Fix plot analysis

- Stop using deprecated ChunkQueueCoordinator and create a new purpose-built coordinator
 - Generation is chunk-by-chunk thus the old blocks cache needs to be filled accordingly
 - Remove the **four** System#gc calls
 - Fixes #3464
 - Fix really weird dumb... maths? in ExpiryTask
 - Fixes #3600

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

@@ -41,7 +41,7 @@ import com.plotsquared.core.plot.flag.GlobalFlagContainer;
 import com.plotsquared.core.plot.flag.PlotFlag;
 import com.plotsquared.core.plot.flag.implementations.AnalysisFlag;
 import com.plotsquared.core.plot.world.PlotAreaManager;
-import com.plotsquared.core.queue.ChunkQueueCoordinator;
+import com.plotsquared.core.queue.BlockArrayCacheScopedQueueCoordinator;
 import com.plotsquared.core.queue.GlobalBlockQueue;
 import com.plotsquared.core.queue.QueueCoordinator;
 import com.plotsquared.core.util.ChunkManager;
@@ -136,6 +136,11 @@ public class HybridUtils {
          *
          */
         TaskManager.runTaskAsync(() -> {
+            final PlotArea area = this.plotAreaManager.getPlotArea(world, null);
+            if (!(area instanceof HybridPlotWorld hpw)) {
+                return;
+            }
+
             final BlockVector3 bot = region.getMinimumPoint();
             final BlockVector3 top = region.getMaximumPoint();
 
@@ -152,17 +157,8 @@ public class HybridUtils {
             final int height = area.getMaxGenHeight() - area.getMinGenHeight() + 1;
             final int minHeight = area.getMinGenHeight();
 
-            final PlotArea area = this.plotAreaManager.getPlotArea(world, null);
-
-            if (!(area instanceof HybridPlotWorld hpw)) {
-                return;
-            }
-
-            ChunkQueueCoordinator chunk = new ChunkQueueCoordinator(worldUtil.getWeWorld(world), bot, top, false);
-            hpw.getGenerator().generateChunk(chunk, hpw);
-
             final BlockState airBlock = BlockTypes.AIR.getDefaultState();
-            final BlockState[][][] oldBlocks = chunk.getBlocks();
+            final BlockState[][][] oldBlocks = new BlockState[height][width][length];
             final BlockState[][][] newBlocks = new BlockState[height][width][length];
             for (final BlockState[][] newBlock : newBlocks) {
                 for (final BlockState[] blockStates : newBlock) {
@@ -175,8 +171,20 @@ public class HybridUtils {
                 }
             }
 
-            System.gc();
+            BlockArrayCacheScopedQueueCoordinator oldBlockQueue = new BlockArrayCacheScopedQueueCoordinator(
-            System.gc();
+                    oldBlocks,
+                    area.getMinGenHeight(),
+                    Location.at("", region.getMinimumPoint()),
+                    Location.at("", region.getMaximumPoint())
+            );
+
+            region.getChunks().forEach(blockVector2 -> {
+                int relChunkX = blockVector2.getX() - cbx;
+                int relChunkZ = blockVector2.getZ() - cbz;
+                oldBlockQueue.setOffsetX(relChunkX << 4);
+                oldBlockQueue.setOffsetZ(relChunkZ << 4);
+                hpw.getGenerator().generateChunk(oldBlockQueue, hpw);
+            });
 
             QueueCoordinator queue = area.getQueue();
             queue.addReadChunks(region.getChunks());
@@ -301,8 +309,6 @@ public class HybridUtils {
                 analysis.data_sd = (int) (MathMan.getSD(data, analysis.data) * 100);
                 analysis.air_sd = (int) (MathMan.getSD(air, analysis.air) * 100);
                 analysis.variety_sd = (int) (MathMan.getSD(variety, analysis.variety) * 100);
-                System.gc();
-                System.gc();
                 whenDone.value = analysis;
                 whenDone.run();
             });

Core/src/main/java/com/plotsquared/core/plot/expiration/ExpiryTask.java

@@ -75,9 +75,9 @@ public class ExpiryTask {
                     plots = plots != null ? plots : getPlotsToCheck();
                     int diff = settings.REQUIRED_PLOTS;
                     boolean min = true;
-                    if (settings.REQUIRED_PLOTS - plots.size() < settings.REQUIRED_PLOTS) {
+                    if (plots.size() > settings.REQUIRED_PLOTS) {
                         min = false;
-                        diff = settings.REQUIRED_PLOTS - plots.size();
+                        diff = plots.size() - settings.REQUIRED_PLOTS;
                     }
                     List<Long> entireList =
                             plots.stream().map(plot -> ExpireManager.IMP.getAge(plot, settings.DELETE_IF_OWNER_IS_UNKNOWN))

Core/src/main/java/com/plotsquared/core/queue/BlockArrayCacheScopedQueueCoordinator.java

