
+diff --git a/src/main/java/org/bukkit/block/BlockType.java b/src/main/java/org/bukkit/block/BlockType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/block/BlockType.java
+++ b/src/main/java/org/bukkit/block/BlockType.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.Nullable;
+  * changes may occur. Do not use this API in plugins.
+  */
+ @ApiStatus.Internal
+-public interface BlockType extends Keyed, Translatable, net.kyori.adventure.translation.Translatable { // Paper - add translatable
+public interface BlockType extends Keyed, Translatable, net.kyori.adventure.translation.Translatable, io.papermc.paper.world.flag.FeatureDependant { // Paper - add translatable & feature flag API
+ 
+     /**
+      * Typed represents a subtype of {@link BlockType}s that have a known block
+diff --git a/src/main/java/org/bukkit/enchantments/Enchantment.java b/src/main/java/org/bukkit/enchantments/Enchantment.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/enchantments/Enchantment.java
+++ b/src/main/java/org/bukkit/enchantments/Enchantment.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.Nullable;
+ /**
+  * The various type of enchantments that may be added to armour or weapons
+  */
+-public abstract class Enchantment implements Keyed, Translatable, net.kyori.adventure.translation.Translatable { // Paper - Adventure translations
+public abstract class Enchantment implements Keyed, Translatable, net.kyori.adventure.translation.Translatable, io.papermc.paper.world.flag.FeatureDependant { // Paper - Adventure translations & feature flag API
+     /**
+      * Provides protection against environmental damage
+      */
+diff --git a/src/main/java/org/bukkit/entity/EntityType.java b/src/main/java/org/bukkit/entity/EntityType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/entity/EntityType.java
+++ b/src/main/java/org/bukkit/entity/EntityType.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.Contract;
+ import org.jetbrains.annotations.NotNull;
+ import org.jetbrains.annotations.Nullable;
+ 
+-public enum EntityType implements Keyed, Translatable, net.kyori.adventure.translation.Translatable { // Paper - translatable
+public enum EntityType implements Keyed, Translatable, net.kyori.adventure.translation.Translatable, io.papermc.paper.world.flag.FeatureDependant { // Paper - translatable
+ 
+     // These strings MUST match the strings in nms.EntityTypes and are case sensitive.
+     /**
+diff --git a/src/main/java/org/bukkit/generator/WorldInfo.java b/src/main/java/org/bukkit/generator/WorldInfo.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/generator/WorldInfo.java
+++ b/src/main/java/org/bukkit/generator/WorldInfo.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.NotNull;
+ /**
+  * Holds various information of a World
+  */
+-public interface WorldInfo {
+public interface WorldInfo extends io.papermc.paper.world.flag.FeatureFlagSetHolder { // Paper - feature flag API
+ 
+     /**
+      * Gets the unique name of this world
+diff --git a/src/main/java/org/bukkit/inventory/ItemType.java b/src/main/java/org/bukkit/inventory/ItemType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/inventory/ItemType.java
+++ b/src/main/java/org/bukkit/inventory/ItemType.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.Nullable;
+  * changes may occur. Do not use this API in plugins.
+  */
+ @ApiStatus.Experimental // Paper - already required for registry builders
+-public interface ItemType extends Keyed, Translatable, net.kyori.adventure.translation.Translatable { // Paper - add Translatable
+public interface ItemType extends Keyed, Translatable, net.kyori.adventure.translation.Translatable, io.papermc.paper.world.flag.FeatureDependant { // Paper - add Translatable & feature flag API
+ 
+     /**
+      * Typed represents a subtype of {@link ItemType}s that have a known item meta type
+diff --git a/src/main/java/org/bukkit/potion/PotionEffectType.java b/src/main/java/org/bukkit/potion/PotionEffectType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/potion/PotionEffectType.java
+++ b/src/main/java/org/bukkit/potion/PotionEffectType.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.Nullable;
+ /**
+  * Represents a type of potion and its effect on an entity.
