OrbitOS | High-Performance VFS & Command Dispatch Engine

OrbitOS is a specialized Virtual File System (VFS) and command execution engine implemented in C++17. Architected for low-latency environments, it demonstrates advanced systems programming patterns including custom hash-mapped dispatchers, N-ary tree recursion, and strict RAII memory management.

🚀 Technical Core & Engineering Patterns

1. Constant-Time Dispatch Engine ($O(1)$)

Unlike standard shells that use linear string comparisons, OrbitOS utilizes a Jump Table Dispatcher.

• X-Macros: Used to generate function prototypes and mapping logic simultaneously, ensuring the command list remains a single source of truth.
• Custom Hashing: Implements a localized hash function with linear probing to map command strings to function pointers, mimicking the interrupt vector tables found in real-time kernels.

2. Memory Architecture & RAII

The system is built on a Zero-Leak Guarantee using modern C++ memory primitives.

• Ownership Model: Employs std::unique_ptr for child node management. This creates a cascading destruction chain; when a parent node is deallocated, the entire sub-tree is safely purged from the heap.
• Stateful Navigation: Maintains a Persistent Context (CWD) via raw pointers (File*) to avoid ownership cycles while providing $O(1)$ access to the current environment.

3. N-ary Tree & Recursive Logic

The filesystem is modeled as a dynamic N-ary tree, optimized for:

• DFS Discovery: Global search operations (find, fc) utilize Depth-First Search to traverse the hierarchy.
• Persistence: Features custom binary serialization for state recovery, allowing the entire tree structure to be written to and read from disk while maintaining pointer integrity.

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📂 Project Structure

OrbitOS/
├── src/            # Core logic (.cpp)
├── include/        # Declarations & X-Macros (.h)
├── tests/          # Automated diagnostic suite
├── data/           # Persistent VFS disk images (Git ignored)
├── build/          # Compiled binaries (Git ignored)
└── Makefile        # Project automation
🛠 Command Set
Navigation: cd, pwd, ls, tree

Manipulation: mkdir, wtf (write to file), rm, cp

System: stats (node counting), save/load (persistence), help

Security: fv (Favorite/Write-protect toggle), showfv

Scripting: Supports semicolon-separated command strings and quoted arguments.

🔧 Building & Testing
OrbitOS uses a centralized Makefile for streamlined development.

1. Build and Run the OS
Bash
make run
2. Run Automated Diagnostic Suite
The test runner executes a silent validation of the hashing engine and filesystem integrity, providing a verbose report only on failure.

Bash
make test
3. Clean Project
Bash
make clean
🛡 Security & Real-Time Track
OrbitOS is developed with a focus on Real-Time Systems. Future iterations include:

Integration of PID Control and Kalman Filter simulation modules for drone flight-data logging.

Multi-user permission layers (Root/User) for file access.

Memory-mapped file I/O for high-speed data retrieval.

Author: Eyal Braun

Environment: Linux (Neovim / G++17)