From 3a1e723a51407a7b3886223c2cc9919e87f429c5 Mon Sep 17 00:00:00 2001
From: "Lukas Rieger (Blue)" <github@bluecolored.de>
Date: Fri, 23 Feb 2024 00:55:11 +0100
Subject: [PATCH] Improve linear region efficiency by caching the whole
 region-file data

---
 .../bluemap/core/world/mca/MCAWorld.java      |  4 +-
 .../core/world/mca/region/LinearRegion.java   | 40 ++++++++++++-------
 2 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/MCAWorld.java b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/MCAWorld.java
index b4a70032..992d80c5 100644
--- a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/MCAWorld.java
+++ b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/MCAWorld.java
@@ -56,7 +56,7 @@ public class MCAWorld implements World {
     private final ChunkLoader chunkLoader = new ChunkLoader(this);
     private final LoadingCache<Vector2i, Region> regionCache = Caffeine.newBuilder()
             .executor(BlueMap.THREAD_POOL)
-            .maximumSize(64)
+            .maximumSize(32)
             .expireAfterWrite(10, TimeUnit.MINUTES)
             .build(this::loadRegion);
     private final LoadingCache<Vector2i, Chunk> chunkCache = Caffeine.newBuilder()
@@ -176,11 +176,13 @@ public class MCAWorld implements World {
 
     @Override
     public void invalidateChunkCache() {
+        regionCache.invalidateAll();
         chunkCache.invalidateAll();
     }
 
     @Override
     public void invalidateChunkCache(int x, int z) {
+        regionCache.invalidate(VECTOR_2_I_CACHE.get(x >> 5, z >> 5));
         chunkCache.invalidate(VECTOR_2_I_CACHE.get(x, z));
     }
 
diff --git a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/region/LinearRegion.java b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/region/LinearRegion.java
index 9ff42c3d..1d79a4e1 100644
--- a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/region/LinearRegion.java
+++ b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/region/LinearRegion.java
@@ -69,6 +69,16 @@ public class LinearRegion implements Region {
     private final Path regionFile;
     private final Vector2i regionPos;
 
+    private boolean initialized = false;
+
+    private byte version;
+    private long newestTimestamp;
+    private byte compressionLevel;
+    private short chunkCount;
+    private int dataLength;
+    private long dataHash;
+    private byte[] compressedData;
+
     public LinearRegion(MCAWorld world, Path regionFile) throws IllegalArgumentException {
         this.world = world;
         this.regionFile = regionFile;
@@ -86,26 +96,14 @@ public class LinearRegion implements Region {
         this.regionFile = world.getRegionFolder().resolve(getRegionFileName(regionPos.getX(), regionPos.getY()));
     }
 
-    @Override
-    public void iterateAllChunks(ChunkConsumer consumer) throws IOException {
+    private synchronized void init() throws IOException {
+        if (initialized) return;
+
         if (Files.notExists(regionFile)) return;
 
         long fileLength = Files.size(regionFile);
         if (fileLength == 0) return;
 
-        int chunkStartX = regionPos.getX() * 32;
-        int chunkStartZ = regionPos.getY() * 32;
-
-        byte[] chunkDataBuffer = null;
-        byte[] compressedData;
-
-        byte version;
-        long newestTimestamp;
-        byte compressionLevel;
-        short chunkCount;
-        int dataLength;
-        long dataHash;
-
         try (
                 InputStream in = Files.newInputStream(regionFile, StandardOpenOption.READ);
                 BufferedInputStream bIn = new BufferedInputStream(in);
@@ -136,6 +134,18 @@ public class LinearRegion implements Region {
 
         }
 
+        initialized = true;
+    }
+
+    @Override
+    public void iterateAllChunks(ChunkConsumer consumer) throws IOException {
+        if (!initialized) init();
+
+        int chunkStartX = regionPos.getX() * 32;
+        int chunkStartZ = regionPos.getY() * 32;
+
+        byte[] chunkDataBuffer = null;
+
         try (
                 InputStream in = new ZstdInputStream(new ByteArrayInputStream(compressedData));
                 BufferedInputStream bIn = new BufferedInputStream(in);