From 821c5c8577518add23e8a91fec1d7dc1ca81d7f2 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 9a2ec0793..f88444c7e 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -315,6 +315,11 @@ 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 afeb0685b..a4c4a9486 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -249,6 +249,14 @@ public class ChunkProviderServer implements IChunkProvider {
         ArrayList arraylist = Lists.newArrayList(this.chunks.values());
         Iterator iterator = arraylist.iterator();
 
+        // 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
         while (iterator.hasNext()) {
             Chunk chunk = (Chunk) iterator.next();
 
@@ -260,7 +268,7 @@ public class ChunkProviderServer implements IChunkProvider {
                 this.saveChunk(chunk, false); // Spigot
                 chunk.a(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 2f1488ee5..859148cb8 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -137,6 +137,8 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
         }
     }
 
+    public int getQueueSize() { return queue.size(); } // Paper
+
     // CraftBukkit start - Add async variant, provide compatibility
     @Nullable
     public synchronized Chunk a(GeneratorAccess generatoraccess, int i, int j, Consumer<Chunk> consumer) throws IOException {
-- 
2.18.0