From e58b0d4d3e4c3ead75b9d947c623d2a4c3f5a2c8 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 3 Nov 2016 21:52:22 -0400
Subject: [PATCH] Prevent Auto Save if Save Queue is full

If the save queue already has 50 (configurable) of chunks pending,
then avoid processing auto save (which would add more)

diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 220ecaf8d..4ca44afa9 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -376,6 +376,11 @@ public class PaperWorldConfig {
         maxAutoSaveChunksPerTick = getInt("max-auto-save-chunks-per-tick", 24);
     }
 
+    public int queueSizeAutoSaveThreshold = 50;
+    private void queueSizeAutoSaveThreshold() {
+        queueSizeAutoSaveThreshold = getInt("save-queue-limit-for-auto-save", 50);
+    }
+
     public boolean removeCorruptTEs = false;
     private void removeCorruptTEs() {
         removeCorruptTEs = getBoolean("remove-corrupt-tile-entities", false);
diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
index 71df9e4aa..0fb1f8427 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -254,6 +254,14 @@ public class ChunkProviderServer implements IChunkProvider {
         int i = 0;
 
         // CraftBukkit start
+        // Paper start
+        final ChunkRegionLoader chunkLoader = (ChunkRegionLoader) world.getChunkProviderServer().chunkLoader;
+        final int queueSize = chunkLoader.getQueueSize();
+        if (queueSize > world.paperConfig.queueSizeAutoSaveThreshold){
+            return false;
+        }
+        final int autoSaveLimit = world.paperConfig.maxAutoSaveChunksPerTick;
+        // Paper end
         Iterator iterator = this.chunks.values().iterator();
         while (iterator.hasNext()) {
             Chunk chunk = (Chunk) iterator.next();
@@ -267,7 +275,7 @@ public class ChunkProviderServer implements IChunkProvider {
                 this.saveChunk(chunk);
                 chunk.f(false);
                 ++i;
-                if (!flag && i >= world.paperConfig.maxAutoSaveChunksPerTick) { // Spigot - // Paper - Incremental Auto Save - cap max per tick
+                if (!flag && i >= autoSaveLimit) { // Spigot - // Paper - Incremental Auto Save - cap max per tick
                     return false;
                 }
             }
diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
index 90d069539..895882b2e 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -32,6 +32,8 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
         this.e = dataconvertermanager;
     }
 
+    public int getQueueSize() { return queue.size(); } // Paper
+
     // CraftBukkit start - Add async variant, provide compatibility
     @Nullable
     public Chunk a(World world, int i, int j) throws IOException {
-- 
2.12.2