Move IJ/xyz cache out of MainUItil to its own class

Bukkit/src/main/java/com/plotsquared/bukkit/generator/BukkitPlotGenerator.java

@@ -36,7 +36,6 @@ import com.plotsquared.core.plot.PlotArea;
 import com.plotsquared.core.plot.world.PlotAreaManager;
 import com.plotsquared.core.queue.ScopedLocalBlockQueue;
 import com.plotsquared.core.util.ChunkManager;
-import com.plotsquared.core.util.MainUtil;
 import com.sk89q.worldedit.math.BlockVector2;
 import lombok.Getter;
 import org.bukkit.World;
@@ -74,7 +73,6 @@ public class BukkitPlotGenerator extends ChunkGenerator
         this.populators = new ArrayList<>();
         this.populators.add(new BlockStatePopulator(this.plotGenerator, this.plotAreaManager));
         this.full = true;
-        MainUtil.initCache();
     }
 
     public BukkitPlotGenerator(final String world, final ChunkGenerator cg, @Nonnull final PlotAreaManager plotAreaManager) {
@@ -87,7 +85,6 @@ public class BukkitPlotGenerator extends ChunkGenerator
         this.full = false;
         this.platformGenerator = cg;
         this.plotGenerator = new DelegatePlotGenerator(cg, world);
-        MainUtil.initCache();
     }
 
     @Override public void augment(PlotArea area) {

Bukkit/src/main/java/com/plotsquared/bukkit/queue/GenChunk.java

@@ -31,7 +31,7 @@ import com.plotsquared.bukkit.util.BukkitUtil;
 import com.plotsquared.core.location.ChunkWrapper;
 import com.plotsquared.core.location.Location;
 import com.plotsquared.core.queue.ScopedLocalBlockQueue;
-import com.plotsquared.core.util.MainUtil;
+import com.plotsquared.core.util.ChunkUtil;
 import com.plotsquared.core.util.PatternUtil;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
 import com.sk89q.worldedit.function.pattern.Pattern;
@@ -151,12 +151,12 @@ public class GenChunk extends ScopedLocalBlockQueue {
     }
 
     private void storeCache(final int x, final int y, final int z, final BlockState id) {
-        int i = MainUtil.CACHE_I[y][x][z];
+        int i = y >> 4;
         BlockState[] v = this.result[i];
         if (v == null) {
             this.result[i] = v = new BlockState[4096];
         }
-        int j = MainUtil.CACHE_J[y][x][z];
+        int j = ChunkUtil.getJ(x, y, z);
         v[j] = id;
     }
 
@@ -171,7 +171,7 @@ public class GenChunk extends ScopedLocalBlockQueue {
     }
 
     @Override public BlockState getBlock(int x, int y, int z) {
-        int i = MainUtil.CACHE_I[y][x][z];
+        int i = y >> 4;
         if (result == null) {
             return BukkitBlockUtil.get(chunkData.getType(x, y, z));
         }
@@ -179,7 +179,7 @@ public class GenChunk extends ScopedLocalBlockQueue {
         if (array == null) {
             return BlockTypes.AIR.getDefaultState();
         }
-        int j = MainUtil.CACHE_J[y][x][z];
+        int j = ChunkUtil.getJ(x, y, z);
         return array[j];
     }
 

Core/src/main/java/com/plotsquared/core/generator/HybridUtils.java

@@ -45,7 +45,6 @@ import com.plotsquared.core.queue.ChunkBlockQueue;
 import com.plotsquared.core.queue.GlobalBlockQueue;
 import com.plotsquared.core.queue.LocalBlockQueue;
 import com.plotsquared.core.util.ChunkManager;
-import com.plotsquared.core.util.MainUtil;
 import com.plotsquared.core.util.MathMan;
 import com.plotsquared.core.util.RegionManager;
 import com.plotsquared.core.util.RegionUtil;
@@ -141,7 +140,6 @@ public class HybridUtils {
             final int cbz = bz >> 4;
             final int ctx = tx >> 4;
             final int ctz = tz >> 4;
-            MainUtil.initCache();
             final int width = tx - bx + 1;
             final int length = tz - bz + 1;
 
@@ -251,7 +249,6 @@ public class HybridUtils {
                 whenDone.run();
             });
             System.gc();
-            MainUtil.initCache();
             Location botLoc = Location.at(world, bot.getX(), bot.getY(), bot.getZ());
             Location topLoc = Location.at(world, top.getX(), top.getY(), top.getZ());
             ChunkManager.chunkTask(botLoc, topLoc, new RunnableVal<int[]>() {