@@ -0,0 +1,168 @@
+/*
+ *       _____  _       _    _____                                _
+ *      |  __ \| |     | |  / ____|                              | |
+ *      | |__) | | ___ | |_| (___   __ _ _   _  __ _ _ __ ___  __| |
+ *      |  ___/| |/ _ \| __|\___ \ / _` | | | |/ _` | '__/ _ \/ _` |
+ *      | |    | | (_) | |_ ____) | (_| | |_| | (_| | | |  __/ (_| |
+ *      |_|    |_|\___/ \__|_____/ \__, |\__,_|\__,_|_|  \___|\__,_|
+ *                                    | |
+ *                                    |_|
+ *            PlotSquared plot management system for Minecraft
+ *               Copyright (C) 2014 - 2022 IntellectualSites
+ *
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ *
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.plotsquared.core.queue;
+
+import com.plotsquared.core.location.Location;
+import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.worldedit.function.pattern.Pattern;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.world.biome.BiomeType;
+import com.sk89q.worldedit.world.block.BaseBlock;
+import com.sk89q.worldedit.world.block.BlockState;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * {@link QueueCoordinator} that caches all blocks set to it in a given array of form BlockState[][][]. An offset can be
+ * applied to blocks set to it, and the scope limited.
+ */
+public class BlockArrayCacheScopedQueueCoordinator extends ScopedQueueCoordinator {
+
+    private final BlockState[][][] blockStates;
+    private final int height;
+    private final int width;
+    private final int length;
+    private final int minY;
+    private final int maxY;
+    private final int scopeMinX;
+    private final int scopeMinZ;
+    private final int scopeMaxX;
+    private final int scopeMaxZ;
+
+    private int offsetX = 0;
+    private int offsetZ = 0;
+
+    /**
+     * Construct a new instance
+     *
+     * @param blockStates Array of form BlockState[y][x][z]. Must be fully initialised.
+     * @param minY        Minimum applicable y value. Used to account for negative world heights (e.g. -64). Inclusive
+     * @param min         Inclusive location of the minimum point to limit the scope to.
+     * @param max         Exclusive location of the maximum point to limit the scope to.
+     */
+    public BlockArrayCacheScopedQueueCoordinator(@NonNull BlockState[][][] blockStates, int minY, Location min, Location max) {
+        super(null, min, max);
+        this.blockStates = blockStates;
+        this.height = blockStates.length;
+        this.width = blockStates[0].length;
+        this.length = blockStates[0][0].length;
+        this.minY = minY;
+        this.maxY = height + minY; // exclusive
+
+        this.scopeMinX = min.getX() & 15;
+        this.scopeMinZ = min.getZ() & 15;
+        this.scopeMaxX = scopeMinX + width;
+        this.scopeMaxZ = scopeMinZ + length;
+    }
+
+    @Override
+    public boolean setBlock(int x, final int y, int z, final @NonNull BlockState id) {
+        x += offsetX;
+        z += offsetZ;
+        if (x >= scopeMinX && x < scopeMaxX && y >= minY && y < maxY && z >= scopeMinZ && z < scopeMaxZ) {
+            blockStates[y - minY][x - scopeMinX][z - scopeMinZ] = id;
+        }
+        return false;
+    }
+
+    @Override
+    public boolean setBlock(final int x, final int y, final int z, @NonNull final Pattern pattern) {
+        int rx = x + offsetX;
+        int rz = z + offsetZ;
+        if (rx >= scopeMinX && rx < scopeMaxX && y >= minY && y < maxY && rz >= scopeMinZ && rz < scopeMaxZ) {
+            BlockState state = pattern
+                    .applyBlock(super.getMin().getBlockVector3().add(BlockVector3.at(x, y, z)))
+                    .toImmutableState();
+            blockStates[y - minY][rx - scopeMinX][rz - scopeMinZ] = state;
+        }
+        return false;
+    }
+
+    @Override
+    public @NonNull Location getMin() {
+        return super.getMin().add(offsetX - scopeMinX, 0, offsetZ - scopeMinZ);
+    }
+
+    @Override
+    public @NonNull Location getMax() {
+        return getMin().add(15, 0, 15).withY(maxY);
+    }
+
+    @Override
+    public boolean setBlock(int x, int y, int z, final @NonNull BaseBlock id) {
+        x += offsetX;
+        z += offsetZ;
+        if (x >= scopeMinX && x < scopeMaxX && y >= minY && y < maxY && z >= scopeMinZ && z < scopeMaxZ) {
+            blockStates[y - minY][x][z] = id.toImmutableState();
+        }
+        return false;
+    }
+
+    @Override
+    public @Nullable BlockState getBlock(final int x, final int y, final int z) {
+        if (x >= 0 && x < width && y >= minY && y < maxY && z >= 0 && z < length) {
+            return blockStates[y - minY][x][z];
+        }
+        return null;
+    }
+
+    public void setOffsetX(final int offsetX) {
+        this.offsetX = offsetX;
+    }
+
+    public void setOffsetZ(final int offsetZ) {
+        this.offsetZ = offsetZ;
+    }
+
+    @Override
+    public int size() {
+        return height * width * length;
+    }
+
+    @Override
+    public boolean setBiome(final int x, final int z, @NonNull final BiomeType biome) {
+        //do nothing
+        return false;
+    }
+
+    @Override
+    public boolean setBiome(final int x, final int y, final int z, @NonNull final BiomeType biome) {
+        //do nothing
+        return false;
+    }
+
+    @Override
+    public void fillBiome(final BiomeType biome) {
+        //do nothing
+    }
+
+    @Override
+    public boolean setTile(final int x, final int y, final int z, @NonNull final CompoundTag tag) {
+        //do nothing
+        return false;
+    }
+
+}