Make sure inlined getChunkAt has inlined logic for loaded chunks

Tux did some profiling some time ago and showed that the
previous getChunkAt method which had inlined logic for loaded
chunks did get inlined, but the standard CPS.getChunkAt
method was not inlined.

paper-server/patches/sources/net/minecraft/world/level/Level.java.patch

@@ -270,7 +270,7 @@
      public boolean isInWorldBounds(BlockPos pos) {
          return !this.isOutsideBuildHeight(pos) && Level.isInWorldBoundsHorizontal(pos);
      }
-@@ -179,18 +345,73 @@
+@@ -179,18 +345,80 @@
          return y < -20000000 || y >= 20000000;
      }
  
@@ -283,12 +283,19 @@
 -    public LevelChunk getChunk(int chunkX, int chunkZ) {
 -        return (LevelChunk) this.getChunk(chunkX, chunkZ, ChunkStatus.FULL);
 +    public final LevelChunk getChunk(int chunkX, int chunkZ) { // Paper - final to help inline
-+        return (LevelChunk) this.getChunk(chunkX, chunkZ, ChunkStatus.FULL, true); // Paper - avoid a method jump
++        // Paper start - Perf: make sure loaded chunks get the inlined variant of this function
++        net.minecraft.server.level.ServerChunkCache cps = ((ServerLevel)this).getChunkSource();
++        LevelChunk ifLoaded = cps.getChunkAtIfLoadedImmediately(chunkX, chunkZ);
++        if (ifLoaded != null) {
++            return ifLoaded;
++        }
++        return (LevelChunk) cps.getChunk(chunkX, chunkZ, ChunkStatus.FULL, true); // Paper - avoid a method jump
++        // Paper end - Perf: make sure loaded chunks get the inlined variant of this function
      }
  
 +    // Paper start - if loaded
      @Nullable
-+    @Override
+     @Override
 +    public final ChunkAccess getChunkIfLoadedImmediately(int x, int z) {
 +        return ((ServerLevel)this).chunkSource.getChunkAtIfLoadedImmediately(x, z);
 +    }
@@ -341,13 +348,13 @@
 +        return getWorldBorder().isWithinBounds(blockposition) ? getBlockStateIfLoaded(blockposition) : null;
 +    }
 +
-     @Override
++    @Override
      public ChunkAccess getChunk(int chunkX, int chunkZ, ChunkStatus leastStatus, boolean create) {
 +        // Paper end
          ChunkAccess ichunkaccess = this.getChunkSource().getChunk(chunkX, chunkZ, leastStatus, create);
  
          if (ichunkaccess == null && create) {
-@@ -207,6 +428,18 @@
+@@ -207,6 +435,18 @@
  
      @Override
      public boolean setBlock(BlockPos pos, BlockState state, int flags, int maxUpdateDepth) {
@@ -366,7 +373,7 @@
          if (this.isOutsideBuildHeight(pos)) {
              return false;
          } else if (!this.isClientSide && this.isDebug()) {
-@@ -214,45 +447,125 @@
+@@ -214,45 +454,125 @@
          } else {
              LevelChunk chunk = this.getChunkAt(pos);
              Block block = state.getBlock();
@@ -507,7 +514,7 @@
      public void onBlockStateChange(BlockPos pos, BlockState oldBlock, BlockState newBlock) {}
  
      @Override
-@@ -270,9 +583,26 @@
+@@ -270,9 +590,26 @@
              return false;
          } else {
              FluidState fluid = this.getFluidState(pos);
@@ -536,7 +543,7 @@
              }
  
              if (drop) {
-@@ -340,10 +670,18 @@
+@@ -340,10 +677,18 @@
  
      @Override
      public BlockState getBlockState(BlockPos pos) {
@@ -556,7 +563,7 @@
  
              return chunk.getBlockState(pos);
          }
-@@ -446,34 +784,53 @@
+@@ -446,34 +791,53 @@
              this.pendingBlockEntityTickers.clear();
          }
  
@@ -608,26 +615,26 @@
 +            entity.discard(org.bukkit.event.entity.EntityRemoveEvent.Cause.DISCARD);
 +            // Paper end - Prevent block entity and entity crashes
          }
-+    }
+     }
 +    // Paper start - Option to prevent armor stands from doing entity lookups
 +    @Override
 +    public boolean noCollision(@Nullable Entity entity, AABB box) {
 +        if (entity instanceof net.minecraft.world.entity.decoration.ArmorStand && !entity.level().paperConfig().entities.armorStands.doCollisionEntityLookups) return false;
 +        return LevelAccessor.super.noCollision(entity, box);
-     }
++    }
 +    // Paper end - Option to prevent armor stands from doing entity lookups
  
      public boolean shouldTickDeath(Entity entity) {
          return true;
-@@ -510,13 +867,32 @@
+@@ -510,13 +874,32 @@
      @Nullable
      @Override
      public BlockEntity getBlockEntity(BlockPos pos) {
 -        return this.isOutsideBuildHeight(pos) ? null : (!this.isClientSide && Thread.currentThread() != this.thread ? null : this.getChunkAt(pos).getBlockEntity(pos, LevelChunk.EntityCreationType.IMMEDIATE));
 +        // CraftBukkit start
 +        return this.getBlockEntity(pos, true);
-     }
++    }
- 
++
 +    @Nullable
 +    public BlockEntity getBlockEntity(BlockPos blockposition, boolean validate) {
 +        // Paper start - Perf: Optimize capturedTileEntities lookup
@@ -638,8 +645,8 @@
 +        // Paper end - Perf: Optimize capturedTileEntities lookup
 +        // CraftBukkit end
 +        return this.isOutsideBuildHeight(blockposition) ? null : (!this.isClientSide && Thread.currentThread() != this.thread ? null : this.getChunkAt(blockposition).getBlockEntity(blockposition, LevelChunk.EntityCreationType.IMMEDIATE));
-+    }
+     }
-+
+ 
      public void setBlockEntity(BlockEntity blockEntity) {
          BlockPos blockposition = blockEntity.getBlockPos();
  
@@ -653,7 +660,7 @@
              this.getChunkAt(blockposition).addAndRegisterBlockEntity(blockEntity);
          }
      }
-@@ -643,7 +1019,7 @@
+@@ -643,7 +1026,7 @@
  
                  for (int k = 0; k < j; ++k) {
                      EnderDragonPart entitycomplexpart = aentitycomplexpart[k];
@@ -662,7 +669,7 @@
  
                      if (t0 != null && predicate.test(t0)) {
                          result.add(t0);
-@@ -912,7 +1288,7 @@
+@@ -912,7 +1295,7 @@
  
      public static enum ExplosionInteraction implements StringRepresentable {