+  */
+-public abstract class PotionEffectType implements Keyed, Translatable, net.kyori.adventure.translation.Translatable { // Paper - implement Translatable
+public abstract class PotionEffectType implements Keyed, Translatable, net.kyori.adventure.translation.Translatable, io.papermc.paper.world.flag.FeatureDependant { // Paper - implement Translatable & feature flag API
+     private static final BiMap<Integer, PotionEffectType> ID_MAP = HashBiMap.create();
+ 
+     /**
+diff --git a/src/main/java/org/bukkit/potion/PotionType.java b/src/main/java/org/bukkit/potion/PotionType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/potion/PotionType.java
+++ b/src/main/java/org/bukkit/potion/PotionType.java
+@@ -0,0 +0,0 @@ import org.jetbrains.annotations.Nullable;
+  * This enum reflects and matches each potion state that can be obtained from
+  * the Creative mode inventory
+  */
+-public enum PotionType implements Keyed {
+public enum PotionType implements Keyed, io.papermc.paper.world.flag.FeatureDependant { // Paper - feature flag API
+     WATER("water"),
+     MUNDANE("mundane"),
+     THICK("thick"),
--- a/patches/api/Add-basic-Datapack-API.patch
+++ b/patches/api/Add-basic-Datapack-API.patch
@ -81,7 +81,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      * @return the manager
      */
     @NotNull
-+    @Deprecated(forRemoval = true)
+    @Deprecated(forRemoval = true, since = "1.20")
     public static DataPackManager getDataPackManager() {
         return server.getDataPackManager();
     }
@ -100,6 +100,18 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
     // Paper end
 
     @NotNull
+diff --git a/src/main/java/org/bukkit/Material.java b/src/main/java/org/bukkit/Material.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/Material.java
+++ b/src/main/java/org/bukkit/Material.java
+@@ -0,0 +0,0 @@ public enum Material implements Keyed, Translatable, net.kyori.adventure.transla
+      * @param world the world to check
+      * @return true if this material can be used in this World.
+      */
+    @Deprecated(forRemoval = true, since = "1.20") // Paper
+     public boolean isEnabledByFeature(@NotNull World world) {
+         if (isItem()) {
+             return Bukkit.getDataPackManager().isEnabledByFeature(asItemType(), world);
 diff --git a/src/main/java/org/bukkit/Server.java b/src/main/java/org/bukkit/Server.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/Server.java
@ -112,7 +124,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      * @return the manager
      */
     @NotNull
-+    @Deprecated(forRemoval = true) // Paper
+    @Deprecated(forRemoval = true, since = "1.20") // Paper
     public DataPackManager getDataPackManager();
 
     /**
@ -128,6 +140,18 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    io.papermc.paper.datapack.DatapackManager getDatapackManager();
     // Paper end
 }
+diff --git a/src/main/java/org/bukkit/entity/EntityType.java b/src/main/java/org/bukkit/entity/EntityType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/entity/EntityType.java
+++ b/src/main/java/org/bukkit/entity/EntityType.java
+@@ -0,0 +0,0 @@ public enum EntityType implements Keyed, Translatable, net.kyori.adventure.trans
+      * @param world the world to check
+      * @return true if this EntityType can be used to spawn an Entity for this World.
+      */
+    @Deprecated(forRemoval = true, since = "1.20") // Paper
+     public boolean isEnabledByFeature(@NotNull World world) {
+         return Bukkit.getDataPackManager().isEnabledByFeature(this, world);
+     }
 diff --git a/src/main/java/org/bukkit/packs/DataPack.java b/src/main/java/org/bukkit/packs/DataPack.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/packs/DataPack.java
@ -138,7 +162,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  * @see <a href="https://minecraft.wiki/w/Data_pack">Minecraft wiki</a>
 + * @deprecated use {@link io.papermc.paper.datapack.Datapack}
  */
-+@Deprecated(forRemoval = true) // Paper
+@Deprecated(forRemoval = true, since = "1.20") // Paper
 public interface DataPack extends Keyed {
 
     /**
@ -152,7 +176,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  * Manager of data packs.
