path: root/patches/api/0484-Registry-Modification-API.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Wed, 2 Mar 2022 13:36:21 -0800
Subject: [PATCH] Registry Modification API


diff --git a/src/main/java/io/papermc/paper/registry/RegistryBuilder.java b/src/main/java/io/papermc/paper/registry/RegistryBuilder.java
new file mode 100644
index 0000000000000000000000000000000000000000..6edf300c1d81c1001756141c9efd022ba0e372cd
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/RegistryBuilder.java
@@ -0,0 +1,13 @@
+package io.papermc.paper.registry;
+
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * To be implemented by any type used for modifying registries.
+ *
+ * @param <T> registry value type
+ */
+@ApiStatus.NonExtendable
+@ApiStatus.Experimental
+public interface RegistryBuilder<T> {
+}
diff --git a/src/main/java/io/papermc/paper/registry/RegistryView.java b/src/main/java/io/papermc/paper/registry/RegistryView.java
new file mode 100644
index 0000000000000000000000000000000000000000..bc25a03b5c06473300cc1b6d505780e68e5e82fc
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/RegistryView.java
@@ -0,0 +1,20 @@
+package io.papermc.paper.registry;
+
+import net.kyori.adventure.key.Key;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Provides read-only access to a registry.
+ *
+ * @param <T> registry value type
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface RegistryView<T> extends Iterable<T> {
+
+    @Nullable T get(final @NonNull Key key);
+
+    @NonNull T getOrThrow(final @NonNull Key key);
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/RegistryEntryAddEvent.java b/src/main/java/io/papermc/paper/registry/event/RegistryEntryAddEvent.java
new file mode 100644
index 0000000000000000000000000000000000000000..d6722f7b55e260bab4bab5c361f9c0e9888c6752
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/RegistryEntryAddEvent.java
@@ -0,0 +1,33 @@
+package io.papermc.paper.registry.event;
+
+import io.papermc.paper.registry.RegistryBuilder;
+import io.papermc.paper.registry.TypedKey;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Event object for {@link RegistryEventProvider#entryAdd()}. This
+ * event is fired right before a specific entry is registered in/added to registry.
+ * It provides a way for plugins to modify parts of this entry.
+ *
+ * @param <T> registry entry type
+ * @param <B> registry entry builder type
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface RegistryEntryAddEvent<T, B extends RegistryBuilder<T>> extends RegistryEvent<T> {
+
+    /**
+     * Gets the builder for the entry being added to the registry.
+     *
+     * @return the object builder
+     */
+    @NonNull B builder();
+
+    /**
+     * Gets the key for this entry in the registry.
+     *
+     * @return the key
+     */
+    @NonNull TypedKey<T> key();
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/RegistryEvent.java b/src/main/java/io/papermc/paper/registry/event/RegistryEvent.java
new file mode 100644
index 0000000000000000000000000000000000000000..c83dc6ef3cbe5ec40d464ad96387d7c3d04f1458
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/RegistryEvent.java
@@ -0,0 +1,32 @@
+package io.papermc.paper.registry.event;
+
+import io.papermc.paper.plugin.lifecycle.event.LifecycleEvent;
+import io.papermc.paper.registry.RegistryKey;
+import io.papermc.paper.registry.RegistryView;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Base type for all registry events.
+ *
+ * @param <T> registry entry type
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface RegistryEvent<T> extends LifecycleEvent {
+
+    /**
+     * Get the key for the registry this event pertains to.
+     *
+     * @return the registry key
+     */
+    @NonNull RegistryKey<T> registryKey();
+
+    /**
+     * Get a view of the registry which may or may not
+     * be complete based on the event.
