Adding disk optimization. Pascal only.

app/cli-acx/src/main/java/io/github/applecommander/acx/Main.java

@@ -57,6 +57,7 @@ import java.util.logging.Logger;
             ListCommand.class,
             LockCommand.class,
             MkdirCommand.class,
+            OptimizeCommand.class,
             ProofCommand.class,
             ReadCommand.class,
             RenameFileCommand.class,

app/cli-acx/src/main/java/io/github/applecommander/acx/command/OptimizeCommand.java

@@ -0,0 +1,55 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2026 by Robert Greene and others
+ * robgreene at users.sourceforge.net
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package io.github.applecommander.acx.command;
+
+import com.webcodepro.applecommander.storage.FormattedDisk;
+import io.github.applecommander.acx.base.ReadWriteDiskCommandOptions;
+import org.applecommander.os.DiskOptimizer;
+import picocli.CommandLine.Command;
+
+import java.util.Optional;
+
+@Command(name = "optimize", aliases = { "krunch" }, description = "Optimize disk image.")
+public class OptimizeCommand extends ReadWriteDiskCommandOptions {
+    @Override
+    public int handleCommand() throws Exception {
+        int completed = 0;
+        int skipped = 0;
+        for (FormattedDisk disk : selectedDisks()) {
+            Optional<DiskOptimizer> opt = disk.get(DiskOptimizer.class);
+            if (opt.isEmpty()) {
+                System.out.printf("Optimization not supported for disk %s of type %s.\n", disk.getFilename(), disk.getFormat());
+                skipped++;
+                continue;
+            }
+            DiskOptimizer optimizer = opt.get();
+            if (!optimizer.canOptimizeDisk()) {
+                System.out.printf("Disk %s does not need optimization.\n", disk.getFilename());
+                skipped++;
+                continue;
+            }
+            optimizer.optimizeDisk();
+            completed++;
+            System.out.printf("Disk %s has been optimized.\n", disk.getFilename());
+        }
+        System.out.printf("%d disks were optimized, %d disks were skipped.\n", completed, skipped);
+        return 0;
+    }
+}

lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/pascal/PascalDiskOptimizer.java

@@ -0,0 +1,79 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2026 by Robert Greene and others
+ * robgreene at users.sourceforge.net
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package com.webcodepro.applecommander.storage.os.pascal;
+
+import com.webcodepro.applecommander.storage.FileEntry;
+import org.applecommander.os.DiskOptimizer;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * A simple Pascal disk optimizer. This should emulate a "krunch" to the front of the disk.
+ */
+public class PascalDiskOptimizer implements DiskOptimizer {
+    private PascalFormatDisk disk;
+
+    public PascalDiskOptimizer(PascalFormatDisk disk) {
+        this.disk = disk;
+    }
+
+    @Override
+    public boolean canOptimizeDisk() {
+        int nextBlock = 6;
+        for (PascalFileEntry fileEntry : getSortedFiles()) {
+            if (fileEntry.getFirstBlock() != nextBlock) {
+                return true;
+            }
+            nextBlock = fileEntry.getLastBlock();
+        }
+        return false;
+    }
+
+    @Override
+    public void optimizeDisk() {
+        int nextBlock = 6;
+        for (PascalFileEntry fileEntry : getSortedFiles()) {
+            if (fileEntry.getFirstBlock() != nextBlock) {
+                int offset = fileEntry.getFirstBlock() - nextBlock;
+                // We move both pointers where we think they should be. And then save the file to move the data.
+                byte[] fileData = fileEntry.getFileData();
+                fileEntry.setFirstBlock(fileEntry.getFirstBlock() - offset);
+                fileEntry.setLastBlock(fileEntry.getLastBlock() - offset);
+                try {
+                    fileEntry.setFileData(fileData);
+                } catch (Exception e) {
+                    throw new RuntimeException("Unexpected error", e);
+                }
+            }
+            nextBlock = fileEntry.getLastBlock();
+        }
+    }
+
+    public List<PascalFileEntry> getSortedFiles() {
+        List<PascalFileEntry> sortedFiles = new ArrayList<>();
+        for (FileEntry fileEntry : disk.getFiles()) {
+            sortedFiles.add((PascalFileEntry) fileEntry);
+        }
+        sortedFiles.sort(Comparator.comparingInt(PascalFileEntry::getFirstBlock));
+        return sortedFiles;
+    }
+}

lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/pascal/PascalFormatDisk.java

@@ -119,6 +119,7 @@ public class PascalFormatDisk extends FormattedDisk {
 	}
 
 	private final BlockDevice device;
+	private final PascalDiskOptimizer optimizer;
 	
