From 51bb05aed16f053631bf97be648970b8dd966da2 Mon Sep 17 00:00:00 2001
From: Alfie Cleveland <alfeh@me.com>
Date: Tue, 4 Jul 2017 23:05:53 +0100
Subject: [PATCH] ChunkMap caching


diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index d3453f644..e228a0b29 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -12,8 +12,8 @@ import java.util.concurrent.atomic.AtomicInteger; // PaperSpigot
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-
 import org.bukkit.Bukkit; // CraftBukkit
+import org.spigotmc.SpigotConfig;
 
 public class Chunk {
 
@@ -75,6 +75,63 @@ public class Chunk {
     }
     // CraftBukkit end
 
+    // MineHQ start
+    private ChunkMap chunkMap17;
+    private ChunkMap chunkMap18;
+    private int emptySectionBits;
+
+    public ChunkMap getChunkMap(boolean groundUpContinuous, int primaryBitMask, int version) {
+        if (!SpigotConfig.cacheChunkMaps || !groundUpContinuous || (primaryBitMask != 0 && primaryBitMask != '\uffff')) {
+            return PacketPlayOutMapChunk.a(this, groundUpContinuous, primaryBitMask, version);
+        }
+
+        if (primaryBitMask == 0) {
+            ChunkMap chunkMap = new ChunkMap();
+            chunkMap.a = new byte[0];
+            return chunkMap;
+        }
+
+        boolean isDirty = false;
+        for (int i = 0; i < sections.length; ++i) {
+            ChunkSection section = sections[i];
+            if (section == null) {
+                if ((emptySectionBits & (1 << i)) == 0) {
+                    isDirty = true;
+                    emptySectionBits |= (1 << i);
+                }
+            } else {
+                if ((emptySectionBits & (1 << i)) == 1) {
+                    isDirty = true;
+                    emptySectionBits &= ~(1 << i);
+                    section.isDirty = false;
+                } else if (section.isDirty) {
+                    isDirty = true;
+                    section.isDirty = false;
+                }
+            }
+        }
+
+        if (isDirty) {
+            chunkMap17 = null;
+            chunkMap18 = null;
+        }
+
+        if (version < 24) {
+            if (chunkMap17 == null) {
+                chunkMap17 = PacketPlayOutMapChunk.a(this, true, '\uffff', version);
+            }
+
+            return chunkMap17;
+        } else {
+            if (chunkMap18 == null) {
+                chunkMap18 = PacketPlayOutMapChunk.a(this, true, '\uffff', version);
+            }
+
+            return chunkMap18;
+        }
+    }
+    // MineHQ end
+
     public Chunk(World world, int i, int j) {
         this.sections = new ChunkSection[16];
         this.v = new byte[256];
diff --git a/src/main/java/net/minecraft/server/ChunkSection.java b/src/main/java/net/minecraft/server/ChunkSection.java
index b0e92d6c9..527559097 100644
--- a/src/main/java/net/minecraft/server/ChunkSection.java
+++ b/src/main/java/net/minecraft/server/ChunkSection.java
@@ -18,6 +18,7 @@ public class ChunkSection {
     private byte compactData;
     private byte compactEmitted;
     private byte compactSky;
+    public boolean isDirty = false;
 
     // Pre-generated (read-only!) NibbleArrays for every possible value, used for chunk saving
     private static NibbleArray[] compactPregen = new NibbleArray[16];
@@ -143,6 +144,7 @@ public class ChunkSection {
 
         this.blockIds[j << 8 | k << 4 | i] = (byte) (i1 & 255);
         // MineHQ start
+        isDirty = true;
         /*
         if (i1 > 255) {
             if (this.extBlockIds == null) {
@@ -175,6 +177,7 @@ public class ChunkSection {
             this.blockData = expandCompactNibble(this.compactData);
         }
         // CraftBukkit end
+        isDirty = true; // MineHQ
         this.blockData.a(i, j, k, l);
     }
 
@@ -199,6 +202,7 @@ public class ChunkSection {
             this.skyLight = expandCompactNibble(this.compactSky);
         }
         // CraftBukkit end
+        isDirty = true; // MineHQ
         this.skyLight.a(i, j, k, l);
     }
 
@@ -220,6 +224,7 @@ public class ChunkSection {
             this.emittedLight = expandCompactNibble(this.compactEmitted);
         }
         // CraftBukkit end
+        isDirty = true; // MineHQ
         this.emittedLight.a(i, j, k, l);
     }
 
diff --git a/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java b/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java
index fed2f0492..1ae362328 100644
--- a/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java
+++ b/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java
@@ -36,7 +36,7 @@ public class PacketPlayOutMapChunk extends Packet {
             return;
         }
         // MineHQ end
-        ChunkMap chunkmap = a(chunk, flag, i, version);
+        ChunkMap chunkmap = chunk.getChunkMap(flag, i, version); // MineHQ
 
         this.d = chunkmap.c;
         this.c = chunkmap.b;
diff --git a/src/main/java/net/minecraft/server/PacketPlayOutMapChunkBulk.java b/src/main/java/net/minecraft/server/PacketPlayOutMapChunkBulk.java
index 28e966fe0..0c8b4a4c1 100644
--- a/src/main/java/net/minecraft/server/PacketPlayOutMapChunkBulk.java
+++ b/src/main/java/net/minecraft/server/PacketPlayOutMapChunkBulk.java
@@ -47,7 +47,7 @@ public class PacketPlayOutMapChunkBulk extends Packet {
 
         for (int k = 0; k < i; ++k) {
             Chunk chunk = (Chunk) list.get(k);
-            ChunkMap chunkmap = PacketPlayOutMapChunk.a(chunk, true, '\uffff', version);
+            ChunkMap chunkmap = chunk.getChunkMap(true, '\uffff', version); // MineHQ
 
             // Spigot start
             world = chunk.world;
diff --git a/src/main/java/org/spigotmc/SpigotConfig.java b/src/main/java/org/spigotmc/SpigotConfig.java
index 7e328ab51..931c4b25b 100644
--- a/src/main/java/org/spigotmc/SpigotConfig.java
+++ b/src/main/java/org/spigotmc/SpigotConfig.java
@@ -520,6 +520,11 @@ public class SpigotConfig
     private static void disableEntityCollisions() {
         disableEntityCollisions = getBoolean("settings.disable.general.entity-collisions", false);
     }
+
+    public static boolean cacheChunkMaps;
+    private static void cacheChunkMaps() {
+        cacheChunkMaps = getBoolean("settings.cache-chunk-maps", false);
+    }
     // MineHQ end
 
     public static boolean reduceArmorDamage;
-- 
2.13.3