+     *
+     * @return a registry view
+     */
+    @NonNull RegistryView<T> registry();
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/RegistryEventProvider.java b/src/main/java/io/papermc/paper/registry/event/RegistryEventProvider.java
new file mode 100644
index 0000000000000000000000000000000000000000..793208a46680d7b9e164c14012d2b7c9af55499f
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/RegistryEventProvider.java
@@ -0,0 +1,83 @@
+package io.papermc.paper.registry.event;
+
+import io.papermc.paper.plugin.bootstrap.BootstrapContext;
+import io.papermc.paper.plugin.lifecycle.event.handler.LifecycleEventHandler;
+import io.papermc.paper.plugin.lifecycle.event.handler.configuration.LifecycleEventHandlerConfiguration;
+import io.papermc.paper.plugin.lifecycle.event.handler.configuration.PrioritizedLifecycleEventHandlerConfiguration;
+import io.papermc.paper.plugin.lifecycle.event.types.LifecycleEventType;
+import io.papermc.paper.registry.RegistryBuilder;
+import io.papermc.paper.registry.RegistryKey;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Provider for registry events for a specific registry.
+ * <p>
+ * Supported events are:
+ * <ul>
+ *     <li>{@link RegistryEntryAddEvent} (via {@link #entryAdd()})</li>
+ *     <li>{@link RegistryFreezeEvent} (via {@link #freeze()})</li>
+ * </ul>
+ *
+ * @param <T> registry entry type
+ * @param <B> registry entry builder type
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface RegistryEventProvider<T, B extends RegistryBuilder<T>> {
+
+    /**
+     * Gets the event type for {@link RegistryEntryAddEvent} which is fired just before
+     * an object is added to a registry.
+     * <p>
+     * Can be used in {@link io.papermc.paper.plugin.lifecycle.event.LifecycleEventManager#registerEventHandler(LifecycleEventType, LifecycleEventHandler)}
+     * to register a handler for {@link RegistryEntryAddEvent}.
+     *
+     * @return the addition event type
+     */
+    LifecycleEventType.@NonNull Prioritizable<BootstrapContext, RegistryEntryAddEvent<T, B>> entryAdd();
+
+    /**
+     * Shortcut for calling {@link #entryAdd()} followed by {@link LifecycleEventType#newHandler(LifecycleEventHandler)}.
+     * <p>
+     * Can be used in {@link io.papermc.paper.plugin.lifecycle.event.LifecycleEventManager#registerEventHandler(LifecycleEventHandlerConfiguration)}
+     * to register a handler for {@link RegistryEntryAddEvent}
+     *
+     * @param handler the event handler for {@link RegistryEntryAddEvent}
+     * @return the configuration for further use
+     */
+    default @NonNull PrioritizedLifecycleEventHandlerConfiguration<BootstrapContext> newEntryAddHandler(final @NonNull LifecycleEventHandler<? super RegistryEntryAddEvent<T, B>> handler) {
+        return this.entryAdd().newHandler(handler);
+    }
+
+    /**
+     * Gets the event type for {@link RegistryFreezeEvent} which is fired just before
+     * a registry is frozen. It allows for the registration of new objects.
+     * <p>
+     * Can be used in {@link io.papermc.paper.plugin.lifecycle.event.LifecycleEventManager#registerEventHandler(LifecycleEventType, LifecycleEventHandler)}
+     * to register a handler for {@link RegistryFreezeEvent}.
+     *
+     * @return the pre-freeze event type
+     */
+    LifecycleEventType.@NonNull Prioritizable<BootstrapContext, RegistryFreezeEvent<T, B>> freeze();
+
+    /**
+     * Shortcut for calling {@link #freeze()} followed by {@link LifecycleEventType#newHandler(LifecycleEventHandler)}.
+     * <p>
+     * Can be used in {@link io.papermc.paper.plugin.lifecycle.event.LifecycleEventManager#registerEventHandler(LifecycleEventHandlerConfiguration)}
+     * to register a handler for {@link RegistryFreezeEvent}
+     *
+     * @param handler the event handler for {@link RegistryFreezeEvent}
+     * @return the configuration for further use
+     */
+    default @NonNull PrioritizedLifecycleEventHandlerConfiguration<BootstrapContext> newFreezeHandler(final @NonNull LifecycleEventHandler<? super RegistryFreezeEvent<T, B>> handler) {
+        return this.freeze().newHandler(handler);
+    }
+
+    /**
+     * Gets the registry key associated with this event type provider.