Core/src/main/java/com/plotsquared/core/util/ChunkUtil.java

@@ -0,0 +1,93 @@
+package com.plotsquared.core.util;
+
+import lombok.experimental.UtilityClass;
+import org.jetbrains.annotations.Range;
+
+/**
+ * This cache is used for world generation and just saves a bit of calculation time when checking if something is in the plot area.
+ */
+@UtilityClass
+public class ChunkUtil {
+
+
+    /**
+     * Cache of mapping x,y,z coordinates to the chunk array<br>
+     * - Used for efficient world generation<br>
+     */
+    private static short[] x_loc;
+    private static short[][] y_loc;
+    private static short[] z_loc;
+    private static short[][][] CACHE_J = null;
+
+    static {
+        x_loc = new short[4096];
+        y_loc = new short[16][4096];
+        z_loc = new short[4096];
+        for (int i = 0; i < 16; i++) {
+            int i4 = i << 4;
+            for (int j = 0; j < 4096; j++) {
+                int y = i4 + (j >> 8);
+                int a = j - ((y & 0xF) << 8);
+                int z1 = a >> 4;
+                int x1 = a - (z1 << 4);
+                x_loc[j] = (short) x1;
+                y_loc[i][j] = (short) y;
+                z_loc[j] = (short) z1;
+            }
+        }
+        CACHE_J = new short[256][16][16];
+        for (int x = 0; x < 16; x++) {
+            for (int z = 0; z < 16; z++) {
+                for (int y = 0; y < 256; y++) {
+                    short j = (short) ((y & 0xF) << 8 | z << 4 | x);
+                    CACHE_J[y][x][z] = j;
+                }
+            }
+        }
+    }
+
+    /**
+     * Get the J value for Chunk block storage from the chunk xyz coordinates.
+     * J is in the range 0 to 4095 where it represents a position in an array of 16x16x16 xyz (ChunkSection  Array[4096]).
+     *
+     * @param x Relative x coordinate
+     * @param y Relative y coordinate
+     * @param z Relative z coordinate
+     * @return J value for xyz position in Array[4096].
+     */
+    public static int getJ(@Range(from = 0, to = 15) int x, @Range(from = 0, to = 255) int y,
+        @Range(from = 0, to = 15) int z) {
+        return CACHE_J[y][x][z];
+    }
+
+    /**
+     * Gets the x coordinate for a specific J value for a ChunkSection 16x16x16 xyz Array[4096].
+     *
+     * @param j Position in the xyz Array[4096].
+     * @return x coordinate within the chunk
+     */
+    public static int getX(@Range(from = 0, to = 4095) int j) {
+        return x_loc[j];
+    }
+
+    /**
+     * Gets the y coordinate for specific I and J values for a Chunk 16x16x16x16 layerxyz Array[16][4096].
+     *
+     * @param i Relative layer of the position in the layerxyz Array[16][4096].
+     * @param j Position in the xyz Array[4096].
+     * @return x coordinate within the chunk
+     */
+    public static int getY(@Range(from = 0, to = 15) int i, @Range(from = 0, to = 4095) int j) {
+        return y_loc[i][j];
+    }
+
+    /**
+     * Gets the z coordinate for a specific J value for a ChunkSection 16x16x16 xyz Array[4096].
+     *
+     * @param j Position in the xyz Array[4096].
+     * @return z coordinate within the chunk
+     */
+    public static int getZ(@Range(from = 0, to = 4095) int j) {
+        return z_loc[j];
+    }
+}

Core/src/main/java/com/plotsquared/core/util/MainUtil.java

@@ -44,53 +44,6 @@ import javax.annotation.Nonnull;
     private static final Logger logger =
         LoggerFactory.getLogger("P2/" + MainUtil.class.getSimpleName());
 
-    /**
-     * Cache of mapping x,y,z coordinates to the chunk array<br>
-     * - Used for efficient world generation<br>
-     */
-    public static short[][] x_loc;
-    public static short[][] y_loc;
-    public static short[][] z_loc;
-    public static short[][][] CACHE_I = null;
-    public static short[][][] CACHE_J = null;
-
-    /**
-     * This cache is used for world generation and just saves a bit of calculation time when checking if something is in the plot area.
-     */
-    public static void initCache() {
-        if (x_loc == null) {
-            x_loc = new short[16][4096];
-            y_loc = new short[16][4096];
-            z_loc = new short[16][4096];
-            for (int i = 0; i < 16; i++) {
-                int i4 = i << 4;
-                for (int j = 0; j < 4096; j++) {
-                    int y = i4 + (j >> 8);
-                    int a = j - ((y & 0xF) << 8);
-                    int z1 = a >> 4;
-                    int x1 = a - (z1 << 4);
-                    x_loc[i][j] = (short) x1;
-                    y_loc[i][j] = (short) y;
-                    z_loc[i][j] = (short) z1;
-                }
-            }
-        }
-        if (CACHE_I == null) {
-            CACHE_I = new short[256][16][16];
-            CACHE_J = new short[256][16][16];
-            for (int x = 0; x < 16; x++) {
-                for (int z = 0; z < 16; z++) {
-                    for (int y = 0; y < 256; y++) {
-                        short i = (short) (y >> 4);
-                        short j = (short) ((y & 0xF) << 8 | z << 4 | x);
-                        CACHE_I[y][x][z] = i;
-                        CACHE_J[y][x][z] = j;
-                    }
-                }
-            }
-        }
-    }
-
     /**
      * Send a message to the player.
      *