 + * @deprecated use {@link io.papermc.paper.datapack.DatapackManager}
  */
-+@Deprecated(forRemoval = true) // Paper
+@Deprecated(forRemoval = true, since = "1.20") // Paper
 public interface DataPackManager {
 
     /**
--- a/patches/server/Add-FeatureFlag-API.patch
+++ b/patches/server/Add-FeatureFlag-API.patch
@ -0,0 +1,395 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jake Potrebic <jake.m.potrebic@gmail.com>
+Date: Wed, 29 May 2024 19:50:21 -0700
+Subject: [PATCH] Add FeatureFlag API
+
+
+diff --git a/src/main/java/io/papermc/paper/world/flag/PaperFeatureDependent.java b/src/main/java/io/papermc/paper/world/flag/PaperFeatureDependent.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/java/io/papermc/paper/world/flag/PaperFeatureDependent.java
+@@ -0,0 +0,0 @@
+package io.papermc.paper.world.flag;
+
+import java.util.Set;
+import net.minecraft.world.flag.FeatureElement;
+import org.bukkit.FeatureFlag;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.Unmodifiable;
+
+public interface PaperFeatureDependent extends FeatureDependant {
+
+    <M extends FeatureElement> M getHandle();
+
+    @Override
+    default @Unmodifiable @NonNull Set<FeatureFlag> requiredFeatures() {
+        return PaperFeatureFlagProviderImpl.fromNms(this.getHandle().requiredFeatures());
+    }
+}
+diff --git a/src/main/java/io/papermc/paper/world/flag/PaperFeatureFlagProviderImpl.java b/src/main/java/io/papermc/paper/world/flag/PaperFeatureFlagProviderImpl.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/java/io/papermc/paper/world/flag/PaperFeatureFlagProviderImpl.java
+@@ -0,0 +0,0 @@
+package io.papermc.paper.world.flag;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.ImmutableBiMap;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import net.minecraft.world.flag.FeatureElement;
+import net.minecraft.world.flag.FeatureFlagSet;
+import net.minecraft.world.flag.FeatureFlags;
+import org.bukkit.FeatureFlag;
+import org.bukkit.craftbukkit.entity.CraftEntityType;
+import org.bukkit.craftbukkit.entity.CraftEntityTypes;
+import org.bukkit.craftbukkit.potion.CraftPotionType;
+import org.bukkit.craftbukkit.util.CraftMagicNumbers;
+import org.bukkit.entity.EntityType;
+import org.bukkit.potion.PotionType;
+
+public class PaperFeatureFlagProviderImpl implements FeatureFlagProvider {
+
+    public static final BiMap<FeatureFlag, net.minecraft.world.flag.FeatureFlag> FLAGS = ImmutableBiMap.of(
+        FeatureFlag.VANILLA, FeatureFlags.VANILLA,
+        FeatureFlag.BUNDLE, FeatureFlags.BUNDLE,
+        FeatureFlag.TRADE_REBALANCE, FeatureFlags.TRADE_REBALANCE
+    );
+
+    @Override
+    public Set<FeatureFlag> requiredFeatures(final FeatureDependant dependant) {
+        final FeatureFlagSet requiredFeatures = getFeatureElement(dependant).requiredFeatures();
+        return fromNms(requiredFeatures);
+    }
+
+    public static Set<FeatureFlag> fromNms(final FeatureFlagSet flagSet) {
+        final Set<FeatureFlag> flags = new HashSet<>();
+        for (final net.minecraft.world.flag.FeatureFlag nmsFlag : FeatureFlags.REGISTRY.names.values()) {
+            if (flagSet.contains(nmsFlag)) {
+                flags.add(FLAGS.inverse().get(nmsFlag));
+            }
+        }
+        return Collections.unmodifiableSet(flags);
+    }
+
+    static FeatureElement getFeatureElement(final FeatureDependant dependant) {
+        if (dependant instanceof final EntityType entityType) {
+            // TODO remove when EntityType is server-backed
+            return CraftEntityType.bukkitToMinecraft(entityType);
+        } else if (dependant instanceof final PotionType potionType) {
+            return CraftPotionType.bukkitToMinecraft(potionType);
+        } else {
