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/net/minecraft/nbt/NBTCompressedStreamTools.java b/src/main/java/net/minecraft/nbt/NBTCompressedStreamTools.java
index 20410a5853e34c90c872f5e9592d50c4727e914d..860f084de38dc3f8723d881ff78fb1873f2b602a 100644
--- a/src/main/java/net/minecraft/nbt/NBTCompressedStreamTools.java
+++ b/src/main/java/net/minecraft/nbt/NBTCompressedStreamTools.java
@@ -51,6 +51,7 @@ public class NBTCompressedStreamTools {
         return nbttagcompound;
     }
 
+    public static NBTTagCompound readNBT(InputStream inputstream) throws IOException { return a(inputstream); } // Paper - OBFHELPER
     public static NBTTagCompound a(InputStream inputstream) throws IOException {
         DataInputStream datainputstream = new DataInputStream(new BufferedInputStream(new GZIPInputStream(inputstream)));
         Throwable throwable = null;
@@ -106,6 +107,7 @@ public class NBTCompressedStreamTools {
 
     }
 
+    public static void writeNBT(NBTTagCompound nbttagcompound, OutputStream outputstream) throws IOException { a(nbttagcompound, outputstream); } // Paper - OBFHELPER
     public static void a(NBTTagCompound nbttagcompound, OutputStream outputstream) throws IOException {
         DataOutputStream dataoutputstream = new DataOutputStream(new BufferedOutputStream(new GZIPOutputStream(outputstream)));
         Throwable throwable = null;
diff --git a/src/main/java/net/minecraft/util/datafix/DataConverterRegistry.java b/src/main/java/net/minecraft/util/datafix/DataConverterRegistry.java
index 6527509e6aed7187667c681af682e9a02937a224..28e36ee76da533f8aa0a09cfc4f1fc0f744af715 100644
--- a/src/main/java/net/minecraft/util/datafix/DataConverterRegistry.java
+++ b/src/main/java/net/minecraft/util/datafix/DataConverterRegistry.java
@@ -208,6 +208,7 @@ public class DataConverterRegistry {
         return datafixerbuilder.build(SystemUtils.e());
     }
 
+    public static DataFixer getDataFixer() { return a(); } // Paper - OBFHELPER
     public static DataFixer a() {
         return DataConverterRegistry.c;
     }
diff --git a/src/main/java/net/minecraft/world/item/ItemStack.java b/src/main/java/net/minecraft/world/item/ItemStack.java
index 661f400ae4f5cebef5d1743819529ecf647b6681..0468f80b7f52ee45fc9364470b23f80f7cd0cb57 100644
--- a/src/main/java/net/minecraft/world/item/ItemStack.java
+++ b/src/main/java/net/minecraft/world/item/ItemStack.java
@@ -198,6 +198,7 @@ public final class ItemStack {
         this.checkEmpty();
     }
 
+    public static ItemStack fromCompound(NBTTagCompound nbttagcompound) { return a(nbttagcompound); } // Paper - OBFHELPER
     public static ItemStack a(NBTTagCompound nbttagcompound) {
         try {
             return new ItemStack(nbttagcompound);
diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index 79ac4e1f3aad1a855a5d7ef7df2a3bfd1c4362f2..51aa0c37df947a229eddaa3c4e3372f64575617e 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -360,6 +360,46 @@ 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();
+        NBTTagCompound compound = (item instanceof CraftItemStack ? ((CraftItemStack) item).getHandle() : CraftItemStack.asNMSCopy(item)).save(new NBTTagCompound());
+        compound.setInt("DataVersion", getDataVersion());
+        try {
+            net.minecraft.nbt.NBTCompressedStreamTools.writeNBT(
+                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 {
+            NBTTagCompound compound = net.minecraft.nbt.NBTCompressedStreamTools.readNBT(
+                new java.io.ByteArrayInputStream(data)
+            );
+            int dataVersion = compound.getInt("DataVersion");
+
+            Preconditions.checkArgument(dataVersion <= getDataVersion(), "Newer version! Server downgrades are not supported!");
+            Dynamic<NBTBase> converted = DataConverterRegistry.getDataFixer().update(DataConverterTypes.ITEM_STACK, new Dynamic<NBTBase>(DynamicOpsNBT.a, compound), dataVersion, getDataVersion());
+            return CraftItemStack.asCraftMirror(net.minecraft.world.item.ItemStack.fromCompound((NBTTagCompound) converted.getValue()));
+        } catch (IOException ex) {
+            com.destroystokyo.paper.util.SneakyThrow.sneaky(ex);
+            throw new RuntimeException();
+        }
+    }
     // Paper end
 
     /**