Fix lag caused by water lighting updates

Before: http://aikar.co/timings.php?url=7842564
After: http://aikar.co/timings.php?url=7842536

Spigot-Server-Patches/0030-Better-water-lighting-updates.patch

@@ -0,0 +1,105 @@
+From ff141325520b2a64ed66c1e224df6b5e07096025 Mon Sep 17 00:00:00 2001
+From: Iceee <andrew@opticgaming.tv>
+Date: Wed, 23 Jul 2014 09:42:45 -0500
+Subject: [PATCH] Better water lighting updates
+
+
+diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
+index 406aead..d284614 100644
+--- a/src/main/java/net/minecraft/server/Chunk.java
++++ b/src/main/java/net/minecraft/server/Chunk.java
+@@ -42,6 +42,12 @@ public class Chunk {
+     private int x;
+     protected net.minecraft.util.gnu.trove.map.hash.TObjectIntHashMap<Class> entityCount = new net.minecraft.util.gnu.trove.map.hash.TObjectIntHashMap<Class>(); // Spigot
+ 
++    // PaperSpigot start
++    private boolean waterLightingChanged;
++    private boolean[] waterChanges;
++    private int ticks;
++    // PaperSpigot end
++
+     // CraftBukkit start - Neighbor loaded cache for chunk lighting and entity ticking
+     private int neighbors = 0x1 << 12;
+ 
+@@ -75,6 +81,9 @@ public class Chunk {
+         this.v = new byte[256];
+         this.b = new int[256];
+         this.c = new boolean[256];
++        // PaperSpigot start
++        this.waterChanges = new boolean[256];
++        // PaperSpigot end
+         this.tileEntities = new HashMap();
+         this.x = 4096;
+         this.entitySlices = new List[16];
+@@ -231,6 +240,14 @@ public class Chunk {
+         this.n = true;
+     }
+ 
++    // PaperSpigot start
++    private void scheduleWaterLightingUpdate(int i, int j) {
++        this.waterChanges[i + j * 16] = true;
++        this.waterLightingChanged = true;
++    }
++
++    // PaperSpigot end
++
+     private void e(int i, int j) {
+         this.c[i + j * 16] = true;
+         this.w = true;
+@@ -241,8 +258,11 @@ public class Chunk {
+         if (this.world.areChunksLoaded(this.locX * 16 + 8, 0, this.locZ * 16 + 8, 16)) {
+             for (int i = 0; i < 16; ++i) {
+                 for (int j = 0; j < 16; ++j) {
+-                    if (this.c[i + j * 16]) {
++                    // PaperSpigot start
++                    if (this.c[i + j * 16] || this.waterChanges[i + j * 16]) {
+                         this.c[i + j * 16] = false;
++                        this.waterChanges[i + j * 16] = false;
++                        // PaperSpigot end
+                         int k = this.b(i, j);
+                         int l = this.locX * 16 + i;
+                         int i1 = this.locZ * 16 + j;
+@@ -277,6 +297,9 @@ public class Chunk {
+             }
+ 
+             this.w = false;
++            // PaperSpigot start
++            this.waterLightingChanged = false;
++            // PaperSpigot end
+         }
+ 
+         this.world.methodProfiler.b();
+@@ -507,7 +530,13 @@ public class Chunk {
+                     }
+ 
+                     if (j2 != k2 && (j2 < k2 || this.getBrightness(EnumSkyBlock.SKY, i, j, k) > 0 || this.getBrightness(EnumSkyBlock.BLOCK, i, j, k) > 0)) {
+-                        this.e(i, k);
++                        // PaperSpigot start
++                        if(block.material == Material.WATER) {
++                            this.scheduleWaterLightingUpdate(i, k);
++                        } else {
++                            this.e(i, k);
++                        }
++                        // PaperSpigot end
+                     }
+                 }
+ 
+@@ -961,9 +990,14 @@ public class Chunk {
+     }
+ 
+     public void b(boolean flag) {
+-        if (this.w && !this.world.worldProvider.g && !flag) {
++        // PaperSpigot start
++        ++ticks;
++        if(ticks % 20 == 0 && this.waterLightingChanged) {
++            this.c(this.world.isStatic);
++        } else if (this.w && !this.world.worldProvider.g && !flag) {
+             this.c(this.world.isStatic);
+         }
++        // PaperSpigot end
+ 
+         this.m = true;
+         if (!this.lit && this.done && this.world.spigotConfig.randomLightUpdates) { // Spigot - also use random light updates setting to determine if we should relight
+-- 
+1.9.4.msysgit.0
+