Paper/patches/server/0402-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 16:56:54 +0200
Subject: [PATCH] Add Raw Byte ItemStack Serialization

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

diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index ad8d6a84e1a66e03ae15269e36bc787148f12396..d18f8d7c699893740fa709ef1f0caa4390e7eb20 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -378,6 +378,46 @@ public final class CraftMagicNumbers implements UnsafeValues {
     public boolean isSupportedApiVersion(String apiVersion) {
         return apiVersion != null && SUPPORTED_API.contains(apiVersion);
     }
+
+    @Override
+    public byte[] serializeItem(ItemStack item) {
+        Preconditions.checkNotNull(item, "null cannot be serialized");
+        Preconditions.checkArgument(item.getType() != Material.AIR, "air cannot be serialized");
+
+        java.io.ByteArrayOutputStream outputStream = new java.io.ByteArrayOutputStream();
+        CompoundTag compound = (item instanceof CraftItemStack ? ((CraftItemStack) item).handle : CraftItemStack.asNMSCopy(item)).save(new CompoundTag());
+        compound.putInt("DataVersion", getDataVersion());
+        try {
+            net.minecraft.nbt.NbtIo.writeCompressed(
+                compound,
+                outputStream
+            );
+        } catch (IOException ex) {
+            throw new RuntimeException(ex);
+        }
+
+        return outputStream.toByteArray();
+    }
+
+    @Override
+    public ItemStack deserializeItem(byte[] data) {
+        Preconditions.checkNotNull(data, "null cannot be deserialized");
+        Preconditions.checkArgument(data.length > 0, "cannot deserialize nothing");
+
+        try {
+            CompoundTag compound = net.minecraft.nbt.NbtIo.readCompressed(
+                new java.io.ByteArrayInputStream(data)
+            );
+            int dataVersion = compound.getInt("DataVersion");
+
+            Preconditions.checkArgument(dataVersion <= getDataVersion(), "Newer version! Server downgrades are not supported!");
+            Dynamic<Tag> converted = DataFixers.getDataFixer().update(References.ITEM_STACK, new Dynamic<Tag>(NbtOps.INSTANCE, compound), dataVersion, getDataVersion());
+            return CraftItemStack.asCraftMirror(net.minecraft.world.item.ItemStack.of((CompoundTag) converted.getValue()));
+        } catch (IOException ex) {
+            com.destroystokyo.paper.util.SneakyThrow.sneaky(ex);
+            throw new RuntimeException();
+        }
+    }
     // Paper end
 
     /**