Paper/patches/api/0189-Add-Raw-Byte-ItemStack-Serialization.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Mariell Hoversholm <proximyst@proximyst.com>
Date: Thu, 30 Apr 2020 16:56:31 +0200
Subject: [PATCH] Add Raw Byte ItemStack Serialization

Serializes using NBT which is safer for server data migrations than bukkits format.

Co-authored-by: Nassim Jahnke <nassim@njahnke.dev>

diff --git a/src/main/java/org/bukkit/UnsafeValues.java b/src/main/java/org/bukkit/UnsafeValues.java
index 688fccdbc5cf831008ef2f27db9d15b0921a7561..e4861a8be534bfeae0385f0197261fa6ec1e7bc0 100644
--- a/src/main/java/org/bukkit/UnsafeValues.java
+++ b/src/main/java/org/bukkit/UnsafeValues.java
@@ -151,5 +151,9 @@ public interface UnsafeValues {
     default com.destroystokyo.paper.util.VersionFetcher getVersionFetcher() {
         return new com.destroystokyo.paper.util.VersionFetcher.DummyVersionFetcher();
     }
+
+    byte[] serializeItem(ItemStack item);
+
+    ItemStack deserializeItem(byte[] data);
     // Paper end
 }
diff --git a/src/main/java/org/bukkit/inventory/ItemStack.java b/src/main/java/org/bukkit/inventory/ItemStack.java
index fd3d4dd231d756d51db0155a4c3ad970c4f456ed..331faa8c050ce8d3d10d5c4d91f4cb70e7242312 100644
--- a/src/main/java/org/bukkit/inventory/ItemStack.java
+++ b/src/main/java/org/bukkit/inventory/ItemStack.java
@@ -26,6 +26,7 @@ import org.jetbrains.annotations.Nullable;
  * returns false.</b>
  */
 public class ItemStack implements Cloneable, ConfigurationSerializable, Translatable, net.kyori.adventure.text.event.HoverEventSource<net.kyori.adventure.text.event.HoverEvent.ShowItem> { // Paper
+    private static final byte ARRAY_SERIALIZATION_VERSION = 1; // Paper
     private Material type = Material.AIR;
     private int amount = 0;
     private MaterialData data = null;
@@ -650,6 +651,110 @@ public class ItemStack implements Cloneable, ConfigurationSerializable, Translat
         return Bukkit.getServer().getItemFactory().ensureServerConversions(this);
     }
 
