Implement AnvilChunkLoader coupling

src/main/java/com/falsepattern/chunk/api/ChunkDataManager.java

@@ -1,62 +1,122 @@
 package com.falsepattern.chunk.api;
 
-import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Contract;
 
 import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.chunk.storage.ExtendedBlockStorage;
 
 import java.nio.ByteBuffer;
 
 /**
- * Singleton instances that can manage custom in chunks.
- * <p>
- * Implementations should be stateless and thread-safe.
- * @implNote For performance reasons, you should store any data in the chunk itself using a mixin. The type T is the type
- * of the interface that you are mixing into the chunk.
+ * Singleton instances that can manage custom in chunks. This class only manages the registration of
+ * managers. For the actual networking and data storage, see the internal interfaces of this interface.
+ * Note: This interface does nothing by itself, you also need to implement one or more of the internal interfaces.
+ * One class can have multiple
  */
-public interface ChunkDataManager<T> {
+public interface ChunkDataManager {
 
     /**
      * @return The domain of this manager. Usually the modid of the mod that owns this manager.
      */
+    @Contract(pure = true)
     String domain();
 
     /**
      * @return The id of this manager. Usually the name of the manager. Unique per domain.
      */
+
+    @Contract(pure = true)
     String id();
 
     /**
-     * @implNote This is used to determine the size of the packet compression/decompression buffer.
-     * @return The maximum amount of bytes your data can take up in a packet.
+     * Implement this interface if you want to synchronize your data with the client.
      */
-    int maxPacketSize();
+    interface PacketDataManager extends ChunkDataManager {
+        /**
+         * @implNote This is used to determine the size of the packet compression/decompression buffer.
+         * @return The maximum amount of bytes your data can take up in a packet.
+         */
+        @Contract(pure = true)
+        int maxPacketSize();
+
+        /**
+         * Serializes your data into a packet.
+         *
+         * @param chunk The chunk to serialize.
+         */
+        void writeToBuffer(Chunk chunk, int ebsMask, boolean forceUpdate, ByteBuffer data);
+
+        /**
+         * Deserializes your data from a packet.
+         * Mutates this object.
+         *
+         * @param chunk  The chunk to deserialize.
+         * @param buffer The packet buffer to read from.
+         */
+        void readFromBuffer(Chunk chunk, int ebsMask, boolean forceUpdate, ByteBuffer buffer);
+    }
 
     /**
-     * Serializes your data into a packet.
-     *
-     * @param chunk The chunk to serialize.
+     * Implement this interface if you want to save your data to disk. This is called once per chunk.
      */
-    void writeToBuffer(T chunk, int ebsMask, boolean forceUpdate, ByteBuffer data);
+    interface ChunkNBTDataManager extends ChunkDataManager {
+        /**
+         * If false, the given nbt compound will be a freshly created object that gets inserted into the actual
+         * level NBT tag under the `domain:id` name.
+         * <p>
+         * If true, the nbt tag passed in into the write/read methods will be the raw Level NBT tag without filtering.
+         *
+         * @implNote This is used internally for reimplementing the vanilla logic. Only change this if you know what you're doing.
+         */
+        @Contract(pure = true)
+        default boolean chunkPrivilegedAccess() {
+            return false;
+        }
+
+        /**
+         * Serializes your data into an NBT tag. This is used when saving the chunk to disk.
+         */
+        void writeChunkToNBT(Chunk chunk, NBTTagCompound nbt);
+
+
+        /**
+         * Deserializes your data from an NBT tag. This is used when loading the chunk from disk.
+         * The NBT *may* be null if the chunk was saved before this manager was registered
+         * (e.g., loading save before the mod was added), and the manager is not {@link #chunkPrivilegedAccess() privileged}.
+         * In this case, you should initialize the data to a sane default.
+         */
+        void readChunkFromNBT(Chunk chunk, NBTTagCompound nbt);
+    }
 
     /**
-     * Deserializes your data from a packet.
-     * Mutates this object.
-     *
-     * @param chunk  The chunk to deserialize.
-     * @param buffer The packet buffer to read from.
+     * Implement this interface if you want to save your ExtendedBlockStorage data to disk. This is called once per
+     * ExtendedBlockStorage per chunk. (16 times per chunk)
      */
-    void readFromBuffer(T chunk, int ebsMask, boolean forceUpdate, ByteBuffer buffer);
+    interface SectionNBTDataManager extends ChunkDataManager {
+        /**
+         * If false, the given nbt compound will be a freshly created object that gets inserted into the actual
+         * segment NBT tag under the `domain:id` name.
+         * <p>
+         * If true, the nbt tag passed in into the write/read methods will be the raw segment NBT tag without filtering.
+         *
+         * @implNote This is used internally for reimplementing the vanilla logic. Only change this if you know what you're doing.
+         */
+        @Contract(pure = true)
+        default boolean sectionPrivilegedAccess() {
+            return false;
+        }
+        /**
+         * Serializes your data into an NBT tag. This is used when saving the chunk to disk.
+         */
+        void writeSectionToNBT(Chunk chunk, ExtendedBlockStorage ebs, NBTTagCompound section);
 
-    /**
-     * Serializes your data into an NBT tag. This is used when saving the chunk to disk.
-     * @param tag The tag to write to.
-     */
-    void writeToNBT(T chunk, @NotNull NBTTagCompound tag);
-
-    /**
-     * Deserializes your data from an NBT tag. This is used when loading the chunk from disk.
-     * Mutates this object.
-     * @param tag The tag to read from.
-     */
-    void readFromNBT(T chunk, @NotNull NBTTagCompound tag);
+        /**
+         * Deserializes your data from an NBT tag. This is used when loading the chunk from disk.
+         * The NBT *may* be null if the chunk was saved before this manager was registered
+         * (e.g., loading save before the mod was added), and the manager is not {@link #sectionPrivilegedAccess() privileged}.
+         * In this case, you should initialize the data to a sane default.
+         */
+        void readSectionFromNBT(Chunk chunk, ExtendedBlockStorage ebs, NBTTagCompound section);
+    }
 }