 	/**
 	 * Constructor for PascalFormatDisk.
@@ -126,6 +127,7 @@ public class PascalFormatDisk extends FormattedDisk {
 	public PascalFormatDisk(String filename, BlockDevice device) {
 		super(filename, device.get(Source.class).orElseThrow());
 		this.device = device;
+		this.optimizer = new PascalDiskOptimizer(this);
 	}
 
 	/**
@@ -147,7 +149,7 @@ public class PascalFormatDisk extends FormattedDisk {
 
 	@Override
 	public <T> Optional<T> get(Class<T> iface) {
-		return Container.get(iface, device);
+		return Container.get(iface, device, optimizer);
 	}
 
 	/**

lib/ac-api/src/main/java/org/applecommander/os/DiskOptimizer.java

@@ -0,0 +1,38 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2026 by Robert Greene and others
+ * robgreene at users.sourceforge.net
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package org.applecommander.os;
+
+/**
+ * An optional disk optimizer interface.
+ *
+ * @see org.applecommander.util.Container#get(Class)
+ */
+public interface DiskOptimizer {
+    /**
+     * Indicates if this disk can be optimized.
+     * For instance, a Pascal disk can be "krunched" to pack the files together but it may not need it.
+     */
+    boolean canOptimizeDisk();
+
+    /**
+     * Perform disk optimization.
+     */
+    void optimizeDisk();
+}

lib/ac-api/src/test/java/com/webcodepro/applecommander/storage/os/pascal/PascalDiskOptimizerTest.java

@@ -0,0 +1,91 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2002-2026 by Robert Greene and others
+ * robgreene at users.sourceforge.net
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc., 
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package com.webcodepro.applecommander.storage.os.pascal;
+
+import com.webcodepro.applecommander.storage.DiskConstants;
+import com.webcodepro.applecommander.storage.DiskFullException;
+import com.webcodepro.applecommander.storage.FileEntry;
+import org.applecommander.device.BlockDevice;
+import org.applecommander.device.ProdosOrderedBlockDevice;
+import org.applecommander.os.DiskOptimizer;
+import org.applecommander.source.DataBufferSource;
+import org.applecommander.source.Source;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.Random;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class PascalDiskOptimizerTest {
+    @Test
+    public void testKrunch() throws DiskFullException {
+        Source source = DataBufferSource.create(DiskConstants.APPLE_140KB_DISK, "new-disk").get();
+        BlockDevice blockDevice = new ProdosOrderedBlockDevice(source, BlockDevice.STANDARD_BLOCK_SIZE);
+        PascalFormatDisk[] disks = PascalFormatDisk.create("deleteme.po", "TEST", blockDevice);
+        PascalFormatDisk disk = disks[0];
+
+        // Strategy:
+        // 1. Create a set of files. At least one single block file.
+        // 2. Delete the first file (opening up a gap).
+        // 3. "Krunch"
+        // 4. Check expected block numbers.
+
+        PascalFileEntry file0 = createFileData(disk, "file0", 2000);    // 4 blocks (gets deleted)
+        PascalFileEntry file1 = createFileData(disk, "file1", 2048);    // 4 blocks
+        PascalFileEntry file2 = createFileData(disk, "file2", 4000);    // 8 blocks
+        PascalFileEntry file3 = createFileData(disk, "file3", 500);     // 1 block
+        PascalFileEntry file4 = createFileData(disk, "file4", 2000);    // 4 blocks
+
+        // Need to capture the random data BEFORE optimization occurs
+        final byte[][] expectedFileData = { file1.getFileData(), file2.getFileData(), file3.getFileData(), file4.getFileData() };
+
+        DiskOptimizer optimizer = disk.get(DiskOptimizer.class).orElseThrow();
+        assertFalse(optimizer.canOptimizeDisk());
+
+        file0.delete();
+        assertTrue(optimizer.canOptimizeDisk());
+
+        optimizer.optimizeDisk();
+
+        // Some of the file data is cached, so we do a fresh pull from the image
+        final int[] expectedFirstBlock = { 6, 10, 18, 19 };
+        final int[] expectedLastBlock = { 10, 18, 19, 23 };
+        List<FileEntry> fileEntries = disk.getFiles();
+        assertEquals(4, fileEntries.size());
+        for (int i=0; i<fileEntries.size(); i++) {
+            PascalFileEntry fileEntry = (PascalFileEntry) fileEntries.get(i);
+            assertEquals(expectedFirstBlock[i], fileEntry.getFirstBlock());
+            assertEquals(expectedLastBlock[i], fileEntry.getLastBlock());
+            assertArrayEquals(expectedFileData[i], fileEntry.getFileData());
+        }
+    }
+
+    public PascalFileEntry createFileData(PascalFormatDisk disk, String filename, int size) throws DiskFullException {
+        byte[] fileData = new byte[size];
+        new Random().nextBytes(fileData);
+
+        PascalFileEntry fileEntry = disk.createFile();
+        fileEntry.setFilename(filename);
+        fileEntry.setFiletype("data");
+        fileEntry.setFileData(fileData);
+        return fileEntry;
+    }
+}

lib/ac-swt-common/src/main/java/com/webcodepro/applecommander/ui/swt/DiskExplorerTab.java

