Paper/patches/server/0995-Make-a-PDC-view-accessible-directly-from-ItemStack.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Wed, 12 Jun 2024 10:29:40 -0700
Subject: [PATCH] Make a PDC view accessible directly from ItemStack


diff --git a/src/main/java/io/papermc/paper/persistence/PaperPersistentDataContainerView.java b/src/main/java/io/papermc/paper/persistence/PaperPersistentDataContainerView.java
new file mode 100644
index 0000000000000000000000000000000000000000..122c32e82b299cafd7d0c6a9f4818523470c9f05
--- /dev/null
+++ b/src/main/java/io/papermc/paper/persistence/PaperPersistentDataContainerView.java
@@ -0,0 +1,120 @@
+package io.papermc.paper.persistence;
+
+import com.google.common.base.Preconditions;
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtIo;
+import net.minecraft.nbt.Tag;
+import org.bukkit.NamespacedKey;
+import org.bukkit.craftbukkit.persistence.CraftPersistentDataAdapterContext;
+import org.bukkit.craftbukkit.persistence.CraftPersistentDataContainer;
+import org.bukkit.craftbukkit.persistence.CraftPersistentDataTypeRegistry;
+import org.bukkit.persistence.PersistentDataAdapterContext;
+import org.bukkit.persistence.PersistentDataContainer;
+import org.bukkit.persistence.PersistentDataType;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+@NullMarked
+public abstract class PaperPersistentDataContainerView implements PersistentDataContainerView {
+
+    protected final CraftPersistentDataTypeRegistry registry;
+    protected final CraftPersistentDataAdapterContext adapterContext;
+
+    public PaperPersistentDataContainerView(final CraftPersistentDataTypeRegistry registry) {
+        this.registry = registry;
+        this.adapterContext = new CraftPersistentDataAdapterContext(this.registry);
+    }
+
+    public abstract @Nullable Tag getTag(final String key);
+
+    public abstract CompoundTag toTagCompound();
+
+    @Override
+    public <P, C> boolean has(final NamespacedKey key, final PersistentDataType<P, C> type) {
+        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
+        Preconditions.checkArgument(type != null, "The provided type cannot be null");
+
+        final Tag value = this.getTag(key.toString());
+        if (value == null) {
+            return false;
+        }
+
+        return this.registry.isInstanceOf(type, value);
+    }
+
+    @Override
+    public boolean has(final NamespacedKey key) {
+        Preconditions.checkArgument(key != null, "The provided key for the custom value was null"); // Paper
+        return this.getTag(key.toString()) != null;
+    }
+
+    @Override
+    public <P, C> @Nullable C get(final NamespacedKey key, final PersistentDataType<P, C> type) {
+        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
+        Preconditions.checkArgument(type != null, "The provided type cannot be null");
+
+        final Tag value = this.getTag(key.toString());
+        if (value == null) {
+            return null;
+        }
+
+        return type.fromPrimitive(this.registry.extract(type, value), this.adapterContext);
+    }
+
+    @Override
+    public <P, C> C getOrDefault(final NamespacedKey key, final PersistentDataType<P, C> type, final C defaultValue) {
+        final C c = this.get(key, type);
+        return c != null ? c : defaultValue;
+    }
+
+    @Override
+    public Set<NamespacedKey> getKeys() {
+        final Set<String> names = this.toTagCompound().getAllKeys();
+        final Set<NamespacedKey> keys = new HashSet<>(names.size());
+        names.forEach(key -> {
+            final String[] keyPart = key.split(":", 2);
+            if (keyPart.length == 2) {
+                keys.add(new NamespacedKey(keyPart[0], keyPart[1]));
+            }
+        });
+        return Collections.unmodifiableSet(keys);
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return this.toTagCompound().isEmpty();
+    }
+
+    @Override
+    public void copyTo(final PersistentDataContainer other, final boolean replace) {
+        Preconditions.checkArgument(other != null, "The target container cannot be null");
+        final CraftPersistentDataContainer target = (CraftPersistentDataContainer) other;
+        final CompoundTag tag = this.toTagCompound();
+        for (final String key : tag.getAllKeys()) {
+            if (replace || !target.getRaw().containsKey(key)) {
+                target.getRaw().put(key, tag.get(key).copy());
+            }
+        }
+    }
+
+    @Override
+    public PersistentDataAdapterContext getAdapterContext() {
+        return this.adapterContext;
+    }
+
+    @Override
+    public byte[] serializeToBytes() throws IOException {
+        final CompoundTag root = this.toTagCompound();
+        final ByteArrayOutputStream byteArrayOutput = new ByteArrayOutputStream();
+        try (final DataOutputStream dataOutput = new DataOutputStream(byteArrayOutput)) {
+            NbtIo.write(root, dataOutput);
+            return byteArrayOutput.toByteArray();
+        }
+    }
+}
diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
index 49d2deac8d42a505b75f2196ef895a5564b62cac..756c73a401437566258813946fa10c7caa8f2469 100644
--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
@@ -496,4 +496,34 @@ public final class CraftItemStack extends ItemStack {
         return mirrored;
     }
     // Paper end
+
+    // Paper start - pdc
+    private net.minecraft.nbt.CompoundTag getPdcTag() {
+        if (this.handle == null) {
+            return new net.minecraft.nbt.CompoundTag();
+        }
+        final net.minecraft.world.item.component.CustomData customData = this.handle.getOrDefault(DataComponents.CUSTOM_DATA, net.minecraft.world.item.component.CustomData.EMPTY);
+        // getUnsafe is OK here because we are only ever *reading* the data so immutability is preserved
+        //noinspection deprecation
+        return customData.getUnsafe().getCompound("PublicBukkitValues");
+    }
+
+    private static final org.bukkit.craftbukkit.persistence.CraftPersistentDataTypeRegistry REGISTRY = new org.bukkit.craftbukkit.persistence.CraftPersistentDataTypeRegistry();
+    private final io.papermc.paper.persistence.PaperPersistentDataContainerView pdcView = new io.papermc.paper.persistence.PaperPersistentDataContainerView(REGISTRY) {
+
+        @Override
+        public net.minecraft.nbt.CompoundTag toTagCompound() {
+            return CraftItemStack.this.getPdcTag();
+        }
+
+        @Override
+        public net.minecraft.nbt.Tag getTag(final String key) {
+            return CraftItemStack.this.getPdcTag().get(key);
+        }
+    };
+    @Override
+    public io.papermc.paper.persistence.PersistentDataContainerView getPersistentDataContainer() {
+        return this.pdcView;
+    }
+    // Paper end - pdc
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
index f55fdd57ced259ad5a95878840e98ffaa3db2e05..9d867f1659433ea15f281c8b441db7e339013100 100644
--- a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
+++ b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
@@ -16,11 +16,10 @@ import org.bukkit.persistence.PersistentDataContainer;
 import org.bukkit.persistence.PersistentDataType;
 import org.jetbrains.annotations.NotNull;
 