+     *
+     * @return the registry key
+     */
+    @NonNull RegistryKey<T> registryKey();
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/RegistryEventProviderImpl.java b/src/main/java/io/papermc/paper/registry/event/RegistryEventProviderImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..85a9fbc6aa59e95aac57aa6e626a7366222cf80e
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/RegistryEventProviderImpl.java
@@ -0,0 +1,29 @@
+package io.papermc.paper.registry.event;
+
+import io.papermc.paper.plugin.bootstrap.BootstrapContext;
+import io.papermc.paper.plugin.lifecycle.event.types.LifecycleEventType;
+import io.papermc.paper.registry.RegistryBuilder;
+import io.papermc.paper.registry.RegistryKey;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+@DefaultQualifier(NonNull.class)
+record RegistryEventProviderImpl<T, B extends RegistryBuilder<T>>(RegistryKey<T> registryKey) implements RegistryEventProvider<T, B> {
+
+    static <T, B extends RegistryBuilder<T>> RegistryEventProvider<T, B> create(final RegistryKey<T> registryKey) {
+        return new RegistryEventProviderImpl<>(registryKey);
+    }
+
+    @Override
+    public LifecycleEventType.Prioritizable<BootstrapContext, RegistryEntryAddEvent<T, B>> entryAdd() {
+        return RegistryEventTypeProvider.provider().registryAddition(this);
+    }
+
+    @Override
+    public LifecycleEventType.Prioritizable<BootstrapContext, RegistryFreezeEvent<T, B>> freeze() {
+        return RegistryEventTypeProvider.provider().registryPreFreeze(this);
+    }
+
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/RegistryEventTypeProvider.java b/src/main/java/io/papermc/paper/registry/event/RegistryEventTypeProvider.java
new file mode 100644
index 0000000000000000000000000000000000000000..4e3f041f2c4ee09d806c0528af2f67912525d94c
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/RegistryEventTypeProvider.java
@@ -0,0 +1,23 @@
+package io.papermc.paper.registry.event;
+
+import io.papermc.paper.plugin.bootstrap.BootstrapContext;
+import io.papermc.paper.plugin.lifecycle.event.types.LifecycleEventType;
+import io.papermc.paper.registry.RegistryBuilder;
+import java.util.Optional;
+import java.util.ServiceLoader;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+interface RegistryEventTypeProvider {
+
+    Optional<RegistryEventTypeProvider> PROVIDER = ServiceLoader.load(RegistryEventTypeProvider.class)
+        .findFirst();
+
+    static RegistryEventTypeProvider provider() {
+        return PROVIDER.orElseThrow(() -> new IllegalStateException("Could not find a %s service implementation".formatted(RegistryEventTypeProvider.class.getSimpleName())));
+    }
+
+    <T, B extends RegistryBuilder<T>> LifecycleEventType.Prioritizable<BootstrapContext, RegistryEntryAddEvent<T, B>> registryAddition(RegistryEventProvider<T, B> type);
+
+    <T, B extends RegistryBuilder<T>> LifecycleEventType.Prioritizable<BootstrapContext, RegistryFreezeEvent<T, B>> registryPreFreeze(RegistryEventProvider<T, B> type);
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/RegistryEvents.java b/src/main/java/io/papermc/paper/registry/event/RegistryEvents.java
new file mode 100644
index 0000000000000000000000000000000000000000..1f89945be2ed68f52a544f41f7a151b8fdfe113e
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/RegistryEvents.java
@@ -0,0 +1,14 @@
+package io.papermc.paper.registry.event;
+
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Holds providers for {@link RegistryEntryAddEvent} and {@link RegistryFreezeEvent}
+ * handlers for each applicable registry.