@@ -49,6 +49,7 @@ import org.applecommander.device.Device;
 import org.applecommander.hint.Hint;
 import org.applecommander.image.NibbleImage;
 import org.applecommander.os.DiskCheck;
+import org.applecommander.os.DiskOptimizer;
 import org.applecommander.source.DataBufferSource;
 import org.applecommander.source.Source;
 import org.applecommander.source.Sources;
@@ -112,6 +113,7 @@ public class DiskExplorerTab {
 	private ToolItem saveAsToolItem;
 	private ToolItem changeOrderToolItem;
 	private ToolItem checkDiskToolItem;
+	private ToolItem optimizeDiskToolItem;
 	private Menu changeImageOrderMenu;
 
 	private final UserPreferences userPreferences = UserPreferences.getInstance();
@@ -1342,7 +1344,25 @@ public class DiskExplorerTab {
                 }
             }
 		});
-		
+
+		optimizeDiskToolItem = new ToolItem(toolBar, SWT.PUSH);
+		optimizeDiskToolItem.setImage(imageManager.get(ImageManager.ICON_DISK_OPTIMIZE));
+		optimizeDiskToolItem.setText("Optimize");
+		optimizeDiskToolItem.setToolTipText("Optimize disk.");
+		optimizeDiskToolItem.setEnabled(false);
+		for (FormattedDisk disk : disks) {
+			if (disk.get(DiskOptimizer.class).isPresent()) optimizeDiskToolItem.setEnabled(true);
+		}
+		optimizeDiskToolItem.addSelectionListener(new SelectionAdapter () {
+			public void widgetSelected(SelectionEvent e) {
+				try {
+					optimizeDisk();
+				} catch (Exception ex) {
+					showError(ex);
+				}
+			}
+		});
+
 		new ToolItem(toolBar, SWT.SEPARATOR);
 
 		saveToolItem = new ToolItem(toolBar, SWT.PUSH);
@@ -2198,6 +2218,32 @@ public class DiskExplorerTab {
 		dialog.open();
 	}
 
+	protected void optimizeDisk() {
+		int completed = 0;
+		int didntNeed = 0;
+		int skipped = 0;
+		for (FormattedDisk disk : disks) {
+			Optional<DiskOptimizer> opt = disk.get(DiskOptimizer.class);
+			if (opt.isEmpty()) {
+				skipped++;
+				continue;
+			}
+			DiskOptimizer optimizer = opt.get();
+			if (!optimizer.canOptimizeDisk()) {
+				didntNeed++;
+				continue;
+			}
+			optimizer.optimizeDisk();
+			completed++;
+		}
+
+		MessageBox box = new MessageBox(shell, SWT.ICON_INFORMATION | SWT.CLOSE);
+		box.setText("Optimization results");
+		box.setMessage(String.format("%d disks were optimized, %d disks didn't need optimization, and %d disks were skipped.",
+				completed, didntNeed, skipped));
+		box.open();
+	}
+
 	/**
 	 * Construct the popup menu for the export button on the toolbar.
 	 */

lib/ac-swt-common/src/main/java/com/webcodepro/applecommander/ui/swt/util/ImageManager.java

@@ -72,6 +72,7 @@ public class ImageManager {
 	public static final String ICON_HEALTH_CHECK = "health-check.png";
 	public static final String ICON_PLUS = "plus.png";
 	public static final String ICON_MINUS = "minus.png";
+	public static final String ICON_DISK_OPTIMIZE = "disk-optimize.png";
 
 	public static final String LOGO_EXPORT_WIZARD        = "ExportWizardLogo.jpg";
 	public static final String LOGO_APPLECOMMANDER       = "AppleCommanderLogo.jpg";
@@ -98,6 +99,7 @@ public class ImageManager {
 		ICON_CHANGE_IMAGE_ORDER,    ICON_SHAPE_TABLE,
 		ICON_SETTINGS,				ICON_HEALTH_CHECK,
 		ICON_PLUS,                  ICON_MINUS,
+		ICON_DISK_OPTIMIZE,
 		// Logos:
 		LOGO_EXPORT_WIZARD,			LOGO_APPLECOMMANDER,
 		LOGO_DISK_IMAGE_WIZARD,		LOGO_IMPORT_WIZARD,