From 2ec23d4415fa7cdff14d42f5f46c1b11eea99c63 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 87744dcbfc..355186c111 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -30,6 +30,11 @@ public class ChunkProviderServer implements IChunkProvider {
     public final LongSet unloadQueue = new LongOpenHashSet();
     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
     public final Long2ObjectMap<Chunk> chunks = Long2ObjectMaps.synchronize(new ChunkMap(8192));
     private Chunk lastChunk;
     private final ChunkTaskScheduler chunkScheduler;
@@ -237,6 +242,29 @@ 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 3283b5047d..110c9ef520 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -141,7 +141,13 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
 
     }
 
-    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
@@ -331,6 +337,7 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
     }
 
     protected void a(ChunkCoordIntPair chunkcoordintpair, Supplier<NBTTagCompound> nbttagcompound) { // Spigot
+        queuedSaves++; // Paper
         synchronized (this.queue) { // Paper - synchronize while modifying the map
             queue.add(new QueuedChunk(chunkcoordintpair, nbttagcompound)); // Paper - Chunk queue improvements
             this.b.put(chunkcoordintpair, nbttagcompound);
@@ -356,6 +363,7 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
         } else {
             ChunkCoordIntPair chunkcoordintpair = chunk.coords; // Paper - Chunk queue improvements
             Supplier<NBTTagCompound> nbttagcompound = chunk.compoundSupplier; // Spigot // Paper
+            processedSaves.incrementAndGet(); // Paper
 
             if (nbttagcompound == null) {
                 return true;
-- 
2.18.0