From a64e03a4b423c7339dacffcc1c14168d7f2aba7f 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 ef194312b..8fca62eec 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 Set<Long> unloadQueue = Sets.newHashSet();
     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 ceef6e456..d275eb194 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -32,7 +32,13 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
         this.e = dataconvertermanager;
     }
 
-    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
 
     // CraftBukkit start - Add async variant, provide compatibility
     @Nullable
@@ -142,6 +148,7 @@ 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);
@@ -159,6 +166,7 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
             return false;
         } else {
             ChunkCoordIntPair chunkcoordintpair = chunk.coords; // Paper - Chunk queue improvements
+            processedSaves.incrementAndGet(); // Paper
 
             boolean flag;
 
-- 
2.13.0