+            throw new IllegalArgumentException(dependant + " is not a valid feature dependant");
+        }
+    }
+}
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftFeatureFlag.java b/src/main/java/org/bukkit/craftbukkit/CraftFeatureFlag.java
+deleted file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- a/src/main/java/org/bukkit/craftbukkit/CraftFeatureFlag.java
+++ /dev/null
+@@ -0,0 +0,0 @@
+-package org.bukkit.craftbukkit;
+-
+-import java.util.HashSet;
+-import java.util.Set;
+-import net.minecraft.resources.ResourceLocation;
+-import net.minecraft.world.flag.FeatureFlagSet;
+-import net.minecraft.world.flag.FeatureFlags;
+-import org.bukkit.FeatureFlag;
+-import org.bukkit.NamespacedKey;
+-import org.bukkit.craftbukkit.util.CraftNamespacedKey;
+-import org.jetbrains.annotations.NotNull;
+-
+-public class CraftFeatureFlag implements FeatureFlag {
+-
+-    private final NamespacedKey namespacedKey;
+-    private final net.minecraft.world.flag.FeatureFlag featureFlag;
+-
+-    public CraftFeatureFlag(ResourceLocation minecraftKey, net.minecraft.world.flag.FeatureFlag featureFlag) {
+-        this.namespacedKey = CraftNamespacedKey.fromMinecraft(minecraftKey);
+-        this.featureFlag = featureFlag;
+-    }
+-
+-    public net.minecraft.world.flag.FeatureFlag getHandle() {
+-        return this.featureFlag;
+-    }
+-
+-    @NotNull
+-    @Override
+-    public NamespacedKey getKey() {
+-        return this.namespacedKey;
+-    }
+-
+-    @Override
+-    public String toString() {
+-        return "CraftFeatureFlag{key=" + this.getKey() + ",keyUniverse=" + this.getHandle().universe.toString() + "}";
+-    }
+-
+-    public static Set<CraftFeatureFlag> getFromNMS(FeatureFlagSet featureFlagSet) {
+-        Set<CraftFeatureFlag> set = new HashSet<>();
+-        FeatureFlags.REGISTRY.names.forEach((minecraftkey, featureflag) -> {
+-            if (featureFlagSet.contains(featureflag)) {
+-                set.add(new CraftFeatureFlag(minecraftkey, featureflag));
+-            }
+-        });
+-        return set;
+-    }
+-
+-    public static CraftFeatureFlag getFromNMS(NamespacedKey namespacedKey) {
+-        return FeatureFlags.REGISTRY.names.entrySet().stream().filter(entry -> CraftNamespacedKey.fromMinecraft(entry.getKey()).equals(namespacedKey)).findFirst().map(entry -> new CraftFeatureFlag(entry.getKey(), entry.getValue())).orElse(null);
+-    }
+-}
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java b/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java
+@@ -0,0 +0,0 @@ public abstract class CraftRegionAccessor implements RegionAccessor {
+         return !this.getHandle().noCollision(aabb);
+     }
+     // Paper end
+
+    // Paper start - feature flag API
+    @Override
+    public java.util.Set<org.bukkit.FeatureFlag> getFeatureFlags() {
+        return io.papermc.paper.world.flag.PaperFeatureFlagProviderImpl.fromNms(this.getHandle().enabledFeatures());
+    }
+    // Paper end - feature flag API
+ }
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
+         return this.persistentDataContainer;
+     }
+ 
+-    @Override
+-    public Set<FeatureFlag> getFeatureFlags() {
+-        return CraftFeatureFlag.getFromNMS(this.getHandle().enabledFeatures()).stream().map(FeatureFlag.class::cast).collect(Collectors.toUnmodifiableSet());
+-    }
+    // Paper - replace feature flag API
+ 
+     public void storeBukkitValues(CompoundTag c) {
+         if (!this.persistentDataContainer.isEmpty()) {
+diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftBlockType.java b/src/main/java/org/bukkit/craftbukkit/block/CraftBlockType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlockType.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlockType.java
+@@ -0,0 +0,0 @@ import org.bukkit.craftbukkit.util.Handleable;
