Pears: A simple BitTorrent client

This is a very simple BitTorrent client that I implemented for fun and to learn more about P2P protocols like BitTorrent. On the way, I learned the following:

Python's asyncio library for asyncronous programming
How to structure a big project

Limitations -

Only supports downloading a torrent with single file
Doesn't support seeding

How to run

$ pip install -r requirements.txt

$ python cli.py --file C:\Users\chaitanya\Documents\torrents\linuxmint-18-cinnamon-64bit.iso.torrent

How it works

The main controller is the TorrentClient. It is responsible for the following:

Connecting to Tracker and getting the peer information. Created a Queue with peers that workers will consume from.
Starting workers to consume data from the peers
Using PieceManager to manage the torrent pieces
- PieceManager is also responsible for devising a stratedy as to which piece to be requested next for a peer

Protocol implementes the BitTorrent protocol. The unofficial specification can be found here: https://wiki.theory.org/BitTorrentSpecification

Future work

Support torrents with multiple files
Support seeding aka uploading data to other peers
Improve performance

References

http://www.kristenwidman.com/blog/33/how-to-write-a-bittorrent-client-part-1/

License