tozi

Torrent downloader or leecher.
_{pronounced as TOZ-ee}

Usage

tozi download|continue|verify|info ./path/to/file.torrent|magnet link

Building

zig build

Why ?

• learn kqueue, torrent proto and zig
• replace motrix
• fast
• mine (?)

Notes

• there is no seeding capability, because almost nobody would have a server that is available to the public web. This means nobody can connect to you (unless you messed with your network setup, which I didn't do).
• there is no linux support, because I didn't write epoll wrapper and I didn't use pre-built libraries.
• file read/writes are "blocking". I think i will change this with zig 0.16.0. But to be honest, I didn't find it to be a bottleneck, because usually the network is saturated first. File and hashing are now done in separate threads. It turned out to be easier than i expected. Also discovered new thing std.posix.pipe for threads communications. It integrated nicely with kqueue.
• udp tracker support. Learned that udp is also quite cool, because you receive either whole packet or nothing, which is perfect for torrent tracker.

Support

• BEP-003: Core protocol (I'm not entierly sure this is 100% compliant, but it still downloads torrents)
• BEP-006: Fast extension
• BEP-009: Extension for Metadata Files (TODO: add support for sending metadata messages)
• BEP-010: Extension Protocol
• BEP-011: Peer Exchange (PEX)
• BEP-012: Multiple trackers
• BEP-015: UDP Tracker Protocol for BitTorrent (TODO: add reties)
• BEP-020: Peer ID Conventions
• BEP-023: Tracker Returns Compact Peer Lists
• BEP-040: Canonical Peer Priority
• BEP-054: The lt_donthave extension