From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Cryptite <cryptite@gmail.com>
Date: Fri, 18 Nov 2022 08:37:19 -0600
Subject: [PATCH] Shared DataStorage for maps


diff --git a/src/main/java/io/papermc/paper/configuration/WorldConfiguration.java b/src/main/java/io/papermc/paper/configuration/WorldConfiguration.java
index a1bd848bbf924267e74e61dabdb840628712b1ad..8ffacd63c964b823ac607a05d3388e036fab0b52 100644
--- a/src/main/java/io/papermc/paper/configuration/WorldConfiguration.java
+++ b/src/main/java/io/papermc/paper/configuration/WorldConfiguration.java
@@ -356,6 +356,7 @@ public class WorldConfiguration extends ConfigurationPart {
     public class Maps extends ConfigurationPart {
         public int itemFrameCursorLimit = 128;
         public int itemFrameCursorUpdateInterval = 10;
+        public String sharedDataFolder; // Slice
     }
 
     public Fixes fixes;
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index 571753395ecfe82e3c95ad7f322981991ab0c94d..3aac19995956d0d0116cba0bc1412fb9e8f4c2ad 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -227,6 +227,8 @@ public class ServerLevel extends Level implements WorldGenLevel {
         return thr;
     }
 
+    private @Nullable DimensionDataStorage sharedDataStorage; // Slice
+
     @Override public LevelChunk getChunkIfLoaded(int x, int z) { // Paper - this was added in world too but keeping here for NMS ABI
         return this.chunkSource.getChunkAtIfLoadedImmediately(x, z); // Paper
     }
@@ -605,6 +607,13 @@ public class ServerLevel extends Level implements WorldGenLevel {
 
         this.chunkTaskScheduler = new io.papermc.paper.chunk.system.scheduling.ChunkTaskScheduler(this, io.papermc.paper.chunk.system.scheduling.ChunkTaskScheduler.workerThreads); // Paper - rewrite chunk system
         this.entityLookup = new io.papermc.paper.chunk.system.entity.EntityLookup(this, new EntityCallbacks()); // Paper - rewrite chunk system
+
+        String sharedDataFolder = paperConfig().maps.sharedDataFolder;
+        if (sharedDataFolder != "") {
+            java.io.File sharedDir = new java.io.File(sharedDataFolder);
+            sharedDir.mkdirs();
+            this.sharedDataStorage = new DimensionDataStorage(sharedDir, datafixer);
+        }
     }
 
     public void setWeatherParameters(int clearDuration, int rainDuration, boolean raining, boolean thundering) {
@@ -1318,6 +1327,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
             }// Paper
             // Paper - rewrite chunk system - entity saving moved into ChunkHolder
 
+            if (sharedDataStorage != null) sharedDataStorage.save();
         } else if (close) { chunkproviderserver.close(false); } // Paper - rewrite chunk system
 
         // CraftBukkit start - moved from MinecraftServer.saveChunks
@@ -1944,11 +1954,17 @@ public class ServerLevel extends Level implements WorldGenLevel {
         return this.getChunkSource().getDataStorage();
     }
 
+    // Slice start
+    public DimensionDataStorage getMapDataStorage() {
+        return sharedDataStorage != null ? sharedDataStorage : this.getChunkSource().getDataStorage();
+    }
+    // Slice end
+
     @Nullable
     @Override
     public MapItemSavedData getMapData(String id) {
         // CraftBukkit start
-        return (MapItemSavedData) this.getServer().overworld().getDataStorage().get((nbttagcompound) -> {
+        return (MapItemSavedData) getMapDataStorage().get((nbttagcompound) -> { // Slice
             // We only get here when the data file exists, but is not a valid map
             MapItemSavedData newMap = MapItemSavedData.load(nbttagcompound);
             newMap.id = id;
@@ -1962,12 +1978,22 @@ public class ServerLevel extends Level implements WorldGenLevel {
     @Override
     public void setMapData(String id, MapItemSavedData state) {
         state.id = id; // CraftBukkit
-        this.getServer().overworld().getDataStorage().set(id, state);
+        getMapDataStorage().set(id, state); // Slice
     }
 
     @Override
     public int getFreeMapId() {
-        return ((MapIndex) this.getServer().overworld().getDataStorage().computeIfAbsent(MapIndex::load, MapIndex::new, "idcounts")).getFreeAuxValueForMap();
+        // Slice start
+        DimensionDataStorage storage = getMapDataStorage();
+        MapIndex mapIndex = storage.readSavedData(MapIndex::load, "idcounts");
+        if (mapIndex == null) {
+            mapIndex = new MapIndex();
+        }
+        int newId = mapIndex.getFreeAuxValueForMap();
+        storage.set("idcounts", mapIndex);
+        storage.save();
+        return newId;
+        // Slice end
     }
 
     // Paper start - helper function for configurable spawn radius
diff --git a/src/main/java/net/minecraft/world/level/storage/DimensionDataStorage.java b/src/main/java/net/minecraft/world/level/storage/DimensionDataStorage.java
index 2513069f4ffe594857762ef51f1b9a078b8b1d17..88b13bfa3393d9901c8a1b62bcc37f03919d747b 100644
--- a/src/main/java/net/minecraft/world/level/storage/DimensionDataStorage.java
+++ b/src/main/java/net/minecraft/world/level/storage/DimensionDataStorage.java
@@ -58,7 +58,7 @@ public class DimensionDataStorage {
     }
 
     @Nullable
-    private <T extends SavedData> T readSavedData(Function<CompoundTag, T> readFunction, String id) {
+    public <T extends SavedData> T readSavedData(Function<CompoundTag, T> readFunction, String id) { // Slice private -> public
         try {
             File file = this.getDataFile(id);
             if (file.exists()) {