From 8bb8f8bd55f712dd4285e2e735163dafc2adc4a5 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 4 Nov 2016 02:12:10 -0400
Subject: [PATCH] Chunk Save Stats Debug Option

Adds a command line flag to enable stats on how chunk saves are processing.

Stats on current queue, how many was processed and how many were queued.

diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
index b7afcb2..3b82627 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -28,6 +28,11 @@ public class ChunkProviderServer implements IChunkProvider {
     public final it.unimi.dsi.fastutil.longs.LongSet unloadQueue = new it.unimi.dsi.fastutil.longs.LongArraySet(); // PAIL: private -> public // Paper
     public final ChunkGenerator chunkGenerator;
     private final IChunkLoader chunkLoader;
+    // Paper start - chunk save stats
+    private long lastQueuedSaves = 0L; // Paper
+    private long lastProcessedSaves = 0L; // Paper
+    private long lastSaveStatPrinted = System.currentTimeMillis();
+    // Paper end
     // Paper start
     protected Chunk lastChunkByPos = null;
     public Long2ObjectOpenHashMap<Chunk> chunks = new Long2ObjectOpenHashMap<Chunk>(8192) {
@@ -257,6 +262,30 @@ public class ChunkProviderServer implements IChunkProvider {
         // Paper start
         final ChunkRegionLoader chunkLoader = (ChunkRegionLoader) world.getChunkProviderServer().chunkLoader;
         final int queueSize = chunkLoader.getQueueSize();
+
+        final long now = System.currentTimeMillis();
+        final long timeSince = (now - lastSaveStatPrinted) / 1000;
+        final Integer printRateSecs = Integer.getInteger("printSaveStats");
+        if (printRateSecs != null && timeSince >= printRateSecs) {
+            final String timeStr = "/" + timeSince  +"s";
+            final long queuedSaves = chunkLoader.getQueuedSaves();
+            long queuedDiff = queuedSaves - lastQueuedSaves;
+            lastQueuedSaves = queuedSaves;
+
+            final long processedSaves = chunkLoader.getProcessedSaves();
+            long processedDiff = processedSaves - lastProcessedSaves;
+            lastProcessedSaves = processedSaves;
+
+            lastSaveStatPrinted = now;
+            if (processedDiff > 0 || queueSize > 0 || queuedDiff > 0) {
+                System.out.println("[Chunk Save Stats] " + world.worldData.getName() +
+                    " - Current: " + queueSize +
+                    " - Queued: " + queuedDiff + timeStr +
+                    " - Processed: " +processedDiff + timeStr
+                );
+            }
+        }
+
         if (queueSize > world.paperConfig.queueSizeAutoSaveThreshold){
             return false;
         }
diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
index 9689e69..eb6ded6 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -33,7 +33,13 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
     }
 
     // CraftBukkit start
-    public int getQueueSize() { return queue.size(); } // Paper
+    // Paper start
+    private long queuedSaves = 0;
+    private final java.util.concurrent.atomic.AtomicLong processedSaves = new java.util.concurrent.atomic.AtomicLong(0L);
+    public int getQueueSize() { return queue.size(); }
+    public long getQueuedSaves() { return queuedSaves; }
+    public long getProcessedSaves() { return processedSaves.longValue(); }
+    // Paper end
     public boolean chunkExists(World world, int i, int j) {
         ChunkCoordIntPair chunkcoordintpair = new ChunkCoordIntPair(i, j);
 
@@ -158,6 +164,7 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
         synchronized (lock) {  // Paper - Chunk queue improvements
             this.b.put(chunkcoordintpair, nbttagcompound);
         }
+        queuedSaves++; // Paper
         queue.add(new QueuedChunk(chunkcoordintpair, nbttagcompound)); // Paper - Chunk queue improvements
 
         FileIOThread.a().a(this);
@@ -175,6 +182,7 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
             return false;
         } else {
             ChunkCoordIntPair chunkcoordintpair = chunk.coords; // Paper - Chunk queue improvements
+            processedSaves.incrementAndGet(); // Paper
 
             boolean flag;
 
-- 
2.9.3