SmartSync - Backup Assistant

A cross-platform GUI-based Backup Assistant that helps users automatically copy only new or modified files to an external hard disk. It works like a Git-style deduplication and versioned backup tool. Works on Windows, macOS, and Linux.

Features

• Intelligent Deduplication: Uses SHA256 hashing to detect file changes
• Incremental Backups: Only copies new or modified files
• Destination Duplicate Detection: Optionally scans the destination drive and skips files that already exist there
• Metadata Tracking: SQLite database tracks file history and modification times
• User-Friendly GUI: PyQt5-based interface with progress tracking
• Session Logging: Detailed logs of all backup operations
• Thread-Safe: Non-blocking backup operations using worker threads

Requirements

• Python 3.7 or higher
• PyQt5 (cross-platform GUI framework)
• SQLite3 (included with Python)

Platform-Specific Notes

• Windows: Works out of the box. May need to enable long path support for paths >260 characters.
• macOS: Requires Xcode Command Line Tools for PyQt5. Install with: xcode-select --install
• Linux: May need to install PyQt5 via package manager: sudo apt-get install python3-pyqt5 (Ubuntu/Debian) or sudo yum install python3-qt5 (Fedora/RHEL)

Installation

1. Clone or download this repository
2. Install dependencies:

pip install -r requirements.txt

Usage

Running the Application

From the project root directory:

python app.py

Or use the launcher script:

./launch_gui.sh

Or if installed as a package:

backup-assistant

Using the GUI

1. Select Source Folder: Click "Browse..." next to "Source Folder" and select the directory you want to backup
2. Select Destination Folder: Click "Browse..." next to "Destination Folder" and select where you want to store the backup (e.g., external hard disk)
3. Start Backup: Click "Start Backup" to begin the backup process
4. (Optional) Deduplication: Leave the "Skip files already on destination" checkbox enabled to scan the external drive before copying
5. Monitor Progress: Watch the progress bar and log window for real-time updates
6. Review Results: After completion, review the summary showing copied, skipped, and duplicate counts

How It Works

1. Scanning: The application scans the source folder and calculates SHA256 hashes for all files
2. Comparison: Each file is compared against the database to check if it's new or modified
3. Destination Dedup (optional): If enabled, the destination drive is scanned and duplicate hashes are skipped
4. Copying: Only new or modified (and non-duplicate) files are copied to the destination
5. Tracking: File metadata (hash, modification time, size) is stored in the database for future comparisons

Project Structure

.
├── app.py                      # Main entry point
├── backup_engine/
│   ├── scanner.py             # File traversal and hashing
│   ├── copier.py              # Conditional file copying
│   └── snapshot.py            # Snapshot management
├── db/
│   └── db_manager.py          # SQLite database interface
├── gui/
│   └── main_window.py         # PyQt5 GUI
├── utils/
│   ├── hashing.py             # SHA256 hash generation
│   ├── logger.py              # Logging functionality
│   └── config.py              # Configuration settings
├── data/
│   └── backup_metadata.db     # SQLite database file
├── tests/
│   ├── test_hashing.py
│   ├── test_db_manager.py
│   └── test_backup_logic.py
├── requirements.txt           # Python dependencies
├── setup.py                   # Package setup
└── README.md                  # This file

Configuration

Edit utils/config.py to customize:

• File size limits
• Include/exclude patterns
• Database and log paths
• Default backup settings

Testing

Run the test suite:

pytest tests/

Or run specific test files:

pytest tests/test_hashing.py
pytest tests/test_db_manager.py
pytest tests/test_backup_logic.py

Database Schema

The application uses SQLite to store file metadata:

• file_metadata: Stores file paths, hashes, modification times, and backup timestamps
• backup_sessions: Tracks backup session history

Cross-Platform Support

This application is fully cross-platform and has been tested on:

• ✅ Windows 10/11 - Full support with platform-specific exclusions (Thumbs.db, etc.)
• ✅ macOS - Full support with macOS-specific exclusions (.DS_Store, etc.)
• ✅ Linux/Unix - Full support with Linux-specific exclusions

Platform-Specific Features

• Automatic system file exclusion: Skips platform-specific system files automatically
• Platform-aware data storage: Uses appropriate directories for each OS:
  • Windows: %LOCALAPPDATA%\BackupAssistant\data
  • macOS: ~/Library/Application Support/BackupAssistant/data
  • Linux: ~/.local/share/backup-assistant/data
• Path normalization: Handles path differences between platforms automatically

Limitations

• Large files may take time to hash
• Network drives may have performance limitations
• Windows: Very long paths (>260 chars) may require long path support to be enabled
• Requires Python 3.7+ and PyQt5 (cross-platform)

Future Enhancements

• Scheduled backups
• Snapshot restore functionality
• Compression support
• Cloud storage integration
• Email notifications
• Backup verification

License

This project is provided as-is for educational and personal use.

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

Support

For issues or questions, please open an issue on the project repository.