precalculate pack hash on engine setup (#1138)

core/src/main/java/com/volmit/iris/Iris.java

@@ -672,10 +672,12 @@ public class Iris extends VolmitPlugin implements Listener {
                 metrics.addCustomChart(new DrilldownPie("used_packs", () -> Bukkit.getWorlds().stream()
                         .map(IrisToolbelt::access)
                         .filter(Objects::nonNull)
-                        .map(PlatformChunkGenerator::getTarget)
+                        .map(PlatformChunkGenerator::getEngine)
-                        .collect(Collectors.toMap(target -> target.getDimension().getLoadKey(), target -> {
+                        .collect(Collectors.toMap(engine -> engine.getDimension().getLoadKey(), engine -> {
-                            int version = target.getDimension().getVersion();
+                            var hash32 = engine.getHash32().getNow(null);
-                            String checksum = IO.hashRecursive(target.getData().getDataFolder());
+                            if (hash32 == null) return Map.of();
+                            int version = engine.getDimension().getVersion();
+                            String checksum = Long.toHexString(hash32);
 
                             return Map.of("v" + version + " (" + checksum + ")", 1);
                         }, (a, b) -> {

core/src/main/java/com/volmit/iris/engine/IrisEngine.java

@@ -21,10 +21,10 @@ package com.volmit.iris.engine;
 import com.google.common.util.concurrent.AtomicDouble;
 import com.google.gson.Gson;
 import com.volmit.iris.Iris;
-import com.volmit.iris.core.IrisSettings;
 import com.volmit.iris.core.ServerConfigurator;
 import com.volmit.iris.core.events.IrisEngineHotloadEvent;
 import com.volmit.iris.core.gui.PregeneratorJob;
+import com.volmit.iris.core.loader.ResourceLoader;
 import com.volmit.iris.core.nms.container.BlockPos;
 import com.volmit.iris.core.nms.container.Pair;
 import com.volmit.iris.core.project.IrisProject;
@@ -53,7 +53,6 @@ import com.volmit.iris.util.scheduling.PrecisionStopwatch;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.ToString;
-import org.bukkit.Bukkit;
 import org.bukkit.Material;
 import org.bukkit.block.Biome;
 import org.bukkit.block.data.BlockData;
@@ -63,11 +62,10 @@ import java.io.File;
 import java.io.IOException;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 @Data
 @EqualsAndHashCode(exclude = "context")
@@ -92,6 +90,7 @@ public class IrisEngine implements Engine {
     private final AtomicBoolean cleaning;
     private final ChronoLatch cleanLatch;
     private final SeedManager seedManager;
+    private CompletableFuture<Long> hash32;
     private EngineMode mode;
     private EngineEffects effects;
     private EngineExecutionEnvironment execution;
@@ -174,8 +173,17 @@ public class IrisEngine implements Engine {
             complex = new IrisComplex(this);
             execution = new IrisExecutionEnvironment(this);
             effects = new IrisEngineEffects(this);
+            hash32 = new CompletableFuture<>();
             setupMode();
             J.a(this::computeBiomeMaxes);
+            J.a(() -> {
+                File[] roots = getData().getLoaders()
+                        .values()
+                        .stream()
+                        .map(ResourceLoader::getRoot)
+                        .toArray(File[]::new);
+                hash32.complete(IO.hashRecursive(roots));
+            });
         } catch (Throwable e) {
             Iris.error("FAILED TO SETUP ENGINE!");
             e.printStackTrace();

core/src/main/java/com/volmit/iris/engine/framework/Engine.java

@@ -80,6 +80,7 @@ import java.awt.Color;
 import java.util.Arrays;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -611,6 +612,8 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
 
     int getGenerated();
 
+    CompletableFuture<Long> getHash32();
+
     default <T> IrisPosition lookForStreamResult(T find, ProceduralStream<T> stream, Function2<T, T, Boolean> matcher, long timeout) {
         AtomicInteger checked = new AtomicInteger();
         AtomicLong time = new AtomicLong(M.ms());

core/src/main/java/com/volmit/iris/util/io/IO.java

@@ -111,10 +111,12 @@ public class IO {
         return "¯\\_(ツ)_/¯";
     }
 
-    public static String hashRecursive(File base) {
+    public static long hashRecursive(File... bases) {
         LinkedList<File> files = new LinkedList<>();
         Set<File> processed = new HashSet<>();
-        files.add(base);
+        Arrays.parallelSort(bases, Comparator.comparing(File::getName));
+        files.addAll(Arrays.asList(bases));
+
         try {
             CRC32 crc = new CRC32();
             while (!files.isEmpty()) {
@@ -141,13 +143,13 @@ public class IO {
                 }
             }
 
-            return Long.toHexString(crc.getValue());
+            return crc.getValue();
         } catch (Throwable e) {
             Iris.reportError(e);
             e.printStackTrace();
         }
 
-        return "";
+        return 0;
     }
 
     public static String hash(File b) {