Paper/patches/api/0004-Code-Generation.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Fri, 26 May 2023 18:14:44 -0700
Subject: [PATCH] Code Generation

Currently includes generated key holder classes for types
used in the Registry Modification API

diff --git a/build.gradle.kts b/build.gradle.kts
index 75bfb0ab8049ebbb52240abf661d469de5526767..87e4ee95a8da287b02c13fac5f24f66902bc84c9 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,6 +1,7 @@
 plugins {
     `java-library`
     `maven-publish`
+    idea // Paper
 }
 
 java {
@@ -46,6 +47,22 @@ dependencies {
     testImplementation("org.ow2.asm:asm-tree:9.5")
 }
 
+// Paper start
+val generatedApiPath: java.nio.file.Path = rootProject.projectDir.toPath().resolve("paper-api-generator/generated")
+idea {
+    module {
+        generatedSourceDirs.add(generatedApiPath.toFile())
+    }
+}
+sourceSets {
+    main {
+        java {
+            srcDir(generatedApiPath)
+        }
+    }
+}
+// Paper end
+
 configure<PublishingExtension> {
     publications.create<MavenPublication>("maven") {
         from(components["java"])
@@ -122,3 +139,14 @@ tasks.check {
     dependsOn(scanJar)
 }
 // Paper end
+// Paper start
+val scanJarForOldGeneratedCode = tasks.register("scanJarForOldGeneratedCode", io.papermc.paperweight.tasks.ScanJarForOldGeneratedCode::class) {
+    mcVersion.set(providers.gradleProperty("mcVersion"))
+    annotation.set("Lio/papermc/paper/generated/GeneratedFrom;")
+    jarToScan.set(tasks.jar.flatMap { it.archiveFile })
+    classpath.from(configurations.compileClasspath)
+}
+tasks.check {
+    dependsOn(scanJarForOldGeneratedCode)
+}
+// Paper end
diff --git a/src/main/java/io/papermc/paper/generated/GeneratedFrom.java b/src/main/java/io/papermc/paper/generated/GeneratedFrom.java
new file mode 100644
index 0000000000000000000000000000000000000000..2512dba27edfdccbc4430815b6cba048e3d93484
--- /dev/null
+++ b/src/main/java/io/papermc/paper/generated/GeneratedFrom.java
@@ -0,0 +1,21 @@
+package io.papermc.paper.generated;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Used to mark classes which are generated from
+ * a specific version of minecraft.
+ */
+@ApiStatus.Internal
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface GeneratedFrom {
+
+    String value();
+}
diff --git a/src/main/java/io/papermc/paper/registry/RegistryKey.java b/src/main/java/io/papermc/paper/registry/RegistryKey.java
new file mode 100644
index 0000000000000000000000000000000000000000..5251f922d2d14da35f61098c11694371f591cd2a
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/RegistryKey.java
@@ -0,0 +1,61 @@
+package io.papermc.paper.registry;
+
+import net.kyori.adventure.key.Keyed;
+import org.bukkit.GameEvent;
+import org.bukkit.block.Biome;
+import org.bukkit.generator.structure.StructureType;
+import org.bukkit.inventory.meta.trim.TrimMaterial;
+import org.bukkit.inventory.meta.trim.TrimPattern;
+import org.jetbrains.annotations.ApiStatus;
+
+import static io.papermc.paper.registry.RegistryKeyImpl.create;
+
+/**
+ * Identifier for a specific registry. For use with
+ * {@link TypedKey} and the registry modification API.
+ * <p>
+ * There are 2 types of registries, identified as "built-in"
+ * or "data-driven". The former are not changeable by datapacks (which
+ * doesn't necessarily mean they aren't changeable in the API) and
+ * are loaded first. "Data-driven" registries are all created by
+ * reading in data from the vanilla and other datapacks.
+ *
+ * @param <T> the value type
+ */
+@SuppressWarnings("unused")
+@ApiStatus.Experimental
+public sealed interface RegistryKey<T> extends Keyed permits RegistryKeyImpl {
+
+    /* ******************* *
+     * Built-in Registries *
+     * ******************* */
+    /**
+     * Built-in registry for game events
+     * @see io.papermc.paper.registry.keys.GameEventKeys
+     */
+    RegistryKey<GameEvent> GAME_EVENT = create("game_event");
+    /**
+     * Built-in registry for structure types.
+     * @see io.papermc.paper.registry.keys.StructureTypeKeys
+     */
+    RegistryKey<StructureType> STRUCTURE_TYPE = create("worldgen/structure_type");
+
+    /* ********************** *
+     * Data-driven Registries *