+ */
+@ApiStatus.Experimental
+public final class RegistryEvents {
+
+    private RegistryEvents() {
+    }
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/RegistryFreezeEvent.java b/src/main/java/io/papermc/paper/registry/event/RegistryFreezeEvent.java
new file mode 100644
index 0000000000000000000000000000000000000000..6d34ab36303337551e6318228fd2b28ec7da75d3
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/RegistryFreezeEvent.java
@@ -0,0 +1,27 @@
+package io.papermc.paper.registry.event;
+
+import io.papermc.paper.registry.RegistryBuilder;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Event object for {@link RegistryEventProvider#freeze()}. This
+ * event is fired right before a registry is frozen disallowing further changes.
+ * It provides a way for plugins to add new objects to the registry.
+ *
+ * @param <T> registry entry type
+ * @param <B> registry entry builder type
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface RegistryFreezeEvent<T, B extends RegistryBuilder<T>> extends RegistryEvent<T> {
+
+    /**
+     * Get a view of the registry which supports
+     * the registering of new values.
+     *
+     * @return a writable registry view
+     */
+    @Override
+    @NonNull WritableRegistry<T, B> registry();
+}
diff --git a/src/main/java/io/papermc/paper/registry/event/WritableRegistry.java b/src/main/java/io/papermc/paper/registry/event/WritableRegistry.java
new file mode 100644
index 0000000000000000000000000000000000000000..7a0356b7da3844e7ec9121656dc059f53d48301e
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/event/WritableRegistry.java
@@ -0,0 +1,28 @@
+package io.papermc.paper.registry.event;
+
+import io.papermc.paper.registry.RegistryBuilder;
+import io.papermc.paper.registry.RegistryView;
+import io.papermc.paper.registry.TypedKey;
+import java.util.function.Consumer;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * A registry view which supports registering new objects.
+ *
+ * @param <T> registry entry type
+ * @param <B> registry entry builder type
+ */
+@ApiStatus.NonExtendable
+@ApiStatus.Experimental
+public interface WritableRegistry<T, B extends RegistryBuilder<T>> extends RegistryView<T> {
+
+    /**
+     * Register a new value with the specified key. This will
+     * fire a {@link RegistryEntryAddEvent} for the new entry.
+     *
+     * @param key the entry's key (must be unique from others)
+     * @param value a consumer for the entry's builder
+     */
+    void register(@NonNull TypedKey<T> key, @NonNull Consumer<? super B> value);
+}
diff --git a/src/main/java/org/bukkit/Registry.java b/src/main/java/org/bukkit/Registry.java
index 88bb3b9ae99fae97ec21972b75ec43cb6b7b22b5..661af93e3f73aaf1eca0be08b73fae62c534ecbe 100644
--- a/src/main/java/org/bukkit/Registry.java
+++ b/src/main/java/org/bukkit/Registry.java
@@ -352,6 +352,27 @@ public interface Registry<T extends Keyed> extends Iterable<T> {
      */
     @Nullable
     T get(@NotNull NamespacedKey key);
+    // Paper start
+    /**
+     * Get the object by its key.
+     *
+     * @param key non-null key
+     * @return item or null if it does not exist
+     */
+    default @Nullable T get(final net.kyori.adventure.key.@NotNull Key key) {
+        return key instanceof final NamespacedKey nsKey ? this.get(nsKey) : this.get(new NamespacedKey(key.namespace(), key.value()));
+    }
+
+    /**
+     * Get the object by its typed key.
+     *
+     * @param typedKey non-null typed key
+     * @return item or null if it does not exist
+     */
+    default @Nullable T get(final io.papermc.paper.registry.@NotNull TypedKey<T> typedKey) {
+        return this.get(typedKey.key());
+    }
+    // Paper end
 
     // Paper start - improve Registry
     /**