Lophine/lophine-server/paper-patches/features/0005-World-load-unload-APIs.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrHua269 <mrhua269@gmail.com>
Date: Fri, 1 May 2026 18:37:51 +0800
Subject: [PATCH] World load/unload APIs
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好吧这里这一坨需要说明的太多了而且我也不是很会翻译所以就用中文注释了)

这一整个实现使用了一种安全点的思路，相对于folia pr里和canvas的让每个region自己卸载, 我更偏向于将调度器拆分到每个level中然后实现类似于单个level停服的逻辑,这样会更加符合直觉而且实现要更加快速而且易于排查问题

由于世界卸载可能发生在玩家登录或者传送的过程中,所以我使用了引用计数器来避免这个竟态条件的发生

diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 407191ad9a7f31cc3317a7747ec3489804807b8e..606235c9af5afce55be8bbc963e8af7291a050c5 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -276,7 +276,7 @@ public final class CraftServer implements Server {
     private final StructureManager structureManager;
     final DedicatedServer console;
     private final DedicatedPlayerList playerList;
-    private final Map<String, World> worlds = new LinkedHashMap<>();
+    private final Map<String, World> worlds = new java.util.concurrent.ConcurrentHashMap<>(); // Luminol - Fix level hot loading/unloading apis
     private YamlConfiguration configuration;
     private YamlConfiguration commandsConfiguration;
     private final Yaml yaml = new Yaml(new SafeConstructor(new LoaderOptions()));
@@ -1198,7 +1198,8 @@ public final class CraftServer implements Server {
 
     @Override
     public World createWorld(WorldCreator creator) {
-        if (true) throw new UnsupportedOperationException(); // Folia - not implemented properly yet
+        // if (true) throw new UnsupportedOperationException(); // Folia - not implemented properly yet // Luminol - Level hot load apis
+        io.papermc.paper.threadedregions.RegionizedServer.ensureGlobalTickThread("Call createWorld off global region!"); // Luminol - Level hot load apis
         Preconditions.checkState(this.console.getAllLevels().iterator().hasNext(), "Cannot create additional worlds on STARTUP");
         //Preconditions.checkState(!this.console.isIteratingOverLevels, "Cannot create a world while worlds are being ticked"); // Paper - Cat - Temp disable. We'll see how this goes.
         Preconditions.checkArgument(creator != null, "WorldCreator cannot be null");
@@ -1356,7 +1357,8 @@ public final class CraftServer implements Server {
 
     @Override
     public boolean unloadWorld(World world, boolean save) {
-        if (true) throw new UnsupportedOperationException(); // Folia - not implemented properly yet
+        // if (true) throw new UnsupportedOperationException(); // Folia - not implemented properly yet // Luminol - Level hot unload apis
+        io.papermc.paper.threadedregions.RegionizedServer.ensureGlobalTickThread("Call unloadWorld off global region!"); // Luminol - Level hot unload apis
         //Preconditions.checkState(!this.console.isIteratingOverLevels, "Cannot unload a world while worlds are being ticked"); // Paper - Cat - Temp disable. We'll see how this goes.
         if (world == null) {
             return false;
@@ -1381,7 +1383,7 @@ public final class CraftServer implements Server {
             return false;
         }
 
-        try {
+        /*try { // Luminol - Level hot unload apis
             if (save) {
                 handle.save(null, true, false); // Paper - Fix saving in unloadWorld
             }
@@ -1393,10 +1395,70 @@ public final class CraftServer implements Server {
         }
 
         this.worlds.remove(world.getName().toLowerCase(Locale.ROOT));
-        this.console.removeLevel(handle);
+        this.console.removeLevel(handle);*/ // Luminol - Level hot unload apis
+        // Luminol start - Level hot unload apis
+        handle.levelUnloader.getUnloadCallback().addWaiter((ret, ex) -> {
+            this.worlds.remove(world.getName().toLowerCase(Locale.ROOT));
+        });
+        // use the timeout of folia by default
+        handle.levelUnloader.applySettings(java.time.Duration.ofSeconds(60), save);
+
+        if (!handle.levelUnloader.startUnloading()) {
+            return false;
+        }
+
+        handle.levelUnloader.waitForComplete();
+        // Luminol end
         return true;
     }
 
+    // Luminol start - Async world unloading api
+    @Override
+    public void unloadWorld(World world, boolean save, java.util.concurrent.CompletableFuture<Boolean> callback) {
+        io.papermc.paper.threadedregions.RegionizedServer.ensureGlobalTickThread("Call unloadWorld off global region!"); // Luminol - Level hot unload apis
+
+        if (world == null) {
+            callback.complete(false);
+            return;
+        }
+
+        ServerLevel handle = ((CraftWorld) world).getHandle();
+
+        if (this.console.getLevel(handle.dimension()) == null) {
+            callback.complete(false);
+            return;
+        }
+
+        if (handle.dimension() == net.minecraft.world.level.Level.OVERWORLD) {
+            callback.complete(false);
+            return;
+        }
+
+        if (!handle.players().isEmpty()) {
+            callback.complete(false);
+            return;
+        }
+
+        WorldUnloadEvent event = new WorldUnloadEvent(handle.getWorld());
+        if (!event.callEvent()) {
+            callback.complete(false);
+            return;
+        }
+
+        handle.levelUnloader.getUnloadCallback().addWaiter((_, _) -> {
+            this.worlds.remove(world.getName().toLowerCase(Locale.ROOT));
+
+            callback.complete(true);
+        });
+        // use the timeout of folia by default
+        handle.levelUnloader.applySettings(java.time.Duration.ofSeconds(60), save);
+
+        if (!handle.levelUnloader.startUnloading()) {
+            callback.complete(false);
+        }
+    }
+    // Luminol end
+
     @Override
     public World getRespawnWorld() {
         return this.console.findRespawnDimension().getWorld();