+     * ********************** */
+    /**
+     * Data-driven registry for structure types.
+     * @see io.papermc.paper.registry.keys.BiomeKeys
+     */
+    RegistryKey<Biome> BIOME = create("worldgen/biome");
+    /**
+     * Data-driven registry for structure types.
+     * @see io.papermc.paper.registry.keys.TrimMaterialKeys
+     */
+    RegistryKey<TrimMaterial> TRIM_MATERIAL = create("trim_material");
+    /**
+     * Data-driven registry for structure types.
+     * @see io.papermc.paper.registry.keys.TrimPatternKeys
+     */
+    RegistryKey<TrimPattern> TRIM_PATTERN = create("trim_pattern");
+}
diff --git a/src/main/java/io/papermc/paper/registry/RegistryKeyImpl.java b/src/main/java/io/papermc/paper/registry/RegistryKeyImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..9ad300fa1668cb59bbd85ff8091591db69b8c9dc
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/RegistryKeyImpl.java
@@ -0,0 +1,19 @@
+package io.papermc.paper.registry;
+
+import com.google.common.collect.Sets;
+import java.util.Set;
+import net.kyori.adventure.key.Key;
+import org.intellij.lang.annotations.Subst;
+import org.jetbrains.annotations.NotNull;
+
+record RegistryKeyImpl<T>(@NotNull Key key) implements RegistryKey<T> {
+
+    static final Set<RegistryKey<?>> REGISTRY_KEYS = Sets.newIdentityHashSet();
+
+    static <T> RegistryKey<T> create(@Subst("some_key") final String key) {
+        final RegistryKey<T> registryKey = new RegistryKeyImpl<>(Key.key(Key.MINECRAFT_NAMESPACE, key));
+        REGISTRY_KEYS.add(registryKey);
+        return registryKey;
+    }
+
+}
diff --git a/src/main/java/io/papermc/paper/registry/TypedKey.java b/src/main/java/io/papermc/paper/registry/TypedKey.java
new file mode 100644
index 0000000000000000000000000000000000000000..271454cd1b92ada4301025b57348ea77da9116a1
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/TypedKey.java
@@ -0,0 +1,44 @@
+package io.papermc.paper.registry;
+
+import net.kyori.adventure.key.Key;
+import net.kyori.adventure.key.Keyed;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Represents a key for a value in a specific registry.
+ *
+ * @param <T> the value type for the registry
+ */
+@ApiStatus.Experimental
+public sealed interface TypedKey<T> extends Keyed permits TypedKeyImpl {
+
+    /**
+     * Gets the key for the value in the registry.
+     *
+     * @return the value's key
+     */
+    @Override
+    @NotNull Key key();
+
+    /**
+     * Gets the registry key for the value this key
+     * represents.
+     *
+     * @return the registry key
+     */
+    @NotNull RegistryKey<T> registryKey();
+
+    /**
+     * Create a typed key from a key and a registry key.
+     *
+     * @param registryKey the registry this key is for
+     * @param key the key for the value in the registry
+     * @param <T> value type
+     * @return a new key for the value key and registry key
+     */
+    @ApiStatus.Experimental
+    static <T extends Keyed> @NotNull TypedKey<T> create(final @NotNull RegistryKey<T> registryKey, final @NotNull Key key) {
+        return new TypedKeyImpl<>(key, registryKey);
+    }
+}
diff --git a/src/main/java/io/papermc/paper/registry/TypedKeyImpl.java b/src/main/java/io/papermc/paper/registry/TypedKeyImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..3c3fd73f7742bb8602e2f9164dd4c1208a412255
--- /dev/null
+++ b/src/main/java/io/papermc/paper/registry/TypedKeyImpl.java
@@ -0,0 +1,8 @@
+package io.papermc.paper.registry;
+
+import net.kyori.adventure.key.Key;
+import net.kyori.adventure.key.Keyed;
+import org.jetbrains.annotations.NotNull;
+
+record TypedKeyImpl<T extends Keyed>(@NotNull Key key, @NotNull RegistryKey<T> registryKey) implements TypedKey<T> {
+}
diff --git a/src/main/java/org/bukkit/MinecraftExperimental.java b/src/main/java/org/bukkit/MinecraftExperimental.java
index 2365a8c620be709b280fb08855752bb0995838fc..b63e24b3c4d2f1a08e39434caa527bb2e0edea22 100644
--- a/src/main/java/org/bukkit/MinecraftExperimental.java
+++ b/src/main/java/org/bukkit/MinecraftExperimental.java
@@ -24,4 +24,5 @@ import org.jetbrains.annotations.ApiStatus;
 })
 @ApiStatus.Internal
 public @interface MinecraftExperimental {
+    String value() default ""; // Paper
 }