+ import org.bukkit.inventory.ItemType;
+ import org.jetbrains.annotations.NotNull;
+ 
+-public class CraftBlockType<B extends BlockData> implements BlockType.Typed<B>, Handleable<Block> {
+public class CraftBlockType<B extends BlockData> implements BlockType.Typed<B>, Handleable<Block>, io.papermc.paper.world.flag.PaperFeatureDependent { // Paper - feature flag API
+ 
+     private final NamespacedKey key;
+     private final Block block;
+diff --git a/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java b/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java
+@@ -0,0 +0,0 @@ public class CraftWorldInfo implements WorldInfo {
+     private final long seed;
+     private final int minHeight;
+     private final int maxHeight;
+    private final net.minecraft.world.flag.FeatureFlagSet enabledFeatures; // Paper - feature flag API
+     // Paper start
+     private final net.minecraft.world.level.chunk.ChunkGenerator vanillaChunkGenerator;
+     private final net.minecraft.core.RegistryAccess.Frozen registryAccess;
+@@ -0,0 +0,0 @@ public class CraftWorldInfo implements WorldInfo {
+         this.seed = ((PrimaryLevelData) worldDataServer).worldGenOptions().seed();
+         this.minHeight = dimensionManager.minY();
+         this.maxHeight = dimensionManager.minY() + dimensionManager.height();
+        this.enabledFeatures = worldDataServer.enabledFeatures(); // Paper - feature flag API
+     }
+ 
+     @Override
+@@ -0,0 +0,0 @@ public class CraftWorldInfo implements WorldInfo {
+         };
+     }
+     // Paper end
+
+    // Paper start - feature flag API
+    @Override
+    public java.util.Set<org.bukkit.FeatureFlag> getFeatureFlags() {
+        return io.papermc.paper.world.flag.PaperFeatureFlagProviderImpl.fromNms(this.enabledFeatures);
+    }
+    // Paper end - feature flag API
+ }
+diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemType.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemType.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemType.java
+@@ -0,0 +0,0 @@ import org.bukkit.inventory.meta.ItemMeta;
+ import org.jetbrains.annotations.NotNull;
+ import org.jetbrains.annotations.Nullable;
+ 
+-public class CraftItemType<M extends ItemMeta> implements ItemType.Typed<M>, Handleable<Item> {
+public class CraftItemType<M extends ItemMeta> implements ItemType.Typed<M>, Handleable<Item>, io.papermc.paper.world.flag.PaperFeatureDependent { // Paper - feature flag API
+ 
+     private final NamespacedKey key;
+     private final Item item;
+diff --git a/src/main/java/org/bukkit/craftbukkit/packs/CraftDataPack.java b/src/main/java/org/bukkit/craftbukkit/packs/CraftDataPack.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/packs/CraftDataPack.java
+++ b/src/main/java/org/bukkit/craftbukkit/packs/CraftDataPack.java
+@@ -0,0 +0,0 @@ import net.minecraft.util.InclusiveRange;
+ import org.bukkit.Bukkit;
+ import org.bukkit.FeatureFlag;
+ import org.bukkit.NamespacedKey;
+-import org.bukkit.craftbukkit.CraftFeatureFlag;
+// import org.bukkit.craftbukkit.CraftFeatureFlag; // Paper - replace feature flag API
+ import org.bukkit.craftbukkit.CraftServer;
+ import org.bukkit.craftbukkit.util.CraftChatMessage;
+ import org.bukkit.packs.DataPack;
+@@ -0,0 +0,0 @@ public class CraftDataPack implements DataPack {
+ 
+     @Override
+     public Set<FeatureFlag> getRequestedFeatures() {
+-        return CraftFeatureFlag.getFromNMS(this.getHandle().getRequestedFeatures()).stream().map(FeatureFlag.class::cast).collect(Collectors.toUnmodifiableSet());
+        return io.papermc.paper.world.flag.PaperFeatureFlagProviderImpl.fromNms(this.getHandle().getRequestedFeatures()); // Paper - replace feature flag API
+     }
+ 
+     @Override
