perf: creative node verifies its registration instead of trusting it forever

#29 registered the location once. The old per-tick rewrite also repaired the shared
TileNode.locations map when another mod cleared or altered it. One lookup and four
int compares per tick restore that: generateId runs again as soon as the entry is
missing or different.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

src/main/java/com/pengu/thaumcraft/additions/tileentity/TileCreativeNode.java

@@ -45,12 +45,33 @@ public class TileCreativeNode extends TileVisNode implements INode, IWandable {
 
       if(!this.hasUpdatedOnce) {
          this.hasUpdatedOnce = !this.hasUpdatedOnce;
-      } else if(!this.locationRegistered) {
+      } else if(!this.locationRegistered || !this.isRegistrationIntact()) {
          this.generateId();
       }
 
    }
 
+   /**
+    * True while the shared location map still holds this node's entry unchanged. The old code rewrote the entry every
+    * tick, which also repaired it after another mod cleared or altered the map; checking it is one lookup and four
+    * int compares, and generateId runs again as soon as the entry is missing or different.
+    */
+   private boolean isRegistrationIntact() {
+      if(this.id == null || TileNode.locations == null || this.worldObj == null) {
+         return false;
+      }
+
+      java.util.List entry = (java.util.List)TileNode.locations.get(this.id);
+      if(entry == null || entry.size() != 4) {
+         return false;
+      }
+
+      return Integer.valueOf(this.worldObj.provider.dimensionId).equals(entry.get(0))
+         && Integer.valueOf(this.xCoord).equals(entry.get(1))
+         && Integer.valueOf(this.yCoord).equals(entry.get(2))
+         && Integer.valueOf(this.zCoord).equals(entry.get(3));
+   }
+
    public void invalidate() {
       this.unregisterLocation();
       super.invalidate();

src/test/java/com/pengu/thaumcraft/additions/tileentity/CreativeNodeRegistryTest.java

@@ -71,6 +71,39 @@ public class CreativeNodeRegistryTest {
         assertNotNull(TileNode.locations.get("0:3:70:5"));
     }
 
+    @Test
+    public void aClearedMapIsRepairedOnTheNextTick() {
+        this.node.updateEntity();
+        this.node.updateEntity();
+        assertNotNull(TileNode.locations.get("0:3:70:5"));
+        TileNode.locations.clear(); // another mod or TC4 wipes the shared map
+        this.node.updateEntity();
+        assertNotNull(TileNode.locations.get("0:3:70:5"));
+    }
+
+    @Test
+    public void anAlteredEntryIsRestoredOnTheNextTick() {
+        this.node.updateEntity();
+        this.node.updateEntity();
+        ArrayList wrong = new ArrayList();
+        wrong.add(Integer.valueOf(9));
+        wrong.add(Integer.valueOf(9));
+        wrong.add(Integer.valueOf(9));
+        wrong.add(Integer.valueOf(9));
+        TileNode.locations.put("0:3:70:5", wrong);
+        this.node.updateEntity();
+        assertEquals(Integer.valueOf(3), TileNode.locations.get("0:3:70:5").get(1));
+    }
+
+    @Test
+    public void anIntactEntryIsNotRewritten() {
+        this.node.updateEntity();
+        this.node.updateEntity();
+        ArrayList first = TileNode.locations.get("0:3:70:5");
+        this.node.updateEntity();
+        assertSame(first, TileNode.locations.get("0:3:70:5"));
+    }
+
     public static class FixtureWorld extends WorldServer {
 
         FixtureWorld() {