Reuse buffers for chunk compression to optimize memory use

Instead of allocating a buffer for every chunk compression, reuse
the same 64k sized buffer.

Also stopped doing dynamic compression levels. It wasn't helping enough.

This will improve memory usage and zlib performance of chunk compression.

1 files changed, 40 insertions, 34 deletions

diff --git a/Spigot-Server-Patches/0373-Allow-Saving-of-Oversized-Chunks.patch b/Spigot-Server-Patches/0373-Allow-Saving-of-Oversized-Chunks.patch
index 01219eb379..6be761dfb2 100644
--- a/Spigot-Server-Patches/0373-Allow-Saving-of-Oversized-Chunks.patch
+++ b/Spigot-Server-Patches/0373-Allow-Saving-of-Oversized-Chunks.patch
@@ -1,4 +1,4 @@
-From 0c66385b2ab612b92641c37518e15ba12530b3ff Mon Sep 17 00:00:00 2001
+From bd0b04c85e7127c741ae442a8183085f7a1d1d72 Mon Sep 17 00:00:00 2001
 From: Aikar <[email protected]>
 Date: Fri, 15 Feb 2019 01:08:19 -0500
 Subject: [PATCH] Allow Saving of Oversized Chunks
@@ -31,7 +31,7 @@ this fix, as the data will remain in the oversized file. Once the server returns
 to a jar with this fix, the data will be restored.
 
 diff --git a/src/main/java/net/minecraft/server/NBTCompressedStreamTools.java b/src/main/java/net/minecraft/server/NBTCompressedStreamTools.java
-index 2162d3ad..8b5aeb1b 100644
+index 2162d3ad3..8b5aeb1b0 100644
 --- a/src/main/java/net/minecraft/server/NBTCompressedStreamTools.java
 +++ b/src/main/java/net/minecraft/server/NBTCompressedStreamTools.java
 @@ -39,6 +39,7 @@ public class NBTCompressedStreamTools {
@@ -51,7 +51,7 @@ index 2162d3ad..8b5aeb1b 100644
          a((NBTBase) nbttagcompound, dataoutput);
      }
 diff --git a/src/main/java/net/minecraft/server/RegionFile.java b/src/main/java/net/minecraft/server/RegionFile.java
-index d58cda9a..56783ab5 100644
+index d58cda9aa..542a35d13 100644
 --- a/src/main/java/net/minecraft/server/RegionFile.java
 +++ b/src/main/java/net/minecraft/server/RegionFile.java
 @@ -83,6 +83,7 @@ public class RegionFile {
@@ -87,7 +87,7 @@ index d58cda9a..56783ab5 100644
              if (k1 >= 256) {
                  // Spigot start
 -                if (!ENABLE_EXTENDED_SAVE) return;
-+                if (!USE_SPIGOT_OVERSIZED_METHOD) throw new ChunkTooLargeException(i, j, k1); // Paper - throw error instead
++                if (!USE_SPIGOT_OVERSIZED_METHOD && !RegionFileCache.isOverzealous()) throw new ChunkTooLargeException(i, j, k1); // Paper - throw error instead
                  org.bukkit.Bukkit.getLogger().log(java.util.logging.Level.WARNING,"Large Chunk Detected: ({0}, {1}) Size: {2} {3}", new Object[]{i, j, k1, this.b});
 +                if (!ENABLE_EXTENDED_SAVE) return;
                  // Spigot end
@@ -204,7 +204,7 @@ index d58cda9a..56783ab5 100644
      // Paper end
  
      class ChunkBuffer extends ByteArrayOutputStream {
-@@ -364,8 +470,40 @@ public class RegionFile {
+@@ -364,8 +470,36 @@ public class RegionFile {
              this.c = j;
          }
  
