Use 7zip as archiver and merge tars instead of extracting

lib/api/archive.dart

@@ -0,0 +1,78 @@
+import 'dart:io';
+
+/// API for 7-Zip archive operations
+class ArchiveApi {
+  static const _exe = './7zip/7za.exe';
+
+  /// Get current path
+  static Future<String> get currentPath async {
+    // Get current path
+    try {
+      final result = await Process.run("cmd", ["/c", "cd"], runInShell: true);
+      return result.stdout.toString();
+    } catch (e) {
+      throw Exception('Failed to get current path: $e');
+    }
+  }
+
+  /// Extracts the archive at [archivePath] to [destinationPath]
+  static Future<void> extract(
+      String archivePath, String destinationPath) async {
+    // 7zr.exe x layer2.tar.gz -olayer
+    // Extract archive
+    try {
+      await Process.run(_exe, ['x', archivePath, '-o$destinationPath']);
+    } catch (e) {
+      throw Exception('Failed to extract archive: $e');
+    }
+  }
+
+  /// Merge the archives at [archivePaths] into [destinationPath]
+  static Future<void> merge(
+      List<String> archivePaths, String destinationPath) async {
+    // Merge archives
+    try {
+      // remove trailing zeros from the files
+      final outputFile = File(destinationPath);
+      for (var i = 0; i < archivePaths.length; i++) {
+        final fileName = archivePaths[i];
+        // Read file as byte stream
+        final file = File(fileName);
+        final bytes = await file.readAsBytes();
+        final length = bytes.length;
+
+        // Last layer
+        if (i == archivePaths.length - 1) {
+          await outputFile.writeAsBytes(bytes);
+          break;
+        }
+
+        // Remove trailing zeros
+        int lastBytePos = 0;
+        for (var i = length - 1; i >= 0; i--) {
+          if (bytes[i] != 0) {
+            lastBytePos = i;
+            break;
+          }
+        }
+
+        // Write to new file
+        await outputFile.writeAsBytes(bytes.sublist(0, lastBytePos + 1));
+      }
+    } catch (e) {
+      throw Exception('Failed to merge archives: $e');
+    }
+  }
+
+  /// Compress the tar archive at [filePath] to [destinationPath]
+  static Future<void> compress(String filePath, String destinationPath) async {
+    // 7zr.exe a -tgzip full_image.tar.gz full_image.tar
+    // Compress tar archive
+    try {
+      // 7zr.exe a -ttar combined_image.tar merged\*
+      await Process.run(_exe, ['a', '-tgzip', destinationPath, filePath]);
+    } catch (e) {
+      throw Exception('Failed to compress tar archive: $e');
+    }
+  }
+}

lib/api/docker_images.dart

@@ -3,12 +3,11 @@
 
 import 'dart:convert';
 import 'dart:io';
-import 'package:archive/archive.dart';
-import 'package:archive/archive_io.dart';
 import 'package:chunked_downloader/chunked_downloader.dart';
 import 'package:dio/dio.dart';
 import 'package:flutter/foundation.dart';
 import 'package:localization/localization.dart';
+import 'package:wsl2distromanager/api/archive.dart';
 import 'package:wsl2distromanager/api/safe_paths.dart';
 import 'package:wsl2distromanager/components/helpers.dart';
 import 'package:wsl2distromanager/components/logging.dart';
@@ -433,12 +432,13 @@ class DockerImage {
     // Write the compressed tar file to disk.
     int retry = 0;
 
-    String outArchive = SafePath(distroPath).file('$imageName.tar.gz');
+    final parentPath = SafePath(tmpImagePath);
+    String outTar = parentPath.file('$imageName.tar');
+    String outTarGz = SafePath(distroPath).file('$imageName.tar.gz');
     while (retry < 2) {
       try {
-        Archive archive = Archive();
-
         // More than one layer
+        List<String> paths = [];
         if (layers != 1) {
           for (var i = 0; i < layers; i++) {
             // Read archives layers
@@ -448,34 +448,21 @@ class DockerImage {
             // progress(i, layers, -1, -1);
             Notify.message('Extracting layer $i of $layers');
 
-            // In memory
-            final tarfile = GZipDecoder().decodeBytes(
-                File(SafePath(tmpImagePath).file('layer_$i.tar.gz'))
-                    .readAsBytesSync());
-            final subArchive = TarDecoder().decodeBytes(tarfile);
-
-            // Add files to archive
-            for (final file in subArchive) {
-              archive.addFile(file);
-              if (kDebugMode && !file.name.contains('/')) {
-                if (kDebugMode) {
-                  print('Adding root file ${file.name}');
-                }
-              }
-            }
+            // Extract layer
+            final layerTarGz = parentPath.file('layer_$i.tar.gz');
+            await ArchiveApi.extract(layerTarGz, parentPath.path);
+            paths.add(parentPath.file('layer_$i.tar'));
           }
 
           // Archive as tar then gzip to disk
-          final tarfile = TarEncoder().encode(archive);
-          final gzData = GZipEncoder().encode(tarfile);
-          final fp = File(outArchive);
+          await ArchiveApi.merge(paths, outTar);
+          await ArchiveApi.compress(outTar, outTarGz);
 
