Platform glue diet

- Chunk-scoped visible biome resolver without global cache, per-quart RNG or repeated runtime lookups
- Subterrain probe skips per-sample subterrain lookups in chunks without candidates
- Striped structure volume caches
- Saved biome store reuses deflaters and remembers ready region files
- Semantic journal skips repeated storage and journal stat checks

core/src/test/java/art/arcane/iris/platform/bukkit/nms/BukkitBiomeVisibleResolverTest.java

@@ -0,0 +1,111 @@
+package art.arcane.iris.platform.bukkit.nms;
+
+import art.arcane.iris.generation.biome.IrisBiome;
+import art.arcane.iris.generation.biome.IrisBiomeCustom;
+import art.arcane.iris.generation.mantle.EngineMantle;
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.generation.runtime.GenerationSessionLease;
+import art.arcane.iris.generation.runtime.IrisComplex;
+import art.arcane.iris.generation.runtime.IrisEngine;
+import art.arcane.iris.generation.terrain.IrisDimension;
+import art.arcane.iris.generation.terrain.IrisDimensionCarvingResolver;
+import art.arcane.iris.pack.loading.IrisData;
+import art.arcane.iris.world.IrisWorld;
+import art.arcane.volmlib.nativelib.terrain.NativeBiomeRegistry;
+import art.arcane.volmlib.nativelib.terrain.NativeBiomeSourcePolicy;
+import art.arcane.volmlib.util.collection.KList;
+import org.junit.Test;
+
+import java.lang.reflect.Field;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Answers.CALLS_REAL_METHODS;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class BukkitBiomeVisibleResolverTest {
+    @Test
+    public void chunkResolverMatchesThePerQuartResolution() throws Exception {
+        IrisBiome surface = customBiome("surface", "meadow");
+        IrisBiome cave = customBiome("cave", "grotto");
+        IrisBiome custom = customBiome("custom", "mirage");
+        IrisBiome feature = customBiome("feature", "bloom");
+        IrisDimension dimension = mock(IrisDimension.class);
+        when(dimension.getReachableBiomes(any())).thenReturn(new KList<>(surface, cave, custom, feature));
+        when(dimension.getCustomBiomeKey(anyString())).thenAnswer(invocation -> "pack:" + invocation.getArgument(0));
+        IrisData data = mock(IrisData.class);
+        when(data.customBiomeResourceKey(any(IrisDimension.class), anyString()))
+                .thenAnswer(invocation -> "pack:" + invocation.getArgument(1));
+        IrisComplex complex = mock(IrisComplex.class);
+        when(complex.historicalPhysicalBiomeKeyAt(anyInt(), anyInt(), anyInt())).thenReturn(Optional.empty());
+        EngineMantle mantle = mock(EngineMantle.class);
+        when(mantle.trueHeight(anyInt(), anyInt())).thenAnswer(invocation ->
+                120 + Math.floorMod(invocation.<Integer>getArgument(0) * 7 + invocation.<Integer>getArgument(1) * 3, 160));
+        IrisEngine engine = mock(IrisEngine.class);
+        when(engine.getDimension()).thenReturn(dimension);
+        when(engine.getData()).thenReturn(data);
+        when(engine.getComplex()).thenReturn(complex);
+        when(engine.getMantle()).thenReturn(mantle);
+        when(engine.getWorld()).thenReturn(IrisWorld.builder().minHeight(-64).maxHeight(320).build());
+        when(engine.getMinHeight()).thenReturn(-64);
+        when(engine.getCacheID()).thenReturn(1);
+        when(engine.acquireGenerationLease(anyString())).thenReturn(GenerationSessionLease.noop());
+        when(engine.answersFromNaturalTerrain(anyInt(), anyInt())).thenReturn(false);
+        when(engine.getHostSurfaceBiome(anyInt(), anyInt())).thenAnswer(invocation ->
+                Math.floorMod(invocation.<Integer>getArgument(0) + invocation.<Integer>getArgument(1), 8) == 0 ? custom : surface);
+        when(engine.getCaveBiome(anyInt(), anyInt(), anyInt(), any(IrisDimensionCarvingResolver.State.class)))
+                .thenAnswer(invocation -> invocation.<Integer>getArgument(1) % 3 == 0 ? custom : cave);
+        when(engine.getSubterrainBiome(anyInt(), anyInt(), anyInt())).thenAnswer(invocation ->
+                invocation.<Integer>getArgument(0) == 4 && invocation.<Integer>getArgument(1) == 40 ? feature : null);
+        when(engine.subterrainAbsentInChunk(1, 0)).thenReturn(true);
+        @SuppressWarnings("unchecked")
+        NativeBiomeRegistry<String, String> registry = mock(NativeBiomeRegistry.class);
+        when(registry.lookupCustom(anyString())).thenAnswer(invocation -> invocation.getArgument(0));
+        BukkitBiomePolicy<String, String> policy = policy(engine, registry, "fallback");
+
+        for (int chunkX = 0; chunkX <= 1; chunkX++) {
+            NativeBiomeSourcePolicy.VisibleResolver<String> resolver = policy.visibleResolver();
+            for (int quartY = -16; quartY < 80; quartY++) {
+                for (int localX = 0; localX < 4; localX++) {
+                    for (int localZ = 0; localZ < 4; localZ++) {
+                        int quartX = (chunkX << 2) + localX;
+                        String expected = policy.getVisibleNoiseBiomeWithActiveGenerationLease(
+                                quartX, quartY, localZ, new IrisDimensionCarvingResolver.State());
+                        assertEquals("quart " + quartX + "," + quartY + "," + localZ, expected,
+                                resolver.biome(quartX, quartY, localZ));
+                    }
+                }
+            }
+        }
+    }
+
+    private static IrisBiome customBiome(String key, String customId) {
+        IrisBiome biome = new IrisBiome().setCustomDerivitives(new KList<>(new IrisBiomeCustom().setId(customId)));
+        biome.setLoadKey(key);
+        return biome;
+    }
+
+    @SuppressWarnings("unchecked")
+    private static BukkitBiomePolicy<String, String> policy(Engine engine, NativeBiomeRegistry<String, String> registry,
+                                                            String fallback) throws Exception {
+        BukkitBiomePolicy<String, String> policy = mock(BukkitBiomePolicy.class, CALLS_REAL_METHODS);
+        set(policy, "engine", engine);
+        set(policy, "biomeCustomRegistry", registry);
+        set(policy, "biomeRegistry", registry);
+        set(policy, "fallbackBiome", fallback);
+        set(policy, "runtimeBiomeStates", new ConcurrentHashMap<>());
+        set(policy, "noiseBiomeCache", new ConcurrentHashMap<>());
+        return policy;
+    }
+
+    private static void set(Object target, String name, Object value) throws Exception {
+        Field field = BukkitBiomePolicy.class.getDeclaredField(name);
+        field.setAccessible(true);
+        field.set(target, value);
+    }
+}

