Design Document for Project 5: macOS Disk Usage Visualizer

Design Document for Project 5: macOS Disk Usage Visualizer

Project Name: macOS Disk Usage Visualizer

Objective:

Build a cross-platform application using Java and C++ that visualizes disk usage in macOS. The project combines a C++ disk usage scanner with a Java-based visualization tool.

1. Goals and Non-Goals

Goals:

• Develop a high-performance disk usage scanner in C++.
• Provide a tree-map or bar-chart visualization using JavaFX.
• Ensure compatibility across multiple macOS versions.

Non-Goals:

• Compatibility with Windows or Linux systems.
• Advanced visualization features like zoom or real-time updates.

1. Design Overview
   • Input: Root directory path provided by the user.
   • Output: Visualization of disk usage, including folder sizes and file details.
   • Architecture:
   • C++ Disk Scanner: Scans the directory and calculates folder sizes.
   • Java Frontend: Visualizes the scanned data.
   • JNI Interface: Facilitates communication between Java and C++.
2. System Design
   1. Components
      • Disk Scanner (C++):
      • Traverses the directory recursively to calculate sizes.
      • Outputs results in a structured format (e.g., JSON).
      • Java Visualizer:
      • Parses the JSON output and renders a visualization using JavaFX.
      • JNI Bridge:
      • Connects the Java application with the C++ scanner for seamless integration.
   2. Workflow
      1. Input Handling:
         • User provides the root directory path.
      2. Scanning: • The Disk Scanner processes the directory and generates a JSON file.
      3. Data Parsing: • The Java Visualizer reads and parses the JSON output.
      4. Visualization: • JavaFX renders a tree map or bar chart.
      5. Output: • Disk usage data is displayed, highlighting large files and directories.
3. API and Data Structures

5.1 Core Data Structures • FileInfo (C++):

struct FileInfo { std::string name; uint64_t size; std::vector children; };

• JSON Schema:

{ “name”: “root”, “size”: 100000, “children”: [ { “name”: “folder1”, “size”: 50000, “children”: [] }, { “name”: “folder2”, “size”: 50000, “children”: [] } ] }

5.2 Interfaces • Disk Scanner:

FileInfo scanDirectory(const std::string& rootPath);

•	Java Parser:

List parseJson(String jsonFilePath);

•	JNI Interface:

public native String scanDisk(String rootPath);

1. Multithreading Strategy • Disk Scanner: Use multithreading for traversing subdirectories concurrently. • Load Balancing: Assign threads based on directory size to prevent bottlenecks.

2. Testing • Unit Testing: Verify the correctness of directory traversal and JSON generation. • Integration Testing: Ensure seamless interaction between C++ and Java components. • Visualization Testing: • Validate chart rendering for large and complex directory structures. • Test responsiveness of JavaFX.