Paper/patches/server-remapped/0517-Remove-some-streams-from-structures.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: JRoy <joshroy126@gmail.com>
Date: Mon, 29 Jun 2020 17:03:06 -0400
Subject: [PATCH] Remove some streams from structures

This showed up a lot in the spark profiler, should have a low-medium performance improvement.

diff --git a/src/main/java/net/minecraft/world/level/StructureFeatureManager.java b/src/main/java/net/minecraft/world/level/StructureFeatureManager.java
index e842dbc586234799a05b6df213b686e17b8ed1ac..2f88e015708cadb43a348ba2b144c3dd92bb95a5 100644
--- a/src/main/java/net/minecraft/world/level/StructureFeatureManager.java
+++ b/src/main/java/net/minecraft/world/level/StructureFeatureManager.java
@@ -2,21 +2,22 @@
 package net.minecraft.world.level;
 
 import com.mojang.datafixers.DataFixUtils;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList; // Paper
 import java.util.stream.Stream;
 import javax.annotation.Nullable;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.SectionPos;
-import net.minecraft.core.Vec3i;
 import net.minecraft.server.level.WorldGenRegion;
 import net.minecraft.world.level.chunk.ChunkStatus;
 import net.minecraft.world.level.chunk.FeatureAccess;
 import net.minecraft.world.level.levelgen.WorldGenSettings;
 import net.minecraft.world.level.levelgen.feature.StructureFeature;
+import net.minecraft.world.level.levelgen.structure.StructurePiece;
 import net.minecraft.world.level.levelgen.structure.StructureStart;
 
 public class StructureFeatureManager {
 
-    private final LevelAccessor level;
+    private final LevelAccessor level; public LevelAccessor getLevel() { return level; } // Paper - OBFHELPER
     private final WorldGenSettings worldGenSettings;
 
     public StructureFeatureManager(LevelAccessor world, WorldGenSettings options) {
@@ -42,6 +43,20 @@ public class StructureFeatureManager {
         });
     }
 
+    // Paper start - remove structure streams
+    public java.util.List<StructureStart<?>> getFeatureStarts(SectionPos sectionPosition, StructureFeature<?> structureGenerator) {
+        java.util.List<StructureStart<?>> list = new ObjectArrayList<>();
+        for (Long curLong: getLevel().getChunk(sectionPosition.x(), sectionPosition.z(), ChunkStatus.STRUCTURE_REFERENCES).getReferencesForFeature(structureGenerator)) {
+            SectionPos sectionPosition1 = SectionPos.of(new ChunkPos(curLong), 0);
+            StructureStart<?> structurestart = getStartForFeature(sectionPosition1, structureGenerator, getLevel().getChunk(sectionPosition1.x(), sectionPosition1.z(), ChunkStatus.STRUCTURE_STARTS));
+            if (structurestart != null && structurestart.e()) {
+                list.add(structurestart);
+            }
+        }
+        return list;
+    }
+    // Paper end
+
     @Nullable
     public StructureStart<?> getStartForFeature(SectionPos pos, StructureFeature<?> feature, FeatureAccess holder) {
         return holder.getStartForFeature(feature);
@@ -60,13 +75,21 @@ public class StructureFeatureManager {
     }
 
     public StructureStart<?> getStructureAt(BlockPos pos, boolean matchChildren, StructureFeature<?> feature) {
-        return (StructureStart) DataFixUtils.orElse(this.startsForFeature(SectionPos.of(pos), feature).filter((structurestart) -> {
-            return structurestart.c().b((Vec3i) pos);
-        }).filter((structurestart) -> {
-            return !matchChildren || structurestart.d().stream().anyMatch((structurepiece) -> {
-                return structurepiece.g().b((BaseBlockPosition) blockposition);
-            });
-        }).findFirst(), StructureStart.a);
+        // Paper start - remove structure streams
+        for (StructureStart<?> structurestart : getFeatureStarts(SectionPos.of(pos), feature)) {
+            if (structurestart.c().b(pos)) {
+                if (!matchChildren) {
+                    return structurestart;
+                }
+                for (StructurePiece structurepiece : structurestart.d()) {
+                    if (structurepiece.g().b(pos)) {
+                        return structurestart;
+                    }
+                }
+            }
+        }
+        return StructureStart.a;
+        // Paper end
     }
 