-public class CraftPersistentDataContainer implements PersistentDataContainer {
+public class CraftPersistentDataContainer extends io.papermc.paper.persistence.PaperPersistentDataContainerView implements PersistentDataContainer { // Paper - split up view and mutable
 
     private final Map<String, Tag> customDataTags = new HashMap<>();
-    private final CraftPersistentDataTypeRegistry registry;
-    private final CraftPersistentDataAdapterContext adapterContext;
+    // Paper - move to PersistentDataContainerView
 
     public CraftPersistentDataContainer(Map<String, Tag> customTags, CraftPersistentDataTypeRegistry registry) {
         this(registry);
@@ -28,10 +27,15 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
     }
 
     public CraftPersistentDataContainer(CraftPersistentDataTypeRegistry registry) {
-        this.registry = registry;
-        this.adapterContext = new CraftPersistentDataAdapterContext(this.registry);
+        super(registry); // Paper - move to PersistentDataContainerView
     }
 
+    // Paper start
+    @Override
+    public Tag getTag(final String key) {
+        return this.customDataTags.get(key);
+    }
+    // Paper end
 
     @Override
     public <T, Z> void set(@NotNull NamespacedKey key, @NotNull PersistentDataType<T, Z> type, @NotNull Z value) {
@@ -42,44 +46,7 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
         this.customDataTags.put(key.toString(), this.registry.wrap(type, type.toPrimitive(value, this.adapterContext)));
     }
 
-    @Override
-    public <T, Z> boolean has(@NotNull NamespacedKey key, @NotNull PersistentDataType<T, Z> type) {
-        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
-        Preconditions.checkArgument(type != null, "The provided type cannot be null");
-
-        Tag value = this.customDataTags.get(key.toString());
-        if (value == null) {
-            return false;
-        }
-
-        return this.registry.isInstanceOf(type, value);
-    }
-
-    @Override
-    public boolean has(NamespacedKey key) {
-        Preconditions.checkArgument(key != null, "The provided key for the custom value was null"); // Paper
-        return this.customDataTags.get(key.toString()) != null;
-    }
-
-    @Override
-    public <T, Z> Z get(@NotNull NamespacedKey key, @NotNull PersistentDataType<T, Z> type) {
-        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
-        Preconditions.checkArgument(type != null, "The provided type cannot be null");
-
-        Tag value = this.customDataTags.get(key.toString());
-        if (value == null) {
-            return null;
-        }
-
-        return type.fromPrimitive(this.registry.extract(type, value), this.adapterContext);
-    }
-
-    @NotNull
-    @Override
-    public <T, Z> Z getOrDefault(@NotNull NamespacedKey key, @NotNull PersistentDataType<T, Z> type, @NotNull Z defaultValue) {
-        Z z = this.get(key, type);
-        return z != null ? z : defaultValue;
-    }
+    // Paper - move to PersistentDataContainerView
 
     @NotNull
     @Override
@@ -186,16 +153,7 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
     // Paper end
 
     // Paper start - byte array serialization
-    @Override
-    public byte[] serializeToBytes() throws java.io.IOException {
-        final net.minecraft.nbt.CompoundTag root = this.toTagCompound();
-        final java.io.ByteArrayOutputStream byteArrayOutput = new java.io.ByteArrayOutputStream();
-        try (final java.io.DataOutputStream dataOutput = new java.io.DataOutputStream(byteArrayOutput)) {
-            net.minecraft.nbt.NbtIo.write(root, dataOutput);
-            return byteArrayOutput.toByteArray();
-        }
-    }
-
+    // Paper - move to PersistentDataContainerView
     @Override
     public void readFromBytes(final byte[] bytes, final boolean clear) throws java.io.IOException {
         if (clear) {