rqbit/crates/librqbit/src/dht_utils.rs
2023-11-28 08:03:12 +00:00

117 lines
3.5 KiB
Rust

use std::{collections::HashSet, net::SocketAddr};
use anyhow::Context;
use buffers::ByteString;
use futures::{stream::FuturesUnordered, Stream, StreamExt};
use librqbit_core::torrent_metainfo::TorrentMetaV1Info;
use tracing::debug;
use crate::{
peer_connection::PeerConnectionOptions, peer_info_reader, spawn_utils::BlockingSpawner,
};
use librqbit_core::id20::Id20;
#[derive(Debug)]
pub enum ReadMetainfoResult<Rx> {
Found {
info: TorrentMetaV1Info<ByteString>,
rx: Rx,
seen: HashSet<SocketAddr>,
},
ChannelClosed {
seen: HashSet<SocketAddr>,
},
}
pub async fn read_metainfo_from_peer_receiver<A: Stream<Item = SocketAddr> + Unpin>(
peer_id: Id20,
info_hash: Id20,
mut addrs: A,
peer_connection_options: Option<PeerConnectionOptions>,
) -> ReadMetainfoResult<A> {
let mut seen = HashSet::<SocketAddr>::new();
let first_addr = match addrs.next().await {
Some(addr) => addr,
None => return ReadMetainfoResult::ChannelClosed { seen },
};
seen.insert(first_addr);
let semaphore = tokio::sync::Semaphore::new(128);
let read_info_guarded = |addr| {
let semaphore = &semaphore;
async move {
let token = semaphore.acquire().await?;
let ret = peer_info_reader::read_metainfo_from_peer(
addr,
peer_id,
info_hash,
peer_connection_options,
BlockingSpawner::new(true),
)
.await
.with_context(|| format!("error reading metainfo from {addr}"));
drop(token);
ret
}
};
let mut unordered = FuturesUnordered::new();
unordered.push(read_info_guarded(first_addr));
loop {
tokio::select! {
next_addr = addrs.next() => {
match next_addr {
Some(addr) => {
if seen.insert(addr) {
unordered.push(read_info_guarded(addr));
}
},
None => return ReadMetainfoResult::ChannelClosed { seen },
}
},
done = unordered.next(), if !unordered.is_empty() => {
match done {
Some(Ok(info)) => return ReadMetainfoResult::Found { info, seen, rx: addrs },
Some(Err(e)) => {
debug!("{:#}", e);
},
None => unreachable!()
}
}
};
}
}
#[cfg(test)]
mod tests {
use dht::{Dht, DhtBuilder, Id20};
use librqbit_core::peer_id::generate_peer_id;
use super::*;
use std::{str::FromStr, sync::Once};
static LOG_INIT: Once = Once::new();
fn init_logging() {
#[allow(unused_must_use)]
LOG_INIT.call_once(|| {
// pretty_env_logger::try_init();
})
}
#[tokio::test]
async fn read_metainfo_from_dht() {
init_logging();
let info_hash = Id20::from_str("cf3ea75e2ebbd30e0da6e6e215e2226bf35f2e33").unwrap();
let dht = DhtBuilder::new().await.unwrap();
let peer_rx = dht.get_peers(info_hash).unwrap();
let peer_id = generate_peer_id();
match read_metainfo_from_peer_receiver(peer_id, info_hash, peer_rx, None).await {
ReadMetainfoResult::Found { info, .. } => dbg!(info),
ReadMetainfoResult::ChannelClosed { .. } => todo!("should not have happened"),
};
}
}