+    /**
+     * Deserializes this itemstack from raw NBT bytes. NBT is safer for data migrations as it will
+     * use the built in data converter instead of bukkits dangerous serialization system.
+     *
+     * This expects that the DataVersion was stored on the root of the Compound, as saved from
+     * the {@link #serializeAsBytes()} API returned.
+     * @param bytes bytes representing an item in NBT
+     * @return ItemStack migrated to this version of Minecraft if needed.
+     */
+    @NotNull
+    public static ItemStack deserializeBytes(@NotNull byte[] bytes) {
+        return org.bukkit.Bukkit.getUnsafe().deserializeItem(bytes);
+    }
+
+    /**
+     * Serializes this itemstack to raw bytes in NBT. NBT is safer for data migrations as it will
+     * use the built in data converter instead of bukkits dangerous serialization system.
+     * @return bytes representing this item in NBT.
+     */
+    @NotNull
+    public byte[] serializeAsBytes() {
+        return org.bukkit.Bukkit.getUnsafe().serializeItem(this);
+    }
+
+    /**
+     * Serializes a collection of items to raw bytes in NBT. Serializes empty items as null.
+     * <p>
+     * If you need a string representation to put into a file, you can for example use {@link java.util.Base64} encoding.
+     *
+     * @param items items to serialize
+     * @return bytes representing the items in NBT
+     * @see #serializeAsBytes()
+     */
+    public static byte @NotNull [] serializeItemsAsBytes(java.util.@NotNull Collection<ItemStack> items) {
+        try (final java.io.ByteArrayOutputStream outputStream = new java.io.ByteArrayOutputStream()) {
+            final java.io.DataOutput output = new java.io.DataOutputStream(outputStream);
+            output.writeByte(ARRAY_SERIALIZATION_VERSION);
+            output.writeInt(items.size());
+            for (final ItemStack item : items) {
+                if (item == null || item.isEmpty()) {
+                    // Ensure the correct order by including empty/null items
+                    output.writeInt(0);
+                    continue;
+                }
+
+                final byte[] itemBytes = item.serializeAsBytes();
+                output.writeInt(itemBytes.length);
+                output.write(itemBytes);
+            }
+            return outputStream.toByteArray();
+        } catch (final java.io.IOException e) {
+            throw new RuntimeException("Error while writing itemstack", e);
+        }
+    }
+
+    /**
+     * Serializes a collection of items to raw bytes in NBT. Serializes empty items as null.
+     * <p>
+     * If you need a string representation to put into a file, you can for example use {@link java.util.Base64} encoding.
+     *
+     * @param items items to serialize
+     * @return bytes representing the items in NBT
+     * @see #serializeAsBytes()
+     */
+    public static byte @NotNull [] serializeItemsAsBytes(@Nullable ItemStack @NotNull [] items) {
+        return serializeItemsAsBytes(java.util.Arrays.asList(items));
+    }
+
+    /**
+     * Deserializes this itemstack from raw NBT bytes.
+     * <p>
+     * If you need a string representation to put into a file, you can for example use {@link java.util.Base64} encoding.
+     *
+     * @param bytes bytes representing an item in NBT
+     * @return ItemStack array migrated to this version of Minecraft if needed
+     * @see #deserializeBytes(byte[])
+     */
+    public static @Nullable ItemStack @NotNull [] deserializeItemsFromBytes(final byte @NotNull [] bytes) {
+        try (final java.io.ByteArrayInputStream inputStream = new java.io.ByteArrayInputStream(bytes)) {
+            final java.io.DataInputStream input = new java.io.DataInputStream(inputStream);
+            final byte version = input.readByte();
+            if (version != ARRAY_SERIALIZATION_VERSION) {
+                throw new IllegalArgumentException("Unsupported version or bad data: " + version);
+            }
+
+            final int count = input.readInt();
+            final ItemStack[] items = new ItemStack[count];
+            for (int i = 0; i < count; i++) {
+                final int length = input.readInt();
+                if (length == 0) {
+                    // Empty item, keep entry as null
+                    continue;
+                }
+
+                final byte[] itemBytes = new byte[length];
+                input.read(itemBytes);
+                items[i] = ItemStack.deserializeBytes(itemBytes);
+            }
+            return items;
+        } catch (final java.io.IOException e) {
+            throw new RuntimeException("Error while reading itemstack", e);
+        }
+    }
+
     /**
      * Gets the Display name as seen in the Client.
      * Currently the server only supports the English language. To override this,
diff --git a/src/main/java/org/bukkit/util/io/BukkitObjectInputStream.java b/src/main/java/org/bukkit/util/io/BukkitObjectInputStream.java
index 0f8eb97bd5e2f8b0f0cc03f7c4342aae06c4520c..def243b303b23aa42efcdbb280a29d4a877af3f8 100644
--- a/src/main/java/org/bukkit/util/io/BukkitObjectInputStream.java
+++ b/src/main/java/org/bukkit/util/io/BukkitObjectInputStream.java
@@ -3,8 +3,10 @@ package org.bukkit.util.io;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.ObjectInputStream;
+import java.util.Collection;
 import org.bukkit.configuration.serialization.ConfigurationSerializable;
 import org.bukkit.configuration.serialization.ConfigurationSerialization;
+import org.bukkit.inventory.ItemStack;
 
 /**
  * This class is designed to be used in conjunction with the {@link
@@ -14,7 +16,9 @@ import org.bukkit.configuration.serialization.ConfigurationSerialization;
  * <p>
  * Behavior of implementations extending this class is not guaranteed across
  * future versions.
+ * @deprecated Object streams on their own are not safe. For safer and more consistent serialization of items, use {@link ItemStack#deserializeBytes(byte[])} or {@link ItemStack#deserializeItemsFromBytes(byte[])}.
  */
+@Deprecated // Paper
 public class BukkitObjectInputStream extends ObjectInputStream {
 
     /**
diff --git a/src/main/java/org/bukkit/util/io/BukkitObjectOutputStream.java b/src/main/java/org/bukkit/util/io/BukkitObjectOutputStream.java
index dd1b9ee5f57773f07924aa311823fd8d63195cb2..bd4d48105457dbc6226f84e0e8d1e22878e01ca3 100644
--- a/src/main/java/org/bukkit/util/io/BukkitObjectOutputStream.java
+++ b/src/main/java/org/bukkit/util/io/BukkitObjectOutputStream.java
@@ -4,7 +4,9 @@ import java.io.IOException;
 import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.Serializable;
+import java.util.Collection;
 import org.bukkit.configuration.serialization.ConfigurationSerializable;
+import org.bukkit.inventory.ItemStack;
 
 /**
  * This class is designed to be used in conjunction with the {@link
@@ -14,7 +16,9 @@ import org.bukkit.configuration.serialization.ConfigurationSerializable;
  * <p>
  * Behavior of implementations extending this class is not guaranteed across
  * future versions.
+ * @deprecated Object streams on their own are not safe. For safer and more consistent serialization of items, use {@link ItemStack#serializeAsBytes()} or {@link ItemStack#serializeItemsAsBytes(Collection)}.
  */
+@Deprecated // Paper
 public class BukkitObjectOutputStream extends ObjectOutputStream {
 
     /**