PaperMC/CraftBukkit-Patches/0006-Better-Chunk-Tick-Selection.patch

From 0b4a7be15ef20fd9da2461d422aa8375d8916185 Mon Sep 17 00:00:00 2001
From: md_5 <md_5@live.com.au>
Date: Tue, 11 Jun 2013 12:56:02 +1000
Subject: [PATCH] Better Chunk Tick Selection

An optimized chunk ticking algorithm which better selects chunks around players which are active on the server.

diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 130c54d..9a218e4 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -64,7 +64,7 @@ public abstract class World implements IBlockAccess {
     public Scoreboard scoreboard = new Scoreboard();
     public final boolean isStatic;
     // CraftBukkit - longhashset
-    protected LongHashSet chunkTickList = new LongHashSet();
+    // protected LongHashSet chunkTickList = new LongHashSet(); // Spigot
     private int K;
     public boolean allowMonsters;
     public boolean allowAnimals;
@@ -98,6 +98,31 @@ public abstract class World implements IBlockAccess {
     public long ticksPerMonsterSpawns;
     public boolean populating;
     private int tickPosition;
+
+    // Spigot start
+    protected final gnu.trove.map.hash.TLongShortHashMap chunkTickList;
+    protected float growthOdds = 100;
+    protected float modifiedOdds = 100;
+    private final byte chunkTickRadius;
+
+    public static long chunkToKey(int x, int z)
+    {
+        long k = ( ( ( (long) x ) & 0xFFFF0000L ) << 16 ) | ( ( ( (long) x ) & 0x0000FFFFL ) << 0 );
+        k |= ( ( ( (long) z ) & 0xFFFF0000L ) << 32 ) | ( ( ( (long) z ) & 0x0000FFFFL ) << 16 );
+        return k;
+    }
+
+    public static int keyToX(long k)
+    {
+        return (int) ( ( ( k >> 16 ) & 0xFFFF0000 ) | ( k & 0x0000FFFF ) );
+    }
+
+    public static int keyToZ(long k)
+    {
+        return (int) ( ( ( k >> 32 ) & 0xFFFF0000L ) | ( ( k >> 16 ) & 0x0000FFFF ) );
+    }
+    // Spigot end
+
     public final org.spigotmc.SpigotWorldConfig spigotConfig; // Spigot
 
     public CraftWorld getWorld() {
@@ -119,6 +144,11 @@ public abstract class World implements IBlockAccess {
         this.ticksPerAnimalSpawns = this.getServer().getTicksPerAnimalSpawns(); // CraftBukkit
         this.ticksPerMonsterSpawns = this.getServer().getTicksPerMonsterSpawns(); // CraftBukkit
         // CraftBukkit end
+        // Spigot start
+        this.chunkTickRadius = (byte) ( ( this.getServer().getViewDistance() < 7 ) ? this.getServer().getViewDistance() : 7 );
+        this.chunkTickList = new gnu.trove.map.hash.TLongShortHashMap( spigotConfig.chunksPerTick * 5, 0.7f, Long.MIN_VALUE, Short.MIN_VALUE );
+        this.chunkTickList.setAutoCompactionFactor( 0 );
+        // Spigot end
 
         this.K = this.random.nextInt(12000);
         this.allowMonsters = true;
@@ -1897,17 +1927,44 @@ public abstract class World implements IBlockAccess {
         int k;
         int l;
 
+        // Spigot start
+        int optimalChunks = spigotConfig.chunksPerTick;
+        // Quick conditions to allow us to exist early
+        if ( optimalChunks <= 0 || players.isEmpty() )
+        {
+            return;
+        }
+        // Keep chunks with growth inside of the optimal chunk range
+        int chunksPerPlayer = Math.min( 200, Math.max( 1, (int) ( ( ( optimalChunks - players.size() ) / (double) players.size() ) + 0.5 ) ) );
+        int randRange = 3 + chunksPerPlayer / 30;
+        // Limit to normal tick radius - including view distance
+        randRange = ( randRange > chunkTickRadius ) ? chunkTickRadius : randRange;
+        // odds of growth happening vs growth happening in vanilla
+        this.growthOdds = this.modifiedOdds = Math.max( 35, Math.min( 100, ( ( chunksPerPlayer + 1 ) * 100F ) / 15F ) );
+        // Spigot end
         for (i = 0; i < this.players.size(); ++i) {
             entityhuman = (EntityHuman) this.players.get(i);
             j = MathHelper.floor(entityhuman.locX / 16.0D);
             k = MathHelper.floor(entityhuman.locZ / 16.0D);
             l = this.q();
 
