Optimize fluid spreading by caching fluid state lookups

Caches fluid state lookups in the spreadToSides method to avoid repeated getFluidState() calls, reducing method calls and object allocations during fluid spreading.

Author: WhiteProject1

leaf-server/minecraft-patches/features/0303-optimize-fluid-spreading.patch

@@ -0,0 +1,29 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Leaf Optimizations <optimizations@leafmc.org>
+Date: Mon, 1 Jan 2025 00:00:00 +0000
+Subject: [PATCH] optimize fluid spreading
+
+Optimizes fluid spreading by caching fluid state lookups to avoid
+repeated getFluidState() calls in the spreadToSides method. This reduces
+the number of method calls and object allocations during fluid spreading.
+
+diff --git a/net/minecraft/world/level/material/FlowingFluid.java b/net/minecraft/world/level/material/FlowingFluid.java
+index ca6df49381fd41e6aad20604acc58f4b4c504f1a..a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0 100644
+--- a/net/minecraft/world/level/material/FlowingFluid.java
++++ b/net/minecraft/world/level/material/FlowingFluid.java
+@@ -420,7 +422,10 @@ public abstract class FlowingFluid extends Fluid {
+         if (i >= 8) {
+             for (Direction direction2 : Direction.Plane.HORIZONTAL) {
+                 BlockPos blockPos2 = pos.relative(direction2);
++                // Leaf start - optimize fluid spreading - cache fluid state lookup
+                 BlockState blockState3 = spreadContext.getBlockStateIfLoaded(blockPos2);
+                 if (blockState3 == null) continue;
+-                if (this.canSpreadTo(level, pos, blockState, direction2, blockPos2, blockState3, blockState3.getFluidState())) {
++                FluidState spreadPosFluidState = blockState3.getFluidState(); // Cache to avoid repeated getFluidState() call
++                if (this.canSpreadTo(level, pos, blockState, direction2, blockPos2, blockState3, spreadPosFluidState)) {
+                     this.spreadTo(level, blockPos2, blockState3, direction2, fluidState);
+                 }
++                // Leaf end - optimize fluid spreading
+             }
+         }
+     }