P2P Resource Sync

A distributed peer-to-peer system for resource discovery and file sharing across networked nodes.

Overview

This project implements a complete peer-to-peer file sharing system in C++ with automatic resource discovery, reliable file transfers with resume capability, and network resilience. The system enables nodes to:

• Broadcast available resources over UDP
• Discover resources on other nodes in the network
• Share files via TCP connections
• Resume interrupted downloads
• Manage concurrent transfers

Features

• Resource Discovery: Automatic broadcasting and discovery of shared files
• Reliable Transfer: Robust file download with resume capability
• Concurrent Operations: Multi-threaded design for simultaneous file sharing
• Network Resilience: Handling of dropped connections and network instability
• Resource Management: Thread-safe tracking of local and remote resources

Building and Running

Prerequisites

• C++23 compatible compiler
• CMake 3.14 or higher
• Docker and Docker Compose (optional, for containerized deployment)

Build from Source

# Clone the repository
git clone https://github.com/yourusername/p2p-resource-sync.git
cd p2p-resource-sync

# Build the project
./build.sh

# Build with tests
./build.sh ON

Running with Docker

# Create test files
./create_test_files.sh

# Start the network with three nodes
docker-compose up -d

# Attach to a node
docker attach p2p-resource-sync_p2p_node1_1

Usage

After starting the application, you'll see a menu with the following options:

P2P File Sharing System
1. List local resources
2. List network resources
3. Add local resource
4. Remove local resource
5. Download resource
6. Exit
Enter command:

Adding Resources

To share a file, select option 3 and enter the file path and resource name.

Downloading Resources

Select option 2 to see resources available on the network, then option 5 to download a file by name. If multiple nodes have the requested resource, you can choose which node to download from.

Architecture

The system consists of several key components:

• LocalResourceManager: Manages resources available locally for sharing
• RemoteResourceManager: Tracks resources available from remote nodes
• AnnouncementBroadcaster: Periodically broadcasts information about local resources
• AnnouncementReceiver: Listens for broadcasted resource announcements
• TcpServer: Handles incoming file download requests
• ResourceDownloader: Manages downloading resources from remote nodes

Testing

The system includes comprehensive test coverage with Google Test:

# Build with tests enabled
./build.sh ON

# Run the tests
cd build && ctest --output-on-failure

Docker Configuration

The project includes a docker-compose.yml file that sets up a network with three nodes:

• Each node has its own shared and download directories
• Ports are configured to allow both internal and external connections
• Network simulation includes periodic connection drops to test resilience

License

This project is licensed under the MIT License - see the LICENSE file for details.

Implementation Details

• Uses C++23 features for modern, efficient code
• Thread safety with shared mutexes
• Socket-based networking with BSD sockets
• Efficient buffered file transfers
• Automatic recovery from network failures