refactor: optimize RenderQueue by replacing copy-and-clear logic with atomic set swap

Author: smartcmd

src/main/java/me/daoge/allaymap/render/RenderQueue.java

@@ -4,7 +4,7 @@
 import org.allaymc.api.utils.hash.HashUtils;
 import org.allaymc.api.world.Dimension;
 
-import java.util.HashSet;
+import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -45,24 +45,11 @@ public void markBlockDirty(Dimension dimension, int blockX, int blockZ) {
 
     /**
      * Get and clear all dirty chunks for a dimension.
-     * This method is thread-safe - uses copy-and-clear to avoid losing concurrent adds.
+     * Atomically swaps the set with a new empty one to avoid race conditions.
      */
     public Set<Long> pollDirtyChunks(Dimension dimension) {
-        Set<Long> chunks = this.dirtyChunks.get(dimension);
-        if (chunks == null || chunks.isEmpty()) {
-            return Set.of();
-        }
-
-        // Copy current contents and clear atomically per-element
-        // Using HashSet for the copy since we just need to iterate over it
-        Set<Long> result = new HashSet<>();
-        for (Long key : chunks) {
-            if (chunks.remove(key)) {
-                result.add(key);
-            }
-        }
-
-        return result;
+        var result = this.dirtyChunks.put(dimension, ConcurrentHashMap.newKeySet());
+        return result == null ? Collections.emptySet() : result;
     }
 
     public void removeDimension(Dimension dimension) {