From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrPowerGamerBR <git@mrpowergamerbr.com>
Date: Fri, 24 Nov 2023 23:37:24 -0300
Subject: [PATCH] BlockEntityTickersList optimization tests


diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 94eac6837c06e6fd192c108632f1e365a008d6ad..3588657da9969b4207bbeb8109bc101384c03398 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -1274,8 +1274,8 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         // Iterator iterator = this.blockEntityTickers.iterator();
         int tilesThisCycle = 0;
         // SparklyPaper start - optimize tickBlockEntities
-        // var toRemove = new it.unimi.dsi.fastutil.objects.ObjectOpenCustomHashSet<TickingBlockEntity>(net.minecraft.Util.identityStrategy()); // Paper - use removeAll
-        // toRemove.add(null);
+        var toRemoveOld = new it.unimi.dsi.fastutil.objects.ObjectOpenCustomHashSet<TickingBlockEntity>(net.minecraft.Util.identityStrategy()); // Paper - use removeAll
+        toRemoveOld.add(null);
         var toRemove = new java.util.HashSet<Integer>(); // For some reason, Java's HashSet seems to be faster than fastutil's only if we are removing HUGE amounts of tile entities, idk why
         var startSearchFromIndex = -1;
         var shouldTickBlocksAtLastResult = -1; // -1 = undefined
@@ -1301,13 +1301,13 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
                 // Spigot start
                 tilesThisCycle--;
                 // SparklyPaper start - optimize tickBlockEntities
-                // toRemove.add(tickingblockentity); // Paper - use removeAll
+                toRemoveOld.add(tickingblockentity); // Paper - use removeAll
                 toRemove.add(tileTickPosition);
                 if (startSearchFromIndex == -1)
                     startSearchFromIndex = tileTickPosition;
                 // SparklyPaper end
                 // Spigot end
-            // } else if (this.shouldTickBlocksAt(tickingblockentity.getPos())) { // SparklyPaper start - optimize tickBlockEntities
+                // } else if (this.shouldTickBlocksAt(tickingblockentity.getPos())) { // SparklyPaper start - optimize tickBlockEntities
             } else {
                 long chunkPos = tickingblockentity.getChunkCoordinateKey();
                 boolean shouldTick;
@@ -1319,18 +1319,47 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
                     shouldTickBlocksAtChunkPos = chunkPos;
                 }
                 if (shouldTick) {
-                tickingblockentity.tick();
-                // Paper start - execute chunk tasks during tick
-                if ((this.tileTickPosition & 7) == 0) {
-                    // MinecraftServer.getServer().executeMidTickTasks(); // SparklyPaper - parallel world ticking (only run mid-tick at the end of each tick / fixes concurrency bugs related to executeMidTickTasks)
-                }
-                // Paper end - execute chunk tasks during tick
+                    tickingblockentity.tick();
+                    // Paper start - execute chunk tasks during tick
+                    if ((this.tileTickPosition & 7) == 0) {
+                        // MinecraftServer.getServer().executeMidTickTasks(); // SparklyPaper - parallel world ticking (only run mid-tick at the end of each tick / fixes concurrency bugs related to executeMidTickTasks)
+                    }
+                    // Paper end - execute chunk tasks during tick
                 } // SparklyPaper end
             }
         }
         // SparklyPaper start - optimize tickBlockEntities
-        // this.blockEntityTickers.removeAll(toRemove);
-        this.blockEntityTickers.removeAllByIndex(startSearchFromIndex, toRemove); // We don't need to care about if the startSearchFromIndex can be -1 here, since if it is -1, then the toRemove list is empty and the call will fast fail
+        java.util.ArrayList<TickingBlockEntity> oldList = new java.util.ArrayList<>(this.blockEntityTickers);
+        long diffOld = 0;
+        long diffNew = 0;
+        if (toRemoveOld.size() != 1) { // the old one always have null as the first element
+            var startOld = System.nanoTime();
+            oldList.removeAll(toRemoveOld);
+            var endOld = System.nanoTime();
+            diffOld = endOld - startOld;
+            System.out.println("Old version deleted " + toRemoveOld.size() + " elements, took " + diffOld + "ns");
+        }
+        if (startSearchFromIndex != -1) {
+            var start = System.nanoTime();
+            this.blockEntityTickers.removeAllByIndex(startSearchFromIndex, toRemove); // We don't need to care about if the startSearchFromIndex can be -1 here, since if it is -1, then the toRemove list is empty and the call will fast fail
+            var end = System.nanoTime();
+            System.out.println("(current tick: " + this.getServer().getTickCount() + ") startSearchFromIndex: " + startSearchFromIndex + " - toRemove: " + toRemove);
+            diffNew = end - start;
+            System.out.println("New version deleted " + toRemove.size() + " elements, took " + diffNew + "ns");
+        }
+        if (toRemove.size() != 0) {
+            System.out.println("Equals? " + oldList.equals(this.blockEntityTickers));
+            String winner = "Unknown";
+            long perfIncrease = 0;
+            if (diffOld > diffNew) {
+                winner = "New Version";
+                perfIncrease = diffOld - diffNew;
+            } else {
+                winner = "Old Version";
+                perfIncrease = diffNew - diffOld;
+            }
+            System.out.println("Who won? " + winner + ", by " + perfIncrease + "ns");
+        }
         // SparklyPaper end
         this.timings.tileEntityTick.stopTiming(); // Spigot
         this.tickingBlockEntities = false;