-            for (int i1 = -l; i1 <= l; ++i1) {
-                for (int j1 = -l; j1 <= l; ++j1) {
-                    this.chunkTickList.add(org.bukkit.craftbukkit.util.LongHash.toLong(i1 + j, j1 + k));
+            // Spigot start - Always update the chunk the player is on
+            long key = chunkToKey( j, k );
+            int existingPlayers = Math.max( 0, chunkTickList.get( key ) ); // filter out -1
+            chunkTickList.put( key, (short) ( existingPlayers + 1 ) );
+
+            // Check and see if we update the chunks surrounding the player this tick
+            for ( int chunk = 0; chunk < chunksPerPlayer; chunk++ )
+            {
+                int dx = ( random.nextBoolean() ? 1 : -1 ) * random.nextInt( randRange );
+                int dz = ( random.nextBoolean() ? 1 : -1 ) * random.nextInt( randRange );
+                long hash = chunkToKey( dx + j, dz + k );
+                if ( !chunkTickList.contains( hash ) && this.chunkProvider.isChunkLoaded(dx + j, dz + k ) )
+                {
+                    chunkTickList.put( hash, (short) -1 ); // no players
                 }
             }
+            // Spigot End
         }
 
         this.methodProfiler.b();
diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index 1a6024f..93e5a14 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -344,12 +344,15 @@ public class WorldServer extends World implements IAsyncTaskHandler {
     protected void h() {
         super.h();
         if (this.worldData.getType() == WorldType.DEBUG_ALL_BLOCK_STATES) {
-            Iterator iterator = this.chunkTickList.iterator();
+            // Spigot start
+           gnu.trove.iterator.TLongShortIterator iterator = this.chunkTickList.iterator();
 
             while (iterator.hasNext()) {
-                ChunkCoordIntPair chunkcoordintpair = (ChunkCoordIntPair) iterator.next();
+                iterator.advance();
+                long chunkCoord = iterator.key();
 
-                this.getChunkAt(chunkcoordintpair.x, chunkcoordintpair.z).b(false);
+                this.getChunkAt(World.keyToX( chunkCoord ), World.keyToZ( chunkCoord )).b(false);
+                // Spigot end
             }
 
         } else {
@@ -361,9 +364,21 @@ public class WorldServer extends World implements IAsyncTaskHandler {
             //    ChunkCoordIntPair chunkcoordintpair1 = (ChunkCoordIntPair) iterator1.next();
             //    int k = chunkcoordintpair1.x * 16;
             //    int l = chunkcoordintpair1.z * 16;
-            for (long chunkCoord : chunkTickList.popAll()) {
-                int chunkX = LongHash.msw(chunkCoord);
-                int chunkZ = LongHash.lsw(chunkCoord);
+            // Spigot start
+            for (gnu.trove.iterator.TLongShortIterator iter = chunkTickList.iterator(); iter.hasNext(); )
+            {
+                iter.advance();
+                long chunkCoord = iter.key();
+                int chunkX = World.keyToX( chunkCoord );
+                int chunkZ = World.keyToZ( chunkCoord );
+                // If unloaded, or in procedd of being unloaded, drop it
+                if ( ( !this.chunkProvider.isChunkLoaded( chunkX, chunkZ ) ) || ( this.chunkProviderServer.unloadQueue.contains( chunkX, chunkZ ) ) )
+                {
+                    iter.remove();
+                    continue;
+                }
+                // Spigot end
+                // ChunkCoordIntPair chunkcoordintpair = (ChunkCoordIntPair) iterator.next();
                 int k = chunkX * 16;
                 int l = chunkZ * 16;
                 
@@ -458,6 +473,12 @@ public class WorldServer extends World implements IAsyncTaskHandler {
             }
 
         }
+        // Spigot Start
+        if ( spigotConfig.clearChunksOnTick )
+        {
+            chunkTickList.clear();
+        }
+        // Spigot End
     }
 
     protected BlockPosition a(BlockPosition blockposition) {
diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
index 961ddb4..90a227f 100644
--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
+++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
@@ -68,4 +68,15 @@ public class SpigotWorldConfig
         config.addDefault( "world-settings.default." + path, def );
         return config.getString( "world-settings." + worldName + "." + path, config.getString( "world-settings.default." + path ) );
     }
+
+    public int chunksPerTick;
+    public boolean clearChunksOnTick;
+    private void chunksPerTick()
+    {
+        chunksPerTick = getInt( "chunks-per-tick", 650 );
+        log( "Chunks to Grow per Tick: " + chunksPerTick );
+
+        clearChunksOnTick = getBoolean( "clear-tick-list", false );
+        log( "Clear tick list: " + clearChunksOnTick );
+    }
 }
-- 
2.1.0