+diff --git a/src/main/java/org/bukkit/craftbukkit/potion/CraftPotionEffectType.java b/src/main/java/org/bukkit/craftbukkit/potion/CraftPotionEffectType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/potion/CraftPotionEffectType.java
+++ b/src/main/java/org/bukkit/craftbukkit/potion/CraftPotionEffectType.java
+@@ -0,0 +0,0 @@ import org.bukkit.potion.PotionEffectType;
+ import org.bukkit.potion.PotionEffectTypeCategory;
+ import org.jetbrains.annotations.NotNull;
+ 
+-public class CraftPotionEffectType extends PotionEffectType implements Handleable<MobEffect> {
+public class CraftPotionEffectType extends PotionEffectType implements Handleable<MobEffect>, io.papermc.paper.world.flag.PaperFeatureDependent { // Paper - feature flag API
+ 
+     public static PotionEffectType minecraftHolderToBukkit(Holder<MobEffect> minecraft) {
+         return CraftPotionEffectType.minecraftToBukkit(minecraft.value());
+diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+@@ -0,0 +0,0 @@ import org.bukkit.advancement.Advancement;
+ import org.bukkit.attribute.Attribute;
+ import org.bukkit.attribute.AttributeModifier;
+ import org.bukkit.block.data.BlockData;
+-import org.bukkit.craftbukkit.CraftFeatureFlag;
+// import org.bukkit.craftbukkit.CraftFeatureFlag; // Paper
+ import org.bukkit.craftbukkit.CraftRegistry;
+ import org.bukkit.craftbukkit.CraftServer;
+ import org.bukkit.craftbukkit.attribute.CraftAttribute;
+@@ -0,0 +0,0 @@ public final class CraftMagicNumbers implements UnsafeValues {
+         return CraftAttribute.bukkitToMinecraft(attribute).getDescriptionId();
+     }
+ 
+-    @Override
+-    public FeatureFlag getFeatureFlag(NamespacedKey namespacedKey) {
+-        Preconditions.checkArgument(namespacedKey != null, "NamespaceKey cannot be null");
+-        return CraftFeatureFlag.getFromNMS(namespacedKey);
+-    }
+    // Paper - replace feature flag API
+ 
+     @Override
+     public PotionType.InternalPotionData getInternalPotionData(NamespacedKey namespacedKey) {
+diff --git a/src/main/resources/META-INF/services/io.papermc.paper.world.flag.FeatureFlagProvider b/src/main/resources/META-INF/services/io.papermc.paper.world.flag.FeatureFlagProvider
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/resources/META-INF/services/io.papermc.paper.world.flag.FeatureFlagProvider
+@@ -0,0 +1 @@
+io.papermc.paper.world.flag.PaperFeatureFlagProviderImpl
+diff --git a/src/main/resources/META-INF/services/io.papermc.paper.world.flag.FeatureFlags$FeatureFlagProvider b/src/main/resources/META-INF/services/io.papermc.paper.world.flag.FeatureFlags$FeatureFlagProvider
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/main/resources/META-INF/services/io.papermc.paper.world.flag.FeatureFlags$FeatureFlagProvider
+@@ -0,0 +1 @@
+io.papermc.paper.world.flag.PaperFeatureFlagProviderImpl
+diff --git a/src/test/java/io/papermc/paper/world/flag/FeatureFlagTest.java b/src/test/java/io/papermc/paper/world/flag/FeatureFlagTest.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
+++ b/src/test/java/io/papermc/paper/world/flag/FeatureFlagTest.java
+@@ -0,0 +0,0 @@
+package io.papermc.paper.world.flag;
+
+import io.papermc.paper.adventure.PaperAdventure;
+import io.papermc.paper.registry.PaperRegistries;
+import io.papermc.paper.registry.RegistryAccess;
+import io.papermc.paper.registry.RegistryKey;
+import java.util.HashSet;
+import java.util.Set;
+import net.kyori.adventure.key.Key;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.resources.ResourceKey;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.flag.FeatureElement;
+import net.minecraft.world.flag.FeatureFlagSet;
+import net.minecraft.world.flag.FeatureFlags;
+import org.bukkit.FeatureFlag;
+import org.bukkit.Keyed;
+import org.bukkit.support.AbstractTestingBase;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.fail;