core/src/test/java/art/arcane/iris/platform/bukkit/nms/BukkitSubterrainBiomePrecedenceTest.java

@@ -36,10 +36,12 @@ public class BukkitSubterrainBiomePrecedenceTest {
         owner.setAccessible(true);
         owner.set(policy, engine);
         DimensionStackLayout stack = mock(DimensionStackLayout.class);
+        Class<?> chunkResolution = Class.forName(BukkitBiomePolicy.class.getName() + "$ChunkResolution");
         Method resolve = BukkitBiomePolicy.class.getDeclaredMethod("resolveBiomeResolution", int.class, int.class,
-                int.class, IrisDimensionCarvingResolver.State.class, boolean.class, DimensionStackLayout.class);
+                int.class, IrisDimensionCarvingResolver.State.class, boolean.class, DimensionStackLayout.class,
+                chunkResolution);
         resolve.setAccessible(true);
-        Object resolved = resolve.invoke(policy, 3, 40, -5, null, true, stack);
+        Object resolved = resolve.invoke(policy, 3, 40, -5, null, true, stack, null);
         assertSame(feature, field(resolved, "irisBiome"));
         assertSame(host, field(resolved, "dimension"));
         assertEquals(true, field(resolved, "underground"));

core/src/test/java/art/arcane/iris/structure/nativegen/NativeStructureVolumeIndexCacheTest.java

@@ -0,0 +1,69 @@
+package art.arcane.iris.structure.nativegen;
+
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.volmlib.nativelib.terrain.structure.NativeStructureVolume;
+import art.arcane.volmlib.util.collection.KList;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class NativeStructureVolumeIndexCacheTest {
+    @Test
+    public void concurrentQueriesBuildEachOriginOnceAndAnswerIdentically() throws Exception {
+        Map<Long, AtomicInteger> builds = new ConcurrentHashMap<>();
+        NativeStructureVolumeIndex index = NativeStructureVolumeIndex.forTesting((engine, chunkX, chunkZ) -> {
+            builds.computeIfAbsent(((long) chunkX << 32) ^ (chunkZ & 0xffffffffL), key -> new AtomicInteger()).incrementAndGet();
+            return volumesAt(chunkX, chunkZ);
+        });
+        Engine engine = mock(Engine.class);
+        when(engine.getCacheID()).thenReturn(7);
+        KList<NativeStructureVolume> expected = NativeStructureVolumeIndex.forTesting(
+                (ignored, chunkX, chunkZ) -> volumesAt(chunkX, chunkZ)).resolve(engine, 0, 0, 47, 47);
+        ExecutorService pool = Executors.newFixedThreadPool(8);
+        try {
+            List<Future<KList<NativeStructureVolume>>> results = new ArrayList<>();
+            for (int task = 0; task < 32; task++) {
+                results.add(pool.submit(() -> index.resolve(engine, 0, 0, 47, 47)));
+            }
+            for (Future<KList<NativeStructureVolume>> result : results) {
+                assertEquals(expected, result.get(30, TimeUnit.SECONDS));
+            }
+        } finally {
+            pool.shutdown();
+            assertTrue(pool.awaitTermination(30, TimeUnit.SECONDS));
+        }
+        for (AtomicInteger count : builds.values()) {
+            assertEquals(1, count.get());
+        }
+        int distinct = builds.size();
+        index.evictRuntime(7);
+        assertEquals(expected, index.resolve(engine, 0, 0, 47, 47));
+        assertEquals(distinct, builds.size());
+        for (AtomicInteger count : builds.values()) {
+            assertEquals(2, count.get());
+        }
+    }
+
+    private static KList<NativeStructureVolume> volumesAt(int chunkX, int chunkZ) {
+        if (Math.floorMod(chunkX * 31 + chunkZ * 17, 5) != 0) {
+            return NativeStructureVolume.NONE;
+        }
+        int minX = chunkX << 4;
+        int minZ = chunkZ << 4;
+        return new KList<>(new NativeStructureVolume("test:" + chunkX + "_" + chunkZ,
+                minX - 20, -10, minZ - 20, minX + 36, 40, minZ + 36, null));
+    }
+}