@@ -219,36 +219,32 @@ index d58cda9a..56783ab5 100644
 +            int length = out.size();
 +
 +            RegionFile.this.a(this.b, this.c, bytes, length); // Paper - change to bytes/length
-+            // Paper end
-+        }
-+    }
+         }
+     }
 +
++    private static final byte[] compressionBuffer = new byte[1024 * 64]; // 64k fits most standard chunks input size even, ideally 1 pass through zlib
++    private static final java.util.zip.Deflater deflater = new java.util.zip.Deflater();
++    // since file IO is single threaded, no benefit to using per-region file buffers/synchronization, we can change that later if it becomes viable.
 +    private static DirectByteArrayOutputStream compressData(byte[] buf, int length) throws IOException {
-+        final java.util.zip.Deflater deflater;
-+        if (length > 1024 * 512) {
-+            deflater = new java.util.zip.Deflater(9);
-+        } else if (length > 1024 * 128) {
-+            deflater = new java.util.zip.Deflater(8);
-+        } else {
-+            deflater = new java.util.zip.Deflater(6);
-+        }
++        synchronized (deflater) {
++            deflater.setInput(buf, 0, length);
++            deflater.finish();
 +
 +
-+        deflater.setInput(buf, 0, length);
-+        deflater.finish();
++            DirectByteArrayOutputStream out = new DirectByteArrayOutputStream(length);
++            while (!deflater.finished()) {
++                out.write(compressionBuffer, 0, deflater.deflate(compressionBuffer));
++            }
++            out.close();
++            deflater.reset();
++            return out;
++        }
++    }
++    // Paper end
 +
-+        DirectByteArrayOutputStream out = new DirectByteArrayOutputStream(length);
-+        byte[] buffer = new byte[1024 * (length > 1024 * 124 ? 32 : 16)];
-+        while (!deflater.finished()) {
-+            out.write(buffer, 0, deflater.deflate(buffer));
-         }
-+        out.close();
-+        deflater.end();
-+        return out;
-     }
  }
 diff --git a/src/main/java/net/minecraft/server/RegionFileCache.java b/src/main/java/net/minecraft/server/RegionFileCache.java
-index 15a09ab3..c260a797 100644
+index 15a09ab36..daa7e997a 100644
 --- a/src/main/java/net/minecraft/server/RegionFileCache.java
 +++ b/src/main/java/net/minecraft/server/RegionFileCache.java
 @@ -15,6 +15,7 @@ public class RegionFileCache {
@@ -259,7 +255,7 @@ index 15a09ab3..c260a797 100644
      public static synchronized RegionFile a(File file, int i, int j) {
          File file1 = new File(file, "region");
          File file2 = new File(file1, "r." + (i >> 5) + "." + (j >> 5) + ".mca");
-@@ -73,6 +74,129 @@ public class RegionFileCache {
+@@ -73,6 +74,139 @@ public class RegionFileCache {
              itr.remove();
          }
      }
@@ -268,7 +264,8 @@ index 15a09ab3..c260a797 100644
 +    }
 +
 +    private static final int DEFAULT_SIZE_THRESHOLD = 1024 * 8;
-+    private static final int OVERZEALOUS_THRESHOLD = 1024 * 2;
++    private static final int OVERZEALOUS_TOTAL_THRESHOLD = 1024 * 64;
++    private static final int OVERZEALOUS_THRESHOLD = 1024;
 +    private static int SIZE_THRESHOLD = DEFAULT_SIZE_THRESHOLD;
 +    private static void resetFilterThresholds() {
 +        SIZE_THRESHOLD = Math.max(1024 * 4, Integer.getInteger("Paper.FilterThreshhold", DEFAULT_SIZE_THRESHOLD));
@@ -276,6 +273,11 @@ index 15a09ab3..c260a797 100644
 +    static {
 +        resetFilterThresholds();
 +    }
++
++    static boolean isOverzealous() {
++        return SIZE_THRESHOLD == OVERZEALOUS_THRESHOLD;
++    }
++
 +    private static void writeRegion(File file, int x, int z, NBTTagCompound nbttagcompound) throws IOException {
 +        RegionFile regionfile = getRegionFile(file, x, z);
 +
@@ -329,11 +331,15 @@ index 15a09ab3..c260a797 100644
 +    private static void filterChunkList(NBTTagCompound level, NBTTagCompound extra, String key) {
 +        NBTTagList list = level.getList(key, 10);
 +        NBTTagList newList = extra.getList(key, 10);
++        int totalSize = 0;
 +        for (Iterator<NBTBase> iterator = list.list.iterator(); iterator.hasNext(); ) {
 +            NBTBase object = iterator.next();
-+            if (getNBTSize(object) > SIZE_THRESHOLD) {
++            int nbtSize = getNBTSize(object);
++            if (nbtSize > SIZE_THRESHOLD || (SIZE_THRESHOLD == OVERZEALOUS_THRESHOLD && totalSize > OVERZEALOUS_TOTAL_THRESHOLD)) {
 +                newList.add(object);
 +                iterator.remove();
++            } else  {
++                totalSize += nbtSize;
 +            }
 +        }
 +        level.set(key, list);
@@ -389,7 +395,7 @@ index 15a09ab3..c260a797 100644
      // Paper End
  
      public static synchronized void a() {
-@@ -97,6 +221,12 @@ public class RegionFileCache {
+@@ -97,6 +231,12 @@ public class RegionFileCache {
      // CraftBukkit start - call sites hoisted for synchronization
      public static NBTTagCompound d(File file, int i, int j) throws IOException { // Paper - remove synchronization
          RegionFile regionfile = a(file, i, j);
@@ -402,7 +408,7 @@ index 15a09ab3..c260a797 100644
  
          DataInputStream datainputstream = regionfile.a(i & 31, j & 31);
  
-@@ -108,11 +238,14 @@ public class RegionFileCache {
+@@ -108,11 +248,14 @@ public class RegionFileCache {
      }
  
      public static void e(File file, int i, int j, NBTTagCompound nbttagcompound) throws IOException { // Paper - remove synchronization
@@ -423,5 +429,5 @@ index 15a09ab3..c260a797 100644
      // CraftBukkit end
  
 -- 
-2.20.1
+2.21.0