PeerWire

PeerWire is a distributed file sharing system implemented in C++. It eliminates reliance on a single server by allowing peers to both download and upload file chunks concurrently.

Overview

The system follows a tracker-based architecture. Peers register themselves and discover other peers sharing the same file. Each file is divided into fixed-size chunks, and each chunk is verified using cryptographic hashes (SHA-256) to ensure data integrity.

Features

• Decentralized file transfer (P2P)
• Tracker-based peer discovery
• Parallel chunk downloading
• Cryptographic data verification
• Cross-platform support (Windows/Linux)

Build Instructions

Prerequisites

• C++17 compliant compiler
• CMake 3.10 or higher

Building

You can use the provided Makefile or scripts:

# Using Make
make

# Using Script
scripts/build.sh

The executables (tracker and peer) will be placed in build/bin.

Usage

Shortcuts (Scripts)

Convenience scripts are in the scripts/ directory:

• scripts/run_tracker.sh: Starts the Tracker.
• scripts/run_daemon.sh: Starts the Daemon.
• scripts/tui.sh: Starts the TUI Client.

Documentation

• Detailed Walkthrough
• Architecture & Design
• Project Tasks

Usage

See the scripts/ directory for run scripts.

1. Enter your listening port (e.g., 9001) when prompted.
2. Default tracker is 127.0.0.1:8080. Use tracker <IP> <Port> to change it.
3. Use commands:
   • seed <file>
   • download <hash> <outfile>
   • help

CLI Mode (Legacy)

1. Start Support Server (Tracker)

The tracker coordinates peers.

./build/bin/tracker

2. Seeding a File

To share a file, start a peer in seed mode.

./build/bin/peer <MyPort> <TrackerIP> <TrackerPort> seed <FilePath>

Example:

./build/bin/peer 9001 127.0.0.1 8080 seed mydata.txt

3. Downloading a File

To download a file, start a peer in download mode using the file hash obtained from the seeder.

./build/bin/peer <MyPort> <TrackerIP> <TrackerPort> download <FileHash> <OutputFileName>

Example:

./build/bin/peer 9002 127.0.0.1 8080 download a1b2c3... downloaded_data.txt

Documentation

See the docs/ directory for detailed information:

• docs/architecture.md: System design and components.
• docs/protocol.md: Communication protocol specification.

Testing

Unit Tests

The project includes unit tests for core utilities (SHA256).

./build/bin/unit_tests

Integration Tests

A Python script is provided to verify the full flow (Tracker + Seeder + Downloader).

python run_tests.py

Note: This script requires Python 3 and builds the project automatically if needed. test change