           Notify.message('writingtodisk-text'.i18n());
-          fp.writeAsBytesSync(gzData!);
         } else if (layers == 1) {
           // Just copy the file
           File(SafePath(tmpImagePath).file('layer_0.tar.gz'))
-              .copySync(outArchive);
+              .copySync(outTarGz);
         }
 
         retry = 2;
@@ -495,7 +482,7 @@ class DockerImage {
     Notify.message('creatinginstance-text'.i18n());
 
     // Check if tar file is created
-    if (!File(outArchive).existsSync()) {
+    if (!File(outTarGz).existsSync()) {
       throw Exception('Tar file is not created');
     }
     // Wait for tar file to be created

lib/dialogs/create_dialog.dart

@@ -67,6 +67,18 @@ createDialog() {
   );
 }
 
+progressFn(current, total, currentStep, totalStep) {
+  if (currentStep != -1) {
+    String progressInMB = (currentStep / 1024 / 1024).toStringAsFixed(2);
+    // String totalInMB = (total / 1024 / 1024).toStringAsFixed(2);
+    String percentage = (currentStep / totalStep * 100).toStringAsFixed(0);
+    Notify.message('${'downloading-text'.i18n()}'
+        ' Layer ${current + 1}/$total: $percentage% ($progressInMB MB)');
+  } else {
+    Notify.message('extractinglayers-text'.i18n(['$current', '$total']));
+  }
+}
+
 Future<void> createInstance(
   TextEditingController nameController,
   TextEditingController locationController,
@@ -117,21 +129,12 @@ Future<void> createInstance(
         // Download image
         Notify.message('${'downloading-text'.i18n()}...');
         var docker = DockerImage()..distroName = distroName;
-        await docker.getRootfs(name, image, tag: tag,
-            progress: (current, total, currentStep, totalStep) {
-          if (currentStep != -1) {
-            String progressInMB =
-                (currentStep / 1024 / 1024).toStringAsFixed(2);
-            // String totalInMB = (total / 1024 / 1024).toStringAsFixed(2);
-            String percentage =
-                (currentStep / totalStep * 100).toStringAsFixed(0);
-            Notify.message('${'downloading-text'.i18n()}'
-                ' Layer ${current + 1}/$total: $percentage% ($progressInMB MB)');
-          } else {
-            Notify.message(
-                'extractinglayers-text'.i18n(['$current', '$total']));
-          }
-        });
+        try {
+          await docker.getRootfs(name, image, tag: tag, progress: progressFn);
+        } catch (e) {
+          Notify.message('error-text'.i18n());
+          return;
+        }
         Notify.message('downloaded-text'.i18n());
         // Set distropath with distroName
         distroName = DockerImage().filename(image, tag);

pubspec.lock

@@ -5,10 +5,10 @@ packages:
     dependency: "direct main"
     description:
       name: archive
-      sha256: "0763b45fa9294197a2885c8567927e2830ade852e5c896fd4ab7e0e348d0f373"
+      sha256: ecf4273855368121b1caed0d10d4513c7241dfc813f7d3c8933b36622ae9b265
       url: "https://pub.dev"
     source: hosted
-    version: "3.5.0"
+    version: "3.5.1"
   args:
     dependency: transitive
     description:

pubspec.yaml

@@ -12,7 +12,7 @@ dependencies:
     sdk: flutter
   flutter_localizations:
     sdk: flutter
-  archive: ^3.3.7
+  archive: ^3.5.1
   async: ^2.11.0
   chunked_downloader: ^0.0.2
   desktop_window: ^0.4.0

test/dockerimages_test.dart

@@ -192,5 +192,55 @@ void main() {
     // Verify that the file exists and has > 2MB
     expect(await file.exists(), true);
     expect(await file.length(), greaterThan(2 * 1024 * 1024));
-  }, timeout: const Timeout(Duration(minutes: 2)));
+  }, timeout: const Timeout(Duration(minutes: 10)));
+
+  // Test almalinux latest
+  test('Create instance test almalinux:latest', () async {
+    TextEditingController nameController = TextEditingController(text: 'test');
+    TextEditingController locationController = TextEditingController(text: '');
+    TextEditingController autoSuggestBox =
+        TextEditingController(text: 'dockerhub:almalinux:latest');
+
+    final file =
+        File('C:/WSL2-Distros/distros/library_almalinux_latest.tar.gz');
+    if (await file.exists()) {
+      await file.delete();
+    }
+
+    // Delete the instance
+    await WSLApi().remove('test');
+
+    // Test build context
+    await createInstance(
+      nameController,
+      locationController,
+      WSLApi(),
+      autoSuggestBox,
+      TextEditingController(text: ''),
+    );
+
+    // Verify that the file exists and has > 2MB
+    expect(await file.exists(), true);
+    expect(await file.length(), greaterThan(2 * 1024 * 1024));
+    expect(await isInstance('test'), true);
+
+    // Delete the instance
+    await WSLApi().remove('test');
+
+    expect(await isInstance('test'), false);
+
+    // Test creating it without re-downloading the rootfs
+    await createInstance(
+      nameController,
+      locationController,
+      WSLApi(),
+      autoSuggestBox,
+      TextEditingController(text: ''),
+    );
+
+    expect(await isInstance('test'), true);
+
+    // Delete the instance
+    await WSLApi().remove('test');
+  }, timeout: const Timeout(Duration(minutes: 10)));
 }