Cargo.toml

[package]
name = "TrackerWithHandshake"
version = "0.1.0"
authors = ["GGist <amiller4421@gmail.com>"]

[dependencies]
bip_handshake = "0.5"
bip_utracker  = "0.3"
futures       = "0.1"
tokio-core    = "0.1"

main.rs

extern crate bip_handshake;
extern crate bip_utracker;
extern crate futures;
extern crate tokio_core;

use bip_handshake::{InitiateMessage, HandshakerBuilder, HandshakerSink, DiscoveryInfo, PeerId, HandshakerConfig};
use bip_handshake::transports::TcpTransport;
use bip_utracker::{TrackerClient, ClientMetadata, ClientRequest};
use futures::future::{self, Either};
use futures::{Sink, AsyncSink, StartSend, Poll};
use futures::sync::mpsc::SendError;
use tokio_core::reactor::{Core};

struct MetadataHandshaker {
    sink: HandshakerSink
}

impl DiscoveryInfo for MetadataHandshaker {
    fn port(&self) -> u16 {
        self.sink.port()
    }

    fn peer_id(&self) -> PeerId {
        self.sink.peer_id()
    }
}

impl Sink for MetadataHandshaker {
    type SinkItem = Either<InitiateMessage, ClientMetadata>;
    type SinkError = SendError<InitiateMessage>;

    fn start_send(&mut self, item: Either<InitiateMessage, ClientMetadata>) -> StartSend<Self::SinkItem, Self::SinkError> {
        match item {
            Either::A(init_msg) => {
                println!("Sending Initiate Message");

                self.sink.start_send(init_msg).map(|res| {
                    match res {
                        AsyncSink::NotReady(init_msg) => AsyncSink::NotReady(Either::A(init_msg)),
                        AsyncSink::Ready              => AsyncSink::Ready
                    }
                })
            },
            Either::B(metadata) => {
                println!("Got Metadata: {:?}", metadata);

                Ok(AsyncSink::Ready)
            }
        }
    }

    fn poll_complete(&mut self) -> Poll<(), Self::SinkError> {
        self.sink.poll_complete()
    }
}

fn main() {
    let mut core = Core::new().unwrap();

    // Only have to set this to a high value if you dont want too much backpressure
    // in the tracker (ie, you want all sends to complete so your metadata is sent back faster)
    //let mut config = HandshakerConfig::default();
    //config.set_sink_buffer_size(20000);

    let handshaker = HandshakerBuilder::new()
        .build::<TcpTransport>(core.handle())
        .unwrap();
    let (handshake_send, _handshake_recv) = handshaker.into_parts();

    let wrapped_handshaker = MetadataHandshaker{ sink: handshake_send };
    let mut client = TrackerClient::new("0.0.0.0:0".parse().unwrap(), wrapped_handshaker).unwrap();

    let hash = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00].into();
    println!("{:?}", client.request("151.80.120.112:2710".parse().unwrap(), ClientRequest::Scrape(hash)));

    core.run(future::empty::<(), ()>()).unwrap();
}