     // Spigot start
diff --git a/src/main/java/net/minecraft/world/level/biome/Biome.java b/src/main/java/net/minecraft/world/level/biome/Biome.java
index ed83335175bb882741dfaef251ab30ce1590f74c..2422dbb8691b8c45401a68602a33d4d7f1718dfb 100644
--- a/src/main/java/net/minecraft/world/level/biome/Biome.java
+++ b/src/main/java/net/minecraft/world/level/biome/Biome.java
@@ -39,6 +39,7 @@ import net.minecraft.world.level.levelgen.WorldgenRandom;
 import net.minecraft.world.level.levelgen.feature.ConfiguredFeature;
 import net.minecraft.world.level.levelgen.feature.StructureFeature;
 import net.minecraft.world.level.levelgen.structure.BoundingBox;
+import net.minecraft.world.level.levelgen.structure.StructureStart;
 import net.minecraft.world.level.levelgen.surfacebuilders.ConfiguredSurfaceBuilder;
 import net.minecraft.world.level.levelgen.synth.PerlinSimplexNoise;
 import net.minecraft.world.level.material.FluidState;
@@ -238,9 +239,11 @@ public final class Biome {
                     int l1 = j1 << 4;
 
                     try {
-                        structureAccessor.startsForFeature(SectionPos.of(pos), structuregenerator).forEach((structurestart) -> {
-                            structurestart.a(region, structureAccessor, chunkGenerator, random, new BoundingBox(k1, l1, k1 + 15, l1 + 15), new ChunkPos(i1, j1));
-                        });
+                        // Paper start - remove structure streams
+                        for (StructureStart<?> structureStart : structureAccessor.getFeatureStarts(SectionPos.of(pos), structuregenerator)) {
+                            structureStart.a(region, structureAccessor, chunkGenerator, random, new BoundingBox(k1, l1, k1 + 15, l1 + 15), new ChunkPos(i1, j1));
+                        }
+                        // Paper end
                     } catch (Exception exception) {
                         CrashReport crashreport = CrashReport.forThrowable(exception, "Feature placement");
 
diff --git a/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java b/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
index 04adec255e4650ead8d80bee32a681c98686fb95..20f3899b7e39033ebc0f833e75fbdba29777a168 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
@@ -41,6 +41,7 @@ import net.minecraft.world.level.levelgen.feature.structures.StructureTemplatePo
 import net.minecraft.world.level.levelgen.structure.BoundingBox;
 import net.minecraft.world.level.levelgen.structure.PoolElementStructurePiece;
 import net.minecraft.world.level.levelgen.structure.StructurePiece;
+import net.minecraft.world.level.levelgen.structure.StructureStart;
 import net.minecraft.world.level.levelgen.synth.ImprovedNoise;
 import net.minecraft.world.level.levelgen.synth.PerlinNoise;
 import net.minecraft.world.level.levelgen.synth.PerlinSimplexNoise;
@@ -455,7 +456,7 @@ public final class NoiseBasedChunkGenerator extends ChunkGenerator {
         while (iterator.hasNext()) {
             StructureFeature<?> structuregenerator = (StructureFeature) iterator.next();
 
-            accessor.startsForFeature(SectionPos.of(chunkcoordintpair, 0), structuregenerator).forEach((structurestart) -> {
+            for (StructureStart<?> structurestart : accessor.getFeatureStarts(SectionPos.of(chunkcoordintpair, 0), structuregenerator)) { // Paper - remove structure streams
                 Iterator iterator1 = structurestart.d().iterator();
 
                 while (iterator1.hasNext()) {
@@ -487,7 +488,7 @@ public final class NoiseBasedChunkGenerator extends ChunkGenerator {
                     }
                 }
 
-            });
+            } // Paper - remove structure streams
         }
 
         double[][][] adouble = new double[2][this.chunkCountZ + 1][this.chunkCountY + 1];