+
+class FeatureFlagTest extends AbstractTestingBase {
+
+    @Test
+    void testFeatureFlagParity() {
+        final Set<ResourceLocation> locations = new HashSet<>();
+        for (final FeatureFlag flag : FeatureFlag.ALL_FLAGS.values()) {
+            locations.add(PaperAdventure.asVanilla(flag.getKey()));
+        }
+        FeatureFlags.REGISTRY.fromNames(locations, unknown -> {
+            fail("Unknown api feature flag: " + unknown);
+        });
+
+        for (final ResourceLocation nmsFlag : allNames()) {
+            assertNotNull(FeatureFlag.ALL_FLAGS.value(Key.key(nmsFlag.toString())), "can't find api flag for " + nmsFlag);
+        }
+    }
+
+    @Test
+    void testFeatureFlagConversion() {
+        assertEquals(allNames().size(), PaperFeatureFlagProviderImpl.FLAGS.size());
+        for (final FeatureFlag featureFlag : PaperFeatureFlagProviderImpl.FLAGS.keySet()) {
+            final net.minecraft.world.flag.FeatureFlag nmsFlag = PaperFeatureFlagProviderImpl.FLAGS.get(featureFlag);
+            final ResourceLocation nmsFlagName = FeatureFlags.REGISTRY.toNames(FeatureFlagSet.of(nmsFlag)).iterator().next();
+            assertEquals(nmsFlagName.toString(), featureFlag.key().asString());
+        }
+    }
+
+    static Set<ResourceLocation> allNames() {
+        return FeatureFlags.REGISTRY.toNames(FeatureFlags.REGISTRY.allFlags());
+    }
+
+    @SuppressWarnings({"rawtypes", "unchecked"})
+    static Set<RegistryKey<?>> featureFilteredRegistries() {
+        final Set<RegistryKey<?>> registryKeys = new HashSet<>();
+        for (final ResourceKey filteredRegistry : FeatureElement.FILTERED_REGISTRIES) {
+            if (filteredRegistry == Registries.MENU) continue; // not applicable atm
+            registryKeys.add(PaperRegistries.registryFromNms(filteredRegistry));
+        }
+        return registryKeys;
+    }
+
+    @MethodSource("featureFilteredRegistries")
+    @ParameterizedTest
+    <T extends Keyed> void testFeatureDependent(final RegistryKey<T> registryKey) {
+        final org.bukkit.Registry<T> registry = RegistryAccess.registryAccess().getRegistry(registryKey);
+        final T anyElement = registry.iterator().next();
+        assertInstanceOf(FeatureDependant.class, anyElement, "Registry " + registryKey + " doesn't have feature dependent elements");
+        final FeatureDependant dependant = ((FeatureDependant) anyElement);
+        assertDoesNotThrow(dependant::requiredFeatures, "Failed to get required features for " + anyElement + " in " + registryKey);
+    }
+}
--- a/patches/server/Expose-vanilla-BiomeProvider-from-WorldInfo.patch
+++ b/patches/server/Expose-vanilla-BiomeProvider-from-WorldInfo.patch
@ -100,7 +100,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    private final net.minecraft.core.RegistryAccess.Frozen registryAccess;
 
 -    public CraftWorldInfo(ServerLevelData worldDataServer, LevelStorageSource.LevelStorageAccess session, World.Environment environment, DimensionType dimensionManager) {
-+    public CraftWorldInfo(ServerLevelData worldDataServer, LevelStorageSource.LevelStorageAccess session, World.Environment environment, DimensionType dimensionManager, net.minecraft.world.level.chunk.ChunkGenerator chunkGenerator, net.minecraft.core.RegistryAccess.Frozen registryAccess) {
+    public CraftWorldInfo(PrimaryLevelData worldDataServer, LevelStorageSource.LevelStorageAccess session, World.Environment environment, DimensionType dimensionManager, net.minecraft.world.level.chunk.ChunkGenerator chunkGenerator, net.minecraft.core.RegistryAccess.Frozen registryAccess) {
 +        this.registryAccess = registryAccess;
 +        this.vanillaChunkGenerator = chunkGenerator;
 +        // Paper end