From d5ecea59249849d642ab6a6612650528627f2b2f Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 19 Oct 2014 16:30:48 -0500
Subject: [PATCH] Improve autosave mechanism

Only save modified chunks, or chunks with entities after 4 auto save passes

diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index 9454d4f..86a13e7 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -910,7 +910,7 @@ public class Chunk {
             if (this.o && this.world.getTime() != this.lastSaved || this.n) {
                 return true;
             }
-        } else if (this.o && this.world.getTime() >= this.lastSaved + 600L) {
+        } else if (this.o && this.world.getTime() >= this.lastSaved + MinecraftServer.getServer().autosavePeriod * 4) { // PaperSpigot - Only save if we've passed 2 auto save intervals without modification
             return true;
         }
 
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 953a88c..692e74f 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -657,9 +657,10 @@ public abstract class MinecraftServer implements ICommandListener, Runnable, IMo
             // Spigot Start
             // We replace this with saving each individual world as this.saveChunks(...) is broken,
             // and causes the main thread to sleep for random amounts of time depending on chunk activity
+            // Also pass flag to only save modified chunks -- PaperSpigot
             server.playerCommandState = true;
             for (World world : worlds) {
-                world.getWorld().save();
+                world.getWorld().save(true);
             }
             server.playerCommandState = false;
             // this.saveChunks(true);
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index ea786ae..d67ba8f 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -687,12 +687,18 @@ public class CraftWorld implements World {
     }
 
     public void save() {
+        // PaperSpigot start - Improved autosave
+        save(true);
+    }
+
+    public void save(boolean forceSave) {
+        // PaperSpigot end
         this.server.checkSaveState();
         try {
             boolean oldSave = world.savingDisabled;
 
             world.savingDisabled = false;
-            world.save(true, null);
+            world.save(forceSave, null); // PaperSpigot
 
             world.savingDisabled = oldSave;
         } catch (ExceptionWorldConflict